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SIBOGAEXPEDITIE.

Siboga-Expeditie

UITKOMSTEN

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» GEOLOGISCH

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VERZAMELD IN

NEDERLANDSCH OOST-INDIË 1899— 1900

%'.-

AAN BOORD H. M. SIBOGA ONDER COMMANDO VAN

Luitenant ter zee le kl. G. F. TYDEMAN

UITGEGEVEN DOOR

Dr. MAX WEBER

Prof. in Amsterdam, Leider der Expeditie

(met medewerking van de Maatschappij ter bevordering van het Natuurkundig
Onderzoek der Nederlandsche Koloniën)

BOEKHANDEL EN DRUKKERIJ

'.' ■■■in-i- n

E. J. BJRILL

LEIDEN

Siboga-Expeditie

XXIXa

THE

COPEPODA OF THE SIBOGA EXPEDITION

ANDREW SCOTT

Assocïate of the ÏJnnean Society London,
Honorary I.ecturer on Economie Ichthyology, University of Livevpool

PART I

FREE-SWIMMING, LITTORAL AND SEMI-PARASITIC

COPEPODA

With 69 plates

— ==ê=-§@?-^r=-

late E J. BRILL

PUBLISHERS AND PRINTERS

LEIDEN — 1909

CONTENTS.

Page

Introductory • i

Systematic 7

Tribe Amphascandria 7

Tribe Helerarthrandia 112

Tribe Ampharthrandia 193

Tribe Isokerandria 24 1

List of Literature referred to in this report 273

List of Stations shewing numbers and species of Copepoda taken 278

Systematic List of the species described in this report 314

Index to genera and species ■ 3'°

.^i790

PART I

FREE-SWIMMING, LITTORAL AND SEMI-PARASITIC

COPEPODA.

INTRODUCTORY.

The present report deals with the Free-Swimming, Littoral and Semi-Parasitic Copepoda
obtained principally from the plankton collected by the various tow-nets employed during the
investigations. Three bottles containing washings from dredged invertebrata were also sent to me
for examination. These washings contained a number of interesting species of Harpacti coida,
Lichomolgidae and Asterocheridae which would probably never have been secured by
the ordinary method of tow-netting.

The total number of collections sent for examination was 86, and represents the following
methods employed on board H. M. S. 'Siboga'.

Day Surface Collections 50

Night Surface Collections 13

Hensen Vertical Net, Night Collections from 10 metres with Electric Hght in Net. . 4

Hensen Vertical Net, Collections between 100 and 2000 metres to surface ... 11

Horizontal Cylinder Collections 4

Fowler Closing Net Collections 1

Washings from Dredged Invertebrata 3

Total 86

Only selected samples of the Copepoda were at first submitted for investigation. Every
Copepod in each of these samples was identified and separated out. This furnished some
indication of the value and richness of the material. Finally the whole of the crustacea plankton
was sent for examination at the end of 1902. Owing to the contents of the cases being
incompletely declared, and a portion being preserved in dutiable spirits, very great difficulty
was experienced in getting the collection released by the British Customs Authorities at the
Port of Entry into the Kingdom. After considerable correspondence and representation of the
scientific value of the material, the cases were set free on payment of the duty charge on one

1

SIROGA-EXPEDITIK XXIX il. I

2

gallon of foreign alcohol. By a special indulgence of the Commissioners of Customs, to whom
the difficulty had been submitted, the dutiable spirit was permitted to be destroyed in the
presence of an Officer of the Customs Department at Barrow, and on receipt of his certificate
that this had been done, the duty charge was refunded. The material in each bottle was put
into a fine silk sieve and the foreign spirit allowed to drain away without loss or injury to
the collection. The material was then replaced in the bottle and 70°/o British Methylated spirit added.

From a series of collections taken in an area like that investigated by the 'Siboga' in
1899 — 1900, especially as the Hensen vertical net had been employed to some extent to obtain
the deep water plankton, one could almost expect results rather above the ordinary. The
collection has decidedly proved most interesting and instructive. Much valuable information
relating to the distribution of knovvn species of Copepoda has been gained from the investigation
of the material. Some of the species described by former investigators that had become almost
lost owing to incomplete description and illustration, have been re-discovered and are now
placed on a more satisfactory basis.

The Copepoda noted in this report reach the total of 338 species, and of this number
83 do not appear to have previously been described. This collection has produced a greater
number of species from a definite tropical area than has been secured in modern times, and
distinctly proves the importance of a lengthened systematic collection in securing reliable results.
The following table shews the results of comparatively recent investigations of the Copepoda
in definite tropical areas, compared with what was revealed by the voyage of the 'Challenger'
1873—1876.

'Challenger' Copepoda 107 species.

Gulf of Guinea Copepoda (10 weeks collections) 150 species.

') Ceylon Copepoda (about 6 months investigation) 234 species.

Maldive Area Copepoda 120 species.

'Siboga' Copepoda (exclusive of Asterocheridae and true parasitic forms). 338 species.

Much of the increase in the number of species is without any doubt largely due to the
greatly improved facilities for collecting and investigating material, of course every expedition
now organised has all the previous experience of the others as a guide, and the specialist is
provided with a good supply of literature. At the beginning of the 'Challenger' expedition
many methods had never been tested, or even suggested, and the literature was very scanty.

A good deal of investigation has already been done amongst the Copepoda of the
Indian Ocean, and a fair amount of information is available relating to the Copepoda of even
the Malay Archipelago.

If we compare the families represented in this report with the same families already
recorded from the Indian Ocean, we find the following particulars: — The late Professor Cleve

1) This number includes the seven species of Copepod Fish-Parasites recorded by C. B. Wn.sox in Supplementary Report
XXXIV, Part V (1906), Report on the Pearl Oyster Fisheries of the Gulf Manaar. The Supplementary Report VII by THOMPSON .V SCOTT
(1903) deals with a total of 284 species representing various families, but 57 of these species were obtained from plankton collected during
the traverse to and from Ceylon and were not actually present in the Gulf of Manaar. The last day of the outward journey, and the
first day of the homeward one only, is regarded as part of Ceylon in the above list.

records 85 species from the Malay Archipelago in his report published in 1901. Dr. R. N.
Wolfenden reports on iiS species frorh the plankton collected by J. Stanli s Gardiner around
the Maldive and Laccadive Islands. Professor W. A. Herdman's collections from the Gulf of
Manaar f902 [903 produced [95 species.

The following table gives the families and divisions represented in the present report,
with the number of species belonging to each, and shews the difference between the results
obtained from the investigations of the 'Siboga' when compared with the parts of the Indian
Ocean referred to.

'Siboga'

C a 1 a n 0 i d a .

225

Mormonillidae

1

üithonidae

0

Harpacticoida

44

Monstrillidae .

10

Oncaeidae .

8

Corycaeidae .

16

Sapphirinidae.

18

Lichomolgidae .

1 2

Clausiidae .

1

Total . .

0 1 Ss
.-) .•> °

Ce v Ion

MaldivL- Ai '

Mal

iv Archipelago <

Cleve)

78 . . .

80 .

■ 57

7 . . .

7 •

5

62 . . .

8 .
1

5

4 . . .

5 •

4

14 . . .

1 1

9

8 . . .

6 .

■ ■ 5

20 . . .

2

•

195

118

85

None of the above lists are strictly comparable with each other, as the methods employed
in collecting- the material were not identical in every case. For instance : — No vertical hauls
with the Hensen net were taken in the Gulf of Manaar. During the 'Siboga' expedition fifteen
such hauls were taken from depths between 10 metres and 2000 metres. On the other hand
we examined se ven collections of washings from invertebrata dredged around Ceylon, compared
with the three in the present report. Wolfenden does not give any information about the
methods employed by J. Stanley Gardiner in taking the collection of Copepoda from around
the Maldive and Laccadive Islands, nor are the exact positions given for the occurrence of
the species although the two groups of Islands are roughly 200 miles apart. The species
recorded by Wolfenden, are such as would lead one to suspect that the Copepoda were
obtained from at or near the surface, and at 110 great distance from the Islands. The collection
reported on by the late Professor Cleve appears to have been purely a surface series.

Unless one can deal with Copepoda that have been collected by similar methods in
different areas for some considerable period, it would be pure speculation to attempt to explain
the differences that are apparent in the four series given above, and any conclusions put forward
must necessarily be fallacious to a very considerable extent. It is hopeless at present, for instance,
to compare the Copepod fauna of the sea along the coast of Western Europe, with that of
almost any other part of the world. The Copepoda of the seas round Northern and Western
Europe have been investigated by different observers for nearly a century, and yet a dozen
years ago not even the most optimistic student had any idea that the very deep region to the
West of Ireland and North of Scotland, was populated with so many interesting species as

3

shewn by the results of the investigations now being carried out on the lines laid down by
the Conseil Permanent International pour 1'Exploration de la Mer.

It is demonstrated in the present report that some of the deep water pelagic Copepoda
of the North Atlantic are identical with forms from the deep water of the Malay Archipelago.
To suggest that this similarity may be accidental, or the result of ocean currents, would not
account for the occurrence of such species in areas so widely apart, unless we know a very
great deal regarding the Copepoda inhabiting the vast area of deep water that intervenes. The
Hensen net, if it had opened up no other line of observation than that of obtaining a continuous
vertical sample of plankton from any depth to the surface, has proved of great service where
it has been employed. No plankton observations can now be regarded as satisfactory unless this
particular net is extensively employed along with ordinary nets worked at or near the surface.

An ordinary tow-net is of little use in collecting littoral forms of Copepoda that live at
or on the sea bottom and are rarely able to swim any distance. Other methods, such as dredging
up samples of invertebrata and mud, and washing out the minute Copepoda, or investigating
the shore between tide marks, must be pursued to obtain such types. It would be quite erroneous
to suggest that littoral Copepoda are absent from an area that is only investigated by tow-net,
should none be found.

Dr. Wolfenden in his report on the Copepoda collected by J. Stanley Gardiner around
the Maldive and Laccadive Islands, attempts to draw some conclusions from the species of
Copepoda recorded in his own report when compared with the forms recorded from Ceylon,
especially the paucity of littoral forms in the Maldive area, that appear to be based on insuf-
ficiënt data. The record of no less than 84 species in the report on the Ceylon Copepoda is
chiefly due to a piece of luck, and a suggestion by the writer to save all the debris mixed
with the dredged invertebrata that had been brought back. Many of the larger invertebrata
had been wrapped in paper previous to being placed in the store tanks, but this became greatly
disintegrated in the process of sorting out the material, and added to the labour involved in
working through the sand and mud left after the large specimens had been removed. It is
certainly more troublesome to work through a bottle of debris, especially when largely mixed
with shredded paper, than going over a collection of pelagic forms taken by tow-net. The
washings from a sample of pearl oysters from Muttuvaratu Paar presented us with 32 species
of Harpacticoida that were not found in any of the tow-net collections, or even in any of the
other washings. It must be obvious, that the majority of the littoral Copepoda recorded in the
Ceylon report could not have been obtained had we neglected the debris. Of the eight species
of Harpacticoida recorded by Wolfenden from the Maldive area, no less than five of them
are purely pelagic forms. The other three may have been accidentaly swimming near the
surface in very shallow water. There is no evidence in the report that true littoral species of
Harpacticoida, Lichomolgidae or Asterocheridae were looked for. The more recent origin of
the Maldive group, compared with Ceylon, is not a very satisfactory solution of the apparent
paucity of the littoral Copepoda.

When we find European Harpacticoida like Phyllot/ialestris mysis and Rhynchothalestris
rufocincta both present in the Malay Archipelago, one is inclined to regard the apparent absence

4

5

of truc littoral forms trom any large area that includes very shallow water with some suspicion.
Phyllothalestris mysis was described bj Claus from Mediterranean specimens, and has been
shewn to occur on the coasts of Britain, Norway and Ceylon. Rhynchothalestris rufocincta lias
been obtained by Dr. A. M. Norman, Professor G. S. Bradv and other investigators on various
parts of the British Coast, and by Professor G. O. Saks on the coast of Norway. I have a
rich gathering of Harpacticoida in my possession that was found in the washings from a mere
handful of calcareous and other algae collected on the dead coral-reef flats and Madrcporia
reefs in the Conflict Atoll, off the coast of New Guinea. Some of the species from this distanl
Island, which is of more recent origin than Ceylon, appear to be identical with forms occasionally
found in washings from invertebrata dredged in the Irish Sea.

There is no doubt that the temperature of the sea at between iooo and 2000 metres
in the Malay Archipelago is nearly the same as that of the deep water of the North Atlantic.
Krümmel 1907, shews that the temperature of the deep water is much more uniform throughout
the world, than that of the surface. One is led to suspect, therefore, that when the Copepoda
of the world wide deep cold areas have been fully investigated, there may be a greater uniformity
in the distribution of some species than is known at present. Scattered observations are of great
value as a link in the chain of evidence, but until the chain be complete many pitfalls await
the theorist should he venture into explanations regarding the presence or absence of groups
without sufficiënt data to work from.

The result of the various methods employed on board the 'Siboga' gives one a fair
idea of the Copepod fauna of the region investigated. A comparison of the deep forms with
those of the shallow water, or of the surface and bottom types near the land, and also the
conditions in the daylight and the dark can be obtained from the lists of Copepoda that were
present in each collection as shewn on pages 278 to 314. The greatest number of species
represented in a day surface gathering was 59. One night surface collection contained 64 species.
A vertical net haul at Station 141, from 1500 metres to the surface, contained the astonishing
total of 1 3 1 species of Copepoda. This is at least 1 1 more than was apparently present in the
whole of plankton from the Maldive area. The Horizontal cylinder catches averaged ^j species
per haul and the washings from dredged invertebrata 13 each. The following list gives the
averages for each of the series : —

50 Day Surface Collections, average per sample 29 species.

1 3 Night Surface Collections, average per sample 40 species.

4 Hensen Vertical Net Night Collections, average per sample 49,5 species.

1 1 Hensen Vertical Net deep Collections, average per sample . 88,7 species.

4 Horizontal Cylinder Collections, average per sample . . .37 species.

1 Fowler Closing Net Collection 28 species.

3 Washings from Dredged Invertebrata, average per sample . 1 3 species.

The three tables below give the number of species belonging to the families and divisions
that were represented in the 'Siboga' collection and are also recorded from Ceylon, the Maldive
area, and the Malay Archipelago (Cleve).

5

Ceylon

Maldives

Malay Avchipelago

C a 1 a n o i d a .

61 . 65 50

Oithonidae

->

0

2

2

Harpacticoida

'7

1
0

1

0

Oncaeidae.

0

4

3

Corycaeidae .

1 2

8

8

Sapphirinidae

6

6

4

Lichomolsfidae .

4

Clausiidae .

1

Total

107

88

70

This shews for instance, when compared with the numbers given for the 'Siboga' collection
on page 3 that out of the 44 species of Harpacticoida recorded, 1 7 of them were present at
Ceylon, 3 at the Maldives, and 3 had already been known from the Malay Archipelago. On
the other hand, out of the 85 species recorded by Cleve, 15 of them were apparently not
taken during the cruise of the 'Siboga'.

No excuse is offered for the great length of the report, or for the delay in its preparation,
beyond the fact that, the chief object was to make it worthy of the energy of the part}1 of
Dutch Naturalists who devoted so muc-h time to the investigation of the area, and of the
commendable example of the Dutch Government in meeting the expenses of the exploration,
alone with due consideration for the fulfilment of my official duties under Professor Herdman.
Many dissections had to be made in the course of the work. Each appendage was dissected in
regular order and mounted separately in the majority of the species so it must be obvious that time
was necessary to obtain useful prepara tions. The illustrations are so drawn, that the characteristic
features of each species can readily be detected, without undue crowding of the plates. The
plumose setae of the swimming feet and other appendages have, therefore, not been included
in many cases. The lengthy index, list of literature, and the extensive synonymy under some
of the species, are given with the view to facilitate the investigations of future workers. I am
deeply indebted to the Linnean Society, London, and to the Librarian, Mr. A. W. Kappel, for
the free use of the literature in the library, and also to many investigators for furnishing
reprints of their works on Copepoda. My father's experience and advice proved of the utmost
value in the difficult points that cropped up from time to time, and in the determination of
uncertain species. I am also deeply indebted to Professor Weber for his kindness in giving me
the opportunity of investigating this interesting collection of Copepoda, for his careful supervision
of the printing of the report, and for the very satisfactory photographic reproductions of the
plates from the original indian ink copies.

Piel, Barrow in Furness, April 30, 1909.

SYSTEMATIC.

Tribe AMPHASKANDRIA.
i. Family Calanidae.

Genus Calanus Leach, 1S16.
In the present report, certain species included in the genus Calanus by Brady 1883,

GtESBRECHT I 893, GlESBRECHT & ScHMEIL 1898, SaRS 1905(0:), F.\RRAN 1908, VAN BREÉMEN I guS,

etc, have been removed to other genera on account of structural differences as stated below.

Calanus fiumarchicus (Gunnerus) is regarded as the type of the genus. The antennules
and mouth organs in both sexes are normal in structure. There are five pairs of bi-ramose feet.
Each branch is three-jointed ancl adapted for swimming. The fifth pair of feet in both sexes
is only very slightly different. In the male, the exopodites of the right and left feet are not
quite symmetrical. That on the left side is usually a little longer than the right, and it is
also slightly modified in shape and armature. The anterior surface of the second joint of the
basiopodite of the first feet in both sexes is turnished with a simple plumose seta. There is no
hook at the base of this seta, as in the genus Megacalanus.

Remarks. Under the restrictions adopted in this report, the genus Calanus Is distinguished
from the other genera by the almost complete similarity in the structure of the appendages in
the two sexes. There is no hook-like armature on the anterior surface of the second joint of
the basiopodite of the first feet.

Only two species from the lSiboga' collections apparently possessed these characters.

1 . Calanus minor (Claus).

Cetochilus minor Claus, 1863, p. 172.

Calanus valgus Brady, 1883, p. 33, pi. III, figs. 1 — 7.

Calanus valgus I. C. Thompson, 1888, p. 147.

Calanus minor Giesbrecht, 1893, p. 90, pi. 6, 7, 8.

Calanus valgus T. Scott, 1893, p. 24.

Calanus minor Giesbrecht, 1895, p. 248.

Calanus minor Giesbrecht & Schmeil, 1S98, p. 15.

Calanus minor Wheeler, 1900, p. 165, figs. a, b.

Calanus minor Cleve, 1901, p. 5.

7

Calanus minor Thompson, & Scott, 1903, p. 241.

Calanus minor Geve, 1903, p. 357.

Calanus minor Geve, 1904, p. 186.

Calanus minor Wolfenden, 1905 (a), p. 995, pi. XCVII, figs. 36—38.

Calanus minor Sars, 1905 (a), p. I.

Calanus minor Esterly, 1905, p. 126, fig. 2.

This species although rather rare in the 'Siboga' collections was apparently well distributed
throughout the area investigated, as shewn by the following list of stations where its occurrence
was noted.

Stat. 36. -- Stat. 47'.— Stat. Si.— Stat. 96 (night). — Stat. 118. — Stat. 125. — Stat. 128.—
Stat. 136. — Stat. 141.— Stat. 143. — Stat. 144. — Stat. 14S. — Stat. 157. — Stat. 165. —
Stat. 168. ■ ■ Stat. 184. — Stat. 186. — Stats. 194—7. — Stat. 204. — Stat. 210'. —
Stat. 217. — Stat. 282. — Stat. 304.

Calanus minor appears to be widely distributed in all the warmer seas, and a number
of records of its occurrence have been made since the first description was published. Calanus
valgus Brady 1883, has been included in the synonymy of this species by Giesbrecht. Wolfenden
1 905 (a), draws attention to differences between the figures of Brady and Giesbrecht. The fifth
feet of the males from the 'Siboga' collections agree perfectly with the figures given in the
'Challenger' report, and in the 'Fauna und Flora des Golfes von Neapel'. The only difference
between Calanus valgus Brady and Calanus minor Claus, appears to be in the size. The former
is given as 3,5 mm. but the fema'les of C. minor from the 'Siboga' material are only 1,7 mm. long.

2. Calanus tenuicornis Dana.

Calanus tenuicornis Dana, 1849, p. 15.

Calanus tenuicornis Giesbrecht & Schmeil, 1898, p. 18.

Calanus tenuicornis I. C. Thompson, 1903, p. 15.

Calanus tenuicornis Geve, 1903, p. 357.

Calanus tenuicornis Geve, 1904, p. 186.

Calanus tenuicornis Wolfenden, 1904, p. III.

Calanus tenuicornis Sars, 1905 (a), p. I.

Calanus tenuicornis Esterly, 1905, p. 127, fig. 3.

Calanus tenuicornis Farran, 1905, p. 30.

Calanus tenuicornis Pearson, 1906, p. 5.

Calanus tenuicornis Farran, 1908, p. 20.

Calanus tenuicornis van Breemen, 1908, p. II, fig. 8.

Calanus tenuicornis Dana, appears to be widely distributed in tropical and temperate
seas. It was very rare in the collections taken by the 'Siboga' and was found only in the
plankton from Station 282. There it was represented by three specimens. It is a characteristic
species with moderately long furca and is easily identified.

Genus Canthocalanus nov.

This new genus resembles Calamis in its general appearance. The females might well
pass for true members of that genus, as the antennules and mouth organs are of a similar

structure. There are five pairs of swimming feet in both sexes. Each pair is composed of a
three-jointed endopodite and exopodite. The joints of the basiopodite of the fïrst feet are,
however, distinct from those of true Ca/anus. The apex of the anterior margin of the fïrst joint,
terminates in a well defined hook-like projection. The second joint is furnished with a strong,
naked, pyriform spine, on its anterior surface. The base of this spine, is only slightly attached
to the surface of the joint. A considerable portion of the spine is continued upward, into a
distinct tooth-like process, resulting, with the combination of the hook on the first joint, in the
formation of a feeble prehensile apparatus. The other pairs of feet in the female are of the
normal Calanus type, except that the first joint of the basiopodite of the fifth pair is not serrate
on the inner margin. The fifth pair of feet in the male has a distinct prehensile left exopodite.
The endopodite of that side is three-jointed, rudimentary, and destitute of plumose hairs. The
right foot is normal. The first joint of the basiopodite resembles that of the female in not
being serrate on the inner margin.

Remarks. The type of the genus is Ca/anus pauper Giesbrecht, but the structures on
the joints of the basiopodite of the first feet, and the character of the male left fifth foot,
with its prehensile exopodite and the rudimentary, naked, three-jointed endopodite, distinguish
Canthocalanus from true Calanus. The genus at present is represented by one species.

i. Canthocalanus pauper (Giesbrecht).

Calanus pauper Giesbrecht, 1888, p. 331.

Calanus pauper Giesbrecht, 1S93, p. 91, pis. 6 & 8.

Calanus pauper Giesbrecht & Schmeil, 1898, p. 16.

Calanus pauper I. C. Thompson, 1900, p. 275.

Calanus pauper Cleve, 1901, p. 5.

Calanus pauper A. Scott, 1902, p. 400.

Calanus pauper Thompson & Scott, 1903, p. 241.

Calanus pauper Cleve, 1903, p. 357.

Calanus pauper Wolfenden, 1905 (a), p. 995, pi. XCVII, figs. 29 — 35.

Canthocalanus pauper appeared to be generally distributed throughout the area investigated
by the 'Siboga' and was noted at the following stations.

Stat. 16. — Stat. 37. — Stat. 47''. — Stat. 50. — Stat. 66. — Stat. 71. — Stat. Si. —
Stat. 93. — Stat. 96 (day). — Stat. 96 (night). — Stat. 98. — Stat. 99. — Stat. 101. —
Stat. 106. — Stat. 109. — Stat. 1 10. — Stat. 112. — Stat. 11S. — Stat. 121. — Stat. 125
(night). — Stat. 128. — Stat. 133. — Stat. 136. — Stat. 141. — Stat. 142. — Stat. 143. —
Stat. 144. — Stat. 148. — Stat. 149.— Stat. 165.— Stat. 168. — Stat. 169. — Stat. 172.—
Stat. 184. — Stat. 185. — Stat. 186. — Stat. 189". — Stats. 194—7- — Stat- 203 (1500
metres). — Stat. 204. — Stat. 205. — Stat. 214. — Stat. 2151. — Stat. 217 (horizontal
cylinder). — Stat. 224. — Stat. 225. — Stat. 229. — Stat. 252. — Stat. 271. — Stat. 276. —
Stat. 282. — Stat. 315.

The distribution of this species, so far as is known at present, seems to be limited to
the Mediterranean, Gulf of Suez, Red Sea, Arabian Sea, Indian and Pacific Oceans. Wolfenden,
1905 («), has described and figured the characteristic parts of this copepod from specimens
collected around the Maldive Islands by J. Stanley Gardiner. These figures agree well with
the original ones given by Giesbrecht.

9

SIHOGA-EXrEDITIE XXIX a. 2

IO

Genus Calanoides Brady, 1883.

This genus was established by Brady in the 'Challenger' report, for the reception of a
Calanoid form whose male possessed characters quite distinct from those of Calanus, the most
important being the prehensile structure of the fifth feet. The exopodites of this pair are three-
jointed, elongated, and destitute of plumose setae. The endopodites are rudimentary. That of
the right foot is three-jointed. The left one is reduced to a single small joint. The absence of
plumose setae on the male fifth feet indicate, that they are not adapted for swimming, and thus
differ from those of typical Calanus. The female is of the usual Ca/anus type. Giesbrecht in
his great work 'Fauna und Flora des Golfes von Neapel' and Giesbrecht & Schmeil in 'Das
Tierreich', include this genus under Calanus. The fifth feet of the male however, are so obviously
distinct, that its position there is untenable, and it must therefore be restored as a separate
genus. The presence of a normal fifth pair of feet in the female, indicates that the genus is
related to Calanus, and not to Pseudocalanus or Euchaeta, as suggested by Brady.

No specimens of Calanoides patagonicnsis Brady, the type of the genus, were found in
the 'Siboga' collections, but there is so close a resemblance in the structure of the male fifth
feet of Calanus brevicornis Lubbock, to Calanoides, that it has been included under that genus
in this report. The genus is now represented by two species, one of which occurred in the
plankton collected by the 'Siboga'.

1 . Cala7ioides brevicornis (Lubbock).

Calanus brevicornis Lubbock, 1856, p. II, pi. III.

Calanus brevicornis Giesbrecht, 1893, p. go, pi. 6, 7, 8.

Calanus frontalis Dahl, 1894, p. j6.

Calanus brevicornis Giesbrecht & Schmeil, 1S98, p. 16.

Calanus brevicornis Cleve, 1904, p. 185.

Calanus brevicornis Sars, 1907 (b), p. 4.

This species is easily recognised by its conical and slightly crested forehead, and by the
rather pointed terminations of the last thoracic segment. The female is of the normal Calanus
type. The fifth pair of feet of the male although not so elongated as in Calanoides palagoniensis,
is of a somewhat similar structure to that of Brady's species. The endopodites of both rami
are rudimentary, that of the right side is three-jointed. The left is reduced to one small joint.
It was noted in collections taken at the followinaf stations.

Stat. 165, 20 specimens. — Stat. 168. — Stat. 169, 1 specimen. — Stat. 172, 2 specimens. —
Stat. 185. — Stat. 225, 1 specimen. — Stat. 230, 5 specimens. — • Stat. 276, 3 specimens.

Calanoides brevicornis (Lubbock), has previously been recorded from the Atlantic and
Indian Oceans only.

Genus MegacalaiTUS Wolfenden, 1904.

Wolfenden 1904 (wrongly quoted as 1905 in Plankton Studies, part I) briefly described a
very large Calanoid form under the abovè genus that, was taken in the deep water of the Atlantic,

1 1

between Valentia in Ireland and die Faröe banks, and gave a characteristic figure. This genus is
distinguished from Calanus, by the presence of a remarkable hook on the anterior surface of
the second joint of the basiopodite of the first feet, and by the last joint of the exopodites of
the second, third, and fourth feet being furnished with three spines on the outer margin, instead
of two as in Calanus. Wolfenden fully described his genus in 1905, in Plankton Studies, part 1.
Sars in the same year (1905 a) described a very similar form under the name of Macrocalanus
lougicoruis, and a good deal of confusion arose through no figures accompanying the description.
Sars, however, in 1907^), withdrew his genus in favour of the one named by Wolfenden, which
had the prior claim. Wolfenden in his first description had then only met with one form, to
which he gave the name Megacalanus princeps. In Plankton Studies, part I, the number of species
under Megacalanus was increased to two. The specific name princeps originally adopted for the
type of the genus was dropped in favour of a new specific name, bradyi, while the name princeps
was applied to the additional form, which is clearly not a Megacalanus. There is no doubt,
that Megacalanus bradyi is the same form for which the genus was founded in 1904, as it is
characterised by the prominent hook on the second basal joint of the first feet and the figure 2,
plate I, is identical with the figure given with the original description in 1904. The second
species of the genus, was identified as equal to Brady's Calanus princeps of the Challenger
report, and the basiopodite of the first pair of feet is described as having no tracé of hooks.

In the interval between the publication of Wolfenden's two papers Sars had recorded
the occurrence of Macrocalanus princeps {Calanus princeps Brady).

In Plankton Studies, part II, 1906, Wolfenden has the following note: "Professor G. O.
"Sars has informed me that the genus Megacalanus (Wolfenden) is identical with his genus
"■Macrocalanus (Sars) (Buil. du Musée Océanog. de Monaco), and Megacalanus Bradyi is the
"same as his species Macrocalanus longicornis, and that my name, Megacalanus, however has
"the priority over Macrocalan?is. He also informs me that the species described by me as
" Megacalanus princeps = Calanus princeps (Brady) is not that species, but = Bathycalanus
" Richardi (G. O. Sars), and that Brady's Calanus princeps is a true Megacalanus, differing
"from M. longicornis (G. O. S.) = Megacal. Bradyi (Wolfenden), in the strongly recurved frontal
"appendages, somewhat shorter Anterior Antennae, and the dense ciliation of the spines on the
"Anterior Maxillipedes, which otherwise are quite normal in appearance.

"The genus Bathycalanus differs from Megacalanus in the peculiar armature of the
"frontal part and in the somewhat different structure of the maxillae and maxillipedes (both
"pairs), and in the structure of the first pair of feet, which are without the hooked process of
"the second basal, and have the outer ramus composed of only two joints".

It is quite certain that Wolfenden's second species, Megacalanus princeps (Brady), is
not a Bathycalanus, because Wolfenden in his description of the species states that the first
four pairs of feet have three-jointed rami. Wolfenden, after an examination of the dissections
of Calanus princeps preserved in the British Museum, concludes that Brady's species is neither
a Megacalanus nor a Bathycalanus, vet he finally renames Megacalanus princeps Wolfenden,
not the original one which established the genus in 1904, as Bathycalanus maximus.

Sars 1905(0), and Farran 1908, identify Brady's Calanus princeps with the genus

I 2

Megacalanus, but it is doubtful if they are justified in doing so, as Brady makes no reference
to die remarkable hook on the second joint of the basiopodite of the first feet, vvhich is a
pronounced character in Megacalanus. It is very unlikely that Brady would overlook this hook,
had it been present in his Calanus ftrinceps, as he notes the occurrence of a hook in Calanus
gracilis which is a much smaller form. The hook is quite as pronounced as in Wolfenden's
type of the genus Megacalanus. I regard Brady's Calanus princeps to be a member of a new
genus mentioned later. On the other hand I include under the genus Megacalanus two species
hitherto regarded as true Calanus. They are of much smaller size than the type of the genus,
and have only two marginal spines on the last joint of the exopodites of the second, third, and
fourth feet. They have, however, the strong hook on the anterior surface of the second joint
of the basiopodite of the first feet. This hook is quite distinct from that found in Canthocalanus.
In Megacalanus the hook is a well defined projection from the surface of the joint, and has
a plumose seta articulated to it. In Canthocalanus the seta is transformed into a strong spine
with a hooked base. Three members of this genus were represented in the Siboga plankton.

Remarks. I include under the genus Megacalanus only those Calanoids that have the
anterior surface of the second joint of the basiopodite of the first pair of feet furnished with
a strong hook as originally defined by Wolfenden. I do not think that size alone should have
any generic or specific importance, so long as the principal character established in the original
definition is upheld.

i. Megacalanus gracilis (Dana).

Calanus gracilis Dana, 1849, pp. 18, 24.

Calanus gracilis Brady, 1883, p. 35, pis. V & XLVI.

Calanus gracilis I. C. Thompson, 1888, p. 147.

Calanus gracilis Giesbrecht, 1893, p. 90, pis. I, 6, 7, 8.

Calanus gracilis T. Scott, 1893, p. 25.

Calanus gracilis Giesbrecht, 1895, p. 248.

Calanus gracilis Giesbrecht & Schmeil, 189S, p. 17.

Calanus gracilis I. C. Thompson, 1900, p. 275.

Calanus gracilis I. C. Thompson, 1903, p. 15.

Calanus gracilis Thompson & Scott, 1903, p. 241.

Calanus gracilis Cleve, 1903, p. 357.

Calanus gracilis Sars, 1905 (a), p. 1.

Calanus gracilis Esterly, 1905, p. 128, fig. 4.

Calanus gracilis Pearson, 1906, p. 5.

Calanus gracilis Farran, 1908, p. 20.

Calanus gracilis van Breemen, 1908, p. 10, fig. 7.

Megacalanus gracilis although generally distributed over the area investigated, appeared
to be rather scarce in numbers. It was noted at the following stations.

Stat. 19. — Stat. 35. — Stat. 40. — Stat. 66. — Stat. 75. — Stat. 89. — Stat. 98. —
Stat. 99. — Stat. 110. — Stat. 1 1/\ — Stat. 118. — Stat. 125. — Stat. 125 (night) —
Stat. 12S. — Stat. 129. — Stat. 133. — Stat. 141. — Stat. 143. — Stat. 148. — Stat. 157. —
Stat. 177". — Stat. 189*. — Stats. 194 — 7. — Stat. 203 (1500 metres). — Stat. 204. —
Stat. 220 (vertical net). — Stat. 220 (surface). — Stat. 243. — Stat. 245. — Stat. 252. —
Stat. 276. — Stat. 282.

13

This species appears to be widely distributed in all the oceans. It is evident from Farran's
remarks (1908), and its presence in the deep collection at Station 203, although absent at the
surface, that it occasionally descends to considerable depths. Brady in his 'Challenger' report,
pointed out the characters of Ca/anus gracilis, and was of the opinion that future research
would render necessary the formation of a new genus for this species.

2. Megacalanus robustior (Giesbrecht).

Calanus robustior Giesbrecht, 1888, p. 332.

Calanus robustior Giesbrecht, 1893, p. 91, pis. 7 & 8.

Calanus comptus T. Scott, 1893, p. 26, pis. V & VI.

Calanus robustior Giesbrecht, 1895, p. 248.

Calanus robustior Giesbrecht & Schmeil, 1898, p. iS.

Calanus robustior Thompson & Scott, 1903, p. 242.

Calanus robustior Sars, 1905 (a), p. 1.

Calanus robustior Wolfenden, 1905 («), p. 996, pi. XCVI, figs. 1 — 6.

Calanus robustior Esterly, 1905, p. 129, fig. 5.

This species has a close resemblance to Megacalanus gracilis and without a careful
examination may be easily mistaken for it. The robust form of the animal and the very swollen
genital segment, help to separate it from Megacalatius gracilis. It was noted at the following
'Siboga' stations but appeared to be rather rare.

Stat. ij. — Stat. 40. — Stat. 110. — Stat. 117*. — Stat. 128. — Stat. 141. — Stat. 185. —
Stat. 189». — Stat. 245. — Stat. 276.

The form recorded by my father from the Gulf of Guinea (1893) as ? Calanus cotnptus
Dana, and which he was inclined to consider as only a variety of Calanus gracilis, has been
identified by Giesbrecht & Schmeil as Calanus robustior, a conclusion that appears to be
quite correct.

Megacalanus robustior has been previously recorded from the Atlantic, Pacific, and
Indian Oceans.

3. Megacalanus princeps Wolfenden. Plate I, figs. 12 — 18.

Megacalanus princeps Wolfenden, 1904, p. 112, pi. IX, fig. 1.

Macrocalanus longicornis Sars, 1905 (a), p. 7.

Megacalanus bradyi Wolfenden, 1905, p. 1, figs. 1 — 6.

Megacalanus longicornis Pearson, 1906, p. 6.

Megacalanus longicornis Farran, 1908, p. 21.

Megacalanus longicornis van Breemen, 1908, p. 13, fig. 9.
nee Calanus princeps Brady, 1883, p. 36, pi. IV, figs. 3 — 7.
nee Macrocalanus princeps Sars, 1905 (a), p. 7.

nee Megacalanus princeps Wolfenden, 1905, p. 3, pi. I, figs. 7 — 9.
nee Megacalanus princeps Pearson, 1906, p. 6.
nee Batkycalanus maximus Wolfenden, 1906, p. 26, pi. VIII.
nee Megacalanus princeps Farran, 1908, p. 21.
nee Megacalanus princeps van Breemen, 1908, p. 13.

This fine species was represented in the 'Siboga' material by five specimens, all females,

13

but only one of them was mature. The length of the mature female was 9,5 mm. exclusive
of the caudal setae. It was found at the folio wing stations.

Stat. 148. HENSEN vertical net, 1000 metres to surface, 2 specimens.
Stat. 185. HENSEN vertical net, 1536 metres to surface, 2 specimens.
Stat. 243. HENSEN vertical net, 1000 metres to surface, 1 specimen.

I have been unable to detect any difference between the original description given by
Wolfenden from the North Atlantic specimen, and those from the area investigated by the
'Siboga'. I have also examined specimens from the deep water of the Faröe Channel, and find
that they are identical with the figures given on plate I of this report.

As already stated Wolfenden originally described the species as Megacalanus princeps,
and subsequently withdrew the specific name in favour of bradyi, under the impression that
Brady's Calanus princeps belonged to the same genus. Farran and van Breemen have used
Sars specific name longicomis, as it was given prior to the substitution of the new name by
Wolfenden. Brady's Calanus princeps apparently belongs to the new genus described below
rather than to Megacalanus, and the name originally given by Wolfenden must necessarily
be restored.

Genus Bradycalanus nov.

In general appearance, this new genus resembles Megacalanus Wolfenden, but is at once
distinguished from it by the densely plumose spines on the apex of the first maxillipedes,
and by the absence of the prominent hook on the anterior surface of the second joint of the
basiopodite of the first feet. The endopodites and exopodites of the five pairs of feet are three-
jointed. The last joint of the exopodites of the second, third, and fourth feet are furnished with
three spines on the outer margin instead of two as in Calanus. The generic description of
Bathycalanus Sars i905(«), states that the exopodites of the first feet are two-jointed, and in
this important point it differs from Bradycalanus. The forehead has no tracé of a dorsal crest
which distinguishes Megacalanus and Bathycalanus from Wolfenden's Heterocalatius, a name
by the way that has been previously used in the Gulf of Guinea report for a new Calanoid
that afterwards became a synonym of Pseudodiaptomus. So far, only the female of Bradycalanus
is known.

I think that it is probable that Brady's Calanus princeps belongs to this genus rather
than to Bathycalanus or Heterocalanus, but I do not regard it as identical with the species
upon which this genus is founded.

1. Bradycalanus typieus nov. sp. Plate I, figs. 1 — 11.

Female — length 9 mm.

The head is distinctly separated from the first thoracic segment. It is considerably
contracted in front and produced slightly into a rounded knob as seen from the dorsal aspect,
fig. 1. The fourth and fifth thoracic segments are completely separated. The fifth thoracic
segment is produced posteriorly and ends in distinct points. When viewed from the side the

14

15

segment is seen to terminate in well defïned spines. Thè abdomen is four-jointed, symmetrical,
and equal to one-third of the length of the ccphalothorax. The genital segment is longer than
broad, and is nearly eqnal to the combined lengths of the second and third segments. The
second segment is about half the length of the genital segment. The third segment is equal
to two-thirds of the length of the second. The fourth segment is about half as long as the third.
The furcal joints are short and slightly longer than broad but rather longer than the last
abdominal segment.

The antennules are twenty-five-jointed and extend beyond the end of the abdomen by
at least four joints.

The antennae, mandibles, and maxillae are nearly as in Calanus.

The first maxillipedes are furnished with distinct curved spines on the third, fourth, and
fifth lobes, that on the fifth being quite conspicuous. The apical portion of the first maxillipedes
bears a number of spines, which are densely clothed with short fine hairs.

The second maxillipedes have a general resemblance to those of Calanus but the apical
portion is only indistinctly five-jointed.

The five pairs of feet are bi-ramose and each branch is composed of three joints. The
second joint of the basiopodite of the first pair of feet is furnished with a simple plumose seta
on the anterior surface. The last joint of the exopodites of the second, third, and fourth feet,
bear three marginal spines as in Megacalaims princeps. The fifth pair of feet is of a similar
structure to the fourth, but the last joint of the exopodites has only two marginal spines.

The only record for Bradycalanus typicus in the 'Siboga' material is two mature females
taken in a Hensen net vertical haul at Station 148 from a depth of 1000 metres to the surface.
It is evident that Megacalanus princeps and Bradycalanus typicus, are deep water Calanoids,
as they were only found in the vertical hauls taken between 1000 and 1536 metres.

It is probable, that the present species is specifically distinct from Calanus princeps Brady,
as I think it is very unlikely that Bradv in his description would have overlooked the terminal
spines on the last thoracic segment, had they been present in his species.

I am unable to decide whether Bradycalanus typicus is identical with Sars Megacalanus
princeps or not, as nothing beyond the record of its occurrence has yet appeared. Farran also
unfortunately, has not given illustrations of the Calanoid he recognises to be identical with Calanus
princeps Brady, and Megacalanus princeps Sars. Farran (1908) regards Wolfenden's Hctero-
calauus medius to be generically and specifically identical with Megacalanus princeps (Brady).
In that case Brady's Calanoid cannot be a Megacalanus at all, as Wolfenden distinctly states
that there is no hook on the second joint of the basiopodite of the first feet, and it cannot
be the present species, as Heterocalanus medius is described as having a prominent dorsal crest,
which is quite absent in Bradycalanus typicus.

I have lately had an opportunity of examining a specimen of a large Calanoid with a
dorsal crest, from the deep water of the Faröe Channel. It agreed in every way with Wolfendex's
Heterocalanus medius, but differs from Bradycalanus typicus by the possession of a dorsal crest,
the terminations of the last thoracic segment are rounded, and the apical spines of the first
maxillipedes are more densely clothed with fine hairs.

i6

Heter ocalanus medius Wolfenden, may be the species described by Kroyer 1848 — 49
as Calanus cristattis. Two figures of the forehead of Kroyer's species are given by Giesbrecht
in 'Fauna und Flora des Golfes von Neapel' (pi. 6, figs. 14 — 15).

Genus Undinula nom. nov.
= Undina Dana, 1847. A name preoccupied by Gould, (Aves) 1836 and Munst., (Pisces) 1842.

Giesbrecht 1893, combined the genus Undina Dana, with Calanus Leach, and with
the exception of Sars, subsequent workers adopted this plan. Sars 1902, p. S, points out that
the structure of the fifth feet of the male of Undina differs considerably from the males of true
Calanus, and that the genera ought properly to be kept apart. Very little examination of the
fifth feet of the males of the types of the two genera is required to shew that Sars view is
the correct one. There is no similarity between the left fifth foot of the male of Calanus
finmarchicus, and that of the male of Undina vulgaris. The males of Dana's Undina have
the last joint of the exopodite of the left fifth foot developed into a well defined prehensile organ.

The generic name used by Dana had been established for a genus of birds previous
to its adoption by that author and Undinula has, therefore, been substituted for Undina in
the present report.

The females of Undinula differ very little in the structure of the appendages from typical
Calanus, the only noticeable distinction is an incomplete division of the eighth and ninth joints
of the antennules. There are five pairs of bi-ramose feet, all adapted for swimming, and each
branch is three-jointed. The males are very easily recognised by the structure of the fifth pair
of feet. The foot of the right side is bi-ramose and each branch is three-jointed. The left foot
has the exopodite considerably elongated and its last joint is converted into a powerful bi-ramose
prehensile organ. The endopodite of the left foot may be entirely absent as in Undinula
vulgaris, or very rudimentary, consisting of one small joint, as in Undinula darwini and Undinula
caroli. There are at present three species belonging to this genus and they were all noted in
the 'Sibogra' material.

&■

1. Undinula vulgaris (Dana).

Undina vulgaris Dana, 1849, PP- I7> 1^> 22-

Undina vulgaris Brady, 1883, p. 53, pis. XV & XVIII.

Calanus vulgaris Giesbrecht, 1893, p. 92, pis. 6, 7, 8.

Undina vulgaris T. Scott, 1893, p. 44.

Calanus vulgaris Giesbrecht, 1895, p. 248.

Calanus vulgaris Giesbrecht & Schmeil, 1898, p. 17.

Calanus vulgaris I. C. Thompson, 1900, p. 275.

Calanus vulgaris Cleve, 1901, p. 5.

Calanus vulgaris A. Scott, 1902, p. 400.

Calanus vulgaris Thompson & Scott, 1903, p. 242.

Calanus vulgaris Cleve, 1903, p. 357.

Calanus vulgaris Cleve, 1904, p. 186.

Calanus vulgaris Wolfenden, 1905 (a), p. 994, pis. XCVT & XCVII.

Undina vulgaris Sars, 1905 (a), p. 2.

16

1/

Tl-iis was one of the most common and widely distributed Calanoids found in the material
collected by the 'Siboga' as the following records shew.

Stat. 16, 32 specimens. — Stat. 19, 20 specimens. — Stat. 35, 121 specimens. — ■ Stat. 36, 135
specimens. — Stat. 37, 137 specimens. — - Stat. 40, 5 specimens. — Stat. 47^, 90 specimens. —
Stat. 50. — Stat. 66, 265 specimens. — Stat. 71. — Stat. 75, 6 specimens. — Stat. 81,
io specimens. — Stat. 89, 3 specimens. — Stat. 93, 26 specimens. — Stat. 96 (day). —
Stat. 96 (night). — Stat. 98, 108 specimens. — Stat. 99, 25 specimens. — Stat. 101. —
Stat. 106, 20 specimens. — Stat. 109, 35 specimens. — ■ Stat. 110, 3 specimens. — Stat. 112,
8 specimens. — Stat. 117", 128 specimens. -- Stat. 118, 2 specimens. — Stat. 121. — Stat.
122, 8 specimens. — Stat. 124, 300 specimens. — Stat. 125, 30 specimens. — Stat. 125
(night), 22 specimens. — Stat. 136, 380 specimens. — Stat. 138, 1336 specimens. — Stat.
141, 20 specimens. — Stat. 142, 3 specimens. — Stat. 143. — Stat. 144, 113 specimens. —
Stat. 148, 10 specimens. — Stat. 149, 10 specimens. — Stat. 157, 150 specimens. — Stat. 165,
45 specimens. — Stat. 168, 5 specimens. — Stat. 169, 3 specimens. — Stat. 172, 95 specimens. ■ — ■
Stat. 174, 55 specimens. — Stat. 1771. — Stat. 184, 103 specimens. — Stat. 185, 2 specimens. —
Stat. 1891, 63 specimens. — Stats. 194 — 7, 10 specimens. — ■ Stat. 203 (surface), 35 specimens. —
Stat. 203 (1500) metres, 5 specimens. — Stat. 204, 1 10 specimens. — Stat. 205, 30 specimens. —
Stat. 210', 5 specimens. — Stat. 213, 2 specimens. — Stat. 215*, 20 specimens. — Stat. 216. —
Stat. 217 (horizontal cylinder), 18 specimens. — Stat. 220 (vertical net), 15 specimens. —
Stat. 220 (surface), ^^ specimens. — Stat. 223, 10 specimens. ■ — Stat. 224, 15 specimens. —
Stat. 225, 2,7 specimens. — Stat. 229, 17 specimens. — Stat. 230. — Stat. 243, 5 specimens.—
Stat. 245, 30 specimens. — Stat. 252, 3 specimens. — Stat. 271. — Stat. 276. — Stat. 282,
32 specimens. — Stat. 304, 70 specimens. — Stat. 315.

The numbers of specimens noted above, do not in every case represent the vvhole of
Undinula vu/garis present in the samples.

The female of Undinula vulgaris is easily distinguished from the female of the next
species, by the presence of strong spines at the terminations of the last thoracic segment. In
some specimens the left side has two spines instead of one. The second joint of the exopodites
of the second pair of feet in both sexes, is deeply notched at the base. The exopodite of the
left foot of the male is much elongated. The onter spine of the prehensile apical joint has no
tooth on its inner margin, and the endopodite is absent.

2. Undinula darzvini (Lubbock).

Undina darwini Lubbock, 1860, p. 7, pi. 29.

Undina darwini Brady, 1S83, p. 54, pi. XVI.

Calamis darwini Giesbrecht, 1893, p. 91, pis. 6, 7, 8.

Calanus darwini Giesbrecht, 1895, p. 248.

Ca/anus darwini Giesbrecht & Schmeil, 1898, p. 17.

Ca/anus darwini I. C. Thompson, 1900, p. 275.

Calanus darwini Cleve, 1901, p. 5.

Calanus darzvini A. Scott, 1902, p. 400.

Calanus darzvini Thompson & Scott, 1903, p. 241.

Calanus darwini Cleve, 1903, p. 357.

Calanus darwini Cleve, 1904, p. 185.

Ca/anus darwini Wolfenden, 1905 (a), p. 994, pi. XCVII, fig. 40.

Undinula darwini although less numerous than Undinula vulgaris, was well distributed
throughout the area investigated by the 'Siboga' as shewn by the following records.

17

SlllOGA- EXPEDITIE XXIX tl. 3

i8

Stat. 19, 2 specimens. — Stat. 35, 3 specimens. — Stat. 36, 3 specimens. — Stat. IJ, 15
specimens. - - Stat. 40. — Stat. 66, 5 specimens. — Stat. 75, 16 specimens. — Stat. 81,
4 specimens. ■ — Stat. 93, 7 specimens. — Stat. 96 (day). — Stat. 96 (night). — Stat. 98,
20 specimens. — Stat. 99. — Stat. 106. — Stat. 1 10, 3 specimens. — Stat. 112,3 specimens. —
Stat. H7a. — Stat. 118, 5 specimens. — Stat. 124, 15 specimens. — Stat. 125. — Stat. 128.-
Stat. 129, 3 specimens. — Stat. 133. — Stat. 136, 75 specimens. — Stat. 138, 90 specimens. —
Stat. 144. — Stat. 146. — Stat. 148, 8 specimens. — Stat. 149. — Stat. 157. -- Stat. 165,
33 specimens. — Stat. 168, 3 specimens. — Stat. 169, 46 specimens. — Stat. 172. —
Stat. 177". — Stat. 184, 65 specimens. — Stat. 185. — Stat. 186, 8 specimens. — Stat.
189% 10 specimens. — Stat. 193, 8 specimens. Stat. 203 (surface), 2 specimens. —

Stat. 203 (1500 metres), 8 specimens. — Stat. 204, 25 specimens. — Stat. 205, 10 specimens. —
Stat. 210°, 15 specimens. — Stat. 213, 15 specimens. — Stat. 214. — Stat. 215% 50
specimens. — Stat. 216. — Stat. 217 (horizontal cylinder), 100 specimens. - Stat. 220
(vertical net), 8 specimens. — Stat. 220 (surface), 15 specimens. — Stat. 223, 3 specimens. —
Stat. 224, 7 specimens. — Stat. 225, 5 specimens. — Stat. 229, 10 specimens. — Stat.
243, 10 specimens. — Stat. 245, 5 specimens. — Stat. 276. — Stat. 282, 11 specimens. —
Stat. 304.

The peculiar projection of the last thoracic segment, and the row of fine spines at the
distal end of the abdominal segments, help to identify the females of this species from Undi7iula
vulgaris, and the peculiar form of the exopodite of the left fifth foot, renders the identification
of the males comparatively simple. The endopodite of the male left fifth foot is rudimentary,
and consists of a single small joint. Some care has to be taken in separating the male of
Undinula darwini, from that of Undinula caroli, as the exopodite of the left fifth foot of the
two species has a very similar structure.

3. Undinula caroli (Giesbrecht).

Calanus caroli Giesbrecht, 1888, p. 331.

Calanus caroli Giesbrecht, 1893, p. 91, pi. 8, fig. 36.

Calanus caroli Giesbrecht & Schmeil, 1898, p. 17.

Calanus caroli Wolfenden, 1895(0), p. 994, pi. XCVII, fig. 41.

This species although widely distributed throughout the area traversed by the 'Siboga'
appeared to be comparatively rare. The following are the stations where it was noted.

Stat. 2i7> 2 specimens. — Stat. 75, 2 specimens. — Stat. 93, 1 specimen. — Stat. 98, 2
specimens. — Stat. 124. — Stat. 136, 2 specimens. — Stat. 138, 5 specimens. — Stat. 148,
2 specimens. — Stat. 165, 4 specimens. — Stat. 186, 1 specimen. — Stat. 210% 1 specimen. —
Stat. 217 (horizontal cylinder), 1 specimen. — Stat. 220, 1 specimen.

The difficulty in distinguishing this .species from Undinula darzvini, is no doubt the cause
of the paucity of records since it was established by Giesbrecht. Wolfenden is apparently
doubtful that it is really distinct from Undinula darwini. It must be admitted, that considerable
care is necessary to make out the species when mixed up with Undinula darwini, but when
the difference is once seen, further identification is comparatively easy. The position of the tooth
on the inner edge of the external spine, which is part of the last joint of the exopodite of the
left fifth foot, is the specific character separating the two species. In Undinula caroli, the tooth
is placed about one-sixth from the base of the spine, and five-sixths from the distal end. The

18

19

tooth in l 'ndinala darwini^ is one-third from the base, and two-thirds from the distal end of
the spine.

So far as the records shew, this Calanoid appears to be limited to the Pacific and Indian
Oceans. ( )nly the males have yet been discovered.

2. Family Eucai axidak.

Genus Eucalanus Dana, 1852.

The members of this genus are easily distinguished from those belonging to the other
genera of this family, by the entire absence of a fifth pair of feet in the female. The frontal
part of the head is not produced into a beak-like prominence. The last abdominal segments
and furcal joints are not separated. Seven species of Eucalanus were found in the material
collected by the 'Siboga', one of which appears to be undescribed.

1. Eucalanus crassus Giesbrecht.

Eucalanus crassus Giesbrecht, 1888, p. 333.

Eucalanus crassus Giesbrecht, 1S93, p. 132, pis. 4, 11, 35.

Eucalanus crassus T. Scott, 1897 (a), p. 312.

Eucalanus crassus Giesbrecht & Schmeil, 1898, p. 22.

Eucalanus crassus T. Scott, 1900, p. 3S2.

Eucalanus crassus T. Scott, 1901, p. 236.

Eucalanus crassus Cleve, 1901, p. 6.

Eucalanus crassus Wolfenden, 1902, p. 361.

Eucalanus crassus A. Scott, 1902, p. 401.

Eucalanus crassus T. Scott, 1903, p. 110.

Eucalanus crassus Thompson & Scott, 1903, p. 242.

Eucalanus crassus Cleve, 1903, p. 362.

Eucalanus crassus Cleve, 1904, p. 189.

Eucalanus crassus Wolfenden, 1904, pp. 111, 112.

Eucalanus crassus Wolfenden, 1905(0), p. 996.

Eucalanus crassus Sars, 1905 [o], p. 2.

Eucalanus crassus Esterly, 1905, p. 134, fig. 8.

Eucalanus crassus Farran, 1905, p. 30.

Eucalanus crassus Pearson, 1906, p. 7.

Eucalanus crassus Farran, 1908, p. 22.

Eucalanus crassus van Breemen, 1908, p. 16, fig. 13.

This Eucalanus, which is apparently widely distributed throughout the oceans as shewn
by the above references, occurred at the following stations in the area investigated by the 'Siboga'.

Stat. 16. — Stat. 37. — Stat. 66. — Stat. 75. — Stat. 89. — Stat. 93. — Stat. 98. —
Stat. 99. — Stat. 106. - - Stat. 109. — Stat. 118. — Stat. 124. -- Stat. 125 (day). —
Stat. 125 (night). - - Stat. 138. -- Stat. 141. — Stat. 142. -- Stat. 143. — Stat. 144. -
Stat. 146. — Stat. 148. -- Stat. 165. -- Stat. 169. -- Stat. 172. -- Stat. 184. — Stat. 189'. —
Stats. 194—7- — Stat. 204. — Stat. 216. — Stat. 220 (vertical net). — Stat. 252. —
Stat. 282. — Stat. 315.

l9

20

Eucalanus crassus is easily identified by its tumid body and very swollen, rounded,
genital segment. The body is well covered with short stiff hairs.

2. Eucalanus monachus Giesbrecht.

Eucalanus monachus Giesbrecht, 1888, p. 333.

Eucalanus monachus Giesbrecht, 1893, p. 132, pi. 11 & 35.

Eucalanus monachus Giesbrecht & Schmeil, 1898, p. 21.

Eucalanus monachus Wheeler, 1900, p. 167, fig. 4.

Eucalanus monachus Cleve, 1901, p. 6.

Eucalanus monachus Thompson & Scott, 1903, p. 242.

Eucalanus monachus Cleve, 1903, p. 362.

Eucalanus monachus Cleve, 1904, p. 189.

Eucalanus monachus Sars, 1905(0), p. 2.

Eucalanus monachus Wolfenden, 1905 (a), p. 996.

Eucalanus monachus does not appear to be so widely distributed throughout the oceans
as the previous species. It was apparently rather limited in its occurrence in the region traversed
by the 'Siboga' as shewn by the following records.

Stat. 19. — Stat. 35. — Stat. ^6. — Stat. 37. — Stat. 47". — Stat. 66. — Stat. 75. —
Stat. 93. — Stat. 98. -- Stat. 99. — Stat. 101. — Stat. 110. — Stat. 117". — Stat. 136. —
Stat. 138. — Stat. 141. — Stat. 165. - - Stat. 168. — Stat. 169. — Stat. 205. — Stat.
215". — Stat. 315.

This Eucalanus is distinguished from the other species by the broadly rounded and
somewhat truncate outline of the head when viewed from the side.

3. Eucalanus mucronatus Giesbrecht.

Eucalanus mucronatus Giesbrecht, 1888, p. 333.

Eucalanus mucronatus Giesbrecht, 1893, p. 132, pis. 11 & 35.

Eucalanus mucronatus Giesbrecht & Schmeil, 1898, p. 21.

Eucalanus mucronatus Cleve, 1901, p. 7.

Eucalanus mucronatus Cleve, 1903, p. 362.

Eucalanus mucronatus Cleve, 1904, p. 189.

Eucalanus mucronatus Wolfenden, 1905 (a), p. 996.

This species was moderately common in the 'Siboga' collections, and appeared to be widely
distributed in the area investigated. It was found at the following stations.

Stat. 36. — Stat. 37. — Stat. 47''. — Stat. 66. — Stat. 75. — Stat. 89. — Stat. 93. —
Stat. 96 (night). - - Stat. 98. — Stat. 99. - - Stat. 101. — Stat. 106. — Stat. 110. —
Stat. 117'. - - Stat. 118. - - Stat. 121. -- Stat. 124. -- Stat. 125 (day). — Stat. 128. —
Stat. 129. - - Stat. 133. • - Stat. 136. — Stat. 138. — Stat. 141. — Stat. 142. — Stat.
143. -- Stat. 144. -- Stat. 146. -- Stat. 148. — Stat. 157. — Stat. 165. — Stat. 168. —
Stat. 169. - - Stat. 172. — Stat. 177'. -- Stat. 184. — Stat. 185. — Stat. 186. -- Stat.
i89a. — Stat. 194 — 7. -- Stat. 203 (surface). — Stat. 203 (1500 metres). — Stat. 204. —
Stat. 2iO\ — Stat. 213. -- Stat. 215*. -- Stat. 216. -- Stat. 217 (horizontal cylinder). —
Stat. 220 (vertical net). - - Stat. 220. — Stat. 223. - - Stat. 224. — Stat. 225. - - Stat.
230. -- Stat. 243. -- Stat. 245. -- Stat. 252. — Stat. 271. — Stat. 276. — Stat. 282. —
Stat. 304. — Stat. 315.

21

Eucalanus mucronalus when in good condition, is easily distinguished from the other
species of Eucalanus by the hook-like projection of the forehead when seen from the side.
The forehead of the species hovvever, seems to be easily telescoped, and it is therefore not
always possible to make out the beak at first sight.

4. Eucalanus pileatus Giesbrecht.

Eucalanus pileatus Giesbrecht, 1888, p. 334.

Eucalanus pileatus Giesbrecht, 1893, p. 132, pis. n & 35.

Eucalanus pileatus Giesbrecht & Schmeil, 1898, p. 21.

Eucalanus pileatus Thompson & Scott, 1903, p. 242.

Eucalanus pileatus Cleve, 1904, p. 189.

Eucalanus pileatus Wolfenden, 1905 (a), 996.

This Eucalanus is apparently not a common species. It was rather scarce in the region
traversed by the 'Siboga' as shewn by the records of its occurrence.

Stat. 16. — Stat. 19. — Stat. 35. — Stat. 36. — Stat. 37. — Stat. 471'. — Stat. 93. —
Stat. 96. — Stat. 99. — Stat. ior. — Stat. 106. — Stat. 121. — Stat. 138. — Stat. 165.-
Stat. 168. — Stat. 169. — Stat. i77a. — Stat. 282. — Stat. 315.

This species has been recorded from the Red Sea, Atlantic, Pacific, and Indian Oceans

5-

Eucalanus subcrassus Giesbrecht.

Eucalanus subcrassus Giesbrecht, 1888, p. 334.

Eucalanus subcrassus Giesbrecht, 1893, p 132, pis. 11 & 35.

Eucalanus subcrassus Giesbrecht & Schmeil, 1898, p. 22.

Eucalanus subcrassus Cleve, 1901, p. 7.

Eucalanus subcrassus Thompson & Scott, 1903, p. 242.

Eucalanus subcrassus Cleve, 1903, p. 362.

Eucalanus subcrassus Cleve, 1904, p. 190.

Eucalanus subcrassus Wolfenden, 1905(0), p. 996.

Eucalamis subcrassus although not plentiful, appeared to have a wide distribution in
the area traversed. It was noted at the following stations.

Stat. 35. — Stat. 47''. — Stat. 66. — Stat. 81. — Stat. 89. — Stat. 93. —Stat. 96 (day). -
Stat. 96 (night). — Stat. 98. — Stat. 99. — Stat. 101. — Stat. 106. — Stat. 109. -
Stat. 112. — Stat. 117*. - - Stat. 125 (day). — Stat. 125 (night). — Stat. 129. — Stat.
I33. __ stat. 136. — Stat. 138. — Stat. 141. — Stat. 144. — Stat. 146. — Stat. 148. —
Stat. 157 — Stat. 165. — Stat. 168. —Stat. 172. — Stat. 177". — Stat. 184. — Stat. 1S5. -
Stat. i89a. — Stat. 193. — Stats. 194— 7. — Stat. 203 (surface). — Stat. 203 (1500 metres. -
Stat. 204. — Stat. 205. — Stat. 217 (horizontal cylinder). — Stat. 220 (vertical net). -
Stat. 229. — Stat. 252. — Stat. 315.

This Eucalanus has also been recorded from the Atlantic, Indian, and Pacific Oceans.
and the Red Sea.

6. Eucalanus subtcnuis Giesbrecht.

Eucalanus subtcnuis Giesbrecht, 1888, p. 333.

Eucalanus subtcnuis Giesbrecht, 1893, p. 132, pis. 11 & 35.

22

Eucalanus subtenuis Giesbrecht & Schmeil, 1898, p. 21.

Eucalanus subtenuis Cleve, 1901, p. 7.

Eucalanus subtenuis A. Scott, 1902, p. 401.

Eucalanus subtenuis Thompson & Scott, 1903, p. 242.

Eucalanus subtenuis Cleve, 1903, p. 363.

Eucalanus subtenuis Cleve, 1904, p. 190.

Eucalanus subtenuis Sars, 1905 (a), p. 2.

Eucalanus subtenuis Wolfenden, I905(<?). p. 996.

Eucalanus subtenuis Esterly, 1905, p. 135, fig. 9.

Eucalanus subtennis appeared to have a fairly wide distribution in the area traversed
by the 'Siboga' as shewn by the following records.

Stat. 47,J. — Stat. 66. — Stat. 75. -- Stat. 93. -- Stat. 98. — Stat. 118. - - Stat. 124. -
Stat. 125 (day). — Stat. 125 (night). — Stat. 129. —Stat. 136. — Stat. 138. — Stat. 141. -
Stat. 142. -- Stat. 144. — Stat. 157. — Stat. 165. — Stat. 169. — Stat. 172. — Stat. 184. —
Stat. 189". — Stats. 194 — 7. — Stat. 203 (surface). — Stat. 203 (1500 metres). — Stat. 204. —
Stat. 205. • Stat. 214. - - Stat. 215*. - - Stat. 217 (horizontal cylinder). — Statt. 220
(vertical net). — Stat. 245.

Eucalanus suóleuuis has been recorded from the Atlantic, Pacific, and Indian Oceans
and also from the Arabian Sea.

A considerable amount of care is necessary to distinguish the last three species of
Eucalamts from each other. The external characters are not very well marked, and the points
of difference are frequently obliterated when the specimens are distorted. It is always wise to
make dissections of the appendages before a definite conclusion is arrived at.

7. Ettcalamts dcnlatus nov. sp. Plate II, figs. 1 — 8.

Female — length 2,6 mm.

The head is considerably contracted in front and is produced into a well-marked spiniform
process. When viewed from the side, the spiniform process appears to be directed slightly
upward, terminating in a sharp point, (Plate II, fig. 2). The fourth and fifth thoracic segments
are completely separated. The last thoracic segment has rounded extremities. The apex of the
last thoracic segment is greatly contracted and is very little wider than the base of the genital
segment. The abdomen is three-jointed and symmetrical, with one free segment between the
genital and anal segments.

The antennules are twenty-three jointed, and extend beyond the end of the furca by
five joints.

The antennae are nearly as in Eucalanus crassus. The proximal joint of the endopodite
is about doublé as long as broad.

The mandible palp is furnished with two inner setae on the second joint of the basio-
podite. The first joint of the endopodite is destitute of setae, and the second joint is furnished
with four apical setae. The exopodite is apparently without segmentation, and is furnished with
six setae on the distal end.

The maxillae and maxillipedes are nearly as in Eucalamts altcnuafus. The first and
second joints of the endopodite of the second maxillipedes are furnished with four setae.

23

The four pairs of swimming feet are very similar to those of Eucalanus attenuatus.

Male uriknown.

This species is easily distinguished from the other members of the genus by its strong,
well defined cephalic spine, and by the absence of segmentation in the exopodite of the
mandible palp.

Specimens of this species were found in samples of plankton from the following stations.

Stat. 141, 1 specimen. — Stat. 172, 3 specimens. — Stat. 184, 2 specimens. — Stat. 315,
12 specimens.

Genus Rhincalanus Dana, 1S52.

The members of this genus are distinguished from Eucalanus, by the peculiar beak-like
projection of the forehead, by the spines on the thoracic segments, and by the presence of a
fifth pair of feet in the female. Two species were represented in the plankton collected by
the 'Sibo^a'.

s

1. Rhincalanus cornutus Dana.

Rhincalanus cornutus Dana, 1S52, p. 1083, pi. 76.

Rhincalanus cornutus Brady, 1883, p. 41, pi. VII.

Rhincalanus cornutus I. C. Thompson, 1888, p. 14S.

Rhincalanus cornutus T. Scott, 1893, p. 30.

Rhincalanus cornutus Giesbrecht, 1893, p. 153, pis. 12 & 35.

Rhincalanus cornutus Giesbrecht & Schmeil, 1898, p. 23.

Rhincalanus cornutus I. C. Thompson, 1900, p. 276.

Rhincalanus cornutus Cleve, 1901, p. 8.

Rhincalanus cornutus A. Scott, 1902, p. 402.

Rhincalanus cornutus I. C. Thompson, 1903, p. 16.

Rhincalanus cornutus Thompson & Scott, 1903, p. 242.

Rhincalanus cornutus Cleve, 1903, p. 368.

Rhincalanus cornutus Cleve, 1904, p. 196.

Rhincalanus cornutus Sars, 1905 (a), p. 2.

Rhincalanus cornutus Wolfenden, 1905(0), p. 996.

Rhincalanus cornutus Pearson, 1906, p. 8.

Rhincalanus cornutus van Breemen, 1908, p. 18, fig. 15.

This species although not very common except at Station 141 and Station 148, appeared
to be generally distributed throughout the area traversed by the 'Siboga', as shewn by the
following records.

Stat. 35. — Stat. 36. — Stat. 37. — Stat. 40. — Stat. 50. — Stat. 66. — Stat. 81. —
Stat. 98. -- Stat. 99. — Stat. 106. — Stat. 112. — Stat. H7a. -- Stat. 118. — Stat. 125
(day). — Stat. 128. — Stat. 133. — Stat. 136. — Stat. 13S. — Stat. 141, 160 specimens. —
Stat. 143. — • Stat. 144. — Stat. 146. — Stat. 148, 422 specimens. -- Stat. 157. — Stat.
165. — Stat. 168. — Stat. 169. — Stat. 172. — Stat. 174. — Stat. 177°. — Stat. 184. -
Stat. 1S5. - - Stat. 189°. — Stat. 203 (1500 metres). -- Stat. 204. -- Stat. 213. -- Stat.
216. — Stat. 220 (vertical net). — Stat. 220 (surface). — Stat. 223. — Stat. 230. — Stat.
243. — Stat. 276. — Stat. 282. — Stat. 315.

Rhincalanus cornutus appears to be widely distributed in the warmer seas. Wolfenden

23

24

(1902) recorded it from the Faröe Channel, but in a later report (1904) withdrew the record,
stating that all records of the occurrence of this species beyond 300 N. must be looked upon
with suspicion. The late I. C. Thompson (1903) records the species from the collections taken
during the cruise of the 'Oceana' in 189S, at stations in the Atlantic north of 52°N., and
Professor G. O. Sars (1905) records it from collections taken during the investigations carried
on by the Prince of Monaco.

The very strongly projecting forehead, and the structure of the fifth pair of feet in both
sexes, are the chief points that separate this species from the following one.

2. Rhincalamts gigas Brady.

Rhincalanus gigas Brady, 1S83, p. 42, pi. VIII, figs. 1 — 11.

Rhincalamts gigas I. C. Thompson, 18S8, p. 148.

Rhincalanus nasutus Giesbrecht, 1S88, p. 334.

Rhincalanus nasutus Giesbrecht, 1893, p. 152, pi. 3, 9, 12, 35.

Rhincalanus nasutus Canu, 1896, p. 421.

Rhincalanus nasutus Giesbrecht & Schmeil, 1898, p. 22.

Rhincalanus gigas I. C. Thompson, 1900, p. 276.

Rhincalanus ? gigas T. Scott, 1901, p. 237, pi. XVII, figs. 1 — 4.

Rhincalanus ? gigas T. Scott, 1902, p. 450.

Rhincalanus nasutus Wolfenden, 1902, p. 361.

Rhincalanus nasutus A. Scott, 1902, p. 401.

Rhincalanus grandis Giesbrecht, 1902, p. 8, pi. 1, figs. 15 — 18.

Rhincalanus nasutus Sars, 1902, p. 15, pi. VI & VII.

Rhincalanus nasutus I. C. Thompson, 1903, p. 16.

Rhincalanus nasutus Thompson & Scott, 1903, p. 242.

Rhincalanus nasutus Cleve, 1903, p. 368.

Rhincalanus nasutus Cleve, 1904, p. 196.

Rhincalanus nasutus Wolfenden, 1904, p. 111.

Rhincalanus nasutus Wolfenden, 1905 (a), p. 996.

Rhincalanus nasutus Sars, 1905 (a), p. 2.

Rhincalanus nasutus Esterly, 1905, p. 136, fig. 10.

Rhincalanus nasutus Farran, 1905, p. 30.

Rhincalanus nasutus Pearson, 1906, p. 8.

Rhincalanus nasutus Farran, 190S, p. 22.

Rhincalanus nasutus van Breemen, 190S, p. 18, fig. 14.

- ■, • .

Rhincalanus gigas appeared to be rather a scarce species in the area traversed by the

'Siboga', as shewn by the following records of its occurrence.

Stat. n 8, 2 specimens. ■ Stat. 125 (night). — Stat. 128, 42 specimen. — Stat. 141. —
Stat. 142, 6 specimens. — Stat. 165, 1 specimen. — Stat. 168, 7 specimens. — Stat. 172,
10 specimens. — Stat. 174, 2 specimens. — Stat. 185, 1 specimen. — Stat. 203 (1500
metres), 5 specimens. — Stat. 2io\ 4 specimens. -- Stat. 230. — Stat. 243, 1 specimen. —
Stat. 276, 6 specimens. — Stat. 282.

The characters that are adopted to distinguish Rhincalanus nasutus Giesbrecht, from
Rhincalanus gigas Brady, are of so little importance that for the present I regard Giesbrecht's
species to be only a small form of Rhincalanus gigas. Bradv's figures appear to have been
drawn from imperfect specimens. Giesbrecht himself regarded it as possible, that the form he

24

25

described from the Antarctic as Rkincalanus gra/idis, was identical with Rliincalanus gigas,
and the rather incomplete figures given by Brady, was the chief reason for separating the two
forms. The figure of the entire animal given by Brady, is evidently drawn from a male and
apart from its larger size, there is nothing to distinguish it from the males found in the 'Siboga'
plankton. Dr. W. T. Calman kindly examined the type specimens of Rliincalanus gigas in the
British Museum, and I quote the following remarks from one of his letters to me. 'The bottles
'labelled Rkincalanus gigas in the Challenger collection seem to my eye, to contain specimens
'of more than one species, but I chose one of the largest specimens from Stat. 156 as most
'likely to be what Brady meant. None of the specimens seem to exceed 8,5 mm. in length
'excluding the caudal setae. In this specimen both rami of the first pair of legs have only
'two joints. I had begun to make a camera sketch of the limb to send you but it is so
absolutely like Giesbrecht's fig. 10 on plate 12 of the Naples Monograph that I did not think
'it worth while. The only difference from Giesbrecht's figure which I can see is that the
'terminal setae of the exopodite are relatively a trifle longer'.

The terminal spine on the female fifth pair, apparently varies a good deal in different
individuals of the same size. In some cases it is quite stout and terminates abruptly, in others,
it is rather slender and tapers gradually to a fine point. The largest female from the 'Siboga'
plankton measured 5 mm. in length, exclusive of the caudal setae.

Genus Mecynocera I. C. Thompson, 1888.

The only known member of this genus, is easily distinguished from the other genera
belonging to the family, by its very long antennules, and by the structure of the first and fifth
pairs of feet. The exopodite of the first pair is three-jointed. The endopodite is composed of
one joint only. The fifth pair of feet is rudimentary, and only the exopodites are present. The
exopodite consists of three joints, and is attached to a two-jointed basiopodite. The second joint
of the exopodite is furnished with one plumose seta, and the third joint with five. Giesbrecht &
Schmeil state in 'Das Tierreich', that the male is unknown. Wiieeler (1900), and van Breemen
(1908), also failed to notice, that the male had been obtained both by Thompson at Madeira,
and by my father in the Gulf of Guinea. The late I. C. Thompson in his original description,
says 'males and females were both plentiful, and taken by surface tow-net at all the. places
visited'. In the Report on 'Entomoslraca from the Gulf of Guinea' (1893), my father partly
described and figured the male, stating that the fifth feet are alike in both sexes.

]. JMccyjwcera clausi I. C. Thompson.

Mecynocera clausi I. C. Thompson, 1888, p. 150, pi. XI, figs. 1 — 4.

Leptocalanus filicornis Giesbrecht, 1888, p. 334.
Mecynocera clausi Giesbrecht, 1893, p. 160, pis. 5, 11,
Mecynocera clausi T. Scott, 1893, p. 80, pis. 1 & 2.
Mecynocera clausi Giesbrecht & Schmeil, 1898, p. 23.
Mecynocera clausi Wheeler, 1900, p. 168, fig. 5.
Mecynocera clausi I. C. Thompson, 1903, p. 16.
Mecynocera clausi Thompson & Scott, 1903, p. 242.

25

35-

SIBOGA-EXI'EDITIE XXIX 11.

26

Mecynocera clausi Sars, 1905 (a), p. 2.

Mecynocera clausi Esterly, 1905, p. 137, fig. 16.

Mecynocera clausi Pearson, 1906, p. 8.

Mecynocera clausi van Breemen, 1908, p. 19, fig. 16.

Mecynocera clausi although not common in any of the 'Siboga' plankton samples, had
a moderately wide distribution in the area investigated, as shewn by the following records.

■

Stat. 16. — Stat. 19. — Stat. 35. — Stat. 36. — Stat. 17. — Stat. 40. — Stat. 47''. —
Stat. 96 (day). — Stat. 96 (night). — Stat. 98. — Stat. 101. — Stat. 106. — Stat. 109. —
Stat. 121. — Stat. 141. — Stat. 143. — Stat. 144. — Stat. 146. — Stat. 148. — Stat.
184. — Stat. 203 (surface). — ■ Stat. 203 (1500 metres). — Stat. 213. — Stat. 217 (hori-
zontal cylinder). — Stat. 220 (vertical net) — Stat. 252. — Stat. 276. — Stat. 282. —
Stat. 304. — Stat. 315.

This Calanoid has been recorded from the Mediterranean, Atlantic, Indian, and Pacific Oceans.

3. Family Paracalanidae.
Genus Paracalanus Boeck, 1864.

The known Calanoids belonging to this genus are small and rather robust. The females
can be readily recognised by the presence of a small fifth pair of feet. The fifth feet of the
female is composed of a basal part and one free joint. A form described by Canon Norman
and T. Scott as Paracalanus parvus, var. pcrplcxtts, differs from the typical members of the
genus, in that the left fifth foot of the female has two free joints instead of one. I have
reeen tly detected this variety in plankton from the Irish Sea, but whether it is normal or not,
is difficult to make out, as the material is very limited. The right fifth foot of the males of
Paracalanus is the same as in the female. The left foot is elongated and slightly prehensile,
with four free joints. The largest size that any of the females attain appears to be 1,2 mm.

Two species were represented in the plankton collected by the 'Siboga'.

1. Paracalanus aculeatus Giesbrecht.

Paracalanus aculeatus Giesbrecht, 1888, p. 333.

Paracalanus aculeatus Giesbrecht, 1S93, p. 164, pi. 9.

Paracalanus parvus T. Scott, 1893, p. 26, pi. 1, figs. 9 — 14.

Paracalanus aculeatus Giesbrecht, 1896, p. 318.

Paracalanus aculeatus Giesbrecht & Schmeil, 1898, p. 24.

Paracalanus aculeatus Cleve, 1901, pp. 8 & 47, pi. VI, figs. 1 — 10.

Paracalanus aculeatus A. Scott, 1902, p. 402.

Paracalanus aculeatus Cleve, 1903, p. 366.

Paracalanus aculeatus Cleve, 1904, p. 194.

Paracalanus aculeatus Wolfenden, 1905 (a), p. 998, pi. XCVI, figs. 12 — 15.

Paracalanus aculeatus Sars, 1905 (a), p. 2.

Paracalanus aculeatus appeared to have a wide distribution throughout the region traversed
by the 'Siboga', as shewn by the following records.

26

27

Stat. 35. — Stat. 37. — Stat. 40. — Stat. 47". — Stat. 66. — Stat. 81. — Stat. 101. —
Stat. 118. ■ Stat. 128. — Stat. 136. — Stat. 141. — Slat. 142. — Stat. 143. — Stat.
14S. — Stat. 157. — Stat. 165. -- Stat. 168. — Stat. 184. — Stat. 1S5. — Stat. 186. —
Stats. 194 — 7. — Stat. 203 (1500 metres). — Stat. 205. — Stat. 213. — Stat. 215». —
Stat. 216. - - Stat. 217 (horizontal cylinder). — Stat 220 (vertical net). — Stat. 220 (sur-
face). — Stat. 223. -- Stat. 229. — Stat. 230. — Stat. 243. — Stat. 252. — Stat. 276. —
Stat. 304. — Stat. 315.

This species is closely related to the next one, and some care is required to distinguish
the two at fust. The longer antennules, and the armature of the second joint of the endopodite
oi the fourth foot, are the specific points that separate the two species. The species recorded
from the Gulf of Guinea by my father as Paracalanus parvus (Claus), is probably Giesbrecht's
Paracalanus aculeatus.

2. Paracalanus parvus (Claus).

Calanvs parvus Claus, 1863, p. 173, pi. XXVI, figs. 10 — 14.

Paracalanus parvus Giesbrecht, 1893, p. 164, pis. 1, 6, 9.

Paracalanus parvus Giesbrecht & Schmeil, 1898, p. 24.

Paracalanus parvus T. Scott, 1899, p. 248.

Paracalanus parvus T. Scott, 1900, p. 383.

Paracalanus parvus Wheeler, 1900, p. 168, fig. 6.

Paracalanus parvus T. Scott, 190 1, p. 350.

Paracalanus parvus Cleve, 190 1, p. 8.

Paracalanus parvus Sars, 1902, p. 17, pis. VIII, IX.

Paracalanus parvus A. Scott, 1902, p. 402.

Calanus parvus Wolfenden, 1902, p. 361.

Paracalanus parvus Thompson & Scott, 1903, p. 243.

Paracalanus parvus Farran, 1903, p. 11.

Paracalanus parvus Cleve, 1903, p. 367.

Paracalanus parvus Cleve, 1904, p. 194.

Paracalanus parvus Wolfenden, 1904, p. 111.

Paracalanus parvus Wolfenden, 1905(0), p. 997, pi. XCVI, figs. 7 — 11 & 16.

Paracalanus parvus Sars, 1905 (a), p. 2.

Paracalanus parvus Esterly, 1905, p. 140, fig. 12.

Paracalanus parvus Farran, 1905, p. 30.

Paracalanus parvus Pearson, 1906, p. 8.

Paracalanus parvus T. Scott, 1906(0), p. 298.

Paracalanus parvus Farran, 1908, p. 22.

Paracalanus parvus van Breemen, 1908, p. 20, fig. 17.

This species was well distributed over the area investigated by the 'Siboga', as shewn
by the records of the stations where it was noted.

Stat. 16. — Stat. 35. — Stat. 36. — Stat. 37. — Stat. 40. — Stat. 471'. — Stat. 50. —
Stat. 71. — Stat. 75. — Stat. 81. — Stat. 96 (day). — Stat. 96 (night). — Stat. 99. —
Stat. 101. — Stat. 106. — Stat. 109. — Stat. 112. — Stat. 117». — Stat. 118. — Stat.
121. — Stat. 125 (day). — Stat. 128. — Stat. 133. — Stat. 136. — Stat. 138. — Stat.
141. — Stat. 142. — Stat. 143. — Stat. 144. — Stat. 148. — Stat. 165. — Stat. 168. —
Stat. 169. — Stat. 177^. - - Stat. 184. — Stat. 185. — Stat. 204. — Stat. 205. — Stat.
213. — Stat. 217 (horizontal cylinder). — Stat. 229. — Stat. 243. — Stat. 250. — Stat.
275. — Stat. 304.

27

I have been unable to detect any differences between the specimens regarded as Para-
calanus parvus, collected by the 'Siboga', and those taken frequently in plankton samples from
the Irish Sea. Wolfenden 1905 («), has described some varieties from J. Stanley Gardiner's
Maldive plankton, but whether the minute differences mentioned, are worthy of even making
varieties of, is extremely doubtful. In such a widely distributed species as Paracalanus parvus,
one would expect to find a certain amount of local variation from the type found in the seas
of Northern Europe.

The species described by my father in the report 'On Entomostraca from the Gulf of
Guinea' as Paracalanus pygmaeus, agrees much better with the description and figures of
Paracalanus crassirostris Dahl, than with the imperfect description given by Claus. The very
strong rostrum, and the short spines on the fifth feet of the female, are two important characters,
along with its small size, by which it differs from any of Wolfenden's varieties.

Paracalanus parvus, has a remarkably wide distribution throughout the great Oceans,
as shewn by the record of observers who have noted its occurrence.

Genus AcrocalariUS Giesbrecht, 1888.

This genus is closely allied to Paracalanus, but is distinguished from it, by the outer
margin of the second and third joints of the exopodites of the third and fourth pairs of swimming
feet being armed with teeth. The proximal part of the outer margin of the last joint of the
exopodite of the fourth pair of feet, is nearly doublé as long as the distal portion. The fifth
feet are very rudimentary, or absent in the female. Only the left fifth foot is present in the male.

Four species of Acrocalanus were represented in the material collected by the 'Siboga'.

1. Acrocalanus longicornis Giesbrecht.

Acrocalanus longicornis Giesbrecht, 1888, p. 332.

Acrocalanus longicornis Giesbrecht, 1893, p. 171, pis. 6 & 10.

Acrocalanus longicornis Giesbrecht & Schmeil, 1S9S, p. 25.

Acrocalanus longicornis Cleve, 1901, p. 5.

Acrocalanus longicornis Thompson & Scott, 1903, p. 243.

Acrocalanus longicornis Wolfenden, 1905 (a), p. 1000.

This species proved to be the most common member of the genus, and was noted in
plankton collected at the following stations.

Stat. 16. — Stat. 35. — Stat. 36. — Stat. 40. — Stat. 47''. — Stat. 50. — Stat. 71. —
Stat. 75. - - Stat. 81. - - Stat. 89. -- Stat. 93. -- Stat. 96 (day). -- Stat. 96 (night). -
Stat. 98. -- Stat. 99. -- Stat. 110. — Stat. m. -- Stat. 112. —Stat. 118. — Stat. 121.-
Stat. 125 (day). - - Stat. 128. — Stat. 138. — Stat. 141. — Stat. 142. -- Stat. 143. -
Stat. 144. ■ - Stat. 148. — Stat. 165. - - Stat. 168. -- Stat. 169. -- Stat. 184. -- Stat.
185. - - Stat. 203 (1500 metres to surface). - - Stat. 204. — Stat. 205. -- Stat. 2ioa. -
Stat. 213. - - Stat. 214. -- Stat. 215". -- Stat. 216. -- Stat. 217 (horizontal cylinder). -
Stat. 220 (vertical net). -- Stat. 220 (surface). -- Stat. 223. — Stat. 229. -- Stat. 230.-
Stat. 243. — Stat. 271. — Stat. 315.

Acrocalanus longicornis can be easily separated from the other species, by the length

29

of its antennules. The antennules extend beyond the body by five joints. It can be also
recognised by the armature of the distal part of the last joint of the exopodites of the fourth
pair of feet. The armature consists of a number of very fine teeth.

This species has been recorded from the Atlantic, Indian, and Pacific Oceans, and also
from the Red Sea.

2. Acrocalanus gracilis Giesbrecht.

Acrocalanus gracilis Giesbrecht, 1888, p. 332.
Acrocalanus gracilis Giesbrecht, 1893, p. 171, pis. 6 & 10.
Acrocalanus gracilis Giesbrecht, 1897, p. 318.
Acrocalanus gracilis Giesbrecht & Schmeil, 1898, p. 25.
Acrocalanus gracilis Cleve, 1901, p. 4.
Acrocalanus gracilis Thompson & Scott, 1903, p. 243.
Acrocalanus gracilis Cleve, 1903, p. 356.
Acrocalanus gracilis Cleve, 1904, p. 184.
Acrocalanus gracilis Wolfenden, 1905 (a), p. 1003.

This Acrocalanus although not so common as the preceeding species, was more plentiful
than either of the next two. It occurred at the following stations.

Stat. 16. — Stat. 36. — Stat. 40. — Stat. 75. — Stat. 93. — Stat. 98. — Stat. 99. -
Stat. 101. - - Stat. 109. — Stat. 117». - - Stat. 118. — Stat. 138. -- Stat. 141. -- Stat.

142. — Stat. 143. — Stat. 148. — Stat. 203 (1500 metres to surface). - - Stat. 213. -
Stat. 2 1 5a. — Stat. 2XJ (horizontal cylinder). — Stat. 224. — Stat. 225. — Stat. 229. -
Stat. 243. — Stat. 245. — Stat. 315.

This species is easily distinguished from the other three, by its larger size, and by the
smoothly rounded dorsal surface of the cephalothorax, when viewed from the side.
Acrocalanus gracilis has a distribution similar to the preceeding species.

3. Acrocalanus gibber Giesbrecht.

Acrocalanus gibber Giesbrecht, 1888, p. 332.
Acrocalanus gibber Giesbrecht, 1893, p. 171, pis. 6 & 10.
Acrocalanus gibber Giesbrecht & Schmeil, 1898, p. 65.
Acrocalanus gibber I. C. Thompson, 1900, p. 276.
Acrocalanus gibber Cleve, 1901, p. 4.
Acrocalanus gibber A. Scott, 1902, p. 402.
Acrocalanus gibber Thompson & Scott, 1903, p. 243.
Acrocalanus gibber Cleve, 1903, p. 356.
Acrocalanus gibber Cleve, 1904, p. 184.
Acrocalanus gibber Wolfenden, 1905 («), p. 1003.

Acrocalanus gibber although not common, apparently had a moderately wide distribution
in the area traversed by the 'Siboga', as shewn by the following records.

Stat. 16. — Stat. 19. - - Stat. 35. - - Stat. t,6. — Stat. ^-j. — Stat. 47''. — Stat. 93. —
Stat. 98. — Stat. 112. — Stat. 118. — Stat. 138. — Stat. 141. — Stat. 142. — Stat.

143. — Stat. 184. -- Stat. 2i5a. — Stat. 217 (horizontal cylinder). — Stat. 315.

This species when present, can be easily identified by its very compact body, and although

very like Acrocalaiuis longicornis in general appearance, is readily separated by its smaller
size, and shorter antennules.

This Acrocalanus has a distribution similar to that of the two previous species.

4. Acrocalanus monachus Giesbrecht.

Acrocalanus monachus Giesbrecht, 1888, p. 333.
Acrocalanus monachus Giesbrecht, 1S93, p. 171, pis. 6 & 10.
Acrocalanus monachus Giesbrecht & Schmeil, 1898, p. 25.
Acrocalanus monachus Thompson & Scott, 1903, p. 243.
Acrocalanus monachus Cleve, 1903, p. 356.
Acrocalanus monachus Wolfenden, 1905 (a), p. 1002.

This appeared to be the least common species of the genus, and was only noted at
the following stations.

Stat. 98. — Stat. 99. — Stat. 128. — Stat. 217.

Acrocalanus monachus has a very characteristic head when seen in lateral view, which
makes the identification comparatively easy. The forehead when seen from the side, is mode-
rately broad and nearly truncate in outline.

This species up to the present, has been recorded only from the Pacific and Indian
Oceans, and from the Red Sea.

Genus Calocalanus Giesbrecht, 1888.

The members of this genus are not unlike Paracalanus, but are easily recognised by
the abdomen being composed of only two or three joints, by the long terminal joint of the
antennules, and by the structure of the fifth feet. The fifth feet of the female are symmetrical,
and consist of two or three free joints attached to a basal portion. The right foot of the
male is composed of three free joints, and the left foot of five. The left fifth foot is conside-
rably elongated, and is slightly prehensile.

Two species were obtained from the 'Siboga' plankton.

1. Calocalamis pavo (Dana).

Calanus pavo Dana, 1S49, p. 13.

Calocalanus pavo Giesbrecht, 1893, p. 175, pis. 1, 4, 9, 36.

Calocalanus pavo T. Scott, 1893, p. 37, pi. 6, figs. 9 & 10.

Calocalanus pavo Giesbrecht, 1896, p. 31S.

Calocalanus pavo Giesbrecht & Schmeil, 1898, p. 26.

Calocalanus pavo I. C. Thompson, 1900, p. 277.

Calocalanus pavo Wheeler, 1900, p. 169, fig. 7.

Calocalanus pavo Cleve, 1901, p. 5.

Calocalanus pavo A. Scott, 1902, p. 402.

Calocalanus pavo Thompson & Scott, 1903, p. 243.

Calocalanus pavo Cleve, 1903, p. 357.

Calocalanus pavo Cleve, 1904, p. 186.

Calocalanus pavo Wolfenden, 1904, p. III.

3°

3i

Calocalanus pavo Wolfenden, 1905 (a), p. 999.

Calocalanus pavo Pearson, 1906, p. 9.

Calocalanus pavo van Breemen, 1908, p. 22, fig. 18.

Calocalanus pavo although not common, had a moderately wide distribution throughout
the area traversed by the 'Siboga' as shewn by the records given.

Stat. 16. ■ - Stat. 40. - - Stat. 47". — Stat. 50. -- Stat. 75. -- Stat. 96 (day). -- Stat. 96
(night). — Stat. 99. — Stat. 101. — Stat. 110. — Stat. 118. — Stat. 121. —Stat. 133. —
Stat. 138. -- Stat. 141. — Stat. 148. — Stat. 203 (1500 metres to surface). — Stat. 213. -
Stat. 215". - - Stat. 217 (horizontal cylinder). - - Stat. 220 (vertical net). — Stat. 224. —
Stat. 229. -- Stat. 243. — Stat. 271. -- Stat. 276. — Stat. 282. — Stat. 304.

This species is easily identified by its two-jointed abdomen, and by the peculiar position
of the furcal joints. The furcal joints are symmetrical and are nearly always spread at right
angles to the abdomen. None of the specimens had the caudal setae in the perfect condition
so well shewn by Giesbrecht.

Calocalanus pavo has a wide distribution in the warm seas, and it has been frequently
recorded from various parts of the great oceans.

2. Calocalanus plumulosus (Claus).

Calanus plumulosus Claus, 1863, p. 174, pi. XXVI, figs. 15 & 16.

Calocalanus plumulosus Giesbrecht, 1893, p. 176, pis. 3, 9, 36.

Calocalanus plumulosus T. Scott, 1893, p. 39, pis. 1 & 6.

Calocalanus plumulosus Giesbrecht & Schmeil, 1898, p. 26.

Calocalanus plumulosus Wheeler, 1900, p. 170, fig. 8.

Calocalanus plumulosus A. Scott, 1902, p. 403.

Calocalanus plumulosus Thompson & Scott, 1903, p. 243.

Calocalanus plumulosus Wolfenden, 1905 (a), p. 999.

This Calocalanus appeared to be rather a rare species in the area investigated, and
was only observed in the plankton collected at the following eleven stations.

Stat. 33. — Stat. 47''. — Stat. 75. — Stat. 121. — Stat. 146. — Stat. 148. — Stat. 184. -
Stat. 217 (horizontal cylinder). — Stat. 271. — Stat. 282. — Stat. 304.

Calocalanus plumulosus is easily separated from Calocalanus pavo, by its three-jointed
abdomen and asymmetrical furca. The left furcal joint is larger than the right, and it is not
separated from the anal segment. The left furcal joint is furnished with a very long plumose
seta, but this is seldom perfect in specimens taken in ordinary tow-net collections.

This species has a distribution somewhat similar to the previous one.

4. Family Pseudocalanidae.

Genus Clausocalanus Giesbrecht, 1888.

This genus is distinguished from the other members of the family chiefly by the structure
of the fifth pair of feet of both sexes. The fifth pair is symmetrical in the female and has

31

32

two free joints attached to the basal portion. In the male, the left foot is greatly elongated,

and is composed of five joints. The right foot is very short and consists of one or three joints.

Two species belonging to this genus were represented in the 'Siboga' plankton.

i . Clausocalanus arcuicornis (Dana).

Calanus arcuicornis Dana, 1849, P- I2>

Claitsocalamts arcuicornis Giesbrecht, 1893, p. 186, pis. I, 2, 10, 36.

Clausocalanus arcuicornis T. Scott, 1893, p. 73, pi. 8.

Clausocalanus arcuicornis Giesbrecht & Schmeil, 1898, p. 27.

Clausocalanus arcuicornis I. C. Thompson, 1900, p. 277.

Clausocalanus arcuicornis Wheeler, 1900, p. 171, fig. 9.

Clausocalanus arcuicornis Cleve, 1901, p. 5.

Clausocalanus arcuicornis Thompson & Scott, 1903, p. 243.

Clausocalanus arcuicornis Farran, 1903, p. 1 1.

Clausocalanus arcuicornis Cleve, 1903, p. 359.

Clausocalanus arcuicornis Cleve, 1904, p. 188.

Clausocalanus arcuicornis Esterly, 1905, p. 142, fig. 13.

Clausocalanus arcuicornis Sars, 1905 («), p. 3.

Clausocalanus arcuicornis Wolfenden, 1905 (a), p. 999.

Clausocalanus arcuicornis Pearson, 1906, p. 9.

Clausocalanus arcuicornis Farran, 1908, p. 28.

Clausocalanus arcuicornis van Breemen, 1908, p. 23, fig. 20.

This species was moderately common, and appeared to be generally distributed in the
area investigated, as shewn by the following records.

Stat. 16. — Stat. 19. - - Stat. 35. — Stat. 36. — Stat. 471'. — Stat. 71. — Stat. 75. —
Stat. 93. — Stat. 96 (day). — Stat. 96 (night). -- Stat. 98. -- Stat. 112. -- Stat. 118. —
Stat. 121. -- Stat. 128. — Stat. 141. — Stat. 142. — Stat. 143. — Stat. 148. — Stat. 168. —
Stat. 174. — Stat. 185. -- Stat. 203 (1500 metres to surface). — Stat. 205. — Stat. 213. —
Stat. 215'. - - Stat. 217 (horizontal cylinder). — Stat. 220 (vertical net). -- Stat. 223. —
Stat. 224. -- Stat. 225. -- Stat. 230. — Stat. 243. -- Stat. 276. — Stat. 282. — Stat. 315.

The females of Clausocalanus arcuicornis, are not unlike those of the next species. They
are rather larger than Clausocalanus furcatus, and can be separated by the difference in the
lengths of the segments of the abdomen and furcal joints. In this species the genital segment
is longer than each of the next two segments. The furcal joints are about as long as broad.

This species has a wide distribution in the warm seas. It has also been recorded from
the deep water of the Atlantic, off the West Coast of Ireland by G. P. Farran.

2. Clausocalamis furcatus (Brady).

Drcpanopus furcatus Brady, 1883, p. "/j, pis. IV & XXIV.
Clausocalanus furcatus Giesbrecht, 1893, p. 186, pi. 36.
Clausocalanus furcatus T. Scott, 1893, p. 72.
Clausocalanus furcatus Giesbrecht, 1896, p. 318.
Clausocalanus furcatus Giesbrecht & Schmeil, 1S98, p. 27.
Clausocalanus furcatus Cleve, 1901, p. 5.
Clausocalanus furcatus A. Scott, 1902, p. 403.
Clausocalanus furcatus Thompson & Scott, 1903, p. 244.

33

Clausocalanus furcatus Cleve, 1903, p. 360.
Clausocalanus furcatus Cleve, 1904, p. 188.
Clausocalanus furcatus Sars, 1905 (a), p. 3.
Clausocalanus furcatus Wolfenden, 1905 (a), p. 999.

Clausocalanus furcatus appeared to be almost as widely distributed in the regiem
traversed by the 'Siboga', as the previous species. The following is the record of the stations
where it was noted.

Stat. 16. - ■ Stat. 40. - - Stat. 81. - - Stat. 96 (day). - - Stat. 96 (night). — Stat. 98. —
Stat. 99. -- Stat. 110. — Stat. 112. — Stat. 118. -- Stat. 121. — Stat. 128. -- Stat. 138. —
Stat. 141. -- Stat. 142. -- Stat. 143. — Stat. 148. -- Stat. 168. — Stat.' 184. — Stat. 1S5. —
Stat. 203 (surface). - • Stat. 203 (1500 metres to surface). - - Stat. 204. — Stat. 205. —
Stat. 213. - Stat. 215'. -- Stat. 217 (horizontal cylinder). -- Stat. 220 (vertical net). —
Stat. 224. -- Stat. 230. — Stat. 271. -- Stat. 276. — Stat. 282. — Stat. 315.

The females of this Clausocalanus, are distinguished from those of Clausocalanus arcui-
cornis, by the genital segment being shorter than either of the next two segments, and by the
furcal joints being twice as long as broad.

This species has a similar distribution in the great oceans as the previous one.

Genus Oxycalanus Farran, 1908.

This genus was established by G. P. Farran in 1908, for the reception of a Calanoid
nearly related to Spinocalanus, but the possession of a strong bifurcate rostrum at once separates
it from that genus.

A number of specimens of a form apparently belonging to this genus, were found in the
'Siboga' plankton. I was inclined at first, to regard them as identical with Farran's species, but
further consideration revealed some important differences, which appear worthy of specific rank.

Only one species belonging to this genus was observed.

1. Oxycalanus semispinus nov. sp. Plate II, figs. 9 — 21.

Female — length 2,4 mm.

The ccplialothorax is oblong ovate in dorsal view, and is slightly contracted in front. The
head is completely fused with the first thoracic segment. The fourth and fifth thoracic segments
are fused together. The lateral margins of the last segment are rounded, and slightly produced
posteriorly. The rostrum is well defined, and is produced into two sharp points (PI. II, fig. 1 1).

The abdomen is four-jointed, and is equal to rather more than one-third of the length
of the ccplialothorax. The genital segment is asymmetrical. This is due to a slight protuberance
on the right side. It is equal to the combined length of the second and third segments. The
third segment is slightly shorter than the second. The anal segment is equal to two-thirds of
the length of the third segment. The furcal joints are slightly longer than broad, and are about
as long- as the anal segment.

The antennules are twenty-four-jointed and reach to the anal segment. The terminal joint
is very small, and is furnished with one sensory filament.

33

SIBOGA-EXPED1TIE XXIX ö. _5

34

The antennae, mandibles and maxillae, are similar to those of Farran's species {Oxy-
calanus spinifer).

The first and second pairs of maxillipedes also resemble those of Oxycalanus spinifer.
The lower margin of the basal joint of the second pair of maxillipedes is furnished with a
transverse row of short spines.

The first pair of swimming feet has a three-jointed exopodite, and a one-jointed endo-
podite shewing a faint tracé of subdivision (PI. II, fig. 17).

The second pair of swimming feet has a three-jointed exopodite, and a two-jointed
endopodite. The second joint of the exopodite has one row, and the third joint two rows, of
fine spines (PI. II, fig. 18).

The third and fourth pairs of swimming feet have three-jointed exopodites and endopodites.
The first joint of the basiopodite of the third pair of feet has two rows of fine spines on its surface.
The surface of the second joint of the exopodite of the third pair of feet has one row, and the
third joint two rows, of fine spines. The second and third joints of the endopodite of the third
pair of feet, have each two rows of fine spines. The second joint of the exopodite of the fourth
pair of feet has two rows of fine spines, and the third joint is well covered with fine spines.
The endopodite of the fourth pair of feet has a similar spinulation to that of the third pair.
The first basal joint of the fourth pair of feet has about six spines on the inner margin. There
is a well defined row of long acicular spines traversing the posterior surface of the first joint
of the basiopodite of the left foot only (PI. II, fig. 21). The terminal spines of the second,
third, and fourth pairs of feet, have finely serrate lamina.

The fifth pair is entirely absent.

Male unknown.

Occurrence - - eighteen specimens of this Calanoid were found in collections taken
at the following stations.

Stat. 118, 2 specimens. — Stat. 141, 4 specimens. — Stat. 143, 4 specimens. — Stat. 148,
2 specimens. — Stat. 185, 1 specimen. — Stat. 203 (1500 metres to surface), 2 specimens. —
Stat. 230, 1 specimen. — Stat. 276, 2 specimens.

The species although bearing a general resemblance to Oxycalanus spinifer Farran,
appears to differ from it in the following points: — The genital segment is asymmetrical and
rather longer. The antennules are much longer. The first joint of the basiopodite of the left
fourth foot only, is traversed with a single row of long acicular spines on the posterior surface.
There are no spines on the second joint. Farran states that the second joint of the basiopodite
of the fourth foot of Oxycalanus spinifer, has two transverse rows of long acicular spines, and
does not refer to any armature on the first joint.

Genus Monacilla Sars, 1905 («).

This genus was established by Professor G. O. Sars in 1 905 for the reception of a
Calanoid closely related to Clausoealanus. The characters which separate it from that genus
are : - A more robust body with very short and thick rostral appendages : — The second

34

35

joint of the basiopodite of the second, third, and fourth pairs of swimming feet is not enlarged,
and the surface of the endopodites of these feet is furnished with tine spines. The fifth pair of
feet of the female is rudimentary.

A single specimen, unfortunately a male, but apparently possessing some of these characters,
was found in one of the plankton collections taken by the 'Siboga', and is described below.

Only one representative of the genus was obtained.

i. Monacilla dubia nov. sp. Plate III, figs. 17 — 29.

Male — Iength 2,3 mm.

The cephalothorax is oblong ovate in dorsal view. It is considerably contracted in front,
and is produced into a small knob. The head is separated from the first thoracic segment by
a well defined suture. The fourth and fifth thoracic segments are fused together. The lateral
margins of the last thoracic segment are rounded, and are very slightly produced posteriorly.
The rostrum consists of two small blunt points.

The abdomen is composed of five segments, and is nearly equal to two-fifths of the Iength
of the cephalothorax. The first four segments are of about equal Iength. The fifth segment is
very small, and only about one-third of the Iength of the fourth segment. The furcal joints are
rather longer than broad, and are about twice the Iength of the anal segment.

The antennules are composed of twenty joints, and reach to the end of the fourth
abdominal segment. The eighth joint of the right antennule represents four fusecl joints, and
the same joint of the left side represents five joints.

The antennae, mandibles and mandible palps, resemble those of Oxycalanus semispinus.

The maxillae and first pair of maxillipedes are also similar to those of Oxycalanus semispinus,
with the exception, that the maxillae are somewhat rudimentary, and the claw lobe is absent.

The second pair of maxillipedes have long and slender second and third joints. The last
three joints are very small.

The first four pairs of swimming feet are similar in structure to those of Oxycalanus
semispinus, except in the following particulars : — There is no marginal spine on the first joint
of the exopodite of the first pair of feet. There are no fine spines on the surface of the third
and fourth joints of the exopodite of the second pair of feet. The exopodites, and endopodites,
of the third and fourth pairs of feet, are furnished with surface spines as in Oxycalanus semi-
spinus, but the method of arrangement is slightly different. The last joint of the exopodite of
the fourth pair of feet has only two rows of spines. The first and second joints of the basiopodite
of the fourth pair of feet are not furnished with acicular spines.

The fifth pair of feet is well developed. Each foot consists of a two-jointed basiopodite,
and three free joints. The last free joint of each foot, is furnished at the apex with a moderately
long curved spine. The right foot has a small rudimentary endopodite. The inner distal angle
of the second joint of the basiopodite of the left foot, bears a long spine with a moderately stout
base. The whole of the inner margin of the second free joint, and part of the inner margin
of the third joint, is furnished with fine spines.

35

36

Only one specimen of this peculiar Calanoid was 'observed in all the 'Siboga' material.
It was found in a Hensen vertical net collection, from 1500 metres to the surface at Station 203.

This species is only doubtfully included in the genus Monacilla, as the males were
unknown when Professor G. O. Sars described it. The preliminary description of the female,
without fio-ures, by that author, is insufficiënt to enable one to decide whether the male now
described really belongs to this genus or not. I was at first inclined to regard it as the male
of Oxycalanus, but its very small rostrum apparently separates it from that genus.

5. Family ^Etideidae.
Genus jEtideus Brady, 1S83.

The females of this genus are easily recognised by the very strong and bifurcate rostrum,
by the highly arched forehead when seen in lateral view, and by the well pronounced spiniform
projections of the last thoracic segment.

A considerable amount of doubt has arisen as to the identity of the species originallv
described by Professor Brady, upon which the genus was founded in 1883. Professor G. O. Sars
regards the species described by Brady, to be identical with the Calanoid described by Boeck in
1872, as Pseudocalamts armatus. This view is probably partly correct, and will be dealt with later.

The genus was well represented in the plankton collected during the traverse of the
'Siboga', and one had no difficulty in separating the material into the three apparently distinct
species described below.

1. d5.tideusgiesbrech.ti Cleve. Plate IV, Figs. 1 — 13.

Aitideus armatus Giesbrecht, 1893, p. 213, pis. 2, 14, 36.

Aitideus armatus T. Scott, 1893 (pars), p. 70.

Aitideus armatus Giesbrecht & Schmeil, 1898 (pars), p. 31.

Aitideus armatus Giesbrecht, 1903, p. 200.

Aitideus armatus Wolfenden, 1903, p. 266.

Aitideus armatus Thompson & Scott, 1903 (pars), p. 244.

Aitideus giesbreciiti Cleve, 1904, p. 185.

Aitideus giesbreciiti Sars, 1905 (a), p. 3.

Aitideus gitsbrechti Farran, 1908, p. 29.

This characteristic member of the genus was found in nine of the collections, and was
apparently the most common type in the area investigated by the 'Siboga'. The following are
the stations where it was noted.

Stat. 118, 4 specimens. — Stat. 128, 2 specimens. — Stat. 141, 10 specimens. — Stat. 142,
5 specimens. -- Stat. 143, 10 specimens. — Stat. 185, 10 specimens. — Stat. 203 (1500 metres
to surface), 8 specimens. - - Stat. 220 (vertical net) 1 specimen — Stat. 276, 1 specimen.

There is no doubt, I think, that this is the species Giesbrecht considered to be identical
with Brady's s'Etideus armatus, and is therefore the same Calanoid that was raised to specific
rank by Cleve in 1904. It is a very characteristic form and readily recognised. The forehead

36

37

is highly chitinized, and when viewed from die dorsal aspect, is seen to contract gradually to
a blunt point. There is a distinct crest, and a large horny rostrum with a moderately deep
excavation and slightly divergent points. There are two distinct knobs in the hollow of the rostrum
as shewn by GlESBRECHT (PI. IV, tig. 4). The last thoracic segment is highly chitinized, and is
produced posteriorly into strong spines. The spines extend beyond the end of the second seg-
ment of the abdomen. The proportional lengths of the abdominal segments are distinctly different
from those of the next two species. The combined length of the abdomen and furcal joints, is
rather less than one-third of the length of the cephalothorax from the forehead to the base of
the genital segment. The genital segment is about equal to the combined length of the next
two segments. The second segment is about half the length of the genital segment. The third
segment is about two-thirds the length of the second. The anal segment is as long as the second
segment. The furcal joints are as long as the anal segment, and are about twice as long as broad.

Length of female 2,1 mm.

This species, when carefully looked for, will probably be found to have a moderately
wide distribution in the warmer seas. I found examples of it on re-examining the plankton
collected in the Gulf of Guinea by the 'Buccaneer' early in 1886, and also in the plankton
collected by Professor Herdmax during his traverse between England and Ceylon in 1902.

2. Aïtideus ar ma/ us (Boeck). Plate IV, Figs. 14 — 25.

Pseudocalanus armatus Boeck, 1S72, p. 6.

-Ethletis armatus Brady, 1883 (pars), p. 76.

jEtideus armatus T. Scott, 1893 (pars), p. 70.

jEtideus armatus Giesbrecht & Schmeil, 1898 (pars), p. 31.

JEtideus armatus T. Scott, 1901, p. 238.

^Etideus armatus Wolfenden, 1902 (pars), p. 364.

jEtideus armatus Sars, 1902, p. 25, pis. XIII & XIV.

jEtideus tenuirostris Wolfenden, 1903, p. 266.

jEtideus tenuirostris Wolfenden, 1904, p. 116.

jEtideus armatus Cleve, 1904, p. 185.

JEtideus armatus Sars, [907(0), p. 6.

jEtideus armatus Farran, 1908, p. 28.

jEtideus armatus van Breemen, 190S, p. 30, fig. 30.

This JEtideus, although less common than the preceeding species, had apparently a
slightly wider distribution in the area traversed by the 'Siboga', as shewn by the following records.

Stat. 89, 8 specimen. — Stat. 118, 4 specimens. — Stat. 12S, 3 specimens. — Stat. 141,
6 specimens. — Stat. 143, 2 specimens. — Stat. 203 (1500 metres to surface), 8 speci-
mens. — Stat. 276, 3 specimens.

This particular type from the 'Siboga' collections, appears to be identical with the form
described by Boeck, which was very fully illustrated and described by Professor G. O. Sars in
1902. It is quite distinct from the other two members of the genus described in this report.
This species can be recognised by the following characters : — The forehead is not excep-
tionally strengthened with chitin, and when viewed from the dorsal aspect, the front margin
appears evenly rounded. There is no tracé of a crest, although the forehead appears boldly

37

3§

arched when seen from the side. The rami of the rostrum are slender and sharply pointed, and
the excavation is deeper than in the other two species (PI. IV, fig. i 7). The last thoracic spines
extend to the end of the genital segment only, and are not greatly chitinized. The proportional
lengths of the abdominal segments are very different from ^-Etidetts giesbrcchti. The combined
length of the abdomen and furca is slightly more than one-third of the total length of the
cefikalothorax, from the forehead to the base of the genital segment. The genital segment is
distinctly longer than the combined length of the next two segments. The second, third, and
fourth segments are of nearly equal length. The furcal joints are longer than the anal segment,
and are about twice as long as broacl.

Length of female 2 mm.

ALtideus armatus appears to be widely distributed, if all the records be regarded as
correct. Sars in the appendix to the volume on the Calanoids 'Crustacea of Norway', states,
that he examined two of the 'Challenger' specimens, and could find 110 difference between them
and the Norwegian forms. It was present in the plankton from the Gulf of Guinea, but I was
unable to find it in the Ceylon material.

3. sEtideus bradyi nov. sp. Plate V, figs. 1 — 12.

Jituleus armatus Brady, 1S83 (pars), p. 76, pi. X, figs. 5 — 16.
.l-.tidcus armatus T. Scott, 1893 (pars), p. 70.
JEtideus armatus Giesbrecht & Schmeil, 1898 (pars), p. 31.
JEtideus armatus Thompson & Scott, 1903 (pars), p. 224.

Female — length 1,8 mm.

In general appearance this species resembles ^-Etidctts giesbrechtihwX. it can be distinguished
both from that species, and from ^Etideus armatus, by the following characters : - - Viewecl
from the dorsal aspect, the forehead is marked by a deep constriction just behind the front
margin. A slight expansion is caused by the wide base of the rostrum, and the front margin
appears to have a bluntly rounded, knob-like projection. In lateral view, the forehead is boldlv
arched, and a distinct chitinized crest is present. The rostrum is very large and horny, with a
moderately cleep excavation. The rami are slightly converged at the apex. The last thoracic
segment is distinctly chitinized, and is produced into strong spines. The spines project to near
the middle of the second abdominal segment. The combined length of the abdomen and furca,
is slightly greater than one-third of the total length of the cephalothorax, from the forehead
to the base of the genital segment. The genital segment is equal to the combined length of
the next two segments. The second and fourth segments are of equal length, but the third
segment is distinctly shorter than these two. The furcal joints are about as long as the anal
segment, and are fully twice as long as broad.

The various appendages have a general resemblance to those of the previous species.

Occurrence - twenty-five specimens of this species were obtained from the plankton
collected at the followino- stations.

o

Stat. 11S, 2 specimens. - - Stat. 128, 1 specimen. - - Stat. 141, 4 specimens. — Stat. 143,
2 specimens. — Stat. 185, 4 specimens. — Stat. 203 (1500 metres to surface), 6 specimens. —
Stat. 220 (vertical net), 2 specimens. — Stat. 276, 4 specimens.

08

39

I regard this species to be more closely related to the one originally illustrated in the
'Challenger' report as ^Etideus armatus, than to the species now known as sEtideus armatus
(Boeck). The very strong rostrum described and figured by Brady, is a character not possessed
by Boeck's species. The last thoracic spines in the 'Challenger' specimen, appear to have been
shorter than in the present form, but I have noticed, that these chitinized spines are easily
damaged, ancl perfect specimens with the spines complete, may not always be secnred. With
regard to the specimens from the 'Challenger' collection examined by Sars, and stated to be
identical with Boeck's species: — It is quite possible, that more than one type of ALtideus
was obtained by the 'Challenger', but the difterences were not regarded as worthy of specific
rank at that time, and the type from which Brady's figures were drawn, might easily be
distinct from those examined by Sars. I have found on re-examining the selected specimens
from the Gulf of Guinea plankton, regarded to be identical with the type described in the
'Challenger' report, that all the three forms now figured were present. jEtideus giesbrcchti '.
and the lorm now described as ^Etideus brady i, proved, on the re-examination of the selected
specimens, to have been present in the plankton collected by Professor Herdman, on the way
out to Ceylon.

Wolfexdex (1903, p. 266) refers to a species, ^~Et. bradyi (Brady), but I am unable to
identify it. Brady has not named a species of jEtideus after himself.

Genus Bradyidius Giesbrecht, 1897.

This genus is closely related to JEtideus, but differs from it in the less highly developed
rostrum, and by the endopodite of the second pair of swimming feet being distinctly two-jointed.

One species belonging- to this genus was found in the plankton collected during the
traverse of the 'Siboga'. The specimens differ in some minor details from Sars figures of the
northern type but, I have, for the present, decided to regard them as simply tropical examples
of Bradyidius armatus.

1. Bradyidius armatus (Brady). Plate VI, figs. 1 — 11.

P seudocalanus armatus Brady, 1878, non Boeck 1872, Vol. 1, p. 46, pi. IV.

Undïnopsis bradyi Sars, 1884 (name only).

Bradyanus armatus Vanhoften, 1897, p. 322.

Bradyidius armatus Giesbrecht & Schmeil, 1898, p. 32.

Bradyidius armatus T. Scott, 1898, p. 264, pi. XII, figs. I — 19.

Bradyidius armatus T. Scott, 1899, p. 248.

Bradyidius armatus I. C. Thompson, 1900, p. 278.

Bradyidius armatus T. Scott, 1900, p. 383.

Bradyidius armatus T. Scott, 1901, p. 238.

Bradyidius armatus T. Scott, 1901 (a), p. 350.

Undinopsis bradyi Sars, 1902, p. 32, pis. XIX & XX.

Bradyidius armatus I. C. Thompson, 1903, p. 16.

Bradyidius armatus Wolfenden, 1904, p. 111.

Bradyidius armatus Wolfenden, 1905 (a), p. 1005.

Bradyidius armatus Farran, 1905, p. 31.

Bradyidius armatus Pearson, 1906, p. II.

39

4o

Bradyidius armatus T. Scott, 1 906(0), p. 298.
Bradyidius armatus van Breemen, 1908, p. 31, fïg. 31.

Female — length 1,7 mm.

The cephalothorax seen from above appears oval fusiform in outline, with both extremities
about equally narrowed. Viewed laterally it is seen to be moderately arched, with the forehead
obtusely truncated, and produced into a small bifurcate rostrum with divergent points. The last
thoracic segment is produced posteriorly into moderately strong spines, which scarcely reach
to the end of the genital segment. The combined length of the abdomen and furca is equal
to slightly less than one-third of the total length of the cepJialotJwrax, from the front margin
to the base of the genital segment. The genital segment is nearly as long as the combined
lenoth of the next three segments. The second segment is lon^er than the third. The third and
fourth segments are of nearly equal length. The furcal joints are about as long as the anal
segment, and are slightly longer than broad. The posterior margin of the genital segment is
furnished with a fringe of fine spines.

The various appendages are similar to the figures given by Sars in the 'Crustacea
of Norway'.

The 'Siboga' specimens differ from the Norwegian form in size, and in the length of
the spines of the last thoracic segment. Sars states that the spines reach beyond the genital
segment. I have compared the 'Siboga' specimens with examples found in plankton collected
in the Firth of Clyde, and with the exception of the smaller size, there appears to be no material
difference between theni. This can be seen on comparing the figures now given, with those in
the 'Sixteenth Annual Report of the Fishery Board for Scotland' (1898). Dr. R. N. Wolfenden
records a form obtained from plankton collected around the Maldives, under the name Bradyidius
armatus, which is probably identical with the species now figured. Wolfenden's specimens were
even smaller than those obtained from the 'Siboga' plankton, but unfortunately no figures are
given by that author, to enable a comparison to be made.

This species was only represented by three specimens in the plankton collected during
the traverse of the 'Siboga'. The specimens were obtained at the following stations.

Stat. 141, HENSEN vertical net, 1500 metres to surface, 2 specimens.
Stat. 276, HENSEN vertical net, 750 metres to surface, 1 specimen.

Genus jEtideopsis Sars, 1903.

The genus ^Etidcopsis approaches ^Etideus in general appearance, but is easily distinguished,
by the fourth and fifth thoracic segments being completely separated.

Only one species is known. Specimens not diftering materially from the description and
figures given by Professor G. O. Sars were found in the 'Siboga' plankton. I have, therefore,
placed them under ^Etidcopsis rostrata for the present.

1. ^Etidcopsis rostrata Sars. Plate V, figs. 13 — 24.

-litidcopsis rostrata Sars, 1903, p. 160, pis. IV & V (suppl.).
.litidt-opsis rostrata van Breemen, 1908, p. 33, fig. 35.

4°

4i

Six specimens apparently identical with this species, were obtained from the following
deep water samples of plankton.

Stat. 141, Hensen vertical net, 1500 metres to surface, 2 specimens.
Stat. 143, Hensen vertical net, 1000 metres to surface, 2 specimens.
Stat. 148, Hensen vertical net, 1000 metres to surface, 2 specimens.

The specimens agree in almost every detail, with the description and figures given by
Sars. The minor points of difference are: — The external margins of the rostrum are more
concave, and the excavation between the rami is much narrower than is shewn by Sars' figure.
The specimens are also smaller, being 3,5 mm. instead of 4,4 mm. as given by Sars.

The distribution of this species appears to be very limited. It has hitherto only been
observed in the North Atlantic Ocean. I have recently been able to compare specimens of the
northern type, sent by my father, which he obtained in plankton collected in the deep water
of the Faröe Channel, by the Scottish International Fisheries Cruiser 'Goldseeker'. I do not
see any material difference between the North Atlantic form, and the 'Siboga' specimens.

Genus Chiridius Giesbrecht, 1893.

I follow Giesbrecht's definition of this genus, which was established for the reception of a
Calanoid without a tracé of a rostrum, and having the last thoracic segment produced into spines.

Sars in the first portion of his volume on the Calanoida 'Crustacea of Norway', included
two species possessing a distinct rostrum, under this genus. One of the species, however, was
removed to the genus Gaidius, on the publication of the supplementary part of the Calanoida.

G. P. Farran (1908) follows Sars in including Euchaeta armata Boeck, under the genus
Chiridius, and says, 'The fact that Giesbrecht originally defined the genus as not having a
'rostrum should not in itself have any weight'. This is surely a mistaken view, and if pursued
to any extent, would lead to endless confusion in all systems of classification. I regard the
original definition, so far as the rostrum is concerned, as final, and think that Eucliacta armata
Boeck, ought rightly to be excluded. Wolfenden (1903) has already done this, and has established
a new genus, Pseudactideus, for its reception, which is the most satisfactory solution.

Three species, apparently all distinct, agreeing with Giesbrecht's definition, were found
in the plankton collected during the traverse of the 'Siboga'. In the absence of males, one has
considerable doubt of course, as to whether the various forms ought to be regarded as really
distinct, or only varieties. All the females examined, had the endopodite of the second pair of
swimming feet composed of a single joint with a faint thickening, indicating where a joint may
have been at some time.

1. Chiridius poppei Giesbrecht. Plate XI, figs. 10 — 17.

Chiridius poppei Giesbrecht, 1893, p. 224, pis. 14 & 36.

Chiridius poppei Giesbrecht & Schmeil, 1898, p. 33.

Chiridius poppei Cleve, 1904, p. 187.

Chiridius poppei Sars, 1905 (a), p. 3.

Chiridius poppei van Breemen, 1908, p. 34, fig. 36.

41

SIBOr.A-EXFEUlTlE XXIX a. 6

42

w

The specimens included under this species, so far as can be made out from the fe
figures given by Giesbrecht, appear to agree fairly well with Chiridius poppci. The cephalo-
thorax vievved from above, is moderately robust and oblong ovate in form. The anterior margin
is slio-htly contracted and a little produced in the middle. The spines of the last thoracic segment
project slightlv beyond the middle of the genital segment. The combined length of the abdomen
and furca, is almost equal to one-third of the total length of the cep halothorax, from the frontal
margin to the base of the genital segment. The genital segment is rather longer than the
second segment. The second segment is nearly as long as the third and fourth together. The
anal segment is about half the length of the third segment. The furcal joints are slightly longer
than the anal segment, and are a little longer than broad. The terminal spine of the exopodite
of the fourth pair of feet has twenty-six teeth.

Length of the female, 1,8 mm.

Occurrence — six specimens were found in plankton collected at the following stations.

Stat. 128, HENSEN vertical net, 700 metres to surface, 1 specimen.

Stat. 141, HENSEN vertical net, 1 500 metres to surface, 1 specimen.

Stat. 142, 1 specimen.

Stat. 148, HENSEN vertical net, IOOO metres to surface, 1 specimen.

Stat. 185, HENSEN vertical net, 1536 metres to surface, 1 specimen.

Stat. 276, HENSEN vertical net, 750 metres to surface, 1 specimen.

2. Chiridius ? gracilis Farran. Plate XI, figs. 1 — 9.

Clüridius poppci Farran, 1905, p. 35.

Chiridius gracilis Farran, 1908, p. 30, pi. II, figs. 1 — 3.

The specimens of this form are only doubtfully regarded as Farran's species. They are
less robust than those recorded as Chiridius poppci, and the abdomen is not so slender as in
Farran's Chiridius gracilis.

Female — length 2,4 mm.

Viewed dorsally, the cephalothorax appears less robust than in the previous species,
and although considerably contracted, the frontal margin of the forehead is quite rounded.
The spines of the last thoracic segment are produced distinctly beyond the middle of the
genital segment. The combined length of the abdomen and furca, slightly exceeds one-third
of the total length of the cephalothorax, from the frontal margin to the base of the genital
segment. The second segment is very slightly longer than the third segment. The anal segment
is equal to fully half of the length of the third segment. The furcal joints are about as long
as broad, and are scarcely as long as the anal segment. The terminal spine of the exopodite
of the fourth pair of feet has twenty-two teeth.

Occurrence - - four specimens were found at the following stations.

Stat. 141, HEXSEN vertical net, 1500 metres to surface, 1 specimen.
Stat. 142, 1 specimen.

Stat. 143, HENSEN vertical net, 1000 metres to surface, 1 specimen.
Stat. 148, HENSEN vertical net, IOOO metres to surface, 1 specimen.

42

43
3. Chiridius ? obtusifrons Sars. Plate XLIV, figs. i — 3.

Chiridius armatus Sars (non Boeck) 1900, p. 64, pi. XVII.

Chiridius obtusifrons Sars, 1902, p. 29, pi. XVII.
Chiridius obtusifrons van Breemen, 1908, p. 34, fig. 37.

A single specimen that I ara inclined to regard as identical with Sars' Chiridius obtu-
sifrons, was found in the plankton taken in a Hensen vertical net haul at Station 141, 1500
metres to surface.

The specimen differs, however in the following details: - The length is 2,6 mm. and the
various appendages are the same as in the species identified as Chiridius poppci. The exopodite
of the second, third, and fourth pairs of swimming feet in the 'Siboga' specimen, is distinctly
three-jointed as in the other Chiridius illustrated in this report. The combined length of the
abdomen and furca, is contained about two and a half times in the total length of the cepJialo-
thorax, from the frontal margin to the base of the genital segment.

The very short spines of the last thoracic segment although not divergent, appear to
agree very well with the figure given by Sars, and this is the chief reason for supposing, that
the specimen may only be a tropical variation of the type from the Coast of Norway.

Genus Chirundina Giesbrecht, 1895.

The female of this genus is allied to Euchirella and Uudeuchaeta. The rostrum is
moderately long and one pointed. The forehead has a distinct crest. The last thoracic segment
is produced on each side into a small knob. The exopodite of the first pair of swimming feet
is indistinctly three-jointed, and the inner margin of the first joint of the basiopodite of the
fourth feet is without spines. The fifth pair of feet is absent.

The male was described and partly figured for the first time by C. O. Esterlv. It differs
from the female in the last thoracic segment not being produced into knobs. The abdomen is
composed of five joints. The exopodite of the first pair of feet is distinctly three-jointed, and
there is a well developed prehensile fifth pair of feet.

Only one species is known. It was well represented in the plankton collected by the 'Siboga'.

1. Chirundina streetsi Giesbrecht. Plate XII, figs. 1 — 11.

Chirundina streetsii Giesbrecht, 1895, p. 250, pi. I, figs. 5 — 10.
Chirundina streetsi Giesbrecht & Schmeil, 1898, p. 34.
Euchirella carinata Wolfenden, 1902, p. 366.
Euchirella carinata Wolfenden, 1904, p. 115.

Chirundina streetsi
Chirundina streetsi
Chirundina streetsi
Chirundina streetsi
Chirundina streetsi

Cleve, 1904, p. 187.

Sars, 1905 (a), p. 4.

Esterly, 1906, p. 59, pis. 9, 10, 12, 14.

Pearson, 1906, p. 16.

Farran, 1908, p. 37.

Chirundina streetsi van Breemen, 1908, p. 46.

Chirundina streetsi appears to be a moderately deep water form, and was found in
several of the vertical net hauls, as shewn by the records.

43

44

Stat. 128, 1 specimen. — Stat. 141, 8 specimens. — Stat. 142, 10 specimens. — Stat. 143,
1 specimen. ■ — Stat. 148, 2 specimens. — Stat. 177", 1 specimen. — Stat. 185, 1 specimen. —
Stat. 203 (1500 metres to surface), 2 specimens. — Stat. 230, 3 specimens. — Stat. 243,
6 specimens. — Stat. 276, 20 specimens.

There are slight differences between the figures of the fifth pair of feet of the male given
by Esterly, and that shevvn in this report. The exopodite of the right foot in the 'Siboga'
males appears to be only tvvo-jointed. There is no secondary process at the junction of the
second and third joints of the exopodite of the left foot. The third joint of the left exopodite
terminates in a simple spine.

Length of female 4,8 — 5,3 min. Length of male 4,1 mm.

Fifty females and five males vvere obtained from the 'Siboga' plankton.

Chirundina strcctsi appears to have a wide distribution. It has been obtained in the
warm seas of the tropics, and in the deep water of the North Atlantic, as far north as the
Faröe Channel.

Genus GaetailUS Giesbrecht, 1888.

The members of this genus are distinguished from those belonging to the other genera
of the family .-Elideidac, by the possession of a distinct median spine on the front of the
forehead. The rostrum is short and stated to be one pointed, but all the species from the
'Siboga' collections, except one, shew a distinct attempt of bifurcatibn at the apex. The posterior
margin of the first basal joint of the second maxillipedes, is furnished with a lamella. I think
too much is made of the shape of this lamella in the different species of the genus, as it appears
to be very soft and, therefore, easily distorted.

Adult males of this genus appeared to be unknown, until the discovery of one by
C. O. Esterly which he described in 1906.

Seven species belonging to the genus Gactanus were found in the 'Siboga' plankton.

1. Gaetanus miles Giesbrecht. Plate VIII, figrs. 1 — 8.

Gaetanus miles Giesbrecht, 1888, p. 335.

Gaetanus miles Giesbrecht, 1S93, p. 219, pis. 14 & 36.

Gaetanus miles Giesbrecht & Schmeil, 1898, p. 32.

Gaetanus miles I. C. Thompson, 1903, p. 17.

Gaetanus miles Cleve, 1904, p. 191.

Gaetanus miles Sars, 1905 (a), p. 3.

Gaetanus miles Pearson, 1906, p. 14.

Gaetanus miles Farran, 1908, p. 36.

Gaetanus miles van Breemen, 1908, p. 39, fig. 42.

The whole of the specimens of this species were found in plankton collected with the
Hensen vertical net at the followingf stations.

ö

Stat. 118 (900 metres to surface). — Stat. 128 (700 metres to surface). — Stat. 141 (1500
metres to surface). — Stat. 148 (1000 metres to surface). — Stat. 185 (1536 metres to
surface). - - Stat. 230 (2000 metres to surface). — Stat. 276 (750 metres to surface).

44

45

Gaetanus miles is easily distinguished from the other species, by the great length of the
antennules. The antennules are fully twice as long as the entire animal, from the apex of the
frontal spine to the end of the furca. The frontal spine is very prolonged, and when viewed
laterally, is seen to taper uniformily from the base to the apex. The spines of the last thoracic
segment extend beyond the middle of the genital segment. The combined length of the abdomen
and furca, is slightly less than one-fourth of the total length of the cepkaloth'orax, from the
apex of the cephalic spine to the base of the genital segment. The rostrum is slightly bifid
at the apex. The lamella on the basal joint of the second maxillipedes, has a bluntly rounded
apex, and a very slight excavation. The exopodite of the first pair of feet is two-jointed, with
a very faint line across the middle of the first joint. The lïrst joint of the basiopodite of the
fourth pair of feet, is furnished with about twelve strong short spines on its inner distal angle.

Seven specimens, all females, were found. Length 4,3 mm.

This species has been recorded from the Atlantic and Pacific Oceans. G. P. Farran
has met with it in the deep water plankton taken off the West Coast of Ireland.

The 'Siboga' specimens of this Gaetanus, appear to differ slightly from Giesbrecht's
type, in their larger size, and in possessing twelve instead of six spines on the inner margin
of the first basal joint of the fourth feet.

2. Gaetanus armigcr Giesbrecht. Plate VIII, figs. 16 — 22.

Gaetanus armiger Giesbrecht, 18SS, p. 335.

Gaetanus armiger Giesbrecht, 1893, p. 219, pis. 14 & 36.

Gaetanus armiger T. Scott, 1893, p. 71, pi. 8, figs. 16 — 27.

Gaetanus armiger I. C. Thompson, 1903, p. 17.

Gaetanus armiger Cleve, 1904, p. 191.

Gaetanus armiger Wolfenden, 1904, p. III.

Gaetanus armiger Sars, 1905 (a), p. 4.

Gaetanus armiger Pearson, 1906, p. 14.

Gaetanus armiger van Breemen, 190S, p. 39, fig. 44.

This species appeared to be very rare in the 'Siboga' plankton and was only noted at
two stations as shewn.

Stat. 118, 1 specimen. — Stat. 215% 1 specimen.

Some care is required to identify this Gaetanus, as two species very like it in general
appearance, have been described within recent years.

The antennules extend to the anal segment. The frontal spine is very small and can,
only with difficulty, be observed when the copepod is viewed from the dorsal aspect. The
spines of the last thoracic segment extend beyond the middle of the genital segment. The
combined length of the abdomen and furca, is equal to one-third of the total length of the
cepJialothorax, from the apex of the frontal spine to the base of the genital segment. The
rostrum is small and is distinctly bifid at the apex. I was unable to detect the lamella on the
basal joint of the second maxillipedes. The exopodite of the first pair of feet is distinctly three-
jointed. The first joint of the basiopodite of the fourth pair of feet is furnished with a number
of fine bristles along its inner margin.

45

46

Only two females were found. Length 3,5 mm.

The 'Siboga' specimen that was dissected, and is illustrated in this report, agrees very
well with Giesbrecht's description. I do not attach much importance to the apparent absence
of the lamella on the basal joint of the second maxilliped, as it is evidently very small and
will, therefore, be easily folded up.

Gaetanus armiger has a similar distribution to Gaetaniis miles, but does not appear,
so far, to have been taken in the deep water off the West Coast of Ireland.

3. Gaetanus caudani Canu. Plate VIII, figs. 9 — 15.

Gaetanus caudanï Canu, 1896, p. 422.

Gaetanus caudani Giesbrecht & Schmeil, 1S98, p. 33.

Gaetanus pileatus Farran, 1903, p. 16, pi. XVII, fig. 1 — 11.

Gaetanus caudani Wolfenden, 1904, p. 114. pi. IX, figs. 20, 22.

Gaetanus pileatus Farran, 1905, p. 33.

Gaetanus caudani Sars, 1905 (a), p. 4.

Gaetanus caudani Pearson, 1906, p. 13.

Gaetanus unicornis Esterly, 1906, p. 57, pis. 9, 12, 13.

Gaetanus pileatus Farran, 1908, p. 35.

Gaetanus caudani van Breemen, 1908, p. 42, fig. 48.

Gaetanus caudani was obtained from plankton collected with the Hp:nsen vertical net at
the following stations.

Stat. 118 (900 metres to surface). — Stat. 128 (700 metres to surface). — Stat. 143 (iooo
metres to surface). — Stat. 230 (2000 metres to surface). — Stat. 276 (750 metres to surface).

This Gaetanus, at first sight, looks like a large form of Gaetanus miles, but on careful
examination can readily be separated.

The antennules are equal to one and a half times the length of the body, from the
apex of the cephalic spine to the end of the furca. They extend beyond the furca by the last
seven joints. The frontal spine is greatly prolonged, and viewed laterally, there is seen to be
a sudden change in the continuity of the outline, between the base and the apex. The spines
of the last thoracic segment reach to the middle of the genital segment. The combined length
of the abdomen and furca is distinctly less than one-fourth of the total length of the cephalo-
thorax, from the apex of the frontal spine to the base of the genital segment. The genital
segment is nearly as long as the combined lengths of the next three segments. The furcal
joints are about as long as broad, and are as long as the anal segment. The posterior margin
of the first three abdominal segments is fringed with fine spines. The rostrum is small and is
very faintly bifid at the apex. The lamella on the basal joint of the second maxillipedes is
narrowed at the apex and deeply excavated. The exopodite of the first pair of feet is two-
jointed, with a very faint line across the middle of the first joint. The first joint of the basio-
podite of the fourth pair of feet, is furnished with a number of fine bristles on its inner margin.

Five specimens, all females, of this Gactantis were found. Length 6 mm.
Canu's description although given from an immature specimen, agrees fairly well with
the species now described. The 'Caudan' specimen was apparently an immature female, othervvise

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47

I do not think the first joint of the basiopodite of the fourth pair of feet would possess the
armature described by Canu. The three-jointed exopodite of the tirst pair of feet in Gaetanus
caudani, is the only noteworthy difference between that species, and the form now dealt with.
The three-jointed exopodite might easily be changed, and the rudimentary fifth pair of feet be
suppressed at the final ecdysis.

I regard Farrax's Gaetanus pileatus to be identical with Canu's Gaetanus caudani.
Farrax's type specimen was obtained from the stomach of a mackerel, and even a very short
exposure to the gastric juices would bring about some changes in the appearance of the
copepod. The only difference between Farrax's figures and those now given, appears to be in
the setting of the cephalic spine, and this is probably due to the cause mentioned. Some weight
is given to the view that Gaetanus pileatus is the same as Gaetanus caudani by the fact that
Oöthrix öidentata Farran (1905), is identical with Neoscolecithrix kochleri Canu (1896), and
both these copepods have been taken in some quantity, in the plankton collected from the
deep water of the Faröe Channel, by the Scottish International Fisheries Cruiser 'Goldseeker'.
I have compared the Faröe Channel form of long spined Gaetanus with Gaetanus caudani of
this report, and can find no difference between them.

Esterly's Gaetanus unicornis is, I think, clearly identical with Gaetanus caudani Canu.

Gaetanus caudani has apparently a wide distribution, extending from the deep water of
the Malay Archipelago to the Faröe Channel.

4. Gaetanus minor Farran. Plate IX, flgs. 1 — 8.

Gaetanus minor Farran, 1905, p. 34, pi. V, figs. 1 — 11.

Gaetanus minor Pearson, 1906, p. 14.

Gaetanus minor Farran, 1908, p. 37.

Gaetanus minor van Breemen, 1908, p. 41, fig. 46.

This Gaetanus was obtained from plankton collected with the Hexsex vertical net at

the following two stations.

Stat. 141 (1500 metres to surface). — Stat. 276. (750 metres to surface).

Gaetanus minor is not unlike a small form of Gaetanus armiger, and without careful
examination, may be easily overlooked.

The antennules reach to the middle of the abdomen. The cephalic spine is somewhat
similar to that of Gaetanus armiger, but it is distinctly longer and more conspicuous when
viewed from the dorsal surface. The spines of the last thoracic segment extend nearly to the
end of the genital segment. The combined leng-th of the abdomen and furca, is contained about
three and a half times in the total length of the ceplialothora.w from the apex of the cephalic
spine to the base of the genital segment. The genital segment slightly exceeds the combined
length of the second and third segments. The rostrum is small and does not appear to be
divided at the apex. The lamella on the basal joint of the second maxillipedes is bluntly rounded
at the apex and slightly excavated. The exopodite of the first pair of feet is two-jointed, with
no tracé of a division across the first joint. The first joint of the basiopodite of the fourth pair
of feet, is furnished with a very few bristles on its inner margin.

47

48

Three specimens, all females, of this species were found. Length 2,3 mm.
With the exception of the slightly longer antennules, I see no difference between the
'Siboga' specimens, and the figures given by Farran.

Gaetanus minor has hitherto only been known from the North Atlantic Ocean.

5. Gaetanus kruppii Giesbrecht. Plate IX, figs. 9 — 15 (female). Plate X, figs. 1 — 9 (male}.

Gaetanus kruppii Giesbrecht, 1903, p. 202, pis. 7 &. S.

Gaetanus major Wolfenden, 1903 (a), p. 125.

Gaetanus major Wolfenden, 1904, p. 114, pi. IX, figs. 7 & 8.

Gaetanus kruppi Sars, 1905 (a), p. 4.

Gaetanus major Farran, 1905, p. 33.

Gaetanus major Pearson, 1906, p. 14.

Gaetanus clarus Esterly, 1906, p. 57, pis. 9 & 14.

Gaetanus brevicornis Esterly, 1906, p. 56, pis. 9 & 12.

Gaetanus major Farran, 1908, p. 36.

Gaetanus major van Breemen, 1908, p. 40, fig. 45.

Gaetanus kruppi van Breemen, 1908, p. 41, fig. 47.

All the specimens obtained by the 'Siboga', were found in plankton collected with the
Hensen vertical net at the following stations.

Stat. 118 (900 metres to surface). — Stat. 141 (1500 metres to surface). — Stat. 143 (1000
metres to surface). - - Stat. 243 (1000 metres to surface). — Stat. 276 (750 metres to surface).

Female. This Gaetanus is not unlike a large example of Gaetanus armiger, but it can
be distinguished from that species on careful examination.

The antennules extend beyond the end of the furca, by the last two-joints. The cephalic
spine is small, but quite visible when the copepod is seen from the dorsal aspect. The spines
of the last thoracic segment are very small, and are only about one-third of the length of the
genital segment. The combined length of the abdomen and furca, is distinctly less than one-
third of the total length of the cephalothorax \ from the apex of the frontal spine to the base
of the genital segment. The genital segment is considerably longer than the combined length
of the next two segments. The furcal joints are about as long as broad, and are shorter than
the anal segment. The rostrum is small and is distinctly bifid at the apex. The lamella on the
ventral margin of the first joint of the second maxillipedes is distinctly pointed and deeply
excavated. The exopodite of the first pair of feet is distinctly three-jointed. The first joint of
the basiopodite of the fourth pair of feet is furnished with a number of fine bristles on its
inner margin. Four specimens were found. Length 5,7 mm.

Adult male. This resembles the female in general appearance, but the antennules are
shorter, and the proportional lengths of the abdominal segments are different.

The antennules extend slightly beyond the middle of the abdomen, and are furnished
with a number of sensory organs placed along the dorsal margin of the first or basal half. The
frontal spine is stronger than in the female, and the frontal margin of the head when viewed
from the side is seen to have a distinct swelling. The spines of the last thoracic segment are
short. The combined length of the abdomen and furca, is equal to about one-third of the total

48

49

length of the cephalotkorax^ from the apex of the frontal spine to the base of the genital
segment. The first, third, and fourth segments of the abdomen are of about equal length. The
second segment is dicidedly longer than the others. The fifth segment is very short. The
rostrum is distinctly bïfid at the apex. The mouth organs are considerably modified, and the
mandible is without a toothed biting part. The first basal joint of the second maxilliped does
not appear to have any tracé of a lamella. The exopodite of the first pair of feet is distinctly
three-jointed, and the last joint is furnished with a small spine on the middle of its outer
margin. The first joint of the basiopodite of the fourth pair of feet has no bristles on its inner
margin. The fifth pair of feet is moderately large and prehensile and has rudimentary endopodites.
The right exopodite is two-jointed. The apical portion of the second joint is spiniform and very
faintly articulated. The left exopodite is apparently composed of three joints. The apical half
of the last joint is spiniform and slightly articulated. The endopodite of the right foot is of
moderate size and faintly two-jointed. The apical half is large and triangular in shape. The
endopodite of the left foot is short and rod shaped.

Two specimens were obtained, but one was immature. Length of mature male 5,6 mm.

I regard Wolfenden's Gaetanus major, to be identical with Giesbrecht's Gaetanus kruppii.
Wolfenden's description appeared in a report, 'Plankton of the Faröe Channel', by G. H. Fowlkr,
and was read at a meeting of the Zoological Society, London, on February 3rd, 1903. Volume I,
part 1 , of the proceedings of the Zoological Society, containing papers read in January and
February, is dated June 1903. Gaetanus kruppii is described by Giesbrecht in a report by
S. Lo Bianco, published in Mittheilungen aus der Zoologischen Station zu Neapel, 16 Band,
1 & 2 Heft, which bears the date April 30, 1903. Giesbrecht's description therefore, appears
to be the first that was published.

The species described by Esterly in 1906, as Gaetanus örevicornis, appears to be the
same as Gaetanus major, Wolfenden, and is therefore identical with Giesbrecht's Gaetanus
kruppii. The only apparent difference is that Esterly's species possesses a lamella, and Gaetanus
major is described as having no lamella on the first basal joint of the second maxilliped. I have
examined a number of specimens of a Gaetanus from the deep water of the Faröe Channel,
which agree in all points with Wolfenden's Gaetanus major, except that they have a lamella.
I think it is extremely probable that the lamella in Wolfenden's preparation had been accidently
folded under the joint, and so overlooked.

Gaetanus clarus Esterly, is the same as the male described above, which I regard to
be the male of Gaetanus kruppii.

Gaetanus kruppii is evidently widely distributed, and is not uncommon in the deep
water of the North Atlantic.

6. Gaetanus latifrons G. O. Sars. Plate X, figs. 10 — 17.

Gaetanus latifrons Sars, 1905(0), p. 11.
Gaetanus liolti Farran, 1905, p. 33, pi. VI, figs. 1, 12.
Gaetanus longispinus Wolfenden, 1905, p. 7, pi. III.
Gaetanus latifrons Pearson, 1906, p. 14.

49

SIBOGA-EXPEDITIE XXIX a. 7

5Q

Gaetanus latifrons Farran, 1908, p. 36.

Gaetanus latifrons van Breemen, 1908, p. 39, fig. 43.

One specimen of Gaetanus latifrons, was obtained from the plankton collected with the
Hensen vertical net at Station 276 (750 metres to surface). This species is easily distinguished
from the other knovvn Gaetanus, by the peculiar form of the forehead and cephalic spine, when
seen in lateral view.

The antennules extend beyond the furca by at least three joints. The frontal spine is
prolonged and when viewed laterally, is seen to be slightly curved upwards. The forehead seen
from the side, is wide and truncate, with a slight crest extending from the base of the spine
to beyond the middle of the fontal margin. The spines of the last thoracic segment extend
beyond the middle of the genital segment. The combined length of the abdomen and furca
is equal to one-third of the total length of the cephalothorax, from the apex of the cephalic
spine to the base of the genital segment. The genital segment is nearly as long as the combined
length of the next three segments. The third segment is distinctly smaller than any of the
others. The rostrum is distinctly bifid at the apex but the points are not symmetrical. The
lamella on the base of the first joint of the second maxilliped appears to be quite pointed.
The preparation made from the 'Siboga' specimen is slightly distorted, and the lamella is folded
over the surface of the joint. The exopodite of the first pair of feet is distinctly three-jointed,
and the first joint is furnished with an outer-edge spine. The first joint of the basiopodite of
the fourth pair of feet, is furnished with a number of moderately long and strong bristles on
its inner distal angle. Length of female, 5,4 mm.

There appears to be no difference between the specimen obtained from the Malay
Archipelago, and the figures given by Farran.

Gaetanus latifrons has been recorded from the North Atlantic Ocean by Sars, and
almost at the same time by Farran and Wolfenden. Farran described it as Gaetanus Itolti,
and Wolfenden as Gaetanus longispinus.

7. Gaetanus hamatus nov. sp. Plate IX, figs. 16 — 22.

Female — length 5,4 mm.

Seen from above, the body is moderately robust with a broadly rounded forehead. Viewed
laterally, the cephalic spine is seen to be very small, and similar to that of Gaetanus kruppii.
The spines of the last thoracic segment are very short and stout. The spines are pointed at
almost a right angle, in the dorsal direction from the segment.

The abdomen is composed of four segments. The combined length of the abdomen and
furca is equal to one-third of the total length of the cephalotJiorax, from the apex of the
cephalic spine to the base of the genital segment. The genital segment is slightly longer than
the second segment. The third segment is rather smaller than any of the others. The anal
segment is as long as the genital segment. The furcal joints are slightly longer than broad,
and are fully half as long as the anal segment.

The rostrum is small and the apex is distinctly bifid.

The antennules are twenty-four-jointed, and extend beyond the furca by the last three joints.

5°

5i

The antennae, mandibles, maxillae, and first maxillipedes are nearly similar to those of
Gaetanus /a/i frons.

The lamella on the basal joint of the second maxilliped, appears to be similar to that
of Gaetanus latifrons, but the preparation was slightly damaged during dissection, and the apex
of the lamella was destroyed.

'I he exopodite of the first pair of feet is incompletely three-jointed. The division across
the middle of the first joint, although fairly well defined, does not appear to pass right through.

The inner margin of the first joint of the basiopodite of the fourth pair of feet, is
turnished with seven short spines.

The fifth pair of feet is absent.

Two specimens were obtained from the plankton collected with the Hensen vertical net
at Station 276 (750 metres to surface).

It is only with some hesitation that I describe the above species as new. Both specimens
.although well developed are not quite mature. The narrowly rounded last thoracic segment
with its short, stout and almost upright spines when seen in lateral view, may help to identify
it when mixed up with other species of Gae/anus.

Genus Gaidius Giesbrecht, 1895.

This genus is distinguished from the other members of the family by the short one-
pointed rostrum. The exopodite of the first pair of feet in the female is composed of two joints.
The inner margin of the first joint of the basiopodite of the fourth pair of feet is without
armature. The male has a well developed prehensile fifth pair of feet. The exopodite of the
first pair of feet appears to be indistinctly three-jointed in some specimens.

Two species were obtained from the 'Siboga' material.

1. Gaidiics simi/is (T. Scott). Plate VII, figs. 1 — 11.

Eucliaeta hessei var. similis T. Scott, 1893 (male only), p. 58, pi. VI, figs. 24, 25.

Gaidius pungens Giesbrecht, 1895, p. 249, pi. 1, figs. 1 — 4.

Gaidius pungens Giesbrecht & Schmeil, 1898, p. 32.

Eucliaeta simi/is Giesbrecht & Schmeil, 1898, p. 52.

Cliiridius tenuispinus Sars, 1900, p. 6j, pi. XVIII.

Cliiridius tenuispinus Sars, 1902, p. 30, pi. XVIII.

Gaidius tenuispinus Sars, 1903, p. 162, pi. VI (suppl.), fig. 1.

Gaidius pungens I. C. Thompson, 1903, p. 17.

Eucliaeta hessei var. similis, I. C. Thompson, 1903, p. iS.

Gaidius pungens Wolfenden, 1904, p. 112, pi. IX, fig. 43.

Gaidius pungens Esterly, 1905, p. 146, fig. 15.

Gaidius tenuispinus Farran, 1905, p. 33.

Gaidius tenuispinus Pearson, 1906, p. 13.

Gaidius pungens Pearson, 1906, p. 12.

Gaidius tenuispinus Farran, 1908, p. 32.

Gaidius tenuispinus van Breemen, 1908, p. $6, fig. 39.

Gaidiits simi/is appeared to be rather rare in the plankton collected during the traverse
of the 'Siboga', and was only obtained at the following stations.

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52

Stat. 66, i specimen. — Stat. 141, 2 specimens. ■ — Stat. 142, 1 specimen. — Stat. 203
(Hensen vertical net), 1 specimen. — Stat. 245, 1 specimen. ■ — Stat. 252, 1 specimen.

One female and six males were found. Female — length 3 mm. Male — length 2,87111111.

The species described by my father from the Gulf of Guinea in 1893 as Euckacfa hessei
var. simi/is, appears to be undoubtedly the male of the form described by Giesbrecht in 1895
as Gaidius pungens, from females only. Gaidius pungens Giesbrecht, will therefore, necessarily,
o-ive way to Gaidius similis (T. Scott). The fifth pair of feet of the male figured in the
'Report on Entomostraca from the Gulf of Guinea', only differs from that shewn in the present
report, by the absence of the endopodite of the left foot. This no doubt, is due to the fact
that the endopodite lies close to the exopodite, and may easily become folded under it. I find
too, that the exopodite of the first pair of feet in some of the males may be very indistinctly
three-jointed, according to the state of maturity.

I regard the form described by Sars as Gaidius (Chiridius) tcnuispinus, that lias been
recorded by Farran, Pearson, and van Breemen, from the North Atlantic, to be identical with
this species.

The first joint of the exopodite of the right foot of the males from the 'Siboga' material,
lias a lamella-like process on the middle of the inner margin, which may be very easily overlooked.

The species apparently has a wide distribution.

2. Gaidius notacantlius Sars. Plate XXI, figs. 24 — 33.

Gaidius notacantlius Sars, 1905 (a), p. 9.

Gaidius notacantlius Farran, 1908, p. 33, pi. III, fig. 7.

One specimen, a male, apparently belonging to this species was found in plankton
collected with the Hensen vertical net at Station 148, 1000 metres to surface. Length 5,9 mm.

The fifth pair of feet agrees fairly well with the figure given by Farran, except that
the second joint of the right exopodite is shorter, but this may be due to accident or slight
immaturity.

The records by Sars and Farran appear to be all that is known of the distribution of
this species.

Genus Gaidiopsis nov.

Forehead without cephalic spine, with short one-pointed rostrum. The fourth and fifth
thoracic segments are completely separated, and the fifth segment is produced into strong lateral
spines. The abdomen is composed of four joints. The antennules are twenty-four-jointed. The
antennae, mandibles, maxillae and maxillipedes, are almost similar to those of Gaidius. The
exopodite of the first pair of feet is distinctly three-jointed. The second, third and fourth pairs
of feet are similar to those of Gaidius. The endopodite of the second pair is distinctly two-jointed.

This new genus resembles yEtidcoftsis, in the complete segmentation of the fourth and
iitth thoracic segments, and the distinctly three-jointed exopodite of the first pair of feet. It also
resembles Gaidius in the short one-pointed rostrum.

Only one species was observed and the male is unknown.

53
i. Gaidiopsis crassirostris nov. sp. Plate VII, figs. 12—22.

Female — length 3 mm.

Seen from above, the cepkalothorax is oblong ovate and moderately robust. The frontal
part is considerably contracted, and the frontal margin is produced into a rounded knob. The
head is fused with the first thoracic segment. The fifth thoracic segment is distinctly separated
from the fourth, and is produced into strong lateral spines, which project beyond the middle
of the genital segment. The rostrum is short and very stout, without a tracé of bifurcation.

The combined length of the abdomen and furca, is rather less than one-third of the
total length of the cepkalothorax. from the frontal marmn to the base of the yenital segment
The genital segment is broad and slightly swollen below. It is as long as the combined length
of the next two segments. The second and fourth segments are of about equal length. The
third segment is distinctly shorter than the others. The furcal joints are nearly twice as long
as broad, and are as long as the anal segment.

The antennules are twenty-four-jointed, and extend to the end of the furca.

The antennae, mandibles, maxillae and maxillipedes, are similar to those of the genus
Gaidins.

The exopodite of the first pair of feet is distinctly three-jointed, and the first joint is
furnished with one outer-edge spine.

The second, third, and fourth pairs of feet are similiar in structure to those of Gaidius.
The endopodite of the second pair of feet is distinctly two-jointed. The first joint of the basio-
podite of the third and fourth pairs of feet is furnished with a number of fine hairs on the
inner margin.

The fifth pair of feet is absent.

Occurrence. — One female was found in plankton collected with the Hensen vertical
net at Station 203, 1500 metres to the surface.

The species is easily recognised by its very swollen one-pointed rostrum, and by the
complete segmentation of the fourth and fifth thoracic segments.

Genus Euchirella Giesbrecht, 1888.

Head with or without a crest. Rostrum one spined or absent. Last thoracic segment
rounded or pointed. The endopodite ot the antennae is usually shorter than the exopodite. The
first joint of the basiopodite of the fourth pair of svvimming feet of the female, is furnished
with one or more spines on the inner margin.

Eleven species belonging to this genus were found in the plankton collected by the
'Siboga', three of which appear to be undescribed.

1. Eucliirella amoena Giesbrecht.

Euchirella amoena Giesbrecht, 1888, p. 336.

Euchirella amoena Giesbrecht, 1893, p. 233, pis. 15 & 36.

Euchirella amoena Giesbrecht & Schmeil, 1898, p. 36.

Euchirella amoena Esterly, 1905, p. 155, fig. 21.

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54

A sino-le specimen, a male, undoubtedly belonging to this species was found in the
plankton collected with the Hensen vertical net at Station 128, 700 metres to surface.
Euchirella amoena appears to be only known from the Pacific Ocean.

2. Euchirella hessei (Brady).

Euchaeta hessei Brady, 1883, p. 63, pi. XXIII.

Euchirella bella Giesbrecht, 1888, p. 336.

Euchirella bella Giesbrecht, 1893, p. 233, pi. 15.

Euchirella bella Giesbrecht & Schmeil, 1S98, p. 35.

Euchirella rostrata Thompson & Scott, 1903, p. 244.

Euchirella bella, var. indica Wolfenden, 1905 (a), p. 1006, pi. XCVI.

This was the most common member of the genus in the plankton collected during the
traverse of the 'Siboga', and was found at the following stations.

Stat. 1 17', 1 specimen. — Stat. 1 18 (HENSEN vertical net 900 metres to surface), 2 specimens. —
Stat. 128 (HENSEN vertical net 700 metres to surface), 2 specimens. — Stat. 141 (HENSEN
vertical net 1500 metres to surface), 12 specimens. — Stat. 142, 4 specimens. — Stat. 177",
4 specimens. — Stat. 185 (HENSEN vertical net 1536 metres to surface), 3 specimens. —
Stat. 203 HENSEN vertical net 1500 metres to surface), 3 specimens. -- Stat. 230 (HENSEN
vertical net 2000 metres to surface), 1 specimen. — Stat. 252, 6 specimens.

I regard the species described by Brady in the 'Challenger Report' as Euchaeta hessei,
and the figures given on Plate XXIII, to be identical with the form described by Giesbrecht
as Euchirella bella. Brady's figure of the first joint of the basiopodite of the fourth pair of
feet shews four spines, although he states 'about five very broad and strong spines' in the
description. Eticliirella rostrata has a row of six or seven triangular lainellae on the first joint
of the basiopodite of the fourth pair of feet. Euchirella hessei, with one exception, was obtained
in plankton collected by the 'Challenger' in the Pacific Ocean. Giesbrecht has recorded it from
the Pacific Ocean only. Euchirella rostrata, with the exception of the record by Esterly, is
only known from the Mediterranean, and North Atlantic Ocean. The species recorded in the
Ceylon Report by I. C. Thompson and the present writer, from Stat. 21 (off Minikoi) and Stat.
23 (Maldives to Gulf of Manaar), has proved on re-examination to be identical with Euchirella
bella, and therefore the same as Euchirella hessei (Brady).

I find that the number of spines on the first joint of the basiopodite of the fourth pair
of feet vary from three to four, instead of four, as stated by Giesbrecht and Schmeil. The
two innermost spines apparently fuse in some cases and form one large spine, thus giving
rise to three spines, one of which is decidedly larger than the others, instead of one large and
three smaller spines.

I see nothing to distinguish VYolfenden's variety indica from the specimens collected by
the 'Siboga'.

The form described by Brady as the male of Euchaeta hessei and Cleve's male of Euchi-
rella rostrata (1900), both appear to be identical, but the fifth pair of feet is quite distinct
from that of a true Euchirella.

54

55

3. Euchirella curticauda Giesbrecht.

Euchirella curticauda Giesbrecht, 1S8S, p. 336.

Euchirella curticauda Giesbrecht, 1893, p. 233, pis. 15 & 36.

Euchirella curticauda Giesbrecht & Schmeil, 1S98, p. 36.

Euchirella curticauda I. C. Thompson, 1903, p. 18.

Euchirella curticauda var. atlantica Wolfenden, 1904, p. 116.

Euchirella curticauda Sars, 1905 (a), p. 4.

Euchirella curticauda Farran, 1905, p. 35.

Euchirella curticauda Esterly, 1906, p. 59, pis. 9, 16, 12, 13.

Euchirella curticauda Pearson, 1906, p. 15.

Euchirella curticauda Farran, 1908, p. 3S.

Euchirella curticauda van Breemen, 1908, p. 48, fig. 54.

Seven specimens, all females, were found in plankton collected with the Hensen vertical
net- at the following stations.

Stat. 118 (900 metres to surface), 1 specimen. — Stat. 12S (/oometres to surface), 1 specimen. —
Stat. 141 (1500 metres to surface), 2 specimens. — ■ Stat. 185 (1536 metres to surface), 1
specimen. — Stat. 230 (2000 metres to surface), 1 specimen. — Stat. 276 (750 metres to
surface), 1 specimen.

Euchirella atrlicauda is easily distinguished from the other species of Euchirella, by
the high crest on the forehead, by the absence of a rostrum, by the very short abdomen and
symmetrical genital segment, and by the row of twelve to thirteen teeth on the inner margin
of the first joint of the basiopodite of the fourth pair of feet.

This species is widely distributed fróm the deep water of the Pacific Ocean to the North
Atlantic. I have seen a number of specimens from the deep water of the Faröe Channel, and
they do not differ in any way from those collected by the 'Siboga' in the Malay Archipelago.

4. Eitchirella galeata Giesbrecht.

Euchirella galeata Giesbrecht, 1888, p. 33Ó.

Euchirella galeata Giesbrecht, 1S93, p. 233, pis. 15 & 16.

Euchirella galeata Giesbrecht & Schmeil, 1S98, p. 36.

Euchirella galeata Sars, 1905 (a), p. 4.

Euchirella galeata Esterly, 1905, p. 155, fig. 22.

Euchirella galeata Farran, 1908, p. 37.

Twenty females and two immature males were found in the plankton collected at the
following stations.

Stat. 71, 3 specimens. — Stat. 118 (HENSEN vertical net 900 metres to surface), 1 specimen. —
Stat. 141 (Hensen vertical net 1500 metres to surface), 1 specimen. — Stat. 142, 2 speci-
mens. — Stat. 143 (HENSEN vertical net 1000 metres to surface), 1 specimen. — Stat. 14S
(HENSEN vertical net 1000 metres to surface), 2 specimens. — Stat. 203 (HENSEN vertical
net 1500 metres to surface), 4 specimens. — Stat. 230 (HENSEN vertical net 2000 metres
to surface), 4 specimens. — Stat. 243 (HENSEN vertical net 1000 metres to surface), 2
specimens. — Stat. 276 (HENSEN vertical net 750 metres to surface), 2 specimens.

This species can be readily recognised by its high crest, and by the presence of a rostrum.
The inner margin of the first joint of the basiopodite of the fourth pair of feet is furnished
with one or two moderately long teeth

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56

Euchirella o-aleala has a similar distribution to Euchirella curticaudd, and has been
obtained from the deep water of the Faröe Channel.

5. Euchirella messinensis (Claus).

Undina messinensis Claus, 1863, p. 187, pi. XXXI.

Euchirella messinensis Giesbrecht, 1893, p. 232, pis. 15 & 36.

Euchirella messinensis Canu, 1896, p. 424.

Euchirella messinensis Giesbrecht & Schmeil, 1898, p. 35.

Euchirella messinensis Giesbrecht, 1903, p. 201.

Euchirella messinensis Thompson & Scott, 1903, p. 244.

Euchirella messinensis Cleve, 1904, p. 190.

Euchirella messinensis Sars, 1905 (a), p. 4.

Euchirella messinensis Esterly, 1905, p. 151, fig. 18.

Euchirella messinensis Farran, 1908, p. 37.

Nine females and six males of this Euchirella were found in plankton collected at the

following stations.

Stat. 118 (HENSEN vertical net 900 metres to surface), 1 specimen. — Stat. 133, 1 specimen. —
Stat. 141 (HENSEN vertical net 1500 metres to surface), 2 specimens. — Stat. 143 (HENSEN
vertical net 1000 metres to surface), 2 specimens. — Stat. 185 (HENSEN vertical net 1536
metres to surface), 2 specimens. — Stat. 203 (HENSEN vertical net 1500 metres to surface),
3 specimens. — Stat. 243 (HENSEN vertical net 1000 metres to surface), 3 specimens. —
Stat. 276. — (HENSEN vertical net 750 metres to surface), 1 specimen.

The females of this species have a rostrum but no crest. The genital segment is asym-
metrical, and has a peculiar sack-like projection on the dorsal surface. The inner margin of
the first joint of the basiopodite of the fourth pair of feet is furnished with one or two teeth.

Euchirella messinensis has been recorded from the Mediterranean, North Atlantic and
Pacific Oceans.

6. Euchirella pulchra (Lubbock).

Undina pulchra Lubbock, 1S56, pp. 2 & 20, pis. IV & VII.
Euchaeta pulchra Brady, 1883, (pars) p. 63, pi. XX.
Euchirella pulchra Giesbrecht, 1893, p. 233, pis. 15 & 36.
Euchaeta pulchra T. Scott, 1893, p. 57.
Euchirella pulchra Giesbrecht & Schmeil, 1898, p. 36
Euchirella pulchra I. C. Thompson, 1903, p. 17.
Euchirella pulchra Sars, 1905 (#), p. 4.
Euchirella pulchra Esterly, 1905, p. 153, fig. 20.
Euchirella pulchra van Breemen, 1908, p. 47, fig. 53.

This Euchirella was represented by twenty-eight females, and nine males, obtained trom
the plankton collected at the following stations.

Stat. 117% 1 specimen. — Stat. 118 (HENSEN vertical net 900 metres to surface), 4 speci-
mens. ■ — Stat. 141 (HENSEN vertical net 1500 metres to surface), 4 specimens. — Stat. 142,
5 specimens. — Stat. 143 (HENSEN vertical net 1000 metres to surface), 4 specimens. -
Stat. 185 (HENSEN vertical net 1536 metres to surface), 2 specimens. — Stat. 203 (HENSEN
vertical net 1500 metres to surface), 6 specimens. — Stat. 243 (HENSEN vertical net 1000
metres to surface), 4 specimens. — Stat. 276 (HENSEN vertical net 750 metres to surface),
2 specimens.

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57

The female is distinguished by its low crest and small rostrum. The genital segment is
asymmetrical. The inner margin of the first joint of the basiopodite of the fourth pair of feet
is furnished with one or two moderately long teeth.

Euchirella pulchra has been recorded from the Atlantic and Pacific Oceans.

7. Euchirella venusta Giesbrecht.

Euchirella venusta Giesbrecht, 1SS8, p. 336.

Euchirella venusta Giesbrecht, 1893, p. 253, pis. 15 & 36.

Euchirella venusta Giesbrecht & Schmeil, 1898, p. 35.

Euchirella venusta Cleve, 1904, p. 190.

Euchirella venusta Sars, 1905 (a), p. 4.

Xineteen females of this Euchirella were obtained from the plankton collected at the
followinej stations.

ö

Stat. 117% 3 specimens. — Stat. 118 (HENSEN vertical net 900 metres to surface), 1 speci-
men. — Stat. 141 (HENSEN vertical net 1500 metres to surface), 2 specimens. — Stat. 143
(HENSEN vertical net 1000 metres to surface), 1 specimen. ■ — Stat. 185 (HENSEN vertical
net 1536 metres to surface), 2 specimens. — Stat. 203 (HENSEN vertical net 1500 metres
to surface), 4 specimens. • Stat. 243 (HENSEN vertical net 1000 metres to surface), 1
specimen. — Stat. 276 (HENSEN vertical net 750 metres to surface), 2 specimens. —
Stat. 315, 1 specimen.

Euchirella venusta is closely related to Euchirella messznensis, but may be distinguished
from it by the absence of the sack-like projection on the dorsal surface of che genital segment.
The inner margin of the first joint of the basiopodite of the fourth pair of feet is furnished
with one or two moderately long spines.

This species has been recorded from the Atlantic and Pacific Oceans.

8. Euchirella maxima Wolfenden. Plate XII, fi^s. 12 — 20.

Euchirella maxima Wolfenden, 1905, p. 18, pi. VI, figs. 9, 11.
Euchirella maxima Farran, 1908, p. 38.

Adult female — length 7,2 mm.

The cephalothorax is oblong ovate, moderately robust and slightly contracted in front.
The head is fused with the first thoracic segment. It is furnished with a high trianyular crest
and a small rostrum. The fourth and fifth thoracic segments are completely separated. The last
thoracic segment is produced into a lamelliform process on each side.

The abdomen is four-jointed. The combined length of the abdomen and furca is contained
four and a half times in the total length of the cephalothorax, from the apex of the crest to
the base of the genital segment. The genital segment is symmetrical and only very slightly
swollen below. It is as long as the combined lengths of the next three segments. The second,
third, and fourth segments are of about equal length. The furcal joints are as broad as long,
and are slightly longer than the anal segment. The posterior margins of the first, second, and
third segments, are fringed with fine spines.

The antennules are twenty-four-jointed and extend to the end of the furca.

57

SIBOGA-EXPEDITIE XX1X<7. S

58

The endopodite of the antennae is about equal to one-third of the length of the exopodite.

The second joint of the basiopodite of the maxillae is furnished with one long seta and
two short ones on its distal angle. The exopodite is furnished with eleven long setae and the
endopodite with three.

The mandibles and maxillipedes resemble those of Euchirclla rostrata.

The exopodite of the first pair of feet is indistinctly three-jointed, and is furnished with
three marginal spines. The endopodite is short and one-jointed.

The exopodite of the second pair of feet is three-jointed and the endopodite one-jointed.

The third and fourth pairs of feet have a three-jointed exopodite and endopodite. The
first joint of the basiopodite of the fourth pair of feet is furnished with one strong tooth on
its inner margin (Plate XII, 19 — 20).

Only two specimens, one of which was immature, were obtained from plankton collected

at the following stations.

Stat. 148, HENSEN vertical net 1000 metres to surface, 1 mature female.
Stat. 276, HENSEN vertical net 750 metres to surface, 1 immature female.

I have been unable to detect any difference between the mature female obtained by the

'Siboga', and the description and figures given by Dr. Wolfenden.

Euchirclla maxima has hitherto only been known from the North Atlantic Ocean.

9. Euchirclla granulaia nov. sp. Plate XIII, figs. 1 — 12.

Female — length 5,5 mm.

The ccphalothorax is oblong ovate and very robust. The head is distinctly separated
from the first thoracic segment. It is without a crest, but has a short one-pointed rostrum. The
fourth and fifth thoracic segments are completely separated. The last thoracic segment is very
slightly produced, and the distal margins are narrowly rounded when seen in lateral view.

The abdomen is composed of four joints. The combined length of the abdomen and
furca is contained three and a half times in the total length of the ccphalothorax, from the
frontal margin to the base of the genital segment. The genital segment is symmetrical with
broadly rounded lateral margins, and is greatly swollen below. It is about as broad as long,
and exceeds the combined length of the next three segments. The second and third segments
are of about equal size. The third segment is distinctly shorter than the others. The furcal
joints are about as broad as long, and are slightly shorter than the anal segment. The posterior
portions of the genital segment, and the whole of the second, third, and fourth segments are
well covered with fine hairs.

The antennules are twenty-four-jointed, and extend beyond the end of the furca.

The endopodite of the antennae is about three-fourths of the length of the exopodite,
and bears eight + seven setae on the apical joint.

The mandibles have a strongly toothed cutting edge. The first joint of the endopodite
is furnished with two setae.

The second joint of the basiopodite of the maxillae is furnished with five setae on its
apex. The exopodite is furnished with eleven long setae. The endopodite is apparently indistinctly

5S

59

jointed, and is furnished with groups of seven -|- four -f- f°ur setae from the apex downwards.

The maxillipedes are similar in structure to those of Euchirella rostrata.

The exopodite of the first pair of feet is distinctly three-jointed, and each joint is furnished
with an outer-edge seta. The endopodite is composed of one joint.

The exopodite of the second pair of feet is three-jointed, and the endopodite is distinctly

two-jointed.

I'he third and fourth pairs of feet have a three jointed exopodite and endopodite. The

first joint of the basiopodite of the fourth pair of feet is furnished with a transverse row of fine

bristles on its inner margin (Plate XIII, fig. 12).

The fifth pair of feet is absent.

The whole of the integument, with the exception of that of the mandible-palps, maxillae,
and first maxillipedes, is covered with fine granulations.

O ecu r re nee. — One female was found in plankton collected with the Hensen vertical
net at Station 185, 1536 metres to surface.

10. Euchirella dentata nov. sp. Plate XIII, figs. 13 — 21.

Female — length 7,5 mm.

The cephalothorax is oblong ovate and rather robust. The head is distinctly separated
from the first thoracic segment. It is without a crest but has a conspicuous one-pointed rostrum.
The fourth and fifth thoracic segments are completely separated. The last thoracic segment is
produced into small spines, which, when viewed laterally, are seen to be pointed slightly upward
(Plate XIII, fig. 15).

The abdomen is composed of four joints. The combined length of the abdomen and
furca is contained three and a half times in the total length of the cephalothorax, from the
frontal margin to the base of the genital segment. The genital segment is slightly asymmetrical,
being rather more swollen on the right side than on the left. It is longer than broad and
exceeds the combined length of the next three segments. The second segment is about half the
lenoth of the eenital segment. The third and fourth segments are of about equal length and
are about half the length of the second. The furcal joints are about as long as broad, and are
as long as the anal segment. The posterior margins of the first, second, and third segments
are fringed with fine spines. The whole of the dorso-lateral surface of the abdominal segments
and furca, is covered with short hairs.

The antennules are twenty-four-jointed and extend to the end of the furca.

The endopodite of the antennae is equal to three-fifths of the length of the exopodite.
The apical joint bears eight -J- seven setae.

The mandibles, maxillae, and maxillipedes are similar to those of Euchirella granulaia.

The exopodite of the first pair of feet is indistinctly three-jointed.

The exopodite of the second pair of feet is three-jointed. The endopodite is very
indistinctly two-jointed.

The third and fourth pairs of feet have a three-jointed exopodite and endopodite. The
first joint of the basiopodite of the fourth pair of feet is furnished with seven or eight moderately

59

6o

lono- and strong spines on the inner margin. Fig. 21, Plate XIII shews eight spines and represents
the left foot. The first joint of the basiopodite of the right foot has seven spines.

The fifth pair of feet is absent.

Occurrence. - Two females were found in plankton collected with the Hensen vertical
net at Station 185, 1536 metres to surface.

11. Euchirella ditbia nov. sp. Plate XIV, figs. 1 — 7.

Female — length 7 mm.

The cephalothorax is oblong ovate and moderately robust. The head is distinctly separated
from the first thoracic segment. It is without a crest but has a conspicuous rostrum. The apex
of the rostrum is faintly bifurcate. The fourth and fifth thoracic segments are completely separated.
The last thoracic segment is not produced, and is simply rounded off into the abdomen.

The abdomen is composed of four segments. The combined length of the abdomen and
furca is distinctly less than one-fourth of the total length of the cephalothorax, from the frontal
margin to the base of the genital segment. The genital segment is slightly asymmetrical in
outline and is rather swollen below. It is nearly as long as broad at the widest part, and is
rather longer than the combined length of the next two segments. The second segment is
longer than the third. The third and fourth segments are of about equal length. The furcal
joints are about half as long as broad, and are as long as the anal segment. The posterior
dorso-lateral portions of the abdominal segments are clothed with fine short hairs.

The antennules are twenty-four-jointed and extend to the end of the furca.

The antennae, mandibles, maxillae, and maxillipedes are similar to those of Euchirella den fata.

The exopodite of the first pair of feet is indistinctly three-jointed, and is furnished with
three outer-edge spines, as in the other species described above.

The exopodite of the second pair of feet is three-jointed. The endopodite is distinctly
two-jointed.

The third and fourth pairs of feet have a three-jointed exopodite and endopodite. The
first joint of the basiopodite of the fourth pair of feet, is furnished with a row of eight or ten
spines. Fig. 7, Plate XIV shews ten spines. The first joint of the basiopodite of the other foot
has eight spines.

The fifth pair of feet is absent.

Occurrence. Three females were found in plankton collected with the Hensen

vertical net at Station 185, 1536 metres to surface.

It is quite possible that one or more of the species now described as new, may turn out
to be identical with species obtained by Sars in the plankton collected by the Prince of Monaco,
but as only the preliminary descriptions without figures have yet appeared, I am unable to
determine whether this is so or not at present.

Genus Undeuchaeta Giesbrecht, 1888.

This genus is closely allied to Euchirella, but the females are distinguished from those

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6i

of that genus, by the absence of spines or teeth on the inner margin of the first joint of the
basiopodite of the fourth pair of feet. The rostrum is one-spined, and the exopodite of the first
pair of feet is two-jointed.

Th ree species, one of which appears to be new, were found in the plankton collected
durine the traverse of the 'Sibogfa'.

i. Undeuchaeta major Giesbrecht.

Undeuchaeta major Giesbrecht, 1888, p. 335.

Undeuchaeta major Giesbrecht, 1893, p. 227, pi. 37.

Undeuchaeta major Giesbrecht & Schmeil, 1898, p. 34.

Undeuchaeta major I. C. Thompson, 1900, p. 278.

Scolecithrix cristata I. C. Thompson, 1903 (pars), p. 21, pi. III, male.

Undeuchaeta major Wolfenden, 1904, p. 111.

Undeuchaeta major Geve, 1904, p. 19S.

Undeuchaeta major Farran, 1905, p. 35.

Undeuchaeta major Esterly, 1905 (pars), p. 148, fig. • 16 (pars).

Chirundina angulata Sars, 1905 [d], p. 13.

Undeuchaeta major Pearson, 1906, p. 15.

Undeuchaeta major Sars, 1907 (a), p. 3.

Undeuchaeta major Farran, 1908, p. 37.

Undeuchaeta major van Breemen, 1908 (pars), p. 43, fig. 49 (pars).

Four specimens, all females, of this Undeuchaeta were found in the plankton collected

at the following- stations.

Stat. 117'. — Stat. 141 (HENSEN vertical net 1500 metres to surface). — Stat. 148 (HENSEN
vertical net 1000 metres to surface). — - Stat. 230 (HENSEN vertical net 2000 metres to surface).

The female of this species is distinguished from the others by the presence of a distinct
and moderately high crest, by a blunt projection on the right side of the genital segment, and
also by the hook on the right side of the genital opening.

Undeuchaeta major was first described from the Pacific Ocean, but the distribution has
since been found to extend to the North Atlantic.

The 'Siboga' specimens measured 4,8 — 6,4 mm.

I regard the male of the species recorded by the late I. C. Thompson as Scolecithrix
cristata from plankton collected during the cruise of the 'Oceana', to be the male of Undeuchaeta
major. It is not the male of Scaphocalanus magnus (T. Scott). I recently had the opportunity
of examining a male Copepod taken during one of the cruises of the Scottish International
Fisheries Cruiser 'Goldseeker', in the deep water of the Faröe Channel. This Copepod has a
similar armature on the fifth pair of feet to that shewn by Thompson (1903 pi. III, fig. 5),
and appears to be identical with Undeuchaeta major. The specimen has a median crest and a
one-pointed rostrum.

The form identified and illustrated by Esterly (1905 p. 148, fig. 16), as the male of

l 'ndeuchacta major, is, I think, very doubtfully so. Esterly gives the length of the female as

4^ — — mm. and the male as 6 — 6,5 mm. It is very unusual to find the males of the Calanoids

so much larger than the females. The figure of the left fifth toot resembles that of a species

of Paraaichacta.

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02

Giesbrecht and Schmeil doubtfully refer the two species described by Brady in the
'Challencrer Report', as Etichaeta australis and Euchaeta pulchra, to Undeuchaeta major, but
I reo-ard them to be identical with the form described by Giesbrecht as Undeuchacta minor,
and more correctly with Lubbock's Undiua plumosa.

2. Undeuchaeta plumosa (Lubbock). Plate XXII, figs. i — 8.

Undina plumosa Lubbock, 1856, p. 18, pi. IX, figs. 3 — 5.

Euchaeta australis Brady, 1883, p. 65, pi. XXI, figs. 5 — 11.

Euchaeta pulchra Brady (pars) non Lubbock, 1883, p. 63, pi. XIV, figs. 6 — 9.

Undeuchaeta minor Giesbrecht, 1888, p. 335.

Undeuchacta minor Giesbrecht, 1893, p 228, pis. 14 & u .

Euchaeta australis T. Scott, 1893, p. 58, pi. VI, fig. 23.

Undeuchaeta minor Canu, 1896, p. 424.

Undeuchaeta minor Giesbrecht & Schmeil, 1898, p. 34.

Undina plumosa Giesbrecht & Schmeil, 1898, p. 52.

Undeuchaeta minor Thompson & Scott, 1903, p. 243.

Undeuchaeta minor Wolfenden, 1904, p. 111.

Undeucliaeta minor Cleve, 1904, p. 198.

Undeuchaeta minor Farran, 1905, p. 35.

Undeucliaeta minor Esterly, 1905, p. 149, fig. 17.

Undeuchacta australis Sars, 1905 (a), p. 4.

Undeuchaeta minor Pearson, 1906, p. 15.

Undeuchaeta minor Sars, 1907 (a), p. 3.

Undeucliaeta minor Farran, 1908, p. IJ .

Undeuchacta minor van Breemen, 1908, p. 44, fig. 50.

This species was well represented in the plankton collected by the 'Siboga'. Thirty-nine
females and eleven males were obtained at the following stations.

Stat. 117', 1 specimen. — Stat. 118 (HENSEN vertical net 900 metres to surface), 3 speci-
mens. — Stat. 128 (HENSEN vertical net 700 metres to surface), 5 specimens. — Stat. 141
(HENSEN vertical net 1500 metres to surface), 4 specimens. — Stat. 142, 2 specimens. —
Stat. 143 (HENSEN vertical net 1000 metres to surface), 6 specimens. — Stat. 189', 1 speci-
men. -- Stat. 203 (HENSEN vertical net 1500 metres to surface), 4 specimens. — Stat. 216,
1 specimen. — Stat. 230 (HENSEN vertical net 2000 metres to surface), 7 specimens. —
Stat. 243 (HENSEN vertical net 1000 metres to surface), 6 specimens. — Stat. 245, 4 speci-
mens. — Stat. 276 (HENSEN vertical net 750 metres to surface), 5 specimens.

The female of Undeuchaeta plumosa is distinguished from Undeuchaeta major, by the
absence of any tracé of a median crest on the forehead, and also by the absence of the hooked
spine on the ventral surface of the genital segment of the female.

I think there can be no doubt, after giving careful consideration to Lubbock's description
and figures, that the species described in the Transactions of the Zoological Society for 1856,
as Undina plumosa, is identical with the male of Euchaeta australis Brady, and represents the
missing male of Giesbrecht's Undeuchacta minor. Lubbock's name plumosa ought, therefore, to
be adopted as the specific name for this Undeuchacta instead of either australis or minor.

The species described and figured in the 'Challenger Report' as the female of Etichaeta

pulchra Lubbock, is really the female of Euchaeta australis which I consider is identical with

Undeuchaeta minor and to be the true female of Undeuchacta ( Undina) plumosa. Giesbrecht

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63

and Schmeil doubtfully rcfer the two species describèd by Bradv to Undeuchaeta major, but
I fail to see any reason for this. Neither Brady's descriptions or ligures indicate the presence
of a median crest on the forehead, or of a hooked spine on the ventral surface of the genital
segment. These two characters are quite obvious in the 'Siboga' specimens of the female of
Undeuchaeta major. It is extremely unlikely that Bradv would overlook the median crest, had
it been present in the 'Challenger' specimens. The hook at the genital opening might be broken,
as I have noticed it to be slightly damaged in some of the 'Siboga' specimens, but none had
the median crest damaged in any way. The dorso-lateral spine, on the right of the genital
segment when seen from above, is not always visible when the female is lying perfectly flat
on its left side, and it cannot be seen at all when lying perfectly flat on the right side. A slight
movement one way or the other, from the true lateral position is sufficiënt to bring the spine
into view. This would account for its absence in the figure on Plate XXI, and its presence
in the figure on Plate XIV. The view of the furcal joints in the latter figure shews quite well,
that the specimen was not lying perfectly flat. The absence of the median crest is of more
importance than the want of the spine. Female — length 3,5 — 4,5 mm.

The fifth pair of feet of the males found in the 'Siboga' plankton is identical with the
figures given by Lubbock and by Bradv. The right and left sides have been reversed in the
figure in the 'Challenger Report'.

The exopodite of the right and left foot is three-jointed. The endopodite of the right
foot is apparently two-jointed. The endopodite of the left foot is orily one-jointed. The second
joint of the left exopodite is furnished with a strong spine on its inner distal angle. The middle
of the inner margin of the third joint bears a tuft of setae. The apex of the joint is prolonged
into a spine.

The exopodite of the first pair of feet is distinctly three-jointed, but there is no outer-
edge spine on the first joint. The endopodite of the second pair of feet is only one-jointed.

The various mouth organs are much reduced as in the males of Euchaeta. ■

The last thoracic segment is very slightly produced and the extremities are rounded.
The rostrum is similar to the female but rather smaller. Male — length 3,2 — 3,6 mm.

The species is widely distributed. I have examined males and females from collections
of plankton taken in the deep water of the Faröe Channel, by the Scottish International
Fisheries Cruiser 'Goldseeker'. There appears to be no difference between the Xorth Atlantic
type of Undeuchaeta plumosa, and those taken by the 'Siboga'.

3. Undeuchaeta intermedia nov. sp. Plate XXIII, figs. 1 — 8.

Female — length 4,5 mm.

The cephalothorax is oblong ovate and moderately robust. The head is distinctly separated
from the first thoracic segment, and is furnished with a very faint median crest, which may
only be a slight thickening of the integument, and a moderately long, one-pointed rostrum.
The fourth and fifth thoracic segments are completely fused. The last thoracic segment is
slightly asymmetrical, and both sides are prolonged into fine points.

The abdomen is composed of four segments. The combined length of the abdomen and

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64

furca is contained three and one-third times in the total length of the cepha/othorax, from the
frontal margin to the base of the genital segment. The genital segment is decidedly longer
than the combined length of the next two segments. There is a well defined spine on the
middle of the right side, and a curved spine on the right of the genital opening. The posterior
margin of the segment is fringed with fine spines. The second segment is about half as long
as the first. The third segment is shorter than the second, and the fourth segment is shorter
than the third. The furcal joints are about half as long as broad, and are equal to fully half
the length of the anal segment.

The antennules are twenty-three-jointed, and extend to the end of the second abdominal
segment.

The antennae, mandibles, maxillae and maxillipedes, are similar to those of Undeuchaeta
plumosa.

The exopodite of the first pair of feet is two-jointed, and there is no outer-edge spine
on the middle of the first joint.

The endopodite of the second pair of feet is one-jointed.

The third and fourth pairs of feet have a three-jointed exopodite and endopodite. The inner
margin of the first joint of the basiopodite of the third pair of feet is furnished with a fringe of fine
hairs. The inner margin of the first joint of the basiopodite of the fourth pair of feet is naked.

The male is unknown.

Occurrence. — Eighteen females were found in plankton collected at the following stations.

Stat. 141 (HENSEN vertical net 1500 metres to surface), 4 specimens. — Stat. 142, 2 speci-
mens. — Stat. 215% 2 specimens. — Stat. 243 (HEXSEX vertical net 1000 metres to surface),
5 specimens. — Stat. 276 (HEXSEX vertical net 750 metres to surface), 5 specimens.

This species appears to be an intermediate form between Undeuchaeta major, and
Vndeuchacta plumosa. It is distinguished from the former by the absence of the high crest on
the forehead, and from the latter by the spine on the right of the genital opening, and also
by the faint crest.

6. Family Euchaetidae.
Genus Euchaeta Philippi, 1843.

In this report, the Euchaeta marina type has been separated from the Euchaeta norvegica
type, on account of distinct differences in the character of the fifth pair of feet of the males,
and also in the armature of the apical spines on the first maxilliped of the female.

Euchaeta marina (Prestandrea) appears to be the first known member of the genus
Euchaeta established by Philippi in 1852, and the characters of the appendages of the two sexes
are, therefore, regarded as typical of the true Euchaeta. The armature of the spines on the apex
of the first maxilliped of the female, and the structure of the male fifth feet in Philippi's type,
are decidedly different from what are found in Euchaeta norvegica Boeck. These differences are
now made the distinguishing characters of the two genera, as established in the present report.

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65

In the females, two of the six apical spines on the first maxilliped, in addition to being
furnished with rows of very short spinules, have also a number of moderately long and con-
spicuous spinules. The males of typical Euchaeta are easily separated from those of the next
genus, by the exopodite of both the right and left fifth foot terminating in a long spiniform joint.

Seven species of typical Euchaeta were obtained from the plankton collected by the
'Siboga' in the Malay Archipelago.

i. Euchaeta acuta Giesbrecht. Plate XX, figs. i — 9.

Euchaeta acuta Giesbrecht, 1893, p. 246, pis. 16 & 37.

Euchaeta acuta Giesbrecht & Schmeil, 1898, p. 38.

Euchaeta acuta I. C. Thompson, 1903, p. 18.

Euchaeta acuta Thompson & Scott, 1903, p. 244.

Euchaeta acuta Wolfenden, 1904, p. 111.

Euchaeta acuta Cleve, 1904, p. 190.

Euchaeta acuta Sars, 1905 (a), p. 4.

Euchaeta acuta Farran, 1905, p. 35.

Euchaeta acuta Esterly, 1905, p. 157, fig. 23.

Euchaeta acuta Pearson, 1906, p. 17.

Euchaeta acuta Farran, 1908, p. 40.

Euchaeta acuta van Breemen, 1908, p. 51, fig. 56.

This species appeared to be very rare in the area traversed by the lSiboga'. Only one
female and three males were obtained. The specimens were found in the plankton collected with
the Hensen vertical net at the following stations.

Stat. 141 (1500 metres to surface). — Stat. 148 (1000 metres to surface). — Stat. 185 (1536
metres to surface). — Stat. 203 (1500 metres to surface).

The female of Euchaeta acuta resembles Euchaeta media very closely, but it can be
distinguished from it by the peculiar shape of the genital segment, when viewed from above.
The proximal margin of the left side is produced into a blunt process, which is distinctly notched
on the anterior surface. The posterior margin of the last thoracic segment appears evenly rounded
when seen from above, and from the side. The outer-edge spine on the second joint of the
exopodite of the second pair of feet, scarcely extends to the base of the first outer-edge spine
on the third joint. The second outer-edge spine on the third joint does not extend to the base
of the third outer-edge spine. The appendicular seta on the furcal joints is longer than the
others. Length, female 4,2 mm.

According to the records, Euchaeta acuta has apparently a wide distribution in tropical
and temperate seas.

2. Euchaeta concinna Dana. Plate XIX, figs. 21 — 27.

Euchaeta concinna Dana, 1 849, p. 21.

Euchaeta concinna Giesbrecht, 1893, p. 246, pis. 15, 16, 37.

Euchaeta concinna Giesbrecht & Schmeil, 1898, p. 39.

Euchaeta concinna. Cleve, 1901, p. 7.

Euchaeta concinna Thompson & Scott, 1903, p. 244.

Euchaeta concinna Cleve, 1903, p. 363.

Euchaeta concinna Wolfenden, 1905 (a), p. 1008, pi. C, fig. 1 — 6.

65

SIBOGA-EXPEDITIE XXIX (7. Q

66

Euchaeta concinna, although not very common, appeared to be well distributed throughout
the area investigated by the 'Siboga' as shewn by the following records.

Stat. 16. — Stat. 19. — Stat. 35. — Stat. 36. ■ - Stat. 37. — Stat. 40. — Stat. 66. —
Stat. 81. -- Stat. 89. -- Stat. 98. — Stat. 106. -- Stat. 1 10. -- Stat. 117% — Stat. 124. —
Stat. 125 (day). — Stat. 128. — Stat. 136. — Stat. 138. — Stat. 141. — Stat. 143. —
Stat. 144. — Stat. 146. — Stat. 148. — Stat. 157. — Stat. 165. — Stat. 168. — Stat.
169. -- Stat. 172. — Stat. 177'. -- Stat. 184. -- Stat. 185. -- Stat. 186. -- Stat. 189. —
Stat. 220 (vertical net). — Stat. 230. — Stat. 243. — Stat. 245. — Stat. 252. — Stat.
282. — Stat. 315.

The female of this species is easily recognised, by the peculiar projection on the proximal
end of the right side of the genital segment. The armature on the margin of the second joint
of the left exopodite of the male fifth pair is finer than in Euchaeta marina. The onter-edge spine
on the second joint of the exopodite of the second pair of feet of the female, is moderately long
and stout. It extends nearly to the apex of the first spine on the third joint. The outer-edge
spines on the third joint are very short.

Euchaeta concinna appears to be confined to the tropical seas.

3. Euchaeta longicornis Giesbrecht.

Euchaeta longicornis Giesbrecht, 1888, p. 2,2,7.

Euchaeta longicornis Giesbrecht, 1893, p. 246, pis. 16 & 37.

Euchaeta longicornis Giesbrecht & Schmeil, [898, p. 40.

Euchaeta longicornis Cleve, 1901, p. 7.

Euchaeta longicornis Cleve, 1904, p. 190.

One female belonging to this species was found in the plankton collected with the
Hensen vertical net at Station 141, 1500 metres to surface.

This species is closely related to Euchaeta marina, and some care is required in its
identification. When the antennules are perfect these form a very good character as they extend
beyond the furca.

4. Euchaeta media Giesbrecht. Plate XX, figs. 10 — 18.

Euchaeta media Giesbrecht, 1888, p. 337.

Euchaeta media Giesbrecht, 1893, p. 246, pis. 16 & 37.

Euchaeta media Giesbrecht & Schmeil, 1 898, p. 39.

Euchaeta media Cleve, 1904, p. 190.

Euchaeta media Esterly, 1905, p. 160, fig. 25.

One female belonging to this species was found in the plankton collected with the
Hensen vertical net at Station 230, 2000 metres to surface.

Euchaeta media resembles Euchaeta acuta very closely, but it can be distinguished by
the following characters. The left side of the genital segment, when viewed from above, is seen
to be considerably swollen. It is broadly rounded in outline, but is not produced into a pointed
process. The posterior margin of the last thoracic segment appears distinctly angular, when
seen from above, and from the side. The outer-edge spine on the second joint of the exopodite

66

6;

oi the second pair of feet, projects slightly beyond the base of the first outer-edge spine on
the third joint. The second outer-edge spine on the third joint, extends to the base of the
third outer-edge spine. The appendicular seta on the furcal joints is longer than the others.
Length 3,75 mm.

This species appears to have a very limited distribution.

5. Euchaeta marina (Prestandrea). Plate XIX, figs. 9 — 20.

Cyclops marinus Prestandrea, 1833, p. 12.

Euchaeta prestandrea Philippi, 1 S43, p. 58, pi. 4.

Euchaeta marina Giesbrecht, 1893, p. 246, pis. 1, 15, 16, 37.

Euchaeta marina Giesbrecht & Schmeil, 189S, p. 38.

Euchaeta marina I. C. Thompson, 1900, p. 27S.

Euchaeta marina Cleve, 190 1, p. 7.

Euchaeta marina A. Scott, 1902, p. 403.

Euchaeta marina I. C. Thompson, 1903, p. 18.

Euchaeta marina Thompson & Scott, 1903, p. 244.

Euchaeta marina Cleve, 1903, p. 363.

Euchaeta marina Cleve, 1904, p. 190.

Euchaeta marina Sars, 1905 (a), p. 4.

Euchaeta marina Wolfenden, 1905 («), p. 1007, pi. C, figs. 19 & 20 (male).

Euchaeta indica Wolfenden, 1905(0), p. 1008, pi. C, figs. 12 — 16 (female).

Euchaeta marina Pearson, 1906, p. 16.

Euchaeta marina van Breemen, 1908, p. 50, fig. 55.

This species proved to be very common and was widely distributed in the area, as shevvn
by the following records.

Stat. 16. — Stat. 19. - - Stat. 35. — Stat. 36. - - Stat. 37. - - Stat. 38. — Stat. 40. —
Stat. 47'. — Stat. 50. — Stat. 66. — Stat. 71. — Stat. Si. — Stat. 89. — Stat. 93. —
Stat. 96 (day). — Stat. 96 (night). — Stat. 98. — Stat. 99. -- Stat. 106. — Stat. 109. —
Stat. 110. — Stat. in. — Stat. 112. — Stat. 117». — Stat. 118. — Stat. 121. —
Stat. 124. — Stat. 125 (day). — Stat. 12S. — Stat. 129. — Stat. 133. — Stat. 136. -
Stat. 138. — Stat. 141. — Stat. 142. — Stat. 143. Stat. 144. — Stat. 148. —

Stat. 149. — Stat. 157. — Stat. 165. — Stat. 184. Stat. 185. — Stat. 189". —

Stats. 194 — 7. — Stat. 203 (surface). — Stat. 203 (1500 metres). — Stat. 204. — Stat. 205. —
Stat. 2ioa. — Stat. 213. — Stat. 215*. — Stat. 217 (surface). — Stat. 217 (horizontal
cylmder). — Stat. 220 (vertical net). — Stat. 220 (surface). — Stat. 223. — Stat. 225. -
Stat. 229. — Stat. 230. Stat. 243. — Stat. 245. — Stat. 252. — Stat. 276. ■

Stat. 282. — Stat. 304. — Stat. 315.

The last thoracic segment of the female appears asymmetrical when vievved from above.
The right side is distinctly more produced than the left. The genital segment is also asym-
metrical. The right side is irregular in outline and is dilated near the distal end. The projecting
part of the second joint of the left exopodite of the male fifth pair is coarsely toothed, and is
easily distinguished from Euchaeta concinna.

The female form described and figured by Wolfenden as Euchaeta indica, is identical
with the female of Euchaeta marina.

Ettchaeta marina appears to be generally distributed in the warm seas.

67

68

6. Euchaeta tennis Esterly. Plate XIX, figs. i — 8.

Euchaeta tenuis Esterly, 1906, p. 61, pis. IX & X.

A few specimens of a form which appears to be identical with the above species, were

found in the plankton collected by the 'Siboga', at the following stations.

Stat. 117% 1 specimen. — Stat. 141, 2 specimens. — Stat. 143, 1 specimen. — Stat. 148,
1 specimen. — Stat. 185, 2 specimens. — Stat. 203 (1500 metres), 2 specimens. — Stat.
230, 1 specimen. — Stat. 243, 1 specimen. — Stat. 252, 1 specimen.

The peculiar projection on the ventral surface of the genital segment, when seen from
the side, is the most noteworthy character The outer-edge spine on the second joint of the
exopodite of the second pair of feet, extends beyond the apex of the first outer-edge spine on
the third joint. The second outer-edge spine on the third joint, reaches almost to the base of
the third outer-edge spine. Two minute tubercles are visible at the middle of the dorso-lateral
edges of the genital segment, when viewed from above. The second inner seta on the furcal
joints is much longer than any of the others. The appendicular seta is very short. The females
only were obtained. Length 6,8 mm.

Eucliaeta tennis was described by Esterly from a single specimen obtained in the Pacific
Ocean, and the size is given as 6 mm.

The species is not unlike Euchaeta grandiremis Giesbrecht, but is easily separated from
it by the difference in the proportional lengths of the spines on the exopodite of the second
pair of feet.

7. Euchaeta zvolfcndeni nov. sp. Plate XVII, figs. 1 — 12.

Euchaeta marina Wolfenden, 1905 (a) pars, p. 1007, pi. C, figs. 7, 8, 10, 11, 17, 18.

Female — length 2,4 — 2,9 mm.

This Copepod is very like Euchaeta marina in general appearance, but on close exami-
nation can easily be distinguished from it. The last thoracic segment is quite symmetrical when
viewed from above. The posterior margin, when seen from the side, appears narrowly rounded.

The combined length of the abdomen and furca is slightly less than half the total length
of the cephalothorax, from the frontal projection to the base of the genital segment. The genital
segment is as long as the combined length of the next three segments. The segment is irregular
in outline, when viewed from the dorsal aspect. The posterior end of the right side is
produced into a moderately large and well defined tubercle. A distinct swelling is visible in
the region of the genital opening, when the segment is viewed from the side. The second
segment is about half the length of the genital segment, and is equal to the combined length
of the third and fourth segments. The appendicular seta is much longer than any of the others.
The thoracic and abdominal segments are densely covered with short fine hairs.

The antennules are twenty-three-jointed and extend to the end of the second abdominal
segment.

The antennae, mandibles, maxillae and maxillipedes, are similar to those of Euchaeta
marina. The marginal spines on the two apical setae of the first maxilliped are comparatively long.
The first pair of feet is similar to that of Euchaeta marina.

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69

The outer-edge spines on the exopodite of the second pair of feet are comparatively
short and stout. The outer-edge spine on the second joint is longer and stouter than the others,
but it ialls considerably short of the base of the first outer-edge spine on the third joint.

The third and fourth pairs of feet are almost similar to those of Euchaeta marina.

Male — length 2,7 mm.

The males are very like those of Euchaeta marina in general appearance, but are
easily recognised by the difference of the armature on the projection of the second joint of the
exopodite of the left fifth foot. The spinules are small and closely set, and the apex of the
projection is deeply notched. The second joint of the left exopodite is furnished with four long
and moderately strong spines on the inner margin, opposite the apex of the projection.

The female of Euchaeta wolfendeni, is undoubtedly the same as the form which is wroncdy
described and figured by Wolfenden as Euchaeta marina, in his report .on the Copepocla collected
by J. Stanley Gardinek around the Maldive Islands. There appears to be some confusion
between Wolfenden's description and figure of the exopodite of the second pair of feet, which
renders the identification rather difficult at first sight. The description of the outer-edge spines
on the exopodite of the second pair of feet agrees with what is found in typical Euchaeta
marina, but does not agree with the figure 8 on plate C. The description of the spines both
of Euchaeta indica and of Euchaeta marina in W< u.fknden's report, has evidently been drawn
up from the figure 16 on plate C.

This species appeared to be fairly well distributed in the Malay Archipelago. Males and
females were not uncommon in the plankton collected by the 'Siboga'. The species was present
at the followincr stations.

o

Stat. 36. — Stat. 37. — Stat. 66. — Stat. 81. — Stat. 98. -- Stat. 110. — Stat. ti;a. —
Stat. 121. — Stat. 124. — Stat. 125 (day). -- Stat. 128. - - Stat. 136. — Stat. 138. —
Stat. 141. — Stat. 142. — Stat. 157. — Stat. 165. — Stat. 172. — Stat. 1S4. — Stat. 189". —
Stat. 217 (surface). — Stat. 217 (horizontal cylinder). — Stat. 220 (surface). — Stat. 220
(vertical net). — Stat. 223. — Stat. 224. — Stat. 225. — Stat. 229. — Stat. 245. —
Stat. 276. — Stat. 282. — Stat. 315.

Euchaeta zvolfcndcni may prove to be widely distributed in the warm seas. Owing to
its general resemblance to Euchaeta marina, however, it may be easily overlooked. I have
specimens of this species from the plankton samples collected by Professor Herdman between
Aden and Colombo, during his traverse to Ceylon and back in 1903.

The species is named in compliment to Dr. R. N. Wolfenden, whose investigations of the
plankton of the deep water of the North Atlantic, have revealed a number of interesting Copepoda.

Genus Paraeuchaeta nov.

This genus is establishecl for the reception of the Eztchacta-like forms of which Boeck's
Euchaeta norvegica is the type.

The females are distinguished from true Euchaeta by the armature of the spines on the
apex of the first maxillipedes. These spines are densely furnished with fine short spinules only.
The long spinules, which are so characteristic in true Euchaeta, are entirely absent.

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7o

The males are easily separated by the structure of the left exopodite of the fifth pair
of feet. The second joint is only slightly produced at its inner distal angle. The third joint is
short and rudimentary. In true Euchaeta the third joint is long and spiniform.

Twelve species belonging to this genus were found in the plankton collected by the
'Siboga'. Nine of the species appear to be unknown, but four of them are males which may
prove to be identical with some of the females now recorded.

i. Paraeuchaeta barbata (Brady). Plate XVIII, figs. i — 8.

Euchaeta barbata Brady, 1883, p. 66, pis. XXII, figs. 6 — 12.
Euchaeta barbata Farran, 1908, p. 40, pi. III, figs. 13 & 14.

Five females of this form, which appears to be identical with Euchaeta barbata Brady,
were found in the plankton collected with the Hensen vertical net at Station 230, 2000 metres
to the surface.

The figure illustrating the outer-edge spines on the exopodite of the second pair of feet
given in this report, agrees very well with the figure given by Brady, and also by Farran.
The outer-edge spine on the second joint is long, and reaches to about midway between the
base and apex of the first outer-edge spine on the third joint. The second outer-edge spine
on the third joint is very stout, and extends distinctly beyond the base of the third outer-edge
spine. The sinus at the base of the second outer-edge spine on the third joint is very deep.
The second inner seta on the furcal joints is long, but the appendicular seta is longer than it.
Length of female 7,5 mm.

The form described and figured by Sars in 'Crustacea of Norway', although resembling
Paraeuchaeta barbata very closely, appears to be distinct. Sars states that the legs scarcely
differ in structure from those of Paracitchaeta norvegica. The proportional lengths of the outer-
edge spines on the exopodite of the second pair of feet of Paraeuchaeta norvegica, are very
distinct from that shewn in Brady's figure.

Brady's specimen was obtained in the South Atlantic to the east of Monte Video.
Farran records it from the North Atlantic off the West Coast of Ireland.

2. Paraeuchaeta bisinuata (Sars). Plate XVI, figs. 10 — 17.

Euchaeta bisinuata Sars, 1907 (a), p. 12.

Euchaeta bisinuata Farran, 1908, p. 45, pi. III, figs. 17 — 19; pi. IV, fig. 4.

Females similar to the form iclentified and figured by G. P. Farran as Euchaeta bisi-
nuata Sars, were found in the plankton collected at the following stations in the area investigated
by the 'Siboga'.

Stat. 117', 1 specimen. — Stat. 230 (HENSEN vertical net 2000 metres to surface), 2 speci-
mens. — Stat. 243 (HENSEN vertical net 1000 metres to surface), 1 specimen. -- Stat. 252,
1 specimen. — Stat. 276 (HENSEN vertical net 750 metres to surface), 1 specimen.

Paraeuchaeta bisinuata is easily recognised by the peculiar arrangement of the pro-
tuberance on the ventral surface of the genital segment. The protuberance is divided into three
lobules, and the two antenor ones are paired. The outer-edge spine on the second joint of

70

7'

the exopodite of the second pair of feet, reaches to near the apex of the first outer-edge spine
on the third joint. The second outer-edge spine on the third joint extends to the base of the
third outer-edge spine. The appendicular seta on the furcal joints is longer than any of the
others. Length of female 5 mm.

This species has only been previously recorded from the North Atlantic.

3. Paraeuchaeta californica (Esterly). Plate XV, figs. 1 — 8.

Euchaeta californica Esterly, 1906, p. 60, pis. IX & X.

Ten females of this form, which appears to be identical with the Euchaeta californica,
described by C. O. Esterly, were found in the plankton collectecl by the 'Siboga' at the fol-

lowing stations.

Stat. 141 (HENSEN vertical net 1500 metres to surface), 2 specimens. -- Stat. 143 (HENSEN
vertical net 1000 metres to surface), 2 specimens. -- Stat. 185 (HENSEN vertical net 1536
metres to surface), 1 specimen. - - Stat. 230 (HENSEN vertical net 2000 metres to surface),
2 specimens. — Stat. 252, 1 specimen. — Stat. 276 (HENSEN vertical net 750 metres to
surface), 2 specimens.

The whole of the specimens from the 'Siboga' collections, possessed the peculiar curved
process projecting from the genital opening. The protuberance is paired, but the one on the
left side is rather longer than that on the right. When viewed from the side, the forehead
appears very much contracted, and the rostrum projects forward in an almost continuous line
with the cephalic margin.

The outer-edge spine on the second joint of the exopodite of the second pair of feet,
extends beyond the apex of the first outer-edge spine on the third joint. The second outer-edge
spine on the third joint just reaches the base of the third outer-edge spine. The second inner
seta on the furcal joints is much longer than any of the others.

The figure shewing the lateral view of the genital segment is rather different from that
given by Esterly. The protuberances at the side of the genital opening, appear to be more
pronounced than in Esterly's species but this may be due to age. The 'Siboga' specimens
measured 7 mm. in length.

The species was described by Esterly from a single specimen obtained in the Pacific
Ocean and its length is given as S mm.

4. Paraeuchaeta propinqua (Esterly). Plate XVII, figs. 13 — 20.
Euchaeta propinqua Esterly, 1906, p. 61, pis. IX & X.

Two females which appear to be identical with Esterly's Euchaeta propinqua, were found
in the plankton collected with the Hexsen vertical net at Station 230, 1 500 metres to the surface.

The species bears a close resemblance to Paraeuchaeta californica, but can be distinguished
from it by the less swollen and more elongate genital segment, when viewed from the dorsal
aspect. The outer-edge spines on the exopodite of the second pair of feet are proportionally
shorter than in Paraeuchaeta californica.

The outer-edge spine on the second joint extends to the base of the first outer-edge

/ -

spine on the third joint. The second outer-edge spine on the third joint does not reach the
base of the third outer-edge spine.

The second inner seta on the furcal joints is very long but the appendicular seta is
longer than any of the others. Length of female 10 mm.

Esterly's description and figures were drawn up from a single female obtained in the
Pacific Ocean, and the size is given as 9 mm.

5. Paraettchaeta tonsa. (Giesbrecht). Plate XIV, figs. 8 — 15.

Euchaeta tonsa Giesbrecht, 1895, p. 251, pi. IV, figs. 9 & 10.

Euchaeta tonsa Giesbrecht & Schmeil, 1S98, p. 40.

Euchaeta tonsa Cleve, 1904, p. 190.

Euchaeta tonsa Sars 1905 (a), p. 5.

Euchaeta tonsa Farran, 1905, p. 35.

Euchaeta tonsa Pearson, 1906, p. 17.

Euchaeta tonsa Esterly, 1906, p. 64, pis. IX & X.

Euchaeta tonsa Farran, 1908, p. 44.

Euchaeta tonsa van Breemen, 190S, p. 55, fig. 62.

Females belonging to this species were found in the plankton collected with the Hensen
vertical net at the following stations.

Stat. 142 (1500 metres to surface), 1 specimen. — Stat. 14S (1000 metres to surface), 1 spe-
cimen. • Stat. 230 (2000 metres to surface), 1 specimens. — Stat. 276 (750 metres to
surface), 1 specimen.

Paraeuchaeta tonsa is easily recognised by the bluntly pointed last thoracic segment,
and by the large projection on the genital segment when the female is viewed from the side.
The outer-edge spine on the second joint of the exopodite of the second pair of feet, is longer
than any of the other outer-edge spines. It reaches to about midway between the base and
the apex of the first outer-edge spine on the third joint. The second inner seta on the furcal
joints is much longer than any of the others. Length of 'Siboga' specimens 7 mm.

Paraeuchaeta tonsa appears to have a moderately wide distribution.

6. Paraetuhaeta gracilicauda nov. sp. Plate XVIII, figs. 9 — 16.

Female — length 7 mm.

Seen from above. The body resembles that of Paraeuchaeta óaróata, except that it is
distinctly contracted in the middle of the cephalic segment, and the rostrum is directed down-
wards. The posterior margin of the last thoracic segment appears slightly angular when seen
in lateral view. The epistome is hirsute, ancl the tuft of hairs on the last thoracic segment is
well developed.

The abdomen is very slender. The combined length of the abdomen and furca is
contained one and three-fourth times in the total length of the cep halothorax, from the frontal
prominence to the base of the genital segment. The genital segment is slightly shorter than
the combined length of the second and third segments. It is symmetrical in outline, and the
lobules at the genital opening are similar to those of Paraeuchaeta óaróata. The distance

72

/ .1

between the genital opening and the posterior margin of the segment, is greater than in
Paraeuchacta barbata. The secoiul and third segments are of about equal length. The anal
segment is about one-fourth of the length of the third segment. The furcal joints are rather
longer than broad, and are equal to the length of the anal segment. The appendicular seta is
longer than any of the others.

The antennules extend to about the middle of the eenital segment.

The antennae, mandibles, maxillae and maxillipedes are nearly similar to those of Para-
euchaeta barbata.

The first pair of feet is similar to that of Paraeuchaeta barbata. The exopodite,is in-
distinctly three-jointed, and the outer-edge spine at the incomplete separation of the first and
second joints is very small.

The outer-edge spine on the second joint of the exopodite of the second pair of feet,
extends to midway between the base and the apex of the first outer-edge spine on the third
joint. The second outer-edge spine on the third joint is short, and does not nearly reach the
base of the third outer-edge spine.

The third and fourth pairs of feet are nearly similar to those of Paraeuchaeta barbata.

Male unknown.

This species is easily recognised by its long slender abdomen, and by the distance between
the genital opening and the posterior margin of the segment.

O ecu r ren c e. — This species was found in plankton collected with the Hensen vertical
net at the following stations.

Stat. 230 (2000 metres to surface), 2 specimens. — Stat. 276 (750 metres to surface), 1 specimen.

7. Paraeuchaeta sibogac nov. sp. Plate XVI, figs. 1 — 9.

Female — length 5 mm.

Yiewed from above, the body appears moderately robust. The head is much contracted
in the middle, and is distinctly separated from the first thoracic segment. The last thoracic
segment is asymmetrical. The left posterior margin of the segment is more produced than the
right. Seen from the side, the posterior margin of the last thoracic segment appears angular
in outline. The rostrum is comparatively small and is directed downwards. The epistome is
hirsute, and a tuft of hairs is present on the last thoracic segment.

The abdomen is short. The combined length of the abdomen and furca is equal to
rather less than one-half of the total length of the cephalotJiorax, from the frontal prominence
to the base of the genital segment. The genital segment is nearly as long as the combined
length of the next two segments. Viewed from above, the segment appears slightly asymmetrical,
and the process on each side of the genital opening can be seen projecting beyond the lateral
margins. In side view, the segment appears considerably swollen. The genital opening is flanked
by anteriorly directed tubercles. The tubercle on the right side is larger than the one on the
left. The second abdominal segment is nearly as long as the combined length of the third and
fourth segments. The anal segment is very small, and is only one-third of the length of the

73

SIBOÜA-EXPEDITIE XXIXö.

74

third segment. The furcal joints are longer than broad, and are nearly twice as long as the
anal segment. The appendicular seta on the furcal joints is much longer than any of the others.

The antennules reach to the middle of the genital segment.

The antennae, mandibles, maxillae and maxillipedes are somewhat similar to those of
Paraeuchaeta barbata.

The exopodite of the first pair of feet is indistinctly three-jointed. The outer-edge spine
at the incomplete separation of the first and second joints is moderately long, and extends to
near the end of the combined joint.

The outer-edge spine on the second joint of the exopodite of the second pair of feet
is considerably longer than any of the other outer-edge spines. It extends to the apex of the
first outer-edge spine on the third joint. The second outer-edge spine on the third joint extends
half way along the margin, towards the base of the third outer-edge spine.

The third and fourth pairs of feet resemble those of Paraeuchaeta barbata.

Male unknown.

Paraeuchaeta sibogae is easily distinguished from the other members of the genus, by
the asymmetrical and slightly angular posterior margins of the last thoracic segment, and by
the very swollen genital segment with its pair of strong tubercles as seen in side view.

Occurrence. — Five specimens were found in the plankton collected with the Hensen
vertical net at the following stations.

Stat. 128 (700 metres to surface), 1 specimen. — Stat. 148 (1000 metres to surface), 1 spe-
cimen. — Stat. 230 (2000 metres to surface), 2 specimens. — Stat. 243 (1000 metres to
surface), 1 specimen.

8. Paraeuchaeta weberi nov. sp. Plate XV, figs. 9 — 16.

Female — length 8,5 mm.

Viewed from above, the body appears elongate and moderately robust. The head is
contracted in the middle, and is distinctly separated from the first thoracic segment. The last
thoracic segment is symmetrical and slightly pointed. Viewed from the side, the last thoracic
segment is seen to be triangular in outline, and terminates in a small, but quite distinct point.
The rostrum is moderately large and is directed forward. The epistome is hirsute, but the last
thoracic segment has no tuft of hairs.

The abdomen is short. The combined length of the abdomen and furca is distinctly
less than one-half of the total length of the ccphalothorax, from the frontal process to the base
of the genital segment. The genital segment is rather shorter than the combined length of
the second and third segments. Viewed from above, the genital segment appears quite asym-
metrical. The segment is considerably swollen at the posterior end, but the left side is more
inflated than the right. The middle of the segment is traversed by a deep constriction which
is slightly obscured by an overlapping of the anterior half of the segment. The overlapping
part terminates in two small tubercles. When seen from the side the genital segment has a
most remarkable appearance, due to the constriction on the dorsal surface, and to the pair of
large oval processes that guard the genital opening. The second abdominal segment is rather

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75

longer than the third segment. The anal segment is very small. It is only about one-fourth
of the length of the third segment. The furcal joints are nearly as long as broad, and are
about equal to the length of the anal segment. The second inner seta on the furcal joints is
much longer than any of the others.

The antennules extend to about the middle of the genital segment.

The antennae, mandibles, maxillae and maxillipedes are similar to those of Paracuchaeta
bar ba ia.

1'he exopodite of the first pair of feet is indistinctly three-jointed. The outer edge spine
at the incomplete separation of the first and second joints is very short.

The outer-edge spine on the second joint of the exopodite of the second pair of feet,
extends to near the apex of the first outer-edge spine on the third joint. The second outer-
edge spine on the third joint extends to near the base of the third outer-edge spine. The
sinus at the base of the second outer-edge spine on the third ioint is very deep.

The third and fourth pairs of feet are similar to those of Paraeuchaela barbata.

Male unknown.

Paraeuchaeta weberi is easily recognised by the peculiar form of the genital segment
when seen in side view. It can readily be separated by this character alone, from any of the
other members of the genus.

This distinct form is named in compliment to Professor Max Weber, the director of
the 'Siboga' expedition, which has considerably extended our knowledge regarding the distri-
bution of the deep water Copepoda.

Occurrence. — Eleven specimens were found in the plankton collected with the
Hensen vertical net at the following' stations.

Stat. 185 (1536 metres to surface), 3 specimens. — Stat. 230 (2000 metres to surface), 4
specimens. — Stat. 243 (1000 metres to surface), 3 specimens. — Stat. 276 (756 metres to
surface), 1 specimen.

9. Paraeuchaeta spinifera (Esterly). Plate XXII, figs. 9 — 16.

Euchaeta spinifera Esterly, 1906, p. 62, pis. IX, XI, XIV.

A single male specimen which is doubtfully referred to the species described by Esterly
as Euchaeta spinifera was found in plankton collected with the Hensen vertical net at Station
2 7 6, 750 metres to the surface. Length 5,5 mm.

There is very little to distinguish this species from the male of Paraeuchaeta norvegica,
except the shape and armature of the second joint of the exopodite of the left fifth foot. The
inner distal angle of the joint in this species is produced into a pointed process, and both
sides of the distal margin are fringed with fine spines (Plate XXII, fig. 16).

10. Paraeuchaeta sarsi (Farran). Plate XXI, figs. 9 — 15.

Euchaeta barbata Sars, 1902, p. 41, pi. XXVIII.

Euchaeta barbata Wolfenden, 1904, p. 135, fig. r, Nos. 5 & 6.

Euchaeta sarsi Farran, 1908, p. 41, pi. III, figs. 15 & 16.

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76

One specimen which appears to be identical with the male figured by Sars in 'Crustacea
of Norway' was obtained from the plankton collected with the Hensen vertical net at Station 230,
2000 metres to the surface. Length 7,8 mm.

Farran considers that the form which Sars doubtfully refers to Euchaeta barbata Brady,
is distinct from that species, and is inclined to include it under the new name that he has
established for the reception of a form recorded by Wolfenden as Euchaeta barbata Brady.

I see nothing to distinguish the left fifth foot of the 'Siboga' specimen from Sars'
description and figure of the second joint of the left fifth foot of the male. Sars gives the size
of the male as 10 mm.

11. Paraeuchaeta dentata nov. sp, Plate XXI, figs. 16 — 23.

Male — length 8 mm.

This species resembles the male of Paraeuchaeta norvegica (Boeck) in general appearance,
but the last thoracic segment when viewed from above is seen to be asymmetrical. The left
side is more produced than the right.

The exopodite of the first pair of feet is distinctly three-jointed. The first joint is furnished
with a minute outer-edge spine.

The second outer-edge spine on the third joint of the exopodite of the second pair of
feet is moderately stout, and is distinctly longer than any of the others. The sinus at the base
of the spine is rather shallow. The apical portion of the outer margin of the joint is boldly curved.

The second joint of the left exopodite of the fifth pair of feet is moderately broad, and
the inner distal angle is produced into a blunt point. The inner margin of the apex is concave,
and the whole of the margin of the produced part is rather coarsely serrate. The inner surface
of the proximal part of the joint is furnished with a short stout tooth. (Plate XXI, hg. 23).

The second inner seta on the furcal joints is longer than the others.

Occurrence. — One specimen was found in the plankton collected with the Hensen
vertical net at Station 276, 750 metres to the surface.

12. Paraeuchaeta tuberculata nov. sp. Plate XXI, figs. 1 — 8.

Male — length 6,8 mm.

This species resembles Paraeuchaeta dentata in general appearance, but is easily separated
from it by the structure of the left exopodite of the fifth pair of feet. The first joint has two
tubercles on the middle of the outer margin, and a small spine midway between the distal
tubercle and the apex. The inner distal angle of the second joint is produced to a sharp
unguiform point, not unlike that found in the male of Paraeuchaeta norvegica. The distal half
of the inner margin of the joint is coarsely dentate.

The species has a close resemblance to the male of Paraeuchaeta norvegica in the
structure of the left exopodite of the fifth pair of feet, and may possibly turn out to be a tropical
variation of that species. The produced apex of the inner distal angle of the second joint is not
so sharply pointed or curved, however, as in typical Paraeuchaeta norvegica. In the meantime

76

77

I prefer to regard the 'Siboga' specimens as distinct. The appendicular seta and the second
inner seta on the furcal joints are of about equal length. They are longer than any of the others.
Occurrence. Five specimens were obtained from the plankton collected with the

Hexsen vertical net at the followincr stations.

o

Stat. 230 (2000 metres to surface), 2 specimens. — Stat. 243 (1000 metres to surface), 2
specimens. — Stat. 276 (750 metres to surface), t specimen.

Genus Valdiviella Steuer, 1904.

This genus was established by Steuer in 1 904 for a Calanoid closely related to Euchaeta,
but easily recognised by its bifurcate rostrum. The incomplete jointing of the exopodites of the
first and second pairs of feet, and the indistinctly three-jointed endopodites of the third and
fourth pairs of feet are also characters of this genus.

Two species belonging to this genus were found in the plankton collected by the 'Siboo-a'
in the Malay Archipelago.

1. Valdiviella gigas (Brady). Plate XXII, figs. 17 — 26.
Euchaeta gigas Brady, 1883, p. 65, pi. XXII, figs. 1 — 5.

One specimen of a form apparently identical with the species described by Brady in
the report on the 'Challenger' Copepoda as Euchaeta gigas, was found in the plankton collected
with the Hensen vertical net at Station 230, 2000 metres to the surface.

The rostrum is distinctly bifurcate. The fourth and fifth thoracic segments are completely
separated. The last thoracic segment is produced posteriorly into small points. The specimen
was immature and possessed a fifth pair of feet similar to that shewn by Brady.

The antennules are twenty-three-jointed, and a number of the joints are furnished with
sensory organs.

The antennae, mandibles, maxillae and maxillipedes are of the normal female Paraeuckacia
type. The mandible is well developed and is provided with cutting teeth.

The exopodite of the first pair of feet is composed of two joints. The middle of the
outer margin of the first joint is furnished with a strong spine.

The exopodite of the second pair of feet is very indistinctly three-jointed. The division
between the first and second joint is only marked by an overlapping at the base of the outer-
edge spine, and by a seta on the inner margin. The endopodite is one-jointed.

The exopodites of the third and fourth pairs of feet are indistinctly three-jointed. The
endopodites are tvvo-jointed.

The fifth pair of feet is almost symmetrical but is very rudimentary. Each foot consists
of a two-jointed basiopodite, a moderately long unjointed exopodite, and a small endopodite.

The abdomen is composed of four segments. The genital segment is shorter than any
of the others.

Length 8 mm. The size of the form described in the report on the 'Challenger' Copepoda

is given as 5,25 mm.

77

The bifurcate rostrum and the incomplete segmentation of the swimming feet, indicate
that the 'Siboga' specimen belongs to the genus Valdiviella. The specimen was evidently a
female, and no doubt the rudimentary fifth pair of feet would disappear at the final ecdysis.

2. Valdiviella ? brevicornis Sars. Plate XXII, fig. 27 — 35.
Valdiviella brevicornis Sars, 1905 (a), p. 17.

A single male specimen belonging to the genus Valdiviella, and doubtfully included
under Sars' species Valdiviella brevicornis, was obtained from the plankton collected with the
Hensen vertical net at Station 230, 2000 metres to the surface.

The rostrum is small and distinctly bifurcate. The fourth and fifth thoracic segments are
completely fused. The posterior margins of the last thoracic segment are narrowly rounded.

The antennules are twenty-three-jointed and are well furnished with sensory organs.

The antennae, mandibles, maxillae and maxillipedes are of the normal male Paraeucliaela
type. The mandibles have no toothed biting edge. The maxillae and maxillipedes are much reduced.

The exopodite of the first pair of feet is distinctly three-jointed. Each joint is furnished
with an outer-edge spine.

The exopodites and endopodites of the second, third and fourth pairs of swimming feet
are similar to those of Valdiviella ?io-as.

The fifth pair of feet is well developed and prehensile. The basiopodite is two-jointed.
The second joint of the right basiopodite is much inflated at its proximal end. The distal
portion of the joint is long and narrow. The joints of the basiopodite of the left foot are
moderately long and cylindrical. The exopodite of the right foot is apparently only one-jointed.
The joint is moderately long and has a lamelliform apex. The exopodite of the left foot is
composed of three, short, subequal joints. The last joint is spiniform. The endopodites are
one-jointed. The right endopodite is long and slender with a distinctly inflated apex. The right
endopodite is very short and is somewhat club-shaped.

The abdomen is composed of five segments. The first, second, third and fourth segments
are all of about equal length. The fifth segment is very small.

Length — 5 mm.

The specimen is clearly a Valdiviella by its bifurcate rostrum and by the incomplete
segmentation of the second, third and fourth pairs of feet. It is not unusual to find the exopodite
of the first pair of feet of the males of some of the Calanoids to be slightly different in the
jointing from the females. From its size, the specimen may be the male of Sars' Valdiviella
brevicornis, but as no figures of Sars' species have yet been published its relationship must
be regarded as doubtful. The specimen is proportionally much smaller than either Valdiviella
oligarthra Steuer, or Valdiviella insignis Farran.

Genus Chiridiella Sars, 1907 (a).

This genus was established by G. O. Sars in 1907 for an aberrant Calanoid form,
which Farran suggests may lead a semi-parasitic mode of existence. Only the female is knownT

78

79

and the true position of the genus in the classification wil! probably remain uncertain until the
male is discovered.

The rostrum is entirely absent. The first pair of maxillipedes is peculiarly modified, and
is furnished with powerful claw-like spines. The exopodite and endopodite of the first pair of
feet is composed of a single joint. The exopodites of the second, third and fourth pairs of feet
are three-jointed. The endopodite of the second pair of feet is one-jointed. The endopodites
of the third and fourth pairs of feet are three-jointed. The fifth pair of feet is absent.

One species belonging to this remarkable genus, was represented in the plankton col-
lected by the 'Siboga', during the investigations in the Malay Archipelago.

i. Chiridiclla macrodactyla Sars Plate XXXVI, figs. 9 — 21.

Chiridietta macrodactyla Sars, 1907 (<rz), p. 8.

Chiridiclla macrodactyla Farran, 1908, p. 46, pi. IV, figs. 6 — 14.

A single specimen agreeing very well with Sars' preliminary description of the above
species and with the figures given by Farran, was obtained from the plankton collected with
the Hensen vertical net at Station 148, 1000 metres to the surface.

The specimen measured 2,73 millimetres in length. I see 110 other difference between
the ■Siboga' form and Sars' description, than that the combined length of the abdomen and
furca is very slightly less than one-third of the total length of the cep halothorax, from the
frontal margin to the base of the genital segment.

The specimens from the deep water off the West Coast of Ireland appear to be almost
identical with the 'Siboga' form. The figure of the first maxilliped is the same as that given
in this report. Farran points out some minor differences between his specimens, and the des-
cription given by Sars. Similar differences are also apparent between the figures given in the
present report and those shewn by Farran.

7. Family Phaennidae.
Genus Phaenna Claus, 1863.

The only known member of this genus is distinguished from the other genera that are
included in the family Phaennidae, by the entire absence of a fifth pair of feet in the female,
by the form of the organs on the apex of the first pair of maxillipedes in both sexes, and
by the structure of the fifth pair of feet of the male.

The apex of the first maxilliped is furnished with a strong claw-like spine, and a number
of short cylindrical appendages which terminate in a brush of fine cilia. The fifth pair of feet
is represented in the male by the exopodites only.

One species is known. A few specimens of it were found in the plankton collected by

the 'Siboga'.

79

So

i. Phaenna spinifera Claus.

Phaenna spinifera Claus, 1863, p. 189, pi. XXXI, figs. 1—7.

Phaenna spinifera Giesbrecht, 1893, p. 293, pis. 5, 12, 37.

Phaenna spinifera T. Scott, 1893, p. 81, pis. VI & VII.

Phaenna spinifera Giesbrecht & Schmeil, 1898, p. 50.

Phaenna spinifera I. C. Thompson, 1903, p. 23.

Phaenna spinifera Thompson & Scott, 1903, p. 246.

Phaenna spinifera Cleve, 1903, p. 367.

Phaenna spinifera Wollenden, 1904, p. m.

Phaenna spinifera Cleve, 1904, p. 194.

Phaenna spinifera Sars, 1905 {a), p. 5.

Phaenna spinifera Wolfenden, 1905^), p. 1009.

Phaenna spinifera Farran, 1905, p. 43.

Phaenna spinifera Pearson, 1906, p. 21.

Phaenna spinifera Farran, 1908, p. 47.

Phaenna spinifera van Breemen, 1908, p. 56, fig. 63.

The species appeared to be very scarce in the area investigated by the 'Siboga'. One
specimen was obtained from the plankton collected at each of the following stations.

Stat. 118 (HENSEN vertical net 900 metres to surface). — Stat. 125. — Stat. 143 (HENSEN
vertical net 1000 metres to surface). — Stat. 144. — Stat. 172. — Stat. 185 (HENSEN
vertical net 1536 metres to surface). -- Stat. 252. - - Stat. 276 (HENSEN vertical net 750
metres to surface).

Phaenna spinifera has evidently a moderately wide distribution. It has been recorded
from the deep water off the West of Ireland by Farran, and from off the South African Coast
by Cleve. lts presence in various tropical regions has also been made known by other observers.

Genus XanthocalaniiS Giesbrecht, 1893.

The females of this genus are separated from Phaenna by the presence of a fifth pair
of feet. The body is usually more elongated and the last thoracic segment may be pointed.

The rostrum is bifurcate and the rami are moderately long. The apical lobe of the
first maxillipedes is furnished with a strong claw-like spine, which is coarsely dentate on the
inner margin. Cylindrical sensory appendages are also present. The female fifth pair of feet is
small and three-jointed. In immature females the fifth pair may be only two-jointed. In the
male, the fifth pair of feet is represented by a long slender left exopodite and a very short
right exopodite.

One species was obtained from the plankton collected by the 'Siboga'.

1. Xanthocalanus agilis Giesbrecht. Plate XXXIII, figs. 10 — 18.

Xanthocalanus agilis Giesbrecht, 1893, p. 286, pis. 12 & 3/.
Xanthocalanus agilis Giesbrecht & Schmeil, 1898, p. 50.

One female belonging to this species was found in the plankton collected at each of
the following three stations.

80

Si

Stat. 1 1 8 (HENSEN vertical net 900 metres to surface). Stat. 141 (HENSEN vertical net

1500 metres to surface). -- Stat. 203 (HENSEN vertical net 1500 metres to surface).

The species is very distinct. It is easily identifïed by lts elongate body and greatly
produced last thoracic segment.

The posterior margins of the last thoracic segment reach to near the distal end of the
genital segment. The combined length of the abdomen and furca is equal to one-fourth of the
total length of the cephalothorax, from the frontal margin to the posterior end of the last thoracic
segment. The rami of the rostrum are two-jointed and the apical section is very slender. The
antennules are twenty-four-jointed, and extend to the end of the second abdominal segment.
The fifth pair of feet is composed of two free joints attached to a basal part. The second joint
is furnished with one apical and two subapical spines (Plate XXXIII, fig. 18).

Length of female 2,68 mm.

Xanthocalanus agilis is apparently very rare. It has only been recorded from the Gulf
of Naples by Giesbrecht.

Genus Brachycalanus Farran, 1905.

The members of this genus are separated from the other genera belonging to the family,
chieny by the very strong, slightly bifurcate, and highly chitinised rostrum. The mouth organs
and swimming feet closely resemble those of Xanthocalanus.

The genus was represented in the 'Siboga' plankton by a single immature specimen.

1. Brachycalanus gigas nov. sp. Plate XXXV, figs. 10 — 18.

Length — 7,2 mm.

Yiewed from above, the body appears moderately robust, and elongate ovate in outline.
The head is distinctly separated from the first thoracic segment, and is furnished with a low
median crest. The fourth and fifth thoracic segments are separated. The last thoracic segment
is produced to the end of the first abdominal segment, and terminates in distinct points that
project outwards from the segment. Seen from the side, the forehead is arched, and the median
crest is rounded at the apex. The last thoracic segment is irregularly triangular in outline, with
a small point at the apex. The rostrum is robust, of moderate length, and is slightly bilurcate
at the upturned apex. No filaments are present.

The abdomen is composed of five segments. The combined length of the abdomen and
furca is contained about three and a halPtimes in the total length of the cephalothorax, from
the frontal margin to the base of the genital segment. The abdominal segments are wide, and
are comparatively short. The anal segment is very small. The furcal joints are rather longer
than broad, and are about twice as long as the anal segment.

The antennules are composed of twenty-four joints, and extend to the end of the third
abdominal segment. The eighteenth joint is faintly divided.

The antennae, mandibles and maxillae are similar to those of Xanthocalanus.

The first pair of maxillipedes also resembles that of Xanthocalanus, but the claw-like

81

SIBOHA-EXPEDITIF. XXIX a. '!

82

spines on the apical lobes are more slender and flexible. The internal and external margins of
the claw-like spines are fringed with fine hairs. The apex is furnished with three long plain
filaments and five short organs with inflated heads. (Plate XXXV, fig. 15).

The second pair of maxillipedes is similar to that of XantJwcalanus.

The exopodite of the first pair of feet is three-jointed, and the endopodite is one-jointed.

The exopodite of the second pair of feet is three-jointed, and the endopodite is two-jointed.
The second joint of the endopodite is furnished with three transverse rows of strong spines.

The exopodites and endopodites of the third and fourth pairs of feet are each three-
jointed. The second and third joints of the endopodite of the third pair of feet are each furnished
with two transverse rows of strong spines. The second and third joints of the endopodite of
the fourth pair of feet are furnished with fine spines as shewn (Plate XXXV, fig. 1 7).

The fifth pair of feet is symmetrical, but obviously rudimentary. The basiopodite is two-
jointed. The exopodite is distinctly two-jointed. The first joint is furnished with one outer-edge
spine. The second joint is broadly triangular in outline. It bears one apical and three subapical
spines. (Plate XXXV, fig. 18).

Occurrence. — One specimen was obtained from the plankton collected with the
Hensen vertical net at Station 185, 1536 metres to the surface.

The specimen is apparently an immature male, and the fifth pair of feet is very similar
to the figure given by Farran (1905 pi. XI, fig. 10). Farran regards his species to be closely
related to Oöthrix bidcntata (= Neoscolecithrix koelileri Canu). The present species, however,
does not appear to belong to that genus, as the short sausage-shaped organs, on the apex of
the first maxilliped, which are so characteristic of that genus are absent. Farran's specimens
measured 3,35 mm.

Genus Onchocalanus G. O. Sars, 1905 (a).

This genus is closely related to Xanthocalanus, but the females are easily recognised
by the strongly bifurcate rostrum, and by the apical lobe of the first- pair of maxillipedes being
furnished with a very stout curved claw. The posterior surface of the joints of the swimming
feet is armed with numerous fine spines. The fifth pair of feet is small.

Two of the knovvn species were represented in the plankton collected by the 'Siboga'.

1. Onchocalanus cristatus (Wolfenden). Plate XXXIV, figs. 1 — 8.

Xantliocalanus cristatus Wolfenden, 1904, p. 119, pi. IX, figs. 18 & 19.

Onchocalanus trigoniceps Sars, 1905 (a), p. 20.

Xantliocalanus cristatus Pearson, 1906, p. 20.

Onchocalanus cristatus Sars, 1907 (a), p. 3.

Onchocalanus cristatus Farran, 1908, p. 49.

Xantliocalanus cristatus van Breemen, 1908, p. 62, fig. 70.

One female belonging to this species was found in the plankton collected with the
1 1 ensen vertical net at each of the following two stations.

Stat. 148 (1000 metres to surface). — Stat. 185 (1536 metres to surface).

S2

*3

Onckocalanus cristatus is easily recognised by the presence of a median cephalic crest,
and by the distinct point at the distal ends of the last thoracic segment. The fifth pair of feet
ot the female consists of two free joints attached to a basal part. The second free joint terminates
in a strong spine. The outer margin of the joint is furnished with two spines and the inner
margin with one. Length 6,6 mm.

Onckocalanus cristatus bas been hitherto only obtained from the deep water of the North
Atlantic, where it appears to be not uncommon.

2. Onckocalanus hirtipes Sars. Plate XXXIV, figs. 9 — 17.

Onckocalanus hirtipes Sars, 1905 (a), p. 20.
Onckocalanus hirtipes Farran, 1908, p. 49.

One female apparently identical with this species, was obtained from the plankton
collected with the Hensen vertical net at Station 185, 1536 metres to the surface.

Onckocalanus hirtipes has a general resemblance to Onchocala7ius cristatus, but it can
be distinguished from it by the absence of a median crest. The last thoracic segment is obtusely
triangular in outline when seen from the side, but it is not produced into a spine at the posterior
margin. The rami of the rostrum apparently terminate in a filament, but only the base was
visible in the preparation. The fifth pair of feet is somewhat similar to that of the previous
species. There is only one outer-edge spine on the second free joint and none on the inside.

Length — 5 mm.

This species has only been recorded from the North Atlantic.

Genus Cornucalanus Wolfenden, 1905.

This genus was established by Wolfenden in 1 905 for a Calanoid closely related to
Xantlwcalanus. It is distinguished by the possession of a cephalic spine, and the apex of the
first maxillipedes is furnished with a ver}- powerful curved claw.

The cephalic spine may only be a specific difference between Wolfenden's type species
Cornucalanus niagnus (= Scolccithrix chelifcr I. C. Thompson, 1903) and another form very
briefly described along with the type. The appendages of the second species are identical with
those of the type, but the cephalic spine is absent.

A form apparently identical with Wolfenden's second species was found in the plankton
collected by the 'Siboga'.

1. Cormualanus simplex Wolfenden. Plate XXXY, figs. 1 — 9.

Cornucalanus simplex Wolfenden, 1905, p. 22.
Cornucalanus simplex Sars, 1907 (a), p. 14.

Female — length 5 mm.

Yiewed from above, the body appears moderately robust, and elongate ovate in outline.
The head is separated from the first thoracic segment. The fourth and fifth thoracic segments
are completely separated. The last thoracic segment is produced posteriorly into points. Seen
from the side, the forehead is only slightly arched, and no tracé ot a cephalic spine can be

83

84

observed. The last thoracic segment is obtusely triangular in outline, with the apex very narrowly
rounded. The rostrum is robust and strongly bifurcate. The rami are truncate at the apex and
bear a moderately long curved filament.

The abdomen is composed of four segments. The combined length of the abdomen and
furca is contained about two and a half times in the total length of the cephalolhorax, from
the frontal margin to the base of the genital segment. The genital segment is rather shorter
than the combined length of the second and third segments. The anal segment is very small
and is equal to about one-third of the length of the third segment. The furcal joints are as
long as broad, and are equal to the length of the anal segment.

The antennules are composed of twenty-four joints, and extend to the end of the second
abdominal segment. The basal joint of the antennules appears to be divided.

The antennae, mandibles, maxillae and maxillipedes are similar in structure to those
of Cornucalanus chelifer. The curved spine on the apex of the first maxilliped, is furnished
with a frincre of short hairs on the middle of the internal and external marQÏns. The internal
base of the spine carries a short stout process, which is produced at the apex into a long
whip-like seta. The apex of the first maxilliped bears six short sensory organs with tufted heads,
and two long simple filaments.

The four pairs of swimming feet are similar to those of Onchocalauus.

The fifth pair of feet is very small. Each foot consists of two free joints attached to a
basal part. The first joint is furnished with a small tuft of spinules at its posterior end. The
second joint is furnished with three or four transverse rows of spinules. The joint terminates
in two small apical spines.

No figures of Cormica lamis simplex have previously been given, but so far as Wolfendex's
very brief description goes, the 'Siboga' form appears to agree with that species. The 'Siboga'
specimen is an adult female, and by the absence of the cephalic spine is evidently distinct from
Cornucalanus chelifer. The remarkably strong and curved claw with the peculiar process at
the base, on the apex of the first pair of maxillipedes, is sufficiënt to separate this genus from
any of the other members of the family Phaennidae.

Occurrence. — One female was obtained from the plankton collected with the Hensen
vertical net at Station 143, 1000 metres to the surface.

Genus Amallophora T. Scott, 1893.

This genus was established by my father in 1S93, for a Calanoid, which was readily
distinguished from any other known form by the presence of a peculiar appendage, resembling
a sheaf of corn, on the apex of the first pair of maxillipedes. Other forms were included in
the genus, but these are now clearly not congeneric. Aniallophora was afterwards included under
the genus Xanthocalanus by Giesbrecht and Schmeil.

Saks has recently revived the genus for the reception of one of the species originally
included in it by my father. Farran rightly points out, however, that this use cannot be upheld,
as Amallophora inagna is not congeneric with Aniallophora typica.

S4

«5

The genus Amallophora is restored in the present report for the typical species, which
was represented in the plankton collected by the 'Siboga'.

Amallophora can be distinguished from Xanthocalanus^ or any of the other genera of
the family Phaennidae, by the structure of the first pair of maxillipedes. The apical lobes are
furnished with large rlexible, densely plumose setae, and the sensory apparatus is represented
by one very short and stout appendage, with a densely ciliated head. No other type of sensory
organ is present in the male at anyrate. The rostrum is bifurcate. The rami are drawn out into
slender filaments, but have no tracé of an articulation, as in Xanthocalanus. The vaiïous appen-
dages are somewhat similar to those of Xanthocalanus agilis. The fifth pair of feet of the
female is represented by two free joints attached to a basal portion. The left exopodite of the
male fifth pair is long and slender. The right exopodite is short and rudimentary.

I. Amallophora typica T. Scott. Plate XXXVI, figs. i — 8.

Amallophora typica T. Scott, 1893, p. 54, pis. III & IV.
Xanthocalanus typicus Giesbrecht & Schmeil, 1898, p. 50.
Xanthocalanus typicus Farran, 1908, p. 47, pi. IV, figs. 15 — 17.

One male was obtained from the plankton collected with the Hensen vertical net at
Station 148, 1000 metres to the surface.

Amallophora typica has a close resemblance to Xanthocalanus agilis, but it is easily
separated by the possession of a single stout sensory organ on the apex of the first pair of
maxillipedes, and by the absence of the strong claw-like spines with their coarsely dentate
inner margin. The rami of the rostrum are very stout at the base, and are produced into long
slender filaments.

The exopodites of the four pairs of swimming feet are all distinctly three-jointed. The
endopodite of the first pair of feet is one-jointed, of the second, two-jointed, of the third and
fourth, three-jointed.

The exopodite of the left fifth foot consists of five free joints attached to a basal part.
The inner distal angle of the fourth joint is furnished with a two-jointed appendage, the second
ioint of which is traversed by a transverse row of long hairs. The fifth joint bears a small
apical spine. The right foot is composed of four joints ancl a basal part. The second joint is
furnished with a small outer-edge spine. The fourth joint is truncate at the apex and bears
two small apical spines. Length of male 2,66 mm.

Farran has recently discovered what appears to be the female of this species, in plankton
collected from the deep water off the West of Ireland. It also possesses the single large sensory
appendage on the apex of the first maxillipedes. The fifth pair of feet is somewhat similar in
structure to that of Xanthocalanus, but the second free joint has a truncate apex and bears
two apical spines. The terminal joint of the female fifth foot is not unlike the last joint of the
right foot of the male.

Amallophora typica has, so far, only been recorded from the Gulf of Guinea, and from

the Xorth Atlantic off the Coast of Ireland.

8;

86

Genus Heteramalla G. O. Sars, 1907(0).

The characteristic differences between Heteramalla and the other members of the family
are: (1) A strong chitinised and slightly bifurcate lamelliform rostrum; (2) An extraordinary deve-
lopment of two of the sensory appendages on the apex of the first pair of maxillipedes; and
(3) A two-jointed exopodite of the first pair of swimming feet. The exopodites and endopodites
of the second, third and fourth pairs of feet resemble those of Xanthocalanus. The fifth pair is
very small and rudimentary in the female. The fifth pair of feet of the male is almost similar
to that of the male of Scapkoealanus magnus.

This genus was established by Sars in 1907 for a female Calanoid, apparently identical
with a male form from the Gulf of Guinea, described by my father as Amallophora dubia.

One species is known. It was represented in the 'Siboga' plankton.

1. Heteramalla dubia (T. Scott). Plate XXXIII, figs. 1 — 9.

Amallophora dubia T. Scott, 1893, p. 55, pi. IV, figs. 10 — 18.
Scolecithrix scotti Giesbrecht, 1897, p. 254.
Scolecithrix scotti Giesbrecht & Schmeil, 1898, p. 46.
Heteramalla dubia Sars, 1907 (a), p. 17.

Female — length 3,78 mm.

Yiewed from above, the body appears moderately robust and oval in outline. The head
is distinctly separated from the first thoracic segment. The fourth and fifth thoracic segments
are indistinctly divided. The last thoracic segment is slightly produced and appears pointed.
Seen from the side, the forehead is feebly arched, and is produced into a very stout, short,
chitinised rostrum, bifurcate at the apex and without filaments. The last thoracic segment is
narrowly rounded at the apex and, then slightly emarginate as it passes into the dorsal line.

The abdomen is composed of four segments. The combined length of the abdomen and
furca is contained two and three-fourth times in the total length of the ccphalothorax, from
the frontal margin to the base of the genital segment. The genital segment is equal to the
combined length of the next two segments. The second, third and fourth segments are each
shorter than the segment immediately in front. The furcal joints are about as long as broad,
and are as long as the anal segment.

The antennules are twenty-four-jointed and extend to the end of the genital segment.

The exopodite and the endopodite of the antennae are comparatively short. The endopodite
is only slightly shorter than the exopodite.

The mandibles and maxillae are almost similar to those of Xanthoealanus.

The apical lobes of the first pair of maxillipedes are furnished with flattened plumose
setae. The apex of the first pair of maxillipedes carries three types of sensory organs. The
first type is represented by three long and simple appendages which terminate in a blunt point.
The second type also consists of three appendages, subequal in length, but each one terminates
in a small amalliform head. One of the second series is distinctly stouter than the others and
the head is more expanded. The third type is represented by two very short and stout appendages,
each with an enormously developed amalla, resembling the single one in Amallophora typica.

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§7

The exopodite of the first pair of feet is composed of two joints. The second and third
joints are completely fused together. The junction of the two joints is defined by an outer-edge
spine. The endopodite is one-jointcd.

The exopodite of the second pair of feet is three-jointed. The endopodite is two-jointed.
The second joint of the endopodite is furnished with three transverse rows of spines.

The exopodites and endopodites of the third and fourth pairs of feet are three-jointed.
The second and third joints of the endopodite of the third pair of feet are each furnished
with two transverse rows of spines. The second joint of the endopodite of the fourth pair of
feet is turnished with one transverse rovv, and the third joint with two transverse rows of spines.
The surtace of the joints is closely set with minute points.

The fifth j^air 0f feet Js very small and rudimentary. Each foot consists of two free
joints attached to a basal part. The second joint is moderalely stout and spiniform (Plate
XXXIII, fig. 9).

Occurrence. — One specimen was obtained from the plankton collected with the
Hensen vertical net at Station 143, 1000 metres to the surface.

This species appears to be identical with the form described by Sars (1907^). The only
difference that can be made out between the preliminary description, and that now given, is
in the jointing of the endopodite of the third pair of feet. Sars states that it is two-jointed,
whereas in the 'Siboga' specimen it is distinctly three-jointecl. It also appears to be identical
with Amallophora dubia, described by my father from males only, that were found in plankton
collected in the Gulf of Guinea. The two large amalla on the apex of the first pair of maxilli-
pedes, are clearly shewn amongst the other illustrations (Plate IV, fig. 13) in the report, '< )n
Entomostraca' from the Gulf of Guinea.

I have included Amallophora and Heter amalla in the family Phaennidae, as the sensory
appendages on the apex of the first maxillipedes are quite distinct from those found in the
family Scolecithricidae. The ciliated heads indicate a closer relationship to Phaenna than to
Scolecithrix.

8. Family Scolecithricidae.
Genus Scolecithrix Brady, 1883.

Brady established this genus for the reception of a Calanoid form described by Lubbock
as Undina danae, which is distinguished by the presence of a tuft of worm-like sensory filaments
on the apex of the first pair of maxillipedes. The fifth pair of feet is entirely absent in the female.

A second form, Scolecithrix minor, with a fifth pair of feet in the female, was also
included under the genus by Brady. Giesbrecht and Schmeil subsequently included a number
of species under the genus, the females of which are furnished with fifth feet. Sars rightly
points out, however, in 'Crustacea of Norway', that the inclusion of Scolecitlirix-Wke forms with
a fifth pair of feet is erroneous, and established a new genus for the reception of some of them.

S7

88

Only on e species, properly belonging to this genus, has yet been detected. It was well
represented in the Malay Archipelago.

i. Scolecithrix danae (Lubbock).

Undina danae Lubbock, 1856, p. 15, pi. IX.
Scolecithrix danae Brady, 1883, p. 57, pi. XVII.
Scolecithrix danae Giesbrecht, 1893, p. 265, pis. 13 & 37.
Scolecithrix danae T. Scott, 1893, p. 49.
Scolecithrix danae Giesbrecht & Schmeil, 1898, p. 42.
Scolecithrix dana I. C. Thompson, 1900, p. 279.
Scolecithrix danae Cleve, 1901, p. 9.
Scolecithrix danae A. Scott, 1902, p. 403.
Scolecithrix danae I. C. Thompson, 1903, p. 20.
Scolecithrix danae Thompson & Scott, 1903, p. 245.
Scolecithrix danae Cleve, 1903, p. 368.
Scolecithrix danae Cleve, 1904, p. 197.
Scolecithrix danae Sars, 1905 (a), p. 5.
Scolecithrix danae Wolfenden, 1905 (a). p. 1009.
Scolecithrix danae Esterly, 1905, p. 164, fig. 26.
Scolecithrix danae van Breemen, 1908, p. 70, fig. 80.

Scolecithrix danae was well distributed throughout the area traversed by the 'Siboga'
as the following records shew. It was moderately common in some of the collections.

Stat. 19. — Stat. 36. - ■ Stat. 37. — Stat. 40. — Stat. 47''. — Stat. 50. — Stat. 66. —
Stat. 75. — Stat. 81. ■ - Stat. 93. -- Stat. 96 (day). -- Stat. 96 (night). -- Stat. 98. -
Stat. 109. - - Stat. 117, 60 specimens. — Stat. 118. - - Stat. 124. -- Stat. 125 (day). -
Stat. 128. — Stat. 133. — Stat. 136, 85 specimens. — Stat. 138. — Stat. 141. — Stat.
142. — Stat. 143. - - Stat. 144. — Stat. 148. — Stat. 149. — Stat. 157. — Stat. 165,
70 specimens. - - Stat. 168. — Stat. 1Ó9. — Stat. 172, 70 specimens. — Stat. 174. -
Stat. I77a. — Stat. 184, 45 specimens. — Stat. 185. — Stat. 186. Stat. 189'. —

Stat. 193. — Stats. 194 — 7. — Stat. 203 (surface), 1 specimen. — Stat. 203 (1500 metres
to surface), 12 specimens. -- Stat. 204. — Stat. 213. — Stat. 214. -- Stat. 215", 65 speci-
mens. — Stat. 216. -- Stat. 217 (horizontal cylinder), 55 specimens. -- Stat. 220 (surface),
70 specimens. — Stat. 220 (200 metres to surface), 70 specimens. - - Stat. 223. — Stat.
224. — Stat. 225. - - Stat. 229. — Stat. 243. — Stat. 245. — Stat. 252. — Stat. 271. -
Stat. 276. — Stat. 282. — Stat. 304. — Stat. 315.

This species is easily distinguished by its very robust body and short abdomen. The
female has no fifth feet. The male fifth pair is well developed and prehensile.
Scolecithrix danae appears to be generally distributed in tropical seas.

Genus Scolecithricella G. O. Sars, 1902.

The females of this genus are recognised by the presence of a fifth pair of feet. The
fifth feet of the known males is well developed and forms a prehensile organ. The majority
of the sensory organs on the apex of the first pair of maxillipedes have evenly rounded ends,
but there appears to be a few of the filaments with the apex more or less inflated.

Fourteen species were represented in the plankton collected by the 'Siboga', two of
which appear to be undescribed. It is possible that some of the forms included in the genus

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89

Scolecithricella in this report, will be removed to other genera when complete information
regarding the two sexes becomes available.

i. Scolecithricella abyssalis (Giesbrecht).

Scolecithrix abyssalis Giesbrecht, 1888, p. 338.
Scolecithrix abyssalis Giesbrecht, 1893, p. 266, pi. 13.
Scolecithrix tutnida T. Scott, 1893, p. 52, pi. III, figs. 33 — 38.
Scolecithrix abyssalis Giesbrecht & Schmeil, 1898, p. 43.

Twenty females belonging to this species were obtained from the plankton collected at
the following stations.

Stat. 141 (1500 metres to surface), 3 specimens. - Stat. 142, 1 specimens. — Stat. 143
(1000 metres to surface), 2 specimens. — Stat. 185 (1536 metres to surface), 3 specimens. —
Stat. 203 (1500 metres to surface), 4 specimens. Stat. 230 (2000 metres to surface), 4

specimens. — Stat. 243 (1000 metres to surface), 2 specimens. -- Stat. 276 (750 metres to
surface), 1 specimen.

Scolecithricella abyssalis appears to be closely related to Scolecithricella vittata, but can
be separated from it by the proportional length of the spines on the female fifth feet. The spine
on the inner margin of the free joint is longer than the apical one. In Scolecithricella vittata
the apical spine is much longer than the one on the inner margin.

The form from the Gulf of Guinea plankton described by my father as Scolecithrix
tiimida appears to be identical with Giesbrecht's species.

This species has only previously been recorded from the Pacific Ocean, the Gulf of
Guinea, and the Faröe Channel. The male is unknown.

2. Scolecithricella auropecten (Giesbrecht).

Scolecithrix auropecten Giesbrecht, 1893, p. 266, pis. 13 & 37.
Scolecithrix auropecten Giesbrecht & Schmeil, 1898, p. 45.
Scolecithrix auropecten I. C. Thompson, 1903, p. 20.
Scolecithrix auropecten Thompson & Scott, 1903, p. 245.
Scolecithricella auropecten Sars, 1907 (a), p. 16.
Scolecithrix auropecten van Breemen, 1908, p. 74, flg. 86.

Two females were found in the plankton collected with the Hensen vertical net at the

following two stations.

Stat. 118 (900 metres to surface). — Stat. 14S (1000 metres to surface).

The free joint of the female fifth feet is very small and narrow, and it is furnished
with two apical spines. The inner spine is considerably longer than the outer one.

The distribution of the species appears to be limited and the male is unknown.

3. Scolecithricella bradyi (Giesbrecht).

Scolecithrix bradyi Giesbrecht, 1888, p. 337.
Scolecithrix bradyi Giesbrecht, 1S93, p. 266, pis. 4, 13, t,/.
Scolecithrix bradyi T. Scott, 1893, p. 51, pi. V, figs. 29 — 39.
Scolecithrix bradyi Giesbrecht & Schmeil, 189S, p. 42.

89

SIBOGA-EXrEDITIE XXIX 17.

(co* -*

9o

Scolecithrix bradyi Cleve, 1901, p. 9.
Scolecithrix bradyi I. C. Thompson, 1903, p. 20.
Scolecithrix bradyi Thompson & Scott, 1903, p. 245.
Scolecithrix bradyi Sars, 1905 (a), p. 5.
Scolecitlirix bradyi Esterly, 1905, p. 165, fig. 27.
Scolecitlirix bradyi van Breemen, 1908, p. 71, fig. 81.

Six females and one male were obtained from the plankton collected at the following
stations.

Stat. 141 (1500 metres to surface), 1 specimen. — Stat. 142, 1 specimen. — Stat. 143 (1000
metres to surface, 1 specimen. — Stat. 203 (surface), 1 specimen. — Stat. 243 (1000 metres
to surface), 1 specimen. - - Stat. 276 (750 metres to surface), 1 specimen.

The female is easily recognised by the asymmetrical last thoracic segment when viewed
from above. The posterior margins of the segment are considerably produced, and the right
side extends slightly beyond the end of the genital segment. The genital segment is large
and asymmetrical. It is longer than the combined length of the other abdominal segments.
The fifth pair of feet is very small and easily overlooked. Each foot consists of a lamelliform
appendage with a pointed apex. The male fifth pair is moderately large and prehensile. The
last joint of the right foot is forked.

Scolecitliricella bradyi appears to have a fairly wide distribution.

4. Scolecitkricella longicornis (T. Scott.).

Scolecithrix lo7igicornis T. Scott, 1893, p. 50, pi. V, figs. 20 — 28.
Scolecithrix longicornis Giesbrecht & Schmeil, 1898, p. 45.

Four females belonging to this species were found in the plankton collected at the fol-
lowing stations.

Stat. 142, 1 specimen. — Stat. 143 (1000 metres to surface), 2 specimens. ■ — Stat. 148 (1000
metres to surface), 1 specimen.

Scolecitliricella longicornis is easily recognised by its long antennules, and by the peculiar
form of the fifth pair of feet. The fifth pair of feet is composed of two free joints attached to
a basal part. The apex of the second joint is produced into a point. The inner distal angle
of the joint is furnished with an elongate and moderately strong spine. The male is unknown.

This species has hitherto only been recorded from the Gulf of Guinea.

5. Scolecitliricella longifurca (Giesbrecht).

Scolecithrix longifurca Giesbrecht, 1888, p. 338.
Scolecithrix longifurca Giesbrecht, 1893, p. 266, pis. 13, 37.
Scolecithrix longifurca Giesbrecht & Schmeil, 1898, p. 45.

One female of this species was found in the plankton collected with the Henskn vertical
net at Station 128, 700 metres to the surface.

Scolecitliricella longifurca can be recognised by its moderately long abdomen, and by the
proportional length of the segments. The anal segment is very short and the furcal joints are
twice as long as broad. The female fifth pair is small. Each foot is composed of one free joint

90

9i

and a basal part. The proximal spine on the free joint is about two and onehalf times longer
than the apical spine. The male is unknown.

Scolccithricella longifurca is only known from the Pacific (Jcean.

6. Scolecithricella ctenopus (Giesbrecht).

Scolecithrix ctenopus Giesbrecht, 1888, p. 337.

Scolecithrix ctenopus Giesbrecht, 1893, p. 266, pis. 13 & 37.

Scolecithrix ctenopus T. Scott, 1893, p. 48, pi. V, figs. 2 — 9.

Scolecithrix ctenopus Giesbrecht & Schmeil, 1898, p. 46.

One male belonging to this species was found in the plankton collected with the Hensen
vertical net at Station 118, 900 metres to the surface.

The male is easily identified by the structure of the fifth pair of feet. The left foot is
long and narrow and the end joint is furnished on its inner margin with a comb-like row of
fine spines. The right foot is very small. Only the male of this form is known.

When the female is discovered it will probably be found necessary to remove this species
to another genus, as the fifth pair of feet of the male is more closely related to Xanthocalanus
than to Scolecithricella.

Scolecithricella ctenopus has only been recorded from the Pacific Ocean and from the
Gulf of Guinea.

7. Scolecithricella marginata (Giesbrecht).

Scolecithrix marginata Giesbrecht, 1888, p. 33S.
Scolecithrix marginata Giesbrecht, 1893, p. 266, pi. 13.
Scolecithrix marginata Giesbrecht & Schmeil, 1898, p. 44.

Thirteen females were obtained from the plankton collected at the following stations.

Stat. 16, 1 specimen. — Stat. 40, 1 specimen. — Stat. 47'', 1 specimen. — Stat. 66, 1 spe-
cimen. — Stat. 75, 1 specimen. — Stat. 118, 1 specimen. — Stat. 128, 1 specimen. —
Stat. 142, 1 specimen. — Stat. 143, 1 specimen. — Stat. 185, 2 specimens. — Stat. 203
(surface), 1 specimen. — Stat. 243, 1 specimen.

Scolecithricella marginata bears a close resemblance to Scolecithricella auropecten, but
can be distinguished from it by the character of the armature of the fifth feet. The inner
marginal spine is moderately stout and it is fringed with fine spinules. The male is unknown.

This species is only known from the Pacific Ocean.

8. Scolecithricella profitnda (Giesbrecht).

Scolecithrix profunda Giesbrecht, 1893, p. 266, pi. 13.
Scolecithrix profunda Giesbrecht & Schmeil, 1898, p. 43.

One female was found in the plankton collected with the Hensen vertical net at Station
141, 1500 metres to the surface.

Scolecithricella proftmda resembles Scolecithricella vittata in general appearance, and the
fifth pair of feet is not unlike that of Scolecithricella abyssalis at first sight. The apex of the

91

free joint is broadly rounded in this species, whereas in Scolecithricella abyssalis, the apex is
distinctly pointed. The apical spine on the free joint of Scolecithricella vittata fifth pair is very
long. The male is unknown.

This species has only hitherto been known from the Mediterranean.

9. Scolecithricella obtusifrons (Sars). Plate XXXI, figs. 1 — 9.

Amallopliora obtusifrons Sars, 1905 (a), p. 22.

Scolecithrix emarginata Farran, 1905, p. 36, pi. VII, figs. 6 — 17.

Amallophora obtusifrons Pearson, 1906, p. 17.

Scolecithrix obtusifrons Farran, 1908, p. 54.

Scolecithrix obtusifrons van Breemen, 1908, p. 75, fig. 87.

Five specimens apparently belonging to this species, were obtained from samples of
plankton collected with the Hensen vertical net at the following stations.

Stat. 141 (1500 metres to surface), 2 specimens. — Stat. 148 (1000 metres to surface), 2 spe-
cimens. — Stat. 185 (1536 metres to surface), 1 specimen.

The specimens agree fairly well with Sars' preliminary description, and also with the
figures and description given by Farran (1905).

The rostrum of the 'Siboga' specimens is furnished with long and moderately stout
filaments. The apex of each filament is distinctly bifurcate (Plate XXXI, fig. 4). Length of
female 4,3 mm.

Sars placed the species under the genus Amallophora, but I do not regard the 'Siboga'
specimens to be typical members of that genus.

Scolecithricella obtusifrons has only previously been obtained from the North Atlantic.

10. Scolecithricella tenuipes (T. Scott).

Scolecithrix temiipes T. Scott, 1893, p. 48, pi. V, figs. 10 — 19.
Scolecithrix tenuipes Giesbrecht & Schmeil, 1898, p. 47.
Scolecithrix tenuipes Thompson & Scott, 1903, p. 245.

One specimen was found in the plankton collected with the Hensen vertical net at
Station 141, 1500 metres to the surface.

Scolecithricella tenuipes is easily distinguished from the other members of the genus by
the structure of the fifth pair of feet. The left foot is long and slender and the last joint is
spiniform. There is no fringe of hairs on the last joint. The right foot is very short and rudi-
mentary. Only the male is known.

When the female is discovered, this species will probably require to be removed to
another genus, as the fifth pair of feet of the male is more closely related to Xanthocalanus,
or Neoscolecithrix, than to Scolecithricella.

Scolecithricella tc7inipes has only been recorded from the Gulf of Guinea and from the Red Sea.

11. Scolecithricella valida (Farran). Plate XXXII, figs. 1- — 9.

Scolecithrix valida Farran, 1908, p. 55, pis. V & VI.

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93

Five temales apparently belonging to this species were obtained from the plankton
collected with the Hensen vertical net at the following two stations.

Stat. 14S (1000 metres to surface), 2 specimens. — Stat. 230 (2000 metres to surface), 3 specimens.

The 'Siboga' specimens appear to be rather more robust than those obtained by Farran
from the deep water off the West of Ireland. The rami of the rostrum are very robust and
terminate in a slender filament. The filament is articulated at the base. The fifth pair of feet
is almost identical with Farran's figure. The outer edge spine is nearer the apex of the joint,
however. than is shewn by Farran. Length 3.24 mm.

12. Scolecitkricella eracilis Sars. Plate XXXI, fig-s. 10 — 18.

Scolecitkricella gracilis Sars, 1905 uj), p. 21.

Two females of a form that appears to be identical with the preliminary description
given by Sars of the above species, were found in the plankton collected with the Hensen
vertical net at Station 148, 1000 metres to the surface.

This species is easily identified by its slender body and moderately long abdomen, by
the antennules extending bevond the furca, and by the structure of the fifth pair of feet. Each
foot is composed of a single piece, without any demarkation between the basal part. The basal
portion of the foot is furnished with two transverse rows of small spines, which distinguishes
the species from any other member of the genus. The inner marginal spine is nearly as long
as the whole foot. The apical spine is fully one-third of the length of the inner spine. The
spines are fringed with short spinules. The 'Siboga' specimens are furnished with a small outer-
edge spine near the middle of the foot (Plate XXXI, fig. 18).

Length of female 4 mm. Male unknown.

The fourth and fifth thoracic segments of the 'Siboga' specimens of this species appear
to be indistinctly separated.

13. Scolecitkricella tydemani nov. sp. Plate XXX, figs. 10 — 17.

Female — length 5.7 mm.

Seen from above, the body appears elongate and moderately robust. The head is fused
with the first thoracic segment, and the combined length is nearly twice that of the next four
thoracic segments. The fourth and fifth thoracic segments are completely separated. The last
thoracic segment is produced and apparently pointed. Viewed from the side, the forehead is
evenly rounded and produced into a moderately long rostrum. The last thoracic segment is
somewhat truncate at the apex and the margin is slightly emarginate. The rostrum is composed
of two rather short and moderately stout filaments attached to a projection of the forehead.
Each filament is distinctly bifurcate at the apex. (Plate XXX, fig. 13).

The abdomen is short and composed of four segments. The combined length of the
abdomen and furca is contained three and a half times in the total length of the cephalothorax,
from the frontal margin to the base of the genital segment. The genital segment is as long as

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94

the combined length of the next two segments. The anterior portion of the ventral surface is
produced into a blunt point. The second segment is equal to about two-thirds of the length of
the o-enital segment. The third and fourth segments are of equal length and are half the length
of the genital segment. The furcal joints are slightly longer than broad, and are as long as the
anal segment.

The antennules are twenty-four-jointed and extend to near the end of the furca.
The antennae, mandibles, maxillae and maxillipedes are similar to those of ScolecUhricella
obtusifrons Sars.

The first pair of feet is also similar to that of ScolecUhricella obtusifrons.

The exopodite of the second pair of feet is three-jointed and the joints are moderately
wide. The surface of the second and third joints is well clothed with fine spinules. The second
joint of the endopodite is furnished with three transverse rows of moderately long spinules.

The exopodite of the third pair of feet is three-jointed, and the surface of the joints is
closely set with fine points. The distal end of the surface of the second joint is furnished with
a horse-shoe-shaped row of small stout spines. The surface of the third joint has two horse-
shoe-shaped rows of spines. The second and third joints of the endopodite are each furnished
with two transverse rows of spines.

The fourth pair of feet was damaged.

The fifth pair of feet is represented by two free joints attached to a basal part. The
second free joint is about twice the length of the first and is narrowly pointed at the apex.
The second joint is furnished with one strong inner-edge spine, which is equal to two-thirds
of the length of the joint. The posterior surface of the spine is fringed with fine spines. The
apex of the joint bears one small spine. The outer margin is furnished with two spines, one
is about a third from the base, and the other is close to the apex. (Plate XXX, fig. 17).

The male is unknown.

This form is easily distinguished from any of the other species by the short, stout, bifurcate
filaments of the rostrum, by the broad and slightly emarginate outline of the distal end of the
last thoracic segment when viewed from the side, and by the armature of the second free joint
of the fifth feet.

Occurrence. - - One specimen was found in the plankton collected with the Hensen
vertical net at Station 148, 1000 metres to the surface.

The species is so named in compliment to Lieutenant G. F. Tydemax who commanded
the 'Siboga' during the expedition.

14. Scolecitliricclla curticauda nov. sp. Plate XXX, figs. 1 — 9.

Female — length 6 mm.

Seen from above, the body appears elongate and narrow. The head is completely fused

with the first thoracic segment and its combined length is twice that of the three following

thoracic segments. The last thoracic segment is slightly produced and the posterior margin is

rounded. The fourth and fifth thoracic segments are completely fused, but the junction of the

segments is indicated by a faint thickening of the exoskeleton. Viewed from the side, the dorsal

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95

margin of the head is sinuate, and the front margin is boldly rounded. The last thoracic segment

is contracted posteriorly. The apex of the segment is narrowly rounded, then slightly sinuate as it

merges into the dorsal line. The rostrum is composed of two long and moderately stout filaments

attached to a projection of the forehead. Each filament is distinctly bifurcate at the apex.

Ihe abdomen is composed of four segments. The combined length of the abdomen and

furca is contained four times in the total length of the ccphalothorax, from the frontal margin

to the base of the genital segment. The genital segment is as long as the combined length

of the second and third segments. The anterior portion of the ventral surface is only slightly

produced. The second and third segments are of about equal length. The fourth segment is

very small and is distinctly less than one-half of the length of the third segment. The furcal

joints are about as long as broad, and are slightly longer than the anal segment.

The antennules are twenty-four-jointed and extend slightly beyond the furca.

The antennae, mandibles, maxillae and maxillipedes are similar to those of Scolecithricella
tydemani.

The first pair of feet is also similar to that of the above species.

The exopodite of the second pair of feet is distinctly narrower than in Scolecithricella
tydemani. The surface of the second and third joints is well clothed with fine spines. The
second joint of the endopodite is furnished with three transverse rows of fine spines.

The exopodite and endopodite of the third pair of feet are almost similar in armature
to that of Scolecithricella tydemani.

The exopodite and endopodite of the fourth pair of feet are three-jointed. The joints are
comparatively narrow and the surface is closely set with small points (Plate XXX, fig. 8).

The fifth pair of feet is represented by two free joints attached to a basal part. The
joints are comparatively narrow and the second joint is fully twice the length of the first. The
second joint is furnished with one strong spine near the distal end of the inner margin. The
spine is as long as the joint, and its outer surface is fringed with fine spinules. The apex of
the joint is much contracted and bears one short, stout, naked spine. The apical spine is equal
to about one-fifth of the length of the inner-edge spine. The outer margin of the joint is plain.

The male is unknown.

This species is readily separated from the other members of the genus by its long body
and short abdomen, and by the structure and armature of the fifth pair of feet.

Occurrence. — Two specimens were obtained from the plankton collected with the
Hensen vertical net at Station 148, 1000 metres to the surface.

Genus Scaphocalanus G. O. Sars, 1900.

Sars established this genus in 1 900 for a Calanoid found in the plankton collected during
Nansen's Xorth Polar expedition, but was then unaware that it had previously been described
by my father and placed in the genus Amallophora (1893), as well as by Giesbrecht in
!^95i wno placed it in the genus Scolecithrix. The genus Amallophora was disestablished by
Giesbrecht and Schmeil in 1898. These authors placed Amallophora typica in the genus
Xanthocalamis. The other species described by my father were included in Scolecithrix.

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96

Sars in 1902 recognised the identity of Scolecithrix [Amallophora) magna (T. Scott)
with his Scaphocalanus acroccphalus, and revived the generic name of Amallophora for magna,
and two other species that were originally established in the genus. Sars left the type species,
Amallophora typica, in the genus Xanthocalanus. Farran (1908) points out that this revival
cannot be upheld as Amallophora magna is not congeneric with Amallophora typica, with which
I quite agree. The sensory appendages at the apex of the first pair of maxillipedes of Amallo-
phora magna and Amallophora typica are quite distinct, and very important differences exist
between the structure of the fifth pair of feet of the two sexes of both species. I agree with
Sars, however, that the differences between Amallophora magna, and typical Scolecithrix or
Scolecithricella, are worthy of generic distinction. I have already employed the name Amallophora,
for the separation of the type species from the genus Xanthocalanus, and another generic
name is necessarily required. I have, therefore, revived Sars' generic name Scaphocalanus for
Scolecithrix {Amallophora) magna, and the other allied species. The following are the characters
by which the genus can be distinguished from the other members of the family.

The female, in general appearance, resembles the females of the genus Scolecithricella,
except, that it is less robust and rather more attenuated. A median crest may be present or
absent on the forehead. The rostrum consists of two, very long, simple filaments. The filaments
are slender and are gradually attenuated to a fine point at the apex. The antennules are
composed of twenty-three joints. The endopodite and exopodite of the antennae are of about
equal length. The apical portion of the first maxillipedes is similar to that of Scolecithricella. Tv/o
types of sensory organs are present. Some are moderately long and simple, others are short,
with distinctiy swollen heads. The four pairs of swimming feet are similar to those of Scoleci-
thricella, but the spines on the surface of the joints are stronger and more irregularly placed.
The terminal spine on the exopodite of the second, third and fourth pairs of feet is more
coarsely toothed than in Scolecithricella. The fifth pair of feet is represented by one or two free
joints attached to a basal part. The inner marginal spine, and the apical spine on the last
free joint is of considerable length.

The male resembles the female in appearance, but there is no tracé of a crest in the
males of those females that possess one. The mouth organs are considerably reduced. The
fifth pair of feet forms a well developed prehensile organ. Each foot consists of a two-jointed
basiopodite, an exopodite and an endopodite. The second joint of the basiopodite of the right
foot is greatly swollen in its proximal part, where it bears a styliform endopodite. The distal end
of the joint is much attenuated, and the apex is produced on the inside, into a short blunt process.
The endopodite is two-jointed, short, and slightly curved. The second joint is usually lamelliform.
The two-jointed basiopodite of the left foot is long and cylindrical. The endopodite and exopodite
are three-jointed and subequal. The endopodite is usually a little longer than the exopodite.

The long slender filamentary rami of the rostrum, the long spines on the apical joint
of the female fifth pair, and the structure of the male fifth pair of feet, easily separate this
genus from any of the other known members of the family.

Three species were represented in the plankton collected by the 'Siboga', one of which
appears to be new.

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97

i. Scaphocalanus magnus (T. Scott).

Amallophora magna T. Scott, 1893, p. 55, pi. IV, figs. 5 — 9.

Scolecithrix cristata Giesbrecht, 1895, p. 252, pis. II & III.

Scolecithrix cristata Giesbrecht & Schmeil, 1898, p. 48.

Scaphocalanus acrocephalus Sars, 1900, p. 36, pis. VII, VIII & IX.

Amallophora magna Sars, 1902, p. 51, pis. XXXIV & XXXV.

Scolecithrix cristata I. C. Thompson, 1903, p. 21 (female only).

Amallophora magna Wolfenden, 1904, p. 111.

Scolecithrix cristata Farran, 1905, p. 36.

Amallophora magna Sars, 1905 (a), p. 6.

Amallophora magna Pearson, 1906, p. 17.

Scolecithrix magna Esterly, 1906, p. 66, pis. 9, 11, 12, 13.

Scolecithrix magna Farran, 1908, p. 51.

Scolecithrix magna van Breemen, 1908, p. 76, fig. 89.

Males and females of this species were obtained from the plankton collectecl at the
following stations.

Stat. 96 (day), 1 specimen. — Stat. 118 (HENSEN vertical net 900 metres to surface), 1 spe-
cimen. — Stat. 138, 1 specimen. — Stat. 141 (HENSEN vertical net 1500 metres to surface),
2 specimens. — Stat. 143 (HENSEN vertical net 1000 metres to surface), 2 specimens. —
Stat. 168, 2 specimens. — Stat. 203 (surface), 2 specimens. — Stat. 276 (HENSEN vertical
net 750 metres to surface), 1 specimen.

The females of Scaphocalanus magnus are easily distinguished from the other members
of the genus, by the presence of a distinct helmet-shaped crest on the forehead. Nine females
and three males were obtained. *

Length. — Female 4,5 — 5 mm. Male 4,5 mm.

Scaphocalanus magnus is apparently widely distributed. It ranges from the tropical Atlantic
and Pacific, to the North Polar basin. Farran records it from the West of Ireland, and my
father has obtained it from the Faröe Channel.

2. ScapJiocalanus major (T. Scott).

Scolecithrix major T. Scott, 1893, p. 52, pis. III & V.
Scolecithrix major Giesbrecht & Schmeil, 1898, p. 47.
Scolecithrix major I. C. Thompson, 1903, p. 20.
Scolecithrix major van Breemen, 1908, p. 79, fig. 92.

Five females belonging to this species, were obtained from the plankton collected with
the Hensen vertical net at the following- stations.

Stat. 128 (700 metres to surface), 1 specimen. — Stat. 141 (1500 metres to surface), 1 spe-
cimen. — Stat. 143 (1000 metres to surface), 1 specimen. — Stat. 185 (1536 metres to
surface), 1 specimen. — Stat. 243 (1000 metres to surface), 1 specimen.

The female of this species has no tracé of a median cephalic crest. The last thoracic
segment when viewed from the side, appears very narrowly rounded, but there is no indication
of a point, as in Scaphocalanus magnus, or Scaphocalanus elongatus.

The species was described by my father as a ScolecilJirix, but the character of the spines
on the fifth pair of feet, shew that it is a true member of this genus.

97

SIROGA-EXPEDITIE XXIX a.

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93

Length of 'Siboga' females 2,9 mm.

The known distribution at present is very limited.

3. Scapkocalamis elongatus nov. sp. Plate XXXII, figs. 10 — 16.

Female — length 2,9 mm.

Seen from above, the body is elongate and narrow. The head is fused with the first
thoracic segment, and its combined length is nearly twice that of the three following segments
together. The fourth and fifth thoracic segments are completely fused. The last thoracic segment
is slightly produced and is distinctly pointed. Viewed from the side, the forehead appears narrowly
rounded. The last thoracic segment terminates in a small but distinctly curved point. The rostrum
is represented by two long slender filaments (Plate XXXII, fig. 13).

The abdomen is composed is four segments. The combined length of the abdomen and
furca is contained two ancl two-third times in the total length of the ccphalothorax, from the
frontal margin to the base of the genital segment. The genital segment is slightly longer than
the second segment, and the anterior portion of the ventral surface is slightly produced. The
second and third segments are of equal length. The anal segment is equal to two-thirds of
the length of the third segment. The furcal joints are fully twice as long as broad, and are
slightly longer than the anal segment.

The antennules were incomplete.

The antennae, mandibles, maxillae and maxillipedes are similar to those of Scaphocalanus
magnus.

The four pairs of swimming feet are also similar to those of that species.

The fifth pair of feet consists of two free joints attached to a basal part. The first joint
is short. The second joint is of moderate length, and it is considerably contracted from the
middle to the apex. The inner marginal spine arises from the middle of the joint, and is fully
twice as long as the joint. The apical spine is equal to half of the length of the inner spine.
The outer marginal spine is placed near the apex, and is contained two and a half times in
the length of the apical spine. The outer marginal spine of the right foot is wanting, but this
is probably accidental.

This species is easily distinguished from the other members of the genus, by the distinctly
pointed last thoracic segment when seen in side view, and by the shape of the second free
joint of the fifth foot. The forehead is faintly thickened in the middle line, which may indicate
a very weak crest, but the material was too limited to make certain.

Occurrence. — One female was found in the plankton collected with the Hensen
vertical net at Station 148, 1000 metres to the surface.

Genus Lophothrix Giesbrecht, 1895.

The members of this genus are distinguished by the very short end joint of the exopodite
of the antennae, and by the stout bifurcate rostrum. The rami of the rostrum terminate in a
small spine, but there is 110 articulation between the spine and the basal portion. The female

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99

fïfth pair of teet is composed of two free joints attached to a basal part. The second joint is
furnished with one apical and two subapical spines.

The male has hitherto been unknown and is described below for the first time. The
exopodite of the right and left fïfth loot is three-jointed. The endopodite is present on each
foot and is composed of a single joint.

Giesbrecht described the genus in 1S95, but it was withdrawn on the publication of
the part on the Copepoda in 'Das Tierreich' in 1898. The genus has since been revived and
set aside at intervals, but with the discovery of the male, the position of Lophothrix as a
separate genus now appears to be firmly established.

The type species only, was represented in the plankton collected by the 'Siboga'.

1. Lophothrix frontalis Giesbrecht. Plate XXVI, figs. 11 — 20 (female). Plate XXIX,

figs. 1 — 10 (male).

Lophothrix frontalis Giesbrecht, 1895, p. 254, pi. II.

Scolecithrix frontalis Giesbrecht & Schmeil, 1898, p. 49.

Scolecitkrix frontalis I. C. Thompson, 1903, p. 21.

Lophothrix frontalis Wollenden, 1904, p. 111, pi. IX.

Lophothrix frontalis Sars, 1905(0), p. 6.

Lophothrix frontalis Pearson, 1906, p. 19.

Scolecithrix frontalis Esterly, 1906, p. 65, pis. 9 & 13.

Lophothrix frontalis Farran, 1908, p. 58.

Scolecithrix frontalis van Breemen, 1908, p. 79, fig. 93.

Ten females and two males were obtained from the plankton collected at the following stations.

Stat. 118 (Hensex vertical net 900 metres to surface), 1 specimen. — Stat. 12S (Hexsex vertical
net 700 metres to surface), 1 specimen. — Stat. 141 (HEXSEX vertical net [500 metres to
surface), 1 specimen. — Stat. 148 (Hkx>EX vertical net 1000 metres to surface), 1 specimen. —
Stat. 168 1 specimen. — Stat. 184, 1 specimen. — Stat. 185 (Hexsex vertical net 1536
metres to surface), 1 specimen. — Stat. 203 (Hexsex vertical net 1500 metres to surface),
2 specimens. — Stat. 243 (HENSEN vertical net 1000 metres to surface), 1 specimen. —
Stat. 276. — (Hex>ex vertical net 750 metres to surface), 1 specimen.

The female is easily identified by the moderately high and narrowly rounded median
crest on the forehead, when viewed from the side ; - - By the stout bifurcate rostrum and the small
spine at the apex of the rami, and by the structure of the fïfth feet. The two free joints are
comparatively short. The second joint is distinctly expanded near the apex and bears three
spines, one apical and two subapical. The inner subapical spine is moderately long and somewhat
irregular in shape. The apical spine is slightly curved inwards, and is equal to two-thirds of
the length of the inner subapical spine. The outer subapical spine is about half the length of
the apical spine. The three spines are fringed with fine spinules. Length of female 7,4 mm.

The male has only a slight resemblance to the female. Viewed from above it appears
elongate in outline. The fourth and fïfth thoracic segments are fused, and the junction is marked
by a sudden constriction near the posterior end. The apex of the segment is lamelliform and
pointed. Seen from the side, the forehead is furnished with a low rounded median crest, and
a moderately strong rostrum. The last thoracic segment is narrowly rounded, with a slight

99

IOO

emaro-ination as the apex merges into the dorsal line. The rostrum is moderately large and the
rami are more elongated than in the female.

The abdomen is composed of five segments. The total length of the abdomen and furca
is contained two and one-third times in the total length of the cephalotkorax, from the frontal
margin to the base of the genital segment. The second segment is longer than any of the
others, and is distinctly expanded at its distal end. The fifth segment is very small. The furcal
joints are about as long as broad, and are twice the length of the anal segment.

The antennules are composed of nineteen joints, and extend to the end of the second
abdominal segment. The eighth joint is long and represents the result of the fusing of three
or four joints. The basal joints are furnished with sensory organs.

The antennae, mandibles, maxillae and maxillipedes are nearly similar to those of the
female, and are only slightly modified.

The four pairs of swimming feet are also similar to those of the female, except that the
surface of the second and third joints of the exopodite and exdopodite of the fourth feet, is
beset with groups of fine points.

The fifth pair of feet is moderately large and prehensile. It is not unlike the male fifth
pair of Scaphocalanus in general appearance. The second joint of the right basiopodite is dilated
at the proximal end, where it bears a moderately long styliform endopodite. The endopodite
appears to be one-jointed with a lamelliform distal portion. The distal portion of the second
joint of the right basiopodite is much contracted, and simply merges into the three-jointed
exopodite. The second joint of the exopodite bears a small outer-edge spine at its distal end.
The third joint is irregularly curved, and has a distinct knee-like projection on its inner surface.
The joints of the basiopodite of the left foot are elongated and somewhat cylindrical. The
exopodite is composed of three joints. The terminal joint is short and spiniform and bears a fringe
of short hairs on its inner surface. The endopodite is one-jointed. The joint is of irregular shape
and is rather longer than the exopodite. The outer margin of the distal end is slightly crenulate.

Length of male 5,75 mm.

The character of the male fifth pair with its one-jointed endopodite of both feet, the
structure of the fifth pair of the female, the bifurcate rostrum, and the short terminal joint of
the exopodite of the antennae, are sufficiënt to separate this genus from the other members of
the family.

Lophothrix frontalis has a clistribution somewhat similar to that of Scaphocalanus magnus
in the tropical and temperate regions. It has been recorded by Farran from the deep water
plankton taken off the West of Ireland, and my father has obtained it from the deep water
plankton of the Faröe Channel.

Genus Macandrewella nov.

Female. The head is completely fused with the first thoracic segment and possesses a
circular lens-like organ on the frontal margin. The fourth and fifth thoracic segments are
completely separated. The rostrum is represented by slender filaments attached to a common

IOl

bifurcate base. The antennules are composed of twenty-three joints. The antennae, mandibles,
maxillae and maxillipedes are similar in structure to those of the genus Scokcithricella. The four
pairs of swimming feet are also similar to those of that genus. The fifth pair is very small.
Each foot is composed of a single joint attached to a basal part.

Male. In general appearance it resembles the female. The frontal lens-like organ is
present. The rostral filaments are much longer and the basal part may possess a small secondary
apical spine. The antennules are composed of twenty joints. The antennae, mandibles, maxillae
and maxillipedes are similar to those of the female and are not modified. The four pairs of
swimming feet are also similar to those of the female, but the surface of the joints is less
spinulose. The fifth pair is well developed and prehensile. The basiopodite is two-jointed. The
exopodites of both feet are composed of two joints. The first joint of the right exopodite has
the basal part more or less produced internally. The second joint is forked. The apex of the
second joint of the left exopodite is furnished with a spine, and a tuft of hairs. The endopodite
is present on each foot, and is composed of a single joint.

The form described by Giesbrecht in 1896 as Scolecithrix chelipes, undoubtedly belongs
to this genus. I have compared specimens of it that were found in plankton samples taken by
Professor Herdman in the Red Sea, during his traverse to Ceylon in 1903. The male fifth pair
of these specimens is identical with Giesbrecht's figure, and the forehead possesses the frontal
lens-like organ referred to above.

The peculiar lens-like organ on the forehead of both sexes, along with the structure of
the male fifth pair of feet, readily separates this genus from any of the other members of the family.

One species belonging to this new genus was found in the plankton collected by the
'Siboga'. Both male and female were obtained. The species is distinct from Giesbrecht's
Macatidrezuella {Scolecithrix) cliclipcs.

1. Macandrezuella joanae nov. sp. Plate VI, figs. 12 — 23 (female). Plate XXIII, figs.

9—15 (male).

Female — length 3,6 mm.

Seen from above, the body is oval and robust. The head is considerably contracted in
front, and the last thoracic segment is quite asymmetrical. Each side of the thoracic segment
is produced, and terminates in a curved spine. The spine of the left side is longer than the
one on the right side (Plate VI, fig. 12). Viewed from the side, the forehead appears rounded
and possesses a distinct lens-like organ, situated just behind the base of the rostrum. In end
view the organ is circular and chitinised (Plate VI, fig. 16). The left side of the last thoracic
segment is boldly but narrowly rounded, and is produced into a terminal curved spine, which
extends beyond the middle of the genital segment. The upper basal part of the spine forms
a distinct indentation with the dorsal margin (Plate VI, fig. 14). The right side of the last
thoracic segment is also boldly rounded, but the curved spine only reaches to the middle of the
genital segment. The basal part of the spine forms a distinct tooth with the dorsal margin of
the segment (Plate VI, fig. 15). The rostrum has a stout bifurcate base, and each ramus has
a filament articulated to it.

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102

The abdomen is composed of four segments. The combined length of the abdomen and
furca is contained three and two-third times in the total length of the ceplialothorax, from
the frontal margin to the base of the genital segment. When viewed from above, the genital
segment appears asymmetrical in outline. The right side is more infiated than the left. The
ventral surface is produced posteriorly into a small blunt lobe. The genital segment is as long
as the combined length of the next three segments and furca. The second and third segments
are of about equal length. The fourth segment is slightly shorter than the third segment. The
furcal joints are about as long as broad, and are slightly longer than the anal segment. The
middle seta of the left furcal joint is much longer than any of the others. The posterior margin
of the first, second and third segments is fringed with fine spines.

The antennules are composed of tvventy-three joints and extend to the end of the
genital segment.

The exopodite of the antennae is one and a half times the length of the endopodite.

The mandibles, maxillae and maxillipedes are similar to those of Scolecithricella. The
apex of the first maxilliped is furnished with two types of sensory organs. Some are moderately
long and rounded at the apex. Others are short with distinctly swollen heads.

The exopodites and endopodites of the four pairs of swimming feet are similar in
structure to those of Scolecithricella, but the spines on the surface of the second, third and
fourth pairs of feet are fewer in number and stronger.

The fifth pair is symmetrical and very small. Each foot consists of a single cylindrical
joint attached to a basal part. The apex of the joint bears two short spines. The inner apical
spine is longer than the outer one.

Male — length 3,4 mm.

In general appearance it resembles the female, but the last thoracic segment is sym-
metrical, and is furnished with small spines. The abdomen is composed of five joints. The anal
segment is very small and is almost Obsolete. The posterior margin of the second, third and
fourth segments is fringed with fine spines. The filaments of the rostrum are longer than in the
female, and the bifid basal part is furnished with one small spine on the inner angle of each lobe.

The antennules are composed of twenty joints. The proximal half of the antennule is
furnished with numerous sensory organs.

The antennae, mandibles, maxillae and maxillipedes are similar to those of the female.
Some of the sensory organs on the apex of the first maxilliped appear to be hollow tubes
when seen in end view.

The four pairs of swimming feet are similar to those of the female, but the surface of
the joints is less spinulose.

The fifth pair is large and prehensile. The second joint of the basiopodite of the right
foot is dilated at its proximal part, where it bears a long sinuous one-jointed endopodite, wh'ich
extends to the end of the exopodite. The exopodite is two-jointed. The base of the first joint
is produced internally into a strong curved claw, which exceeds the length of the joint. The
middle of the inner margin of the joint is produced into a short stout tooth. The second joint
is forked at the apex. The joints of the basiopodite of the left foot are long and narrow. The

io3

exopodite is composed of two joints. The first joint is elongate and narrow. The second joint
is short and dilated. The apex of the joint is furnished with a pad of hairs and a spine. The
endopodite is one-jointed, and is in the form of a sickle-shaped spine, which extends to the
end of the exopodite. The distal half of the inner margin of the endopodite is finely serrate
(Plate XXIII, fig. 14).

O ecu rr ene e. Four females and one male were found in the plankton collected

with the Hensen vertical net at Station 14S, 1000 metres to the surface.

The fifth pair of the male of Giesbrecht's species is not unlike the figure given in this
report, but when a comparison is made, it is seen to be distinct. The base of the exopodite
of the right foot is only slightly produced internally, and the endopodite of the left foot is
very broad and strong. It is not sickle-shaped as in Mücandrewella joanae.

This genus and species is dedicated to the memory of my mother, whose encouragement
did much to help me over many difficulties encountered in the study of the Copepoda.

Genus Scottocalanus G. O. Sars, 1905(3).

This genus was established by Sars in 1 905 for a Sco/ecif/irix-\ike form with a peculiar
median crest and a very strong bifurcate rostrum. The structure of the fifth feet of the two
sexes was also made a character of the genus.

The typical species of the genus was first obtained by my father in the plankton col-
lected in the Gulf of Guinea. It was described in the report 'On Entomostraca from the Gulf of
Guinea' as Scolecithrix securifrons. Both male and female were described, but is has since been
shewn by Canu and Farran, that the form regarded as the male really belongs to another
species. Giesbrecht in 1895 described a closely allied species as Scolecithrix per secans. A good
deal of confusion appears to have arisen in the identification of the two forms during the past
few years, and an attempt is made to put these species on their true basis in the present report.

Female. The head is completely fused with the first thoracic segment, and possesses a
well defined chitinised crest on the forehead. The fourth and fifth thoracic segments are com-
pletely fused. The rostrum is bifurcate and highly chitinised. Each ramus bears an apical spine
and there is a distinct articulation between the spine and the basal portion. The abdomen is
composed of four segments. The antennules are twenty-four-jointed. The antennae, mandibles,
maxillae and maxillipedes are somewhat similar to those of Scolecithricclla, except that the
apical lobe of the first maxilliped is furnished with a moderately stout and slightly curved
claw. There are two types of sensory organs. Some are long and rounded at the apex. Others
are shorter with distinctly swollen heads. The four pairs of swimming feet are similar to those
of Scolecithricclla^ but the surface of the joints is only sparsely furnished with spines. The fifth
pair is composed of one free joint attached to a basal part. The apex of the free joint bears
one long curved spine, and one very short spine. The small spine is situated on the apex of
the joint. The long spine is outside the small one and its position is usually subapical.

Male. In general appearance it resembles the female. The abdomen is composed of five
joints, and the genital segment is asymmetrical. The antennules are composed of nineteen to
twenty joints. The antennae, mandibles, maxillae and maxillipedes are similar to those of the

104

female. There is practically no modification in their structure. The four pairs of swimming feet
are also similar to those of the female. The fifth pair is large and prehensile. The basiopodite
is composed of two joints. The exopodite of the right foot is usually very short and may be
one two, or three-jointed. The endopodite may be quite small, or of moderate length, but it
is alvvays present, and is composed of a single joint. The second joint of the basiopodite of
the right foot has frequently an articulated appearance in the swollen region, but this is pro-
bably due to defects in the mounted preparation. The two joints of the basiopodite of the left
foot are slender and cylindrical. The exopodite is two-jointed. The apex of the second joint
is usually furnished with two spines and a pad of hairs. The endopodite is small and one-jointed.
It does not exceed the length of the exopodite. The males appear to be slightly larger than
the females, but this, no doubt, is due to the longer abdomen.

Seven species, four of which appear to be undescribed, were obtained from the plankton
collected by the 'Siboga' during the investigations in the Malay Archipelago.

i. Scottocalanus securifrons (T. Scott). Plate XXV, figs. i — 9 (female). Plate XXVIII,

figs. 1 — 9 (male).

Scolecitlirix securifrons T. Scott, 1893 (pars), p. 47, pis. IV & V.

Scolecithrix securifrons Canu, 1896, p. 425.

Scolecitlirix securifrons Giesbrecht & Schmeil, 1898, p. 49

Scolecithrix securifrons I. C. Thompson, 1903, p. 20.

Scolecitlirix securifrons Cleve, 1904, p. 197.

Lophothrix securifrons Wolfenden, 1904, p. 120, pi. IX.

Scottocalanus acutus Sars, 1905 (b), p. 7.

Scottocalanus securifrons Pearson, 1906, p. 19.

Scottocalanus securifrons Farran, 1908, p. 57.

Scolecithrix securifrons van Breemen, 1908, p. 76, fig. 88.

Ten females and four males belonging to this species were obtained from the plankton
collected at the following stations.

Stat. 118 (HENSEN vertical net 900 metres to surface), 1 specimen. — Stat. 128 (Hensen
vertical net 700 metres to surface), 1 specimen. — Stat. 141 (HENSEX vertical net 1500
metres to surface), 1 specimen. — Stat. 143 (HENSEN vertical net 1000 metres to surface),
1 specimen. — Stat. 148 (HENSEN vertical net 1000 metres to surface), 2 specimens. —
Stat. 184, 1 specimen. — Stat. 185 (HENSEN vertical net 1536 metres to surface), 1 speci-
men. — Stat. 203 (HENSEN vertical net 1500 metres to surface), 2 specimens. ■ — Stat. 216,
1 specimen. — Stat. 243 (HENSEN vertical net 1000 metres to surface), 1 specimen. —
Stat. 276 (HENSEN vertical net 750 metres to surface), 1 specimen.

The females of this species are easily recognised by the produced, outwardly curved,
and pointed terminations of the last thoracic segment. The abdomen is very short. The com-
bined length of the abdomen and furca is contained three and a half times in the total length
of the ccp/ialol/iorax, from the apex of the crest to the base of the genital segment. The genital
tient is considerably swollen at the distal end, and its length is nearly equal to the combined
length of the next three segments. The ventral surface of the segment is much swollen, and
is produced posteriorly into a process, which partly overlapps the second segment. The posterior
rgin of the segment is fringed with fine spines. The rostrum is short and stout, and the apical

104

io5

spines are very minute. The antennules are twenty-four-jointed and extend to the end of the
furca. The long' spines on the apex of the free joints of the fifth pair of feet are asymmetrical.
The spine on the left foot is distinctly thicker than the one on the right. The spines are two
and one-third linies the length of the joint. The small apical spines are equal to one-eighth of
the length of the long ones. Length of female 4,3 mm.

The males can easily be separated from the mal es of the other species, by the minute
spine on the apex ot the rami of the rostrum. The last thoracic segment when viewed from
above, is seen to be much contracted near the posterior end, then curved outwards and ter-
minates in conspicuous spines.

The combined length of the abdomen and furca is contained two and one-third times
in the total length of the cephalothorax, from the apex of the crest to the base of the genital
segment. The second segment is longer than the others.

The antennules are twenty-jointed and extend to the middle of the fourth abdominal
segment.

The distal part of the second joint of the basiopodite of the right fifth foot is distinctly
swollen, and is produced internally into two knob-like processes. The exopodite is one-jointed and
is slightly forked at the apex. The inner surface of the joint is hollowed out, and is furnished
with a lamelliform appendage. The endopodite is very short and is pointed at the apex. The
second joint of the exopodite of the left fifth foot is much longer than the first joint. It is
furnished with an outer subapical lamelliform process. The proximal part of the inner margin
bears a strong tooth, and the distal half of the inner margin is furnished with a pad of fine
spines. The endopodite is of moderate length, and is distinctly forked in the middle into two
lateral processes. The outer margin of the second joint of the basiopodite bears a large tubercle
at its proximal end. Length of male 4,75 mm.

The form recorded by Sars as Scottocalanus actttus, is, according to Farran, identical
with the female of the above species.

Scottocalanus securifrons has been recorded from the Gulf of Guinea by my father,
from the South Atlantic in the vicinity of the Cape of Good Hope by Cleve, and from the
Xorth Atlantic by Farran, Sars, and Wolfenden. I have also seen males and females that
were obtained from the plankton collected in the deep water of the Farüe Channel.

2. Scottocalanus persecans (Giesbrecht). Plate XXVII, figs. 10 — 18.

Scolecitlirix persecans Giesbrecht, 1895, p. 253, pi. III.
Scolecitlirix persecans Giesbrecht & Schmeil, 1898, p. 48.
Scolecitlirix per secans I. C. Thompson, 1903, p. 20.
Scolecitlirix persecans Cleve, 1904, p. 197.
Scolecitlirix per secans Esterly, 1905, p. 166, fig. 28.
Scolecitlirix per secans van Breemen, 1908, p. 80, fig. 94.

Four males belonging to this species were found in the plankton collected with the
Hexsen vertical net at the following stations.

Stat. 118 (900 metres to surface), 1 specimen. — Stat. 128 (700 metres to surface), 1 speci-
men. — Stat. 148 (1000 metres to surface), 2 specimens.

SIBOGA-EXPEDITIE XXIX a. 14

ioó

The male of Scottocalanus persecans is readily distinguished from the males of any of
the other species, bv the moderately long spine on the rami of the rostrum. No other known
species belonging to the genus has the rostral spines so much elongated. The apex of each
spine is distinctly bifid.

When viewed from the side, the posterior margin of the last thoracic segment is seen
to be broadly rounded, and there is a deep notch at the junction with the ventral edge. The
crest is high and rather narrowly rounded at the apex.

The combined length of the abdomen and furca is contained two and a half times in
the total length of the cep halothorax, from the apex of the crest to the base of the genital
segment. The first four segments of the abdomen are of about equal length.

The antennules are nineteen-jointed and extend to the furca.

The exopodite of the right fifth foot is two-jointed and sickle-shaped. The endopodite
is moderately long and spiniform. It is only slightly curved and extends to the distal end of
the second joint of the basiopodite. The two joints of the exopodite are cylindrical and of
nearly equal length. The inner margin of the second joint terminates in a sharp point. The
apex of the joint bears two curved spines and a pad of short hairs. The endopodite is simple
and somewhat spiniform. It is nearly as long as the exopodite. Length of male 4,4 mm.

I do not think there can be any doubt, that this species is identical with the form
described by Giesbrecht as Scolecithrix persecans. The side view of the rostrum, and the iigure
of the fifth pair of feet given by that author, are the same as the figures given in this report.
This species is not the same as the male form illustrated in my father's report lün Entomostraca
from the Gulf of Guinea', which Fakran has recently erroneously made out to be the male of
Scottocalanus persecans.

The female is partly described by Farrax, but this probably requires further verification,
as to the correctness of the identity with Giesbrecht's species.

Some of the records of this species must be regarded with suspicion, owing to the con-
fusion that has occurred between two of the known species. Esterly's record of the male is
correct, and I have seen specimens of the male from the deep water of the Faröe Channel.

3. Scottocalanus farrani nov. sp. Plate XXIV, figs. 1 — 9 (female). Plate XXIX, figs.

1 1 — 18 (male).

Female — length 3,5 mm.

Viewed from above, the body appears elongate ovate and moderately robust. The forehead
is furnished with a high crest. The last thoracic segment is produced posteriorly, and is angular
in outline. Seen from the side, the crest appears high and the apex is narrowly rounded. The
rostral points are short, and the posterior margin of the last thoracic segment is very narrowly
rounded. The basal portion of the rostrum is moderately robust, and the apical points are
equal to the depth of the excavation

The combined length of the abdomen and furca is contained three and a half times in
the total length of the cephalothorax, from the apex of the crest to the base of the genital
segment. The genital segment is nearly as long as the combined length of the next three

106

segments. The ventra] surface of the genital segment is only slightly dilated. The second segment
is as long as the combined length of the third and fourth segments. The furcal joints are as
long as broad, and are equal to the length of the third segment.

The antennules are twenty-four-jointed and extend to the furcal joints.

The antennae, mandibles, maxillae and maxillipedes are similar to those of Scottocalanus
securifrons.

The four pairs of swimming feet are also smilar to those of that species.

The free joint of the fifth pair of feet is distinctly swollen at the distal end, and the
inner margin is sharply concave in the middle. The long spine is three times the length of the
joint, and the small one is only equal to one-twenty-fifth of the length of the long spine.

Male — 3,54 mm.

Yiewed from above, the body is elongate and narrow. It is less robust than in the
male of Scottocalanus persecans. Seen from the sicle, the apex of the crest appears quite angular,
and the rostral spines are much shorter than those of Scottocalanus persecans. The last thoracic
segment is narrowly rounded at the apex, and the notch is less obvious.

The combined length of the abclomen and furca is contained two and one-third times
in the total length of the ccftlialothorax, from the apex of the crest to the base of the genital

segment.

The antennules are composed of twenty joints and extend to to the end of the fourth
abdominal segment.

The antennae, mandibles, maxillae and maxillipedes are similar to those of the female.

The four pairs of swimming feet are also similar to those of the female.

The fifth pair of feet has a general resemblance to that of Scottocalanus persecans, but
can be separated on careful examination. The narrow part of the second joint of the basiopodite
of the right foot, is produced into a strong tooth near the proximal end of the inner margin.
The distal inner margin is distinctly swollen, then concave, and again dilated. The exopodite
is two-jointed. The first joint is comparatively long and is greatly curved. The second joint is
small and lamelliform. lts lensnh is contained fullv four times in the total length of the first
joint. The shape and the proportional length of the joints of exopodite are quite different
from Scottocalanus persecans. The endopodite extends beyond the distal end of the second joint
of the basiopodite, and the apex is lamelliform. The joints of the exopodite of the left foot
are cylindrical and of nearly equal length. The apex of the second joint terminates in a rather
complicated process, and bears two curved spines. The endopodite is moderately stout and is
much shorter than the exopodite.

The male of Scottocalanus farraui, although apparently resembling the male of Scotto-
calanus persecans in appearance, can readily be separated by the comparatively short and undivided
apical spines of the rostrum, by the difference in the proportional length of the joints of the
exopodite of the right fifth foot, and by the endopodite of the left fifth foot being much shorter
than the exopodite.

Occurrence. — Twenty-three females and thirty males were obtained from the plankton

collected at the following 'stations.

107

io8

Stat. 128 (HENSEN vertical net 700 metres to surface), 3 specimens. — Stat. [41 (HENSEN
vertical net 1500 metres to surface), 9 specimens. — Stat. 148 (HENSEN vertical net 1000
metres to surface), 8 specimens. — Stat. 184, 6 specimens. — Stat. 185 (HENSEN vertical
net 1536 metres to surface), 4 specimens. — Stat. 230 (HENSEN vertical net 2000 metres
to surface), 8 specimens. — Stat. 243 (HENSEN vertical net 1000 metres to surface), 3 spe-
cimens. - - Stat. 276 (HENSEN vertical net 750 metres to surface), 6 specimens.

This species is named in compliment to Mr. G. P. Farran, B.A., whose work amongst
the Copepoda of the deep water of the Atlantic slope off the West of Ireland, has considerably
extended the knowledge of the deep sea forms in the North Atlantic.

4. Scottocalamts sctosits, nov. sp. Plate XXIV, figs. 10 — 18.

Female — length 3,3 mm.

Viewed from above, the body appears ovate and moderately robust. The last thoracic
segment is produced somewhat abruptly into a lamelliform extension having a pointed apex.
Seen from the side, the crest is high and distinctly angular at the apex. The last thoracic
segment terminates in a short curved point. The distal portion of the ventral margin of the
segment is sinuate in outline. The rostral points are stout and their length is about equal to
the depth of the excavation.

The combined length of the abdomen and furca is contained nearly four times in the
total length of the cephalothoi-ax, from the apex of the crest to the base of the genital segment.
The genital segment is slightly longer than the combined length of the next three segments.
The ventral margin of the segment is tumicl and broadly rounded. The second segment is as
long as the combined length of the next two segments. The third segment is equal to two-
thirds of the length of the second segment. The furcal joints are distinctly longer than broad,
and are equal to the length of the second abdominal segment. The middle setae on the right
furcal joint, is considerably longer than the corresponding setae on the left furcal joint.

The antennules are twenty-four-jointed and extend to about the base of the furca.

The antennae, mandibles, maxillae and maxillipedes are similar to those of Scottocalanus
securifrons.

The four pairs of swimming feet are also similar to those of that species.

The inner margin of the free joint of the fifth pair of feet is slightly concave, and the
apex of the joint is considerably dilated. The long subapical spine is three and a half times
the length of the joint, and its apex is distinctly bifurcate. The apical spine is very small, and
is equal to about one-fifteenth of the length of the long spine.

Male unknown.

This species is readily distinguished from the other members of the genus, by the somewhat
abrupt prolongations of the last thoracic segment, by the bifurcate apex of the subapical spine
on the fifth pair of feet, and by the long setae on the right furcal joint.

Occurrence. — Thirty-six specimens were obtained from the plankton collected at
the following stations.

Stat. 118 (HENSEN vertical net 900 metres to surface), 2 specimens. — Stat. 141 (HENSEN
vertical net 1500 metres to surface), 6 specimens. — Stat. 145, 4 specimens. — Stat. 148

10S

109

(Hexsen vertical net iooo metres to surface), 3 specimens. - - Stat. 184, 5 specimens. —
Stat. 1S5 (HENSEN vertical net 1536 metres to surface), 4 specimens. -- Stat. 230 (HENSEN
vertical net 2000 metres to surface), 3 specimens. — Stat. 243 (HENSEN vertical net 1000
metres to surface), 3 specimens. — Stat. 276 (HEXSEX vertical net 750 metres to surface),
6 specimens.

5. Scoftocalauus longispinus nov. sp. Plate XXV, figs. 10 — 18.

Female — length 4,75 mm.

Seen from above, the body appears elongate ovate and moderately robust. The anterior
and posterior ends are equally contracted. The greatest width is at thejunction of the cephalotJiorax
with the thoracic segments. The crest is high and conspicuous. The posterior margins of the
last thoracic segment are produced into broadly triangular processes with a pointed apex. Viewed
from the side, the crest is seen to have a distinctly angular apex. The last thoracic segment
terminates in a sharp point, and the proximal portion of the ventral margin is inflated. The
rostral points are stout and their length is equal to half the depth of the excavation.

The combined length of the abdomen and furca is contained three and a half times
in the total length of the cephalotJiorax, from the apex of the crest to the base of the genital
segment. The genital segment is distinctly longer than the combined length of the next three
segments. The segment appears nearly cylindrical when seen from above, but when viewed
from the side the dorsal and ventral surfaces are distinctly gibbous. The second segment is
nearly as long as the combined length of the next two segments. The furcal joints are longer
than broad and are equal to the length of the second abdominal segment.

The antennules are composed of twenty-four joints and extend a little beyond the furca.

The antennae, mandibles, maxillae and maxillipedes are similar to those of Scottocalmus
securifrons.

The four pairs of swimming feet are also similar to those of that species.

The inner margin of the free joint of the fifth pair of feet is sharply concave near the
middle. The apex of the joint is dilated. The long subapical spine is fully four times as long
as the joint, and the distal end is not biturcate. The apical spine is very short, and is only
equal to one-twenty-seventh of the length of the long spine.

Male unknown.

This species is easily separated from the other forms, by the broadly triangular termi-
nations of the last thoracic segment, by the short almost cylindrical abdomen, and by the length
of the spines on the free joint of the fifth pair of feet.

Occurrence. — One specimen was found in the plankton collected with the Hexsen
vertical net at Station 148, 1000 metres to the surface.

6. Scottocalanus thomasi nov. sp. Plate XXVI, figs. 1 — 10 (female). Plate XXVIII,

figs. 10 — 17 (male).

Female — length 5,8 mm.

Seen from above, the body is elongate ovate, but is rather less robust than in the
previous species. The outline of the forehead is sharply triangular and the crest is not very

109 «

I IO

prominent. The lateral margins of the last thoracic segment are evenly contracted, and termi-
nate in a short point. Viewed from the side, the crest is rather low and is broadly rounded
at the apex. The posterior margin of the last thoracic segment is triangular in outline and
sharply pointed. The middle of the ventral margin is distinctly pointed. The rostrum is short
and very broad. The apical spines are very small and stout.

The combined length of the abdomen and furca is contained fully three and a half
times in the total length of the cep/m/otkorax, from the apex of the crest to the base of the
genital segment. The genital segment appears cylindrical when viewed from above, and is equal
to the combined length of the next two segments. The proximal portion of the ventral surface
is produced into a broadly triangular process. The second and third segments are of equal
length. The furcal joints are slightly longer than broad, and are equal to about two-thirds of
the length of the second abdominal segment.

The antennules are composed of twenty-four joints and extend a little beyond the furca.

The antennae, mandibles, maxillae and maxillipedes are nearly similar to those of Scot-
tocalaims securifrons.

The four pairs of swimming feet are also nearly similar to those of that species.

The free joint of the fifth pair of feet is of almost equal width throughout. The inner
margin is slightly concave, and the outer margin is flatly rounded. The long subapical spine
is fully four and a half times as long as the joint, and is bifid at the apex. The apical spine
is short, and is equal to one-nineteenth of the length of the long spine.

Male — length 6 mm.

In general appearance it resembles the female. The crest is low and the last thoracic
segment terminates in small points. Viewed from the side, the crest appears low and broadlv
rounded. The last thoracic segment is rather flatly rounded at the distal end, and is furnished
with a small spine near the lovver edge. The ventral margin of the segment is slightly inflated,
and is sinuous in outline. The rostrum is moderately long and wide. It is narrower than in
the female, and the excavation is deeper. The apical spines are also slightly longer.

The combined length of the abdomen and furca is contained two and one-third times
in the total length of the ccphalothorax, from the apex of the crest to the base of the genital
segment. The furcal joints are very small.

The antennules are composed of nineteen joints, and extend to the middle of the fourth
abdominal segment.

The antennae, mandibles, maxillae and maxillipedes are similar to those of the female.

The four pairs of swimming are also similar to those of the female.

The exopodite of the right fifth foot is three-jointed and is only slightly curved. The
third joint is moderately long and lamelliform. The endopodite is spiniform and extends to the
end of the first joint of the exopodite. The exopodite of the left fifth foot is cylindrical, and
the first joint is rather longer than the second. The apex of the second joint is furnished with
two curved spines and a pad of hairs. The endopodite is lamelliform, and is only a little longer
than the first joint of the exopodite.

The male and female of this species are easily clistinguished from the other members of

I I I

the genus, by the rounded form of the crest when seen from the side, by the shape of the last
thoracic segment, and by the structure of the fifth pair of feet of both sexes.

O cc urr e nee. One female and three males were found in the plankton collected

with the Hensen vertical net at Station 203, 1500 metres to the surface.

This species is named in compliment to my father Mr. Thomas Scott, L.L.Ü., to whom
I owe any knowledge I possess in Natural History. His advice and experience have been of
the greatest value in the preparation of this report.

7. Scottocalamis helenae (Lubbock). Plate XXVII, figs. 1 — 9.

Undina helenae Lubbock, 1S56, p. 19, pis. IV & VII.
Scolecithrix securifrons T. Scott, 1893, p. 47, pi. IV (male).
Undina helenae Giesbrecht & Schmeil, 1898, p. 52.
Scolecithrix persecans Farran, 1908, p. 58.

Male — length 4,9 mm.

Yiewed from above, the body appears elongate and moderately robust. The anterior
and posterior ends are evenly contracted. The crest is high and conspicuous. The lateral margins
of the last thoracic segment are much constricted near the distal end, and are produced into
angularly pointed terminations. Seen from the side, the crest is moderately high and is narrowly
rounded at the apex. The posterior margin of the last thoracic segment is slightly produced and
is narrowly rounded, with a considerable slope on each side- of the apex. The rostrum is short
and stout with moderately long apical spines. Their length exceeds the depth of the excavation.

The antennules are nineteen-jointed and extencl to the end of the third abdominal segment.

The antennae, mandibles, maxillae and maxillipedes are similar to those of the male of
Scottoca la n us secu rif r on s .

The four pairs of swimming feet are also similar to the four pairs of feet of the male
of that species.

The exopodite of the right fitth foot is two-jointed and sickle-shaped. The second joint
is lamelliform, and is equal to half the length of the first joint. The endopodite extends to
the distal end of the second joint of the basiopodite. The distal half of the endopodite is
sickle-shaped, and the outer margin is furnished near the middle with a tooth-like process. The
joints of the exopodite of the left fifth foot are of about equal length. The proximal end of
the inner margin of the second joint is considerably dilated. The apex is furnished with two
curved spines and a pad of hairs. The endopodite is very short and stout. It is only half the
length of the first joint of the exopodite.

Female unknown.

Occurrence. — One specimen of this species was obtained from the plankton col-
lected with the Hensen vertical net at Station 148, 1000 metres to the surface.

This form appears to be identical with the species described and figured by Lubbock
in the Transactions of the Zoological Society for 1856, as Undina helenae. It is identical with
the male described and illustrated in the report, 'On Entomostraca from the Gulf of Guinea',
as the male of Scolecithrix securifrons.

1 I 2

The figure of the fifth pair of feet given by Lubbock shews the right and left sides in
a reversed condition. The endopodite of the true right side is moderately long and curved. It
has a distinct tooth on the middle of the outer margin. These two points distinguish this fifth
pair of feet from that of any of the other known males belonging to the genus Scottocalamis.
The strongly curved endopodite of the right fifth foot, the very short endopodite of the left
foot along with the dilated inner margin of the second joint of the exopodite, are at once
obvious on comparing the figure of the Gulf of Guinea specimen, with the illustration given
in this report. This species differs entirely from Scottocalamis persecans (Giesbrecht), in the
length of the rostral spines, in the shape of the exopodite of the left fifth foot, and also in
the shape of the endopodite of the right and left sides. Farran's suggestion that it is the male
of Scottocalamis persecans is erroneous, as it differs from that species in the particular points
already mentioned.

The absence of a terminal spine on the distal ends of the last thoracic segment shews
that this form cannot be the male of Scottocalamis setosus, or of Scottocalamis longispinus
described in the present report.

Tribe HETERARTHANDRIA.
9. Family Centropagidae.

Genus Centropages Kroyer, 1848.

This genus was established by Kroyer in 1848. The forms belonging to it are readily
recognised by the structure of the fifth pair of feet of the two sexes. The exopodite of the
female fifth pair of feet is three-jointed. The second joint of the exopodite of the right and
left sides is produced internally into a strong spiniform process. The shape, length and armature
of the projection varies in the different species, and forms one of the characters that assist
in distinguishing them. In the male fifth pair of feet, the left exopodite is composed of two
joints. The right exopodite is three-jointed. The second and third joints are greatly developed,
and form a powerful chela.

Five species were represented in the plankton collected in the Malay Archipelago by
the 'Siboga'.

S"

Centropages calanimis (Dana).

Cyclopsina calanina Dana, 1849, p. 25.

Centropages calanimis Giesbrecht, 1S93, p. 305, pis. 17, 18 & 38.
Centropages calaninus Giesbrecht & Schmeil, 1898, p. 58.
Centropages calanimis Cleve, 1901, p. 5.
Centropages calaninus A. Scott, 1902, p. 404.
Centropages calaninus Thompson & Scott, 1903, p. 247.
Centropages calaninus Wolfenden, 1905 (a), p. 1014, pi. XCVIII.

112

n 3

This species was rather scarce in the area investigated. Fifteen specimens vvere obtained
from the following six stations.

Stat. Si, 2 specimens. — Stat. 93, 3 specimens. — Stat. 96 (day), 2 specimens. — Stat. 96
inight), 2 specimens. — Stat. 282, 3 specimens. — Stat. 304, 3 specimens.

Centropages calaninus is not unlike Centropages violaceus in general appearance. The
female can readily be separated, however, by the moderately long anal segment, and by the
structure of the fifth pair of feet. The spiniform projection of the second joint of the exopodite
is nearly straight. It extends beyond the distal end of the third joint. The claw-like third joint
of the exopodite of the right fifth foot of the male, lias a distinct knee near the proximal end.

The species has already been recorded by Cleve from the Malay Archipelago.

2. Centropages elongatus Giesbrecht.

Centropages elongatus Giesbrecht, 1896, p. 322, pi. 5, figs. 3 — 6.
Centropages elongatus Giesbrecht & Schmeil, 1898, p. 58.
Centropages elongatus A. Scott, 1902, p. 404, pi. 1, figs. 13 & 14.
Centropages elongatus Thompson & Scott, 1903, p. 246.
Centropages elongatus Cleve, 1903, p. 359.
Centropages elongatus YVolfenden, 1905(0), p. 1014, pi. XCVIII.

This Centropages was very rare. Only five specimens were obtained from the plankton
collected during the traverse. The following are the stations where it was noted.

Stat. 66, 1 specimen. — Stat. 96 (day), 1 specimen. — Stat. 96 (night), 1 specimen. —
Stat. 128 (HENSEN vertical net, 700 metres to surface), 2 specimens.

The females are readily separated from the females of the other species, by the proportional
length of the segments of the abdomen, and by the length of the projection of the second
joint of the exopodite of the fifth pair of feet. The second and third abdominal segments are
of nearly equal length. When viewed from above, the lateral margins appear regular in outline.
The projection of the second joint of the exopodite of the fifth pair of feet, is very little
longer than the third joint.

Giesbrecht described this Centropages from specimens found in plankton collected from
the water pumped into the sanitary tank of a steamship, when the vessel was traversing the
Red Sea in 1895. I a^so obtained the species from plankton collected in a similar marmer by
Mr. H. C. Robinson, while making a voyage between Suez and Colombo in 1901, and again
from Professor Herdman's samples taken on the same route in 1902. Wolfenden found the
species in the plankton collected by Mr. J. Stanley Gardiner around the Maldive Islands.

Centropages furcatns (Dana).

Catopia furcata Dana, 1S49, p. 25.

Centropages furcatns Brady, 1883, p. 83, pi. XXVIII.

Centropages furcatns Giesbrecht, 1893, p. 304, pis. 17, 18 & 38.

Centropages furcatns T. Scott, 1893, p. jj.

Centropages furcatns Giesbrecht & Schmeil, 1898, p. 56.

Centropages furcatns I. C. Thompson, 1900, p. 279.

113

SIBOGA-EXPED1TIE XXIXtf.

«5

W3

/OC

i 14

Centropages furcatus Cleve, 1901, p. 5.
Centropages furcatus A. Scott, 1902, p. 403.
Centropages furcatus Thompson & Scott, 1903, p. 246.
Centropages furcatus Cleve, 1903, p. 359.
Centropages furcatus Cleve, 1904, p. 187.
Centropages furcatus Wolfenden, 1905 (a), p. 1016.

This was by far, the most common and widely distributed member of the genus represented
in the plankton collected by the 'Siboga' as the following records shew.

Stat. 16. — Stat. 35. — Stat. 37. — Stat. 47". — Stat. 50. — Stat. 66. — Stat. 71. —
Stat. 81. — Stat. 89. • - Stat. 93. — Stat. 96 (day). — Stat. 96 (night). — Stat. 98. —
Stat. 99. — Stat. 101. — Stat. 106. — Stat. 109. — Stat. 117". — Stat. 125 (day). —
Stat. 128 (Hensen vertical net, 700 metres to surface). — Stat. 136. — Stat. 141 (Hensen
vertical net, 1500 metres to surface). — Stat. 142. — Stat. 143 (HENSEN vertical net,
1000 metres to surface). — Stat. 146. — ■ Stat. 148 (HENSEN vertical net, 1000 metres to
surface). — Stat. 165. — Stat. 169. — Stat. 174. — Stat. 184. — Stat. 185 (HENSEN
vertical net, 1536 metres to surface). — Stat. 203 (HENSEN vertical net, 1500 metres to
surface). — Stat. 204. — Stat. 205. — Stat. 213. — Stat. 214. — Stat. 217 (horizontal
cylinder). — Stat. 220 (HENSEN vertical net, 200 metres to surface). — Stat. 224. —
Stat. 245. — Stat. 282. — Stat. 304. — Stat. 315.

Centropages furcatus can readily be recognised by its slender body, by the spiniform
prolongations of the last thoracic segment, and by the very short middle segment of the abdomen
of the female. The structure of the fifth pair of feet of both sexes is also characteristic.

This species has apparently a moderately wide distribution in -the tropical seas.

4. Centropages gracilis (Dana).

Cyclopsina gracilis Dana, 1849, p. 25.

Centropages gracilis Giesbrecht, 1893, p. 305, pis. 17 & 38.

Centropages gracilis Giesbrecht & Schmeil, 1898, p. 57.

Centropages gracilis Cleve, 1901, p. 5.

Centropages gracilis Thompson & Scott, 1903, p. 247.

Centropages gracilis Cleve, 1903, p. 359.

Centropages gracilis Wolfenden, 1905 [o], p. 1013, pi. XCVIII.

This Centropages was not uncommon in the plankton obtained during the investigations
in the Malay Archipelago. The distribution was comparatively wide. Examples of it were found
at the following stations.

Stat. 37. — Stat. 66. — Stat. 81. — Stat. 93. — Stat. 96 (day). — Stat. 96 (night). —
Stat. 98. - - Stat. 118 (Hensen vertical net, 900 metres to surface). — Stat. 13S. — Stat.
203 (Hensen vertical net, 1500 metres to surface). ■ — Stat. 217 (horizontal cylinder). —
Stat. 276 (HENSEN vertical net, 750 metres to surface). — Stat. 282.

Centropages gracilis resembles Centropages violaceus in general appearance. The females
however, can easily be distinguished by the distinct knob-like projection on the lateral margins
of the second abdominal segment when seen from above. The surface of each knob is covered
with fine short spines. The fifth pair of feet of both sexes is also distinct. The projection of
the second joint of the exopodite of the female fifth pair is nearly straight. It is moderately
stout and is almost as long as the third joint. In Centropages violaceus the projection is somewhat

114

sinous in shape, and the distal end is more contracted than in Ccntropagcs gracilis. The right
fifth foot of the male is quite distinct from that of the male of Centropages violaceus.

Wolfenden 1 905(^7) is inclined to doubt the correctness of the record of Centropages
vio/accus in 'the report on the Ceylon Copepoda by the late I. C. Thompson and the present
writer. He suggests that the species is really Ceiüropages gracilis. Both species however, are
recorded in that report from the neighbourhood of Ceylon, in addition to the other records
obtained by examining the samples collected during the voyages out to the Island and back.
Although Wolfenden did not find Ceiüropages violaceus in the Maldive plankton, it does not
follow that it ought to be absent from the Ceylon fauna. Wolfenden's experience amongst the
Copepoda ought to have taught him, that it does not always follow that a marine species,
no matter where it be originally found, will not prove through some future investigation, to
have a wider distribution than its describer could be aware of. The present report gives striking
examples of this. Centropages violaceus was described by Claus (not Giesbrecht as Wolfenden
has it) from Mediterranean specimens. I have undoubted examples of it from the Atlantic, off
Cape Town, obtained from plankton collected by Professor Herdman, during his ocean journeys
to and from the meeting of the British Association, in South Africa in 1905.

Centropages gracilis, so far, is only known from the Indian and Pacific Oceans.

5. Centropages orsinii Giesbrecht.

Centropages orsinii Giesbrecht, 1 889, p. 811.

Centropages orsinii Giesbrecht, 1893, p. 305, pis. 17, iS & 38.

Centropages orsinii Giesbrecht & Schmeil, 189S, p. 57.

Centropages orsinii Cleve, 1901, p. 5.

Centropages orsinii A. Scott, 1902, p. 404.

Centropages orsinii Thompson & Scott, 1903, p. 247.

Centropages orsinii Cleve, 1903, p. 359.

Centropages orsinii Wolfenden, 1905 (a), p. 1015 pi. XCVIII.

This member of the genus appeared to be more common than the last species. It had
also a slightly wider distribution as shewn by the following records.

Stat. 16. — Stat. 40. — Stat. 47''. — Stat. 66. — Stat. 71. — Stat. 96 (day). — Stat. 96
(night). — Stat. 109. — Stat. 1 10. — Stat. 117". — Stat. 118 (HENSEN vertical net, 900
metres to surface). — Stat. 122. — Stat. 133. — Stat. 142. — Stat. 213. — Stat. 282. -
Stat. 304.

Centropages orsinii has a certain amount of resemblance to Centropages kroyeri, but it can
readily be separated from that species by the structure of the fifth pair of feet of the two sexes.
The projection of the second joint of the exopodite of the female fifth pair is short and stout.
It is beset with small spines. In Centropages kroyeri the projection is comparatively slender, and
it is without spines. The claw-like joint of the male right fifth foot is longer than the projection
of the second joint. In Centropages kroyeri the projection is longer than the claw-like joint.

Giesbrecht's type specimens where obtained from the Red Sea. The species is evidently
well distributed in the Indian Ocean as proved by the later records.

"5

n6

10. Family Pseudodiaptomidae.
Genus Pseudodiaptomus Herrick, 1884.

The members of this genus, established by Herrick in 1884, are readily recognised by
the structure of the fifth pair of feet of the two sexes. The fifth pair of the female consists
of a two-jointed basiopodite and an exopodite composed of two or three joints. The endopodite
is • stated to be entirely absent, but one of the species found in the plankton collected by the
'Siboga', shews an indication of what appears to be a very rudimentary endopodite. The male
fifth pair forms a prehensile appendage. The basiopodite is two-jointed. The exopodite of the
right side is composed of two or three joints. The last joint is usually claw-like. The exopodite
of the left side consists usually of two joints. The last joint is frequently lamelliform.

Two species were represented in the plankton collected by the 'Siboga'.

1. Pseudodiaptomus aurivillii Cleve.

Pseudodiaptomus aurivillii Cleve, 1901, p. 48, pis. VI & VII.

Pseudodiaptomus aurivillii Thompson & Scott, 1903, p. 248, pi. II, figs. 24 — 26.

This species although very limited in its distribution, proved to be rather plentiful in
one of the gatherings. It was present at the following stations.

Stat. 16, 4 specimens. — Stat. 71, ó specimens. — Stat. 133, 3 specimens. — Stat. 174, S
specimens. — Stat. 213, 96 specimens.

Pseudodiaptomus aurivillii is easily separated from the other members of the genus,
by the characters of the fifth pair of feet of the two sexes. The second joint of the exopodite
of the female fifth pair is very small. It terminates in a moderately long spiniform claw. The
right foot only of the male is furnished with an endopodite. The second joint of the basiopodite,
and the first joint of the exopodite of the right foot have each a strong outer edge spine.

Cleve obtained the type specimens from plankton collected in the Malay Archipelago.
It has also been recorded, and partly illustrated from specimens found in the collections taken
by Professor Herd.man, during his investigations on the pearl banks in the Gulf of Manaar, Ceylon.

2. Pseudodiaptomus elcvei nov. sp. Plate XXXVII, figs. 1 — 8.

Female — length 1,75 mm.

Seen from above, the female bears a general resemblance to Pseudodiaptomus aurivillii.
The last thoracic segment is produced into strong spines. Two dorsal spines are also present
on the surface of the last thoracic segment, just in front of the junction with the abdomen.
Viewed from the side, the forehead appears evenly rounded. The last thoracic segment is
rather narrowly rounded at the posterior end, and the dorsal spines are quite visible (Plate
XXXVII, fig. 3).

The abdomen is composed of four segments. The combined length of the abdomen and
furca is contained one and a half times in the total length of the cephalothorax, from the

116

frontal margin to the base of the genital segment. The genital segment is distinctly shorter
than the combined lengfth of the second and third segments. Vievved from above, the segment
appears much dilated in the anterior region. In side view the dorsal line is nearly straight.
The ventral surface is much inflated. It is furnished with a well defined tooth-like process at
the proximal end. There are no spines at the genital opening as in P seudodiaptomus aurivillii.
The second, third and fourth segments are subequal in length. The furcal joints exceed the
combined length of the third and fourth abdominal segments. The joints are asymmetrical. The
right joint is distinctly narrower than the left. The posterior margin of the first, second and
third segments is fringed with fine spines.

The antennules are composed of twenty-one joints and extend to the end of the third
abdominal segment.

The antennae, mandibles, maxillae and maxillipedes are somewhat similar to those of
P seudodiaptomus serricaudatus (T. Scott).

The four pairs of swimming feet also resemble those of that species.

The exopodite of the fifth pair of feet is three-jointed. It approaches the shape of that
of P seudodiaptomus salinus and P seudodiaptomus serricaudatus, but the internal distal projection
of the second joint is nearly as long as the claw-like joint. The second joint of the basiopodite
is produced internally, and bears two small spines which may indicate a rudimentary endopodite
(Plate XXXVII, fig. 5).

Male — length 1,52 mm.

The male resembles the female except, that the right antennule is modified for grasping,
the abdomen is composed of five segments, and the furcal joints are shorter than in the female.

The right antennule is composed of nineteen joints. The seventh joint is incompletely
separated. The eleventh, twelfth, thirteenth and fourteenth joints are swollen. The hinge is
situated between the sixteenth and seventeenth joints.

The antennae, mandibles, maxillae and maxillipedes are similar to those of the female.

The four pairs of swimming feet are also similar to those of the female.

The endopodite is entirely absent in the fifth pair of feet. The apical joint of the exo-
podite of the right foot is in the form of a long sickle shaped claw-like spine. The apical joint
of the exopodite ot the left foot is subcircular in outline and lamelliform. The apex is very
broad and bears two small spines. The middle of the outer margin is furnished with one strong
spine (Plate XXXVII, fig. 8).

P seudodiaptomus clevei is easily separated from the other members of the genus, by the
presence of two dorsal spines on the last thoracic segment, in addition to the strong posterio-
lateral spines, and by the structure of the fifth pair of feet of the two sexes.

Occurrence. — Two females and two males were found in the plankton collected
at Station 16.

This species is dedicated to the memory of the late Professor P. T. Cleve whose
researches amongst the oceanic plankton organisms are of the greatest value.

"7

1 1 s

ii. Family Temoridae.

Genus Temora W. Baird, 1850.

The species belonging to this genus are easily distinguished from the other members of
the family by their compact body, cylindrical abdomen and long slender furcal joints, and by
the structure of the fifth pair of feet of both sexes.

Two species were represented in the plankton collected by the 'Siboga'.

1. Temora discaudata Giesbrecht.

Temora discaudata Giesbrecht, 1889, p. 814.

Temora discaudata Giesbrecht, 1893, p. 328, pis. 17 & 38.

Temora discaudata Giesbrecht, 1895, p. 257.

Temora discaudata Giesbrecht & Schmeil, 1898, p. 10 1.

Temora discaudata I. C. Thompson, 1900, p. 280.

Temora discaudata Cleve, 1901, p. 9.

Temora discaudata A. Scott, 1902, p. 405.

Temora discaudata Thompson & Scott, 1903, p. 248.

Temora discaudata Cleve, 1903, p. 369.

Temora discaudata Cleve, 1904, p. 198.

Temora discaudata Wolfenden, 1905 (a), p. 1023.

This species was moderately common and proved to be widely distributed in the Malay
Archipelago as shewn by the following records.

Stat. 16. — Stat. 19. — Stat. 35. — Stat. 36. — Stat. 37. — Stat. 40. — Stat. 47". —
Stat. 50. — Stat. 66. — Stat. 71. — Stat. 75 (Hensen vertical net, 11 metres to surface). —
Stat. 81. — Stat. 89. — Stat. 93. — Stat. 96 (day). — Stat. 96 (night). — Stat. 98. —
Stat. 99. — Stat. 101. ■ — Stat. 109. — Stat. 1 10. — Stat. 112. — Stat. ii7a. — Stat. 118
(HENSEN vertical net, 900 metres to surface). — Stat. 121. — Stat. 122. — Stat. 124. —
Stat. 125 (day). — Stat. 136. — Stat. 138. — Stat. 141 (HENSEN vertical net, 1500 metres
to surface). — Stat. 144. — Stat. 148 (Hensen vertical net, 1000 metres to surface). —
Stat. 165. — Stat. 168. — Stat. 169. — Stat. 172. — Stat. 1S4. — Stat. 185 (Hensen
vertical net, 1536 metres to surface). — Stat. 186. — Stat. 189^. — Stat. 193. — Stats.
194 — 7. — Stat. 203 (surface). — Stat. 203 (HENSEN vertical net, 1500 metres to surface). —
Stat. 204. — Stat. 205. — Stat. 2io\ — Stat. 213. — Stat. 214. — Stat. 215". —
Stat. 216. — Stat. 217 (horizontal cylinder). — Stat. 220 (surface). — Stat. 220 (HENSEN
vertical net, 200 metres to surface). — Stat. 223. — Stat. 225. — Stat. 229. — Stat. 230
(HENSEN vertical net, 2000 metres to surface). — Stat. 245. — Stat. 252. — Stat. 271. —
Stat. 276 (HENSEN vertical net, 750 metres to surface). — Stat. 282. — Stat. 304. —
Stat. 315.

The females are easily identified by the spiniform projections of the last thoracic segment,
and by the very asymmetrical furcal joints.

Temora discaudata appears to be widely distributed in tropical seas.

2. Temora turbinata (Dana).

Calanus turbinatus Dana, 1849, p. 12.

Temora turbinata Giesbrecht, 1893, p. 329, pis. 17 & 38.

11S

i 19

Temora turbinata Giesbrecht & Schmeil, 1S98, p. 101.
Temora turbinata Thompson & Scott, 1903, p. 249.
Temora turbinata Sars, 1905 (b), p. 2.

The forms belonging to this species although less numerous in the plankton than the
representatives of the previous one, were found to have a moderately wide distribution in the
area investigated, as shewn by the following records.

Stat. 16. — Stat. 35. — Stat. 36. — Stat. 37. — Stat. 40. — Stat. 4/''. — Stat. 50. —

Stat. 71. — Stat. 75. — Stat. 141 (HENSEN vertical net, 1500 metres to surface). —

Stat. 142. — Stat. 144. Stat. 14S (HENSEN vertical net, 1000 metres to surface). —

Stat. 165. — Stat. 1S4. Stat. 185 (HENSEN vertical net, 1536 metres to surface). —

Stat. 204. — Stat. 205. — Stat. 220 (HENSEN vertical net, 200 metres to surface). —

Stat. 225. — Stat. 229. — Stat. 230 (HENSEN vertical net, 2000 metres to surface). —

Stat. 245. — Stat. 276 (HENSEN vertical net, 750 metres to surface). — Stat. 315.

This Temora has a very close resemblance to Temora longicornis (Muller), found in the
plankton of the Xorth Atlantic, off the coast of Europe, and can only with difficulty be separated
from it. It may simply be a tropical variation of the well known northern form.

Genus Temoropia T. Scott, 1893.

This genus is separated from the other members of the family by the structure of the
fifth pair of feet of both sexes. The fifth pair of the female is not quite symmetrical in the
type form, but it is quite symmetrical in North Atlantic examples of a nearly related species.
The female fifth pair is represented by two free joints attached to a basal part. The first free
joint is furnished at its inner distal angle with a spiniform process, which may represent a
rudimentary endopodite. The male fifth pair is large and conspicuous.

One species was obtained from the plankton collected by the 'Siboga'.

1 . Temoropia mayitmbaensis T. Scott.

Temoropia mayumbaensis T. Scott, 1893, p. 79, pis. VIII & IX.
Temoropia mayumbaensis Giesbrecht & Schmeil, 189S, p. 96.
Temoropia mayumbaensis Thompson & Scott, 1903, p. 248.

The typical member of the genus was rather rare in the area investigated. Males and
females were obtained from the plankton collected at the following stations.

Stat. 35, 2 specimens. — Stat. 143 (HENSEN vertical net, 1000 metres to surface), 6 speci-
mens. — Stat. 148 (HENSEN vertical net, 1000 metres to surface), 4 specimens. — Stat. 184,
3 specimens. — Stat. 185 (HEXSEN vertical net, 1536 metres to surface), 1 specimen. —
Stat. 203 (HENSEN vertical net, 1500 metres to surface), 8 specimens. — Stat. 220 (HENSEN
vertical net, 200 metres to surface), 4 specimens. — Stat. 243 (HENSEN vertical net, 1000
metres to surface), 4 specimens.

Temoropia mayumbaensis is a very characteristic form and is readily recognised by the
structure of the fifth pair of feet of both sexes. The ventral surface of the genital segment of
the female is greatly inflated. Length, female .94 mm., male .9 mm.

This species has hitherto only been known from the Gulf of Guinea and from the Gulf of Suez.

119

I 20

The form recorded by G. P. Farran (1908), from the deep water off the West of Ireland
as this species, is apparently not identical. Farran states that the fifth pair of feet of the female
is symmetrical, and his illustration shews that the last joint is furnished with a claw-like spine
at the apex. In Tcmoropia mayumbaensis the last joint of the female fifth pair is asymmetrical
and the apex is dentate. The 'Siboga' specimens are identical with the illustrations given in
the report 'On Entomostraca from the Gulf of Guinea'. Farran's specimens measured 7,2 — 8 mm.
in lenoth.

12. Family Metridiidae.
Genus Metridia Boeck, 1864.

The members of this genus are separated from Plcnromamma, chiefly by the absence
of a pigmented luminous organ on the side of the first thoracic segment.

Five species were represented in the plankton collected by the 'Siboga' in the Malay
Archipelago.

1. Metridia boecki Giesbrecht. Plate XXXVII, figs. 12 — 14.

Metridia boecki Giesbrecht, 1889, p. 24.

Metridia boecki Giesbrecht, 1S93, p. 340, pi. 33.

Metridia boecki Giesbrecht & Schmeil, 1898, p. 107.

Metridia boecki Esterly, 1905, p. 178, fig. 354/.

One female belonging to this species, was obtained from the plankton collected with
the Hensen vertical net at each of the following five stations.

Stat. 118 (900 metres to surface). — Stat. 141 (1500 metres to surface). — Stat. 148, fiooo
metres to surface). — Stat. 203 (1500 metres to surface). — Stat. 276 (750 metres to surface).

The females of Metridia boecki bear a close resemblance to the females of Metridia
Ineens, but the furcal joints are as long as the anal segment, and the fifth pair is composed
'of three free joints attached to a basal part. The fifth pair of Metridia ineens has only two
free joints.

The species, so far, has only been recorded by Giesbrecht in the Fauna und Flora
des Golfes von Neapel and by Esterly from the Pacific, off San Diego.

2. Metridia brevicanda Giesbrecht. Plate XXXVII, figs. 9 — 11.

Metridia brevicanda Giesbrecht, 1SS9, p. 24.
Metridia brevicanda Giesbrecht, 1893, p. 340, pi. 33.
Metridia brevicanda Giesbrecht & Schmeil, 1898, p. 108.
Metridia brevicanda Wollenden, 1904, p. 111.
Metridia brevicanda Cleve, 1904, p. 192.
Metridia brevicanda Pearson, 1906, p. 24.
Metridia brevicanda Farran, 1908, p. 60.
Metridia brevicanda van Breemen, 1908, p. 111, fig. 128.

120

I 2 I

Females apparently iclentical with the above species, were obtained from the plankton
collected with the Hensen vertical net at the following stations.

Stat. [l8 (yoo metres to surface), 3 specimens. — Stat. 141 (1500 metres to surface), 4 spe-
cimens. — Stat. 143 (1000 metres to surface), 4 specimens. — Stat. 185 (1536 metres to
surface), 3 specimens. — Stat. 203 (1500 metres to surface), 4 specimens. — Stat. 276
(750 metres to surface), 4 specimens.

The genital segment of the 'Siboga' specimens, is equal to the combined length of the
second and third abdominal segments. The fifth pair of feet is composed of two free joints
attached to a basal part. The apical joint of one foot is furnished with two setae, and the
other with one only. (Plate XXXVII, fig. 11). Length 1,9 mm.

The female fifth pair of feet of Metridia curticauda, a species closely related to Metridia
brevicauda^ has three free joints and a basal part.

Metridia brevicauda has been recorded from the Atlantic and Pacific Oceans.

3. Metridia macrura G. O. Sars. Plate XXXVIII, figs. 8 — 11.
Metridia macrura Sars, 1905 (^), p. 7.

A single female agreeing with the preliminary description of the above species, was
found in the plankton collected with the Hensen vertical net at Station 230, 2000 metres to
the surface. Length 10,5 mm.

The furcal joints are nearly three times the length of the anal segment. The joints are
twelve times longer than broad. The fifth pair of feet is very similar to that of the female of
Metridia princeps.

4. Metridia princeps Giesbrecht. Plate XXXVIII, figs. 1 — 7.

Metridia princeps Giesbrecht, 1889, p. 24.

Metridia princeps Giesbrecht, 1893, p 340, pi. 33.

Metridia princeps Giesbrecht & Schmeil, 1898, p. 107.

Metridia princeps I. C. Thompson, 1903, p. 24, pi. VI, figs. 3 & 4.

Metridia princeps Cleve, 1904, p. 192.

Metridia princeps Sars, 1905 (£), p. 2.

Metridia princeps Farran, 1905, p. 43.

Metridia princeps Pearson, 1906, p. 24.

Metridia princeps Esterly, 1906, p. 69, pis. 11, 13 & 14.

Metridia princeps Farran, 1908, p. 61.

Metridia princeps van Breemen, 1908, p. 1 10, fig. 127.

Nine females and six males were obtained from the plankton collected chiefly with the

Hensen vertical net at the following stations.

Stat. 118 (900 metres to surface). • Stat. 128 (700 metres to surface). — Stat. 141 (1500
metres to surface). — Stat. 148 (1000 metres to surface). — Stat. 185 (1536 metres to
surface). — Stat. 203 (1500 metres to surface). — Stat. 217 (horizontal cylinder). — Stat.
243 (IOOO metres to surface).

The furcal joints of both sexes are twice as long as the anal segment, and five times
longer than broad. Length, female 7,9 — 8,8, male 8,3 mm.

121

SlBOGA-EXl'EUITIE XXIX<7.

16

12 2

This species has been found to be widely distributed. I have seen examples obtained
from the deep water of the Faröe Channel.

5. Metridia venusta Giesbrecht. Plate XXXYII, figs. 15 — 20.

Metridia venusta Giesbrecht, 1889, p. 24.

Metridia venusta Giesbrecht, 1893, p. 340, pi. n (female).

Metridia normani Giesbrecht, 1893, p. 340, pi. 33 (male).

Metridia venusta Giesbrecht & Schmeil, 189S, p. 107.

Metridia normani Giesbrecht & Schmeil, 1898, p. 107.

Metridia normani Wolfenden, 1904, p. 125, pi. IX, fig. 39.

Metridia venusta Cleve, 1904, p. 192.

Metridia venusta Farran, 1905, p. 43.

Metridia venusta Pearson, 1906, p. 23.

Metridia venusta Farran, 1908, p. 60.

Metridia venusta van Breemen, 1908, p. 110, fig. 126.

Metridia normani van Breemen, 1908, p. 109, fig. 125.

Twelve females and six males belonging to the above species were found in the plankton
collected, with one exception, by means of the Hensen vertical net at the following stations.

Stat. 118 (900 metres to surface), 2 specimens. — Stat. 128 (700 metres to surface), 3 spe-
cimens. — Stat. 141 (1500 metres to surface), 3 specimens. — ■ Stat. 142, 1 specimen. —
Stat. 143 (1000 metres to surface), 4 specimens. — Stat. 148 (1000 metres to surface),
2 specimens. — Stat. 203 (1500 metres to surface), 2 specimens. — Stat. 276 (750 metres
to surface), 1 specimen.

The two sexes of this Metridia can readily be recognised by the asymmetrical furcal
joints. The right furcal joint is distinctly shorter than the left. The fifth pair of feet of the
female, consists of one free joint attached to a basal part. Length, female 3,1, male 2,8 mm.

I do not think that there can now be any doubt that the species described by Giesbrecht
as Metridia normani, is only the male of Metridia venusta. The male fifth pair illustrated in
this report is identical with the figure given by Giesbrecht. Wolfenden' s figure of the fifth
pair of the supposed female of Metridia normani is simply the fifth pair of the female of
Metridia venusta. If a line be drawn across from the outer edsre setae to the inner margin
in the figure now given, one would practically have a similar illustration to that shewn by
Wolfenden. The joint shewn by that author is probably due to a defective prepara tion.
Giesbrecht's figure of the female fitth pair, shews the apex of the free joint to be furnished
with two setae. The 'Siboga' females have three as illustrated. (Plate XXXVII, fig. 17).

Metridia venusta has a distribution almost similar to that of Metridia princeps.

Genus Pleuromamma Giesbrecht, 1898.

The members of this genus are readily recognised by the presence of a pigmented
luminous organ on the right or left side of the first thoracic segment.

Three species were represented in the area traversed by the 'Siboga'.

1 . Pleuromamma abdominalis (Lubbock).

Diaptomus abdominalis Lubbock, 1856, p. 22, pi. X.

Pleuromma abdominale Claus, 1863, p. 197, pis. V & VI.

Pleuromma abdominale Brady, 1883, p. 46, pis. XI. XII 8e XXXI.

Pleuromma abdominale Giesbrecht, 1893, pp. 347 & 356, pis. 5, 32 & 33.

Pleuromma abdominale T. Scott, 1893, p. 41.

Pleuromamma abdominalis Giesbrecht & Schmeil, 189S, p. 109.

Pleuromma abdominale Cleve, 1901, p. 8.

Pleuromma abdominale Wolfenden, 1902, p. 362.

Pleuromamma abdominalis A. Scott, 1902, p. 405.

P/euromamma abdominalis I. C. Thompson, 1903, p. 25.

Pleuromamma abdominalis Thompson & Scott, 1903, p. 249.

Pleuromamma abdominalis Cleve, 1903, p. 367.

Pleuromamma abdominalis Wolfenden, 1904, pp. 11 1 & 112.

Pleuromamma abdominalis Cleve, 1904, p. 195.

Pleuromamma abdominalis Wolfenden, 1905 (a), p. 1010.

Pleuromamma abdominalis Sars, 1905 (b), p. 2.

Pleuromamma abdominalis Esterly, 1905, p. 174, fig. 33 a & b.

Pleuromamma abdominalis Farran, 1908, p. 61.

Pleuromamma abdominalis van Breemen, 1908, p. 104, fig. 1 19.

This form appeared to be moderately common. It had a wide distribution in the Malay
Archipelago as shewn by the records now given.

Stat. 37. — Stat. 40. — Stat. 66. — Stat. 71. — Stat. 106. — Stat. 1 10. — Stat. 1 17'. —
Stat. 118 (HENSEN vertical net, 900 metres to surface). — Stat. 128 (HENSEN vertical net,
700 metres to surface). — Stat. 141 (HENSEN vertical net, 1500 metres to surface). —
Stat. 142. — Stat. 143 (HENSEN vertical net, 1000 metres to surface). — Stat. 144. —
Stat. 146. — Stat. 148 (HENSEN vertical net, 1000 metres to surface). — Stat. 177". —
Stat. 185 (HENSEN vertical net, 1536 metres to surface). — Stat. i89a. — Stat. 194 — 7. —
Stat. 203 (HENSEN vertical net, 1500 metres to surface). — Stat. 216. — Stat. 230 (HENSEN
vertical net, 2000 metres to surface). — Stat. 245. — Stat. 276 (HENSEN vertical net, 750
metres 'to surface). — Stat. 304. — Stat. 315.

Plairoi?iamma abdominalis can readily be separated from the other species by the
structure of the fifth pair of feet of the two sexes. The luminous organ may be either on the
right or left side. The right antennule of the male is modified for grasping.

The species is widely distributed in all the great oceans. It has been recorded by many
observers.

Brady has apparently included figures of the next species, and also of Metridia Ineens
in his illustrations of Pleuromamma abdominalis.

2. P lenromamma gracilis (Claus).

Pleuromma gracile Claus, 1863, p. 197, pi. V.

Pleuromma abdominale Brady, 1883, p. 46 (pars), pi. XI, fig. 11, pi. XII, fig. 13.

Pleuromma gracile Giesbrecht, 1893, p. 347, pis. 5, 32 & 33.

Pleuromma gracile T. Scott, 1893, p. 42.

Pleuromamma gracilis Giesbrecht & Schmeil, 1898, p. 1 10.

Pleuromma gracile Cleve, 1901, p. 8.

Pleuromamma gracilis A. Scott, 1902, p. 405.

Pleuromamma gracilis I. C. Thompson, 1903, p. 25.

Pleuromamma gracilis Thompson & Scott, 1903, p. 249.

Pleuromamma gracilis Cleve, 1903, p. 367.

124

Pleuromamma gracilis Cleve, 1904, p. 195.
Pleuromamma gracilis Wolfenden, 1905 (a), p. 1012.
Pleuromamma gracilis Sars, 1905^), p. 2.
Pleuromamma gracilis Esterly, 1905, p. 175, fig. 33 (c).
Pleuromamma gracilis Farran, 190S, p. 61.
Pleuromamma gracilis van Breemen, 1908, p. 106, fig. 122.

This Pleuromamma proved to be almost as numerous, and nearly as widely distributed
as the previous species. It was found in the plankton collected by the 'Siboga' at the following

stations.

Stat. 17. — Stat. 40. — Stat. 66. — Stat. 71. — Stat. 75 (Hensen vertical net, n metres
to surface). — Stat. Si. — Stat. 96 (night). — Stat. 117'. — Stat. 118 (Hexsen vertical
net, 900 metres to surface). — Stat. 128 (HENSEN vertical net, 700 metres to surface). —
Stat. 141 (HENSEN vertical net, 1500 metres to surface). — Stat. 143 (HENSEN vertical
net, iooo metres to surface). — Stat. 144. — Stat. 146. — Stat. 148 (HENSEN vertical net,
1000 metres to surface). — Stat. 185 (HENSEN vertical net, 1536 metres to surface). —
Stat. 1891. — Stat. 203 (Hensen vertical net, 1500 metres to surface). — Stat. 204. ■ —
Stat. 216. — Stat. 225. — Stat. 230 (HENSEN vertical net, 2000 metres to surface). —
Stat. 243 (HEXSEN vertical net, 1 000 metres to surface). — Stat. 245. — Stat. 276 (HENSEN
vertical net, 750 metres to surface). — Stat. 304. — Stat. 315.

The luminous organ in this species is present on the right side only. The left antennule
of the male is modified for grasping. The fifth pair of feet of the female is composed of a
single joint attached to a basal part. The apex of the free joint is furnished with three short spines.

This species appears to be nearly as widely distributed as the previous forin.

Some of Brady's figures in the report on the 'Challenger' Copepoda refer to Pleuro-
mamma gracilis.

3. Pleuromamma xipliias (Giesbrecht).

Pleuromma xiphias Giesbrecht, 1889, p. 25.

Pleuromma xiphias Giesbrecht 1893, p. 347, pis. 32 & 33.

Pleuromamma xiphias Giesbrecht & Schmeil, 1S98, p. 109.

Pleuromamma xiphias Thompson & Scott, 1903, p. 249.

Pleuromamma xiphias Cleve. 1904, p. 195.

Pleuromamma xiphias Wolfenden, 1905 (a), p. 1012.

Pleuromamma xiphias Sars, 1905 (b), p. 2.

Pleuromamma xiphias Esterly, 1905, p. 176, fig. 34.

Pleuromamma xiphias Farran, 1908, p. 61.

Pleuromamma xiphias van Breemen, 1908, p. 105, fig. 120.

This species although represented in fewer plankton samples than either of the other
two was moderately frequent where it did occur. It was noted at the following stations.

Stat. 1171. — Stat. 118 (HENSEN vertical net, 900 metres to surface). — Stat. 128 (HENSEN
vertical net, 700 metres to surface). — Stat. 141 (HENSEN vertical net, 1500 metres to
surface). -- Stat. 143 (Hensen vertical net, 1000 metres to surface). — Stat. 14S (HENSEN
vertical net, 1000 metres to surface). — Stat. 184. — Stat. 185 (HENSEN vertical net, 1536
metres to surface). -- Stat. iSq". — Stat. 203 (HENSEN vertical net, 1500 metres to sur-
face). — Stat. 216. — Stat. 220 (Hensen vertical net, 200 metres to surface). — Stat. 243
(HENSEN vertical net, 1000 metres to surface). — Stat. 276 (HENSEN vertical net, 750
metres to surface). — Stat. 304.

124

I 2^

Pleuromauima xiphias resembles Plcuromamma abdominalis in the strueture of the fifth
feet of the two sexes. The males and females, however, can readily be separated by the presence
of a prominent spiniform process on the forehead.

This species appears to have a moderately wide distribution in the great oceans.

13. Family Lucicutiidae.

Genus Lucicutia Giesbrecht, 1898.

The members of this genus can be recognised by the moderately long abdomen, and
quite symmetrical furcal joints. The fifth pair of feet of the female is somewhat similar to the
third and fourth pairs, but the inner distal angle of the second joint of the exopodite is furnished
with an awl-like spine. The exopodite and endopodite of the male left fifth foot are three-
jointed. The exopodite and endopodite of the right foot are two-jointed. The right exopodite
is claw-like.

Seven species were represented in the plankton collected during the investigations of
the 'Siboga' in the Malay Archipelago. Two of the species appear to be undescribed.

1 . Lucicutia flavicornis (Claus).

Leuckartia flavicornis, Claus, 1863, p. 183, pi. XXXII.

Leuckartia flavicornis, Giesbrecht, 1893, p. 358, pis. 5, 19 & 38.

Lucicutia flavicornis, Giesbrecht & Schmeil, 1898, p. 111.

Leuckartia flavicornis, Cleve, 1901, p. 7.

Leuckartia flavicornis, Wolfenclen, 1902, p. 363.

Lucicutia flavicornis, A. Scott, 1902, p. 405.

Lucicutia flavicornis, I. C. Thompson, 1903, p. 25.

Lucicutia flavicornis Thompson & Scott, 1903, p. 249.

Lucicutia flavicornis Cleve, 1903, p. 364.

Lucicutia flavicornis Wolfenden, 1904, p. 11 1 & 112.

Lucicutia flavicornis Cleve, 1904, p. 192.

Lucicutia flavicornis Wolfenden, 1905 (a), p. 1012.

Lucicutia flavicornis Sars, 1905 (b), p. 3.

Lucicutia flavicornis Farran, 1905, p. 43.

Lucicutia flavicornis Esterly, 1905, pi 180, fig. $6.

Lucicutia flavicornis Pearson, 1906, p. 25.

Lucicutia flavicornis Farran, 190S, p. 64.

Lucicutia flavicornis van Breemen, 1908, p. 112, fig. 129.

This species proved to be well distributed in the Malay Archipelago. It was found in
the plankton collected at the following stations.

Stat 16. — Stat. 35. — Stat. $j. — Stat. 47. -- Stat. 66. — Stat. 75 (Hensex vertical
net, 11 metres to surface). — Stat. 81. — Stat. 96 (night). — Stat. 98. — Stat. 110. -
Stat. u;1. — Stat. 118 (HENSEN vertical net, 900 metres to surface). — Stat. 141 (HENSEN
vertical net, 1500 metres to surface. — Stat. 143 (HENSEN vertical net, 1000 metres to
surface). — Stat. 184. — Stat. 185 (HENSEN vertical net, 1536 metres to surface). — Stat.
203 (HENSEN vertical net, 1500 metres to surface). -- Stat. 205. — Stat. 213. — Stat. 220

I25

I 20

(surface). — Stat. 220 (Hensen vertical net, 200 metres to surface). — Stat. 230 (HENSEN
vertical net, 2000 metres to surface). — Stat. 243 (HENSEN vertical net, 1000 metres to
surface). — Stat. 252. -- Stat. 276 (Hensen vertical net, 750 metres to surface). — Stat.
282. -- Stat. 304. — Stat. 315.

The. antennules extend to about the middle of the furcal joints. The anal segment is
shorter than the segment immediately in front. The furcal joints are equal to the combined
length of the second, third and fourth abdominal segments.

Lucictitia flavicornis is a comparatively small species. It appears to be widely distributed
throughout the great oceans.

2. Lucicutia claitsi (Giesbrecht).

Leuckartia clausi Giesbrecht, 1889, p. 812.

Leuckartia clausi Giesbrecht, 1S93, p. 359, pis. 19 & 38.

Lucicutia clausi Giesbrecht & Schmeil, 1898, p. III.

Leuckartia clausi Cleve, 1901, p. 7.

Lucicutia clausi I. C. Thompson, 1903, p. 26.

Lucicutia clausi Cleve, 1904, p. 192.

Lucicutia clausi Sars, i905(/>), p. 3.

Eight specimens belonging to the above species were obtained from the plankton collected
at the following stations.

Stat. 141 (HENSEN vertical net, 1500 metres to surface), 2 specimens. — Stat. 143 (HENSEN
vertical net, 1000 metres to surface), 1 specimen. — Stat. 184, 1 specimen. — Stat. 203
(HENSEN vertical net, 1500 metres to surface), 3 specimens. — Stat. 230 (HENSEN vertical
net, 2000 metres to surface), 1 specimen.

Lttcicutia c/ausi is a slightly larger form than Litcicutia flavicornis. The two sexes can
easily be distinguished by the presence of a tooth-like projection on each side of the cephalic
segment, when the specimen is viewed from above.

This species appears to be rather rare and its known distribution is limited.

3. Lucicutia bicornuta Wolfenden. Plate XXXIX, figs. 1 — 11.

Lucicutia bicornuta Wolfenden, 1905, p. 24, pi. II.
Lucicutia aurita G. O. Sars, 1905 (b), p. 8.
Lucicutia bicornuta Sars, 1907 («), p. 3.

A single male specimen identical with the form described and illustrated by Wolfenden
in 'Plankton Studies', Part 1, 1905, was found in the plankton collected with the Hensen vertical
net at Station 230, 2000 metres to the surface.

The species is readily recognised by the truncate frontal margin being produced at each
corner into a strong spine, and by the presence of a ventrally directed hook-like spine on
each side of the cephalic segment. The furcal joints are long and slender. Each furcal joint
is as long as the combined length of the whole of the abdominal segments. The rami of the
rostrum are very short and stout. The second joint of the basiopodite of the male left fifth
foot is produced internally into a short stout process with a dentate apex. Length of 'Siboga'
male 8 mm.

126

I 2~

Wolfenden's specimens were obtained from the plankton collected by the 'Gauss'. The
species recorded by Saks as Lucicutia aurita, was found in the plankton collected by the Prince
of Monaco.

4. Lucicutia longiserrata (Giesbrecht).

Leuckartia longiserrata Giesbrecht, 1889, p. 813.

Leuckartia longiserrata Giesbrecht, 1893, p. 359, pis. iy & 38.

Lucicutia longiserrata Giesbrecht & Schmeil, 1S98, p. 112.

Lucicutia longiserrata I. C. Thompson, 1903, p. 25.

Lucicutia longiserrata Farran, 1908, p. 64, pi. VI, figs. 21 — 22.

Lucicutia longiserrata van Breemen, 1908, p. 116, fig. 134.

One female belonging to this species was found in the plankton collected with the Hensen
vertical net at Station 220, 200 metres to surface.

Lucicutia longiserrata has a general resemblance to Lncicutia Jiavicoruis, but it can be
distinguished by the more robust body, and by the antennules extending beyond the end of
the furcal joints. This species is also closely related to Lucicutia longicornis, but the length
of the furcal joints does not exceed the combined length of the third and fourth abdominal
segments.

Lticicutia longiserrata has been recorded from the Pacific and North Atlantic Oceans.

5. Lucicutia maxima Steuer. Plate XLI, figs. 1 — 10.

Lucicutia maxima Steuer, 1904, p. 596, fig. 4. Female.

Two immature females and one mature male were obtained from the plankton collected
with the Hexsen vertical net at the following stations.

Stat. 185 (1536 metres to surface), 1 specimen. — Stat. 230 (2000 metres to surface), 2 specimens.

The three specimens have a general resemblance to Lucicutia clatisi, but they are much
larger and more robust. When vievved from above, each side of the cephalic segment is seen
to be furnished with one tooth-like projection as shewn in the illustration Plate XLI, fig. 1.

Male — length 8,4 mm.

The abdomen is composed of five segments. The combined length of the abdomen and
furca is contained one and one-fourth times in the total length of the cephalothorax, from the
frontal margin to the base of the genital segment. The furcal joints are much longer than
broad. Each joint is equal to half the length of the abdomen.

The rami of the rostrum are very short and stout. They are slightly chitinised.

The right antennule is twenty-three-jointed and reaches to the middle of the furcal joints.

The endopodite of the first pair of feet is three-jointed.

The second joint of the basiopodite of the left fifth foot is produced internally. The
distal end of the process is furnished with two very stout teeth. The inner margin of the second
joint of the basiopodite of the right foot is slightly inflated, and bears four short teeth. The
joints of the right exopodite are of about equal length. The second joint is furnished with two

127

128

outer edge spines and two apical ones. The third joint of the left exopodite bears one outer
edge, one inner edge, and one apical spine (Plate XLI, fig. 10).

This male is quite distinct from the male of Lucicuiia grandis Giesbrecht, and from the
species described as Lucicutia jlavicornis by Bradv in the report on the 'Challenger' Copepoda.

Wolfenden (1905), regards Lucicutia maxima, to be identical with Giesbrecht's Lucictitia
grandis, and also with the Atlantic form recorded by himself as Lucicutia grandis. When full
illustrations are published by Steuer, the question of identity will probably be cleared up. In
the meantime, I consider the male illustrated in this report to be that of Lucicutia maxima
Steuer, and distinct from the male of Giesbrecht's Lucicutia grandis.

6. Lucicutia philyra nov. sp. Plate XL, figs. 10 — 18.

Female — length 3,4 mm.

Seen from above, the body appears oblong ovate, and moderately robust. The cephalic
segment is moderately wide. It is without lateral processes. The rostral papilla is not visible.
The last thoracic segment is much contracted posteriorly. The distal margïns are narrowly rounded.
Viewed from the side, the last thoracic segment is rather truncate at the distal end, and the
posterio-ventral margin is rounded (Plate XL, fig. 12). The rostral filaments are long and slender.

The abdomen is composed of four segments. The combined length of the abdomen and
furca is contained nearly twice in the total length of the ccphalotlwrax\ from the frontal margin
to the distal end of the last thoracic segment. The genital segment is slightly longer than the
combined length of the next two segments. The dorsal surface of the segment is nearly straight.
The ventral surface is much inflated. The second and fourth segments are of nearly equal length.
The third segment is much shorter than the third or fourth segments. The furcal joints are
six times longer than broad. Each furcal joint is as long as the combined length of the last
three abdominal segments and is furnished with one outer edge setae.

The antennules are twenty-five-jointed, and extend slightly beyond the end of the furca.
The last joint is equal to about one-third of the length of the second last joint.

The antennae, mandibles, maxillae and maxillipecles are nearly similar to those of
Lucicutia èicornuta.

The exopodites and endopodites of the five pairs of feet are three-jointed. The inner
distal spine on the second joint of the exopodite of the fifth pair is moderately slender. It is
much attenuated from the middle to the apex. lts length is contained rather more than one
and two-third times in the length of the third joint. The terminal spine on the exopodite of
the fifth pair is distinctly longer than the third joint (Plate XL, fig. 18).

Male unknown.

This species has a certain amount of resemblance to Lucicutia longicornis, but can
readily be distinguished from it by the shorter genital segment, and by the length of the
furcal joints.

O c cu r re nee. — One specimen was obtained from the plankton collected with the
Hensen vertical net at Station 118, 900 metres to the surface.

128

I 29
•j. Lucicutia pera nov. sp. Plate XL, figs. i — 9.

Female — length 4 mm.

Seen from above, the body appears elongate and narrowly ovate. The cephalic segment
is moderately wide. It is very flatly rounded in front, and is without lateral processes. The
posterio-lateral angles of the last thoracic segment are very narrowly rounded. Viewed from the
side, the distal end of the last thoracic segment is rather broadly rounded, then emarginate as
it joins the dorsal line (Plate XL, fig. 3). The rostral filaments are long and slender.

The abdomen is composed of four segments. The combined length of the abdomen and
furca is equal to two-thirds of the total length of the cephalothorax, from the frontal margin
to the end of the last thoracic segment. The genital segment is as long as the combined length
of the second and third segments. It is quite asymmetrical when viewed from above. The distal
portion of the right side is considerably wider than the base of the second abdominal segment.
It has therefore a well defined projection (Plate XL. fig. 1). Seen from the side, the dorsal
surface of the segment is greatly inflated at its posterior end, and forms a well marked protuberance.
The ventral surface is much swollen near the middle (Plate XL, fig. 3). The ventral swelling
may be due to the presence of a spermatophore, however, as shewn in the illustration. The
second and fourth segments are of nearly equal length. The third segment is shorter than the
second and fourth segments. The furcal joints are nearly five times longer than broad. Each
furcal joint is distinctly shorter than the combined length of the third and fourth abdominal
segments. The furcal joints are furnished with two outer edge setae.

The antennules are composed of twenty-five joints and extend to about the middle of the
furca. The last joint is equal to one-half of the length of the second last joint.

The antennae, mandibles, maxillae and maxillipedes are similar to those of Lucicutia philyra.

The exopodites and endopodites of the five pairs of feet are three-jointed. The inner
distal spine on the second joint of the exopodite of the fifth pair is very stout. lts length is
contained one and two-third times in the length of the third joint. The terminal spine on the
third joint of the exopodite of the fifth pair is very short. lts length is contained fully three
times in the length of the joint (Plate XL, fig. 9).

Male unknown.

This species comes very near Lucicutia lucida Farran (1908), but differs from it in the
asymmetrical genital segment when seen from above. The terminal spine on the exopodite of
the fifth pair of feet is shorter than in Farran's species.

Occurrence. — One specimen was obtained from the plankton collected with the
Hensen vertical net at each of the following stations.

Stat. 128 (700 metres to surface). — Stat. 276 (750 metres to surface).

The genital segment was identical in each specimen.

129

SIBOC.A-EXI'EDITIE XXIX cl.

17

14- Family Heterorhabdidae.
Genus Heterorhabdus Giesbrecht 1S98.

The members of this genus are distinguished by the asymmetrical furcal joints, and by
the long second inner setae on the left furcal joint.

Four species were represented in the plankton collected during the investigations carried
out in the Malay Archipelago by the 'Siboga'.

1. Heterorhabdus clausi (Giesbrecht). <

Heterochaeta clausi Giesbrecht, 1889, p. 812.
Heterochaeta clausi Giesbrecht, 1893, p. 372, pi. 20.
Heterorhabdus clausi Giesbrecht & Schmeil, 1S9S, p. 115.
Heterorhabdus clausi I. C. Thompson, 1903, p. 27.
Heterorhabdus clausi Thompson & Scott, 1903, p. 249.
Heterorhabdus clausi Esterly, 1905, p. 185, fig. 39.
Heterorhabdus clausi van Breemen, 1908, p. 122, fig. 140.

Two females and one male belonging to this species were found in the plankton collected
with the Hensen vertical net at the following stations.

Stat. 128 (700 metres to surface), 1 female. — Stat. 148 (1000 metres to surface), 1 male. —
Stat. 276 (750 metres to surface), 1 female.

Hctcrorliabdus clausi resembles Heterorhabdus papilliger in general appearance, but it
can readily be distinguished by the antennules extending bevond the furcal joints. Other differences
are visible between the appendages of the two species.

This species has been recorded from the Xorth Atlantic and Pacific Oceans.

2. Heterorhabdtis spinifrons (Claus).

Heterochaeta spinifrons Claus, 1863, p. 182, pi. XXXII.
Heterochaeta spinifrons Giesbrecht, 1893, p. 372, pis. 20 & 39.
Heterorhabdus spinifrons Giesbrecht & Schmeil, 189S, p. 114.
Heterochaeta spinifrons Wolfenden, 1902, p. 362.
Heterorhabdus spinifrons I. C. Thompson, 1903, p. 27.
Heterorhabdus spinifrons Thompson & Scott, 1903, p. 249.
Heterorhabdus spinifrons Geve, 1904, p. 191.
Heterorhabdus spinifrons Sars, 1905 (b), p. 3.
Heterorhabdus spinifrons Farran, 1905, p. 44.
Heterorhabdus spinifrons Esterly, 1905, p. 183, fig. 37.
Heterorhabdus spinifrons Pearson, 1906, p. 27.
Heterorhabdus spinifrons Esterly, 1906, p. JJ.
Heterorhabdus spinifrons Farran, 190S, p. 65.
Heterorhabdus spinifrons van Breemen, 1908, p. 119, fig. 137.

Sixteen specimens identical with the above species were obtained from the plankton
collected at the followine stations.

13°

I31

Stat. 66, i specimen. - ■ Stat. 141 (Mensen vertical net, 1500 metres to surface), 2 speci-
mens. - Stat. 143 (MENSEN vertical net, 1000 metres to surface), 1 specimen. - - Stat.
148 (HENSEN vertical net, 1000 metres to surface), 1 specimen. Stat. 1 S 5 (HENSEN

vertical net, [536 metres to surface), 2 specimens. -- Stat. 203 (HENSEN vertical net, 1500
metres to surface), 2 specimens. - - Stat. 217 (horizontal cylinder), 1 specimen. Stat.

220 (HENSEN vertical net, 200 metres to surface), 1 specimen. — Stat. 243 (HENSEN vertical
net, 1000 metres to surface), 2 specimens. - ■ Stat. 276 (HENSEN vertical net, 750 metres
to surface), 1 specimen. — ■ Stat. 304, 1 specimen. -- Stat. 315, 1 specimen.

Heterorhabdus spinifrons can readily be separated from the other members of the genus
by the rostral papilla ending in sharp points, and by the strong curved spine on the upper
surface of the first basal joint of the second pair of maxillipedes.

This species has apparently a moderately wide distribution in the great oceans.

3. Heterorhabdus longicornis (Giesbrecht).

Heter ocliaeta longicornis Giesbrecht, 1889, p. 812.
Heterochaeta longicornis Giesbrecht, 1893, p. 373, pis. 20 & 39.
Heterorhabdus longicornis Giesbrecht & Schmeil, 1898, p. 116.
Heterorhabdus longicornis I. C. Thompson, 1903, p. 27.
Heterorhabdus longicornis Wolfenden, 1904, p. 112.
Heterorhabdus longicornis Sars, 1905 (b), p. 3.
Heterorhabdus longicornis Farran, 1905, p. 45.
Heterorhabdus longicornis Esterly, 1905, p. 186, fig. 40.
Heterorhabdus longicornis Pearson, 1906, p. 26.
Heterorhabdus longicornis Esterly, 1906, p. yy.
Heterorhabdus longicornis Farran, 1908, 6y.
Heterorhabdus longicornis van Breemen, 1908, p. 125, fig. 144.

Eight females and three males belonging to this species were found in the plankton
collected at the following stations.

Stat. 128 (HENSEN vertical net, 700 metres to surface), 1 specimen. — Stat. 141 HENSEN
vertical net, 1500 metres to surface), 2 specimens. -- Stat. 143 (HENSEN vertical net, 1000
metres to surface), 2 specimens. — Stat. 148 (HENSEN vertical net, 1000 metres to surface),
2 specimens. — Stat. 203 (HENSEN vertical net, 1500 metres to surface), 1 specimen. -
Stat. 243 (HENSEN vertical net, 1000 metres to surface), 2 specimens. — Stat. 276 (HENSEN
vertical net, 750 metres to surface), 1 specimen.

This species is readily distinguished from the other members of the genus by its very
long antennules. The antennules extend beyond the end of the furca by eight or nine joints.
The distribution appears to be very similar to that of Heterorhabdus spinifrons.

4. Heterorhabdus papilliger (Claus).

Heterochaeta papilligera Claus, 1863, p. 182, pi. XXXII.
Heterochaeta papilligera Giesbrecht, 1893, p. 372, pis. 20 & 39.
Heterorhabdus papilliger Giesbrecht & Schmeil, 1898, p. 114.
Hererochaeta papilligera Cleve, 1901, p. 7.
Heterorhabdus papilliger I. C. Thompson, 1903, p. 27.
Heterorhabdus papilliger Thompson & Scott, 1903, p. 249.

I31

132

Heterorliabdus papilliger Cleve, 1903, p. 363.
Heterorhabdus papilliger Cleve, 1904, p. 191.
Heterorliabdus papilliger Wolfenden, 1905 (a), p. 1012.
Heterorhabdus papilliger Sars, i905(/>), p. 3.
Heterorliabdus papilliger Esterly, 1905, p. 184, fig. 38.
Heterorliabdus papilliger van Breemen, 1908, p. 120, fig. 138.

One female identical with the above species was obtained from the plankton collected
at each of the three following stations.

Stat. 128 (HENSEN vertical net, 700 metres to surface). — Stat. 216. — Stat. 276 (HENSEN
vertical net, 750 metres to surface).

Heterorhabdus papilliger has a close resemblance to Heterorliabdus e/at/si but it can be
separated from that species by the much shorter antennules. The antennules scarcely reach to
the end of the furcal joints. Other differences can be detected on comparing the various
appendages of the two species.

This species appears to have a moderately wide distribution. It has been recorded from
the tropical and colder areas of the great oceans by various observers.

Genus Mesorhabdus G. O. Sars, i905(/>).

This genus was established by Sars in 1905 for the reception of a Calanoid closely related
to Heterorhabdus and Dissela. It is separated from these genera, by the great development of the
spines on the two apical lobes of the first maxillipedes. The furcal joints are quite symmetrical.

One species, apparently undescribed, was represented in the plankton collected by
the 'Siboga'.

1. Mesorhabdus truneatus nov. sp. Plate XXXIX, figs. 12 — 21.

Female — length 7 mm.

Seen from above, the body appears robust and irregularly oval. The greatest width is
in the middle of the first thoracic segment. The frontal margin of the cephalic segment is
boldly rounded. The rostral papilla is very slightly indicated in the middle of the frontal curve.
The distal end of the last thoracic segment is moderately wide. It is almost truncate. The lateral
margins are slightly extended into very small projections (Plate XXXIX, fig. 1 2). Viewed from
the side, the distal end of the last thoracic segment is broadly rounded, then slightly emarginate
as it joins the dorsal line. The rostral- filaments are long and slender (Plate XXXIX, fig. 14).

The abdomen is composed of four segments. The combined length of the abdomen and
furca is contained nearly three times in the total length of the cephalothorax, from the frontal
margfin to the base of the grenital segment. The g/enital segment when viewed from above
appears almost rectangular in outline. It is nearly as broad as long. lts length is slightly less
than the combined length of the next three segments. The ventral surface is considerably
inflated, and is produced in the middle into a blunt pointed process. The second, third and
fourth segments are comparatively short. They are of nearly equal length. The furcal joints

133

are short. The joints are quite symmetrical, and are rather longer than the anal segment. Each
furcal joint is twice as long as broad. The second inner setae on the left furcal joint is much
longer and thicker than any of the others.

The antennules are twenty-five-jointed and reach to the middle of the third abdominal
segment. The last joint is equal to two-thirds of the length of the second last joint.

The antennules, mandibles and maxillae are nearly similar to those of Heter orhabdus.

The apical portion of the first maxillipedes is furnished with two very stout and moderately
long spines. The inner surface of the spines is coarsely serrate (Plate XXXIX, fig. 18).

The second maxillipedes are similar to those of Heterorliabdits.

The exopodite and endopodite of the first, second, third and fourth pairs of swimming
feet are three-jointed.

The exopodite and endopodite of the fifth pair of feet are also three-jointed. The joints
are short. The inner distal angle of the second joint of the exopodite is furnished with a
short, stout spine. The spine is rather suddenly contracted in the distal portion. The inner
margin of the first and second joints of the endopodite bears one moderately strong spine.
The proximal portion of each spine is finely plumose. The distal portion is rather coarsely
dentate (Plate XXXIX, fig. 21).

Male unknown.

This species is readily recognised by the truncate form of the last thoracic segment
when viewed from above, by the proportional length of the segments of the abdomen, by
the short symmetrical furcal joints, and by the armature of the two strong spines on the inner
margin of the endopodite of the fifth pair of feet.

Occurrence. — One specimen was obtained from the plankton collected with the
Hexsen vertical net at Station 230, 2000 metres to the surface.

Genus Disseta Giesbrecht, 1889.

The members of this genus appear to be intermediate between Lucicutia and Hetcror-
habdus. The various appendages shew a close relationship to those of Lucicutia. The biting
edge of the mandible is almost identical in both types but it is quite distinct from Heterorhabdus.
The furcal joints are asymmetrical and resemble those of Heterorhabdus. The left joint is
longer and distinctly stouter than the right one. The male fifth pair of feet is quite distinct
from that of the male of Lucicutia or Heterorhabdus.

Two species were represented in the plankton collected by the 'Siboga'.

1. Disseta palumboi Giesbrecht. Plate XLI, figs. 11 — 21.

Disseta palumboi Giesbrecht, 1889, p. 812.
Disseta palumboi Giesbrecht, 1893, p. 369, pis. 29 & 38.
Disseta palumboi Giesbrecht & Schmeil, 1898, p. 112.
Heterorhabdus grandis Wolfenden, 1904, p. 120, pi. IX, fig. 36.
Disseta palumboi Sars, 1905^), p. 3.

Heterorhabdus grandis Wolfenden, 1905, p. 8, pi. IV, figs. 7 & 8 (male).
Heterorliabdits grandis Pearson, 1906, p. 26.

133

134

Disseta grandis Esterly, 1906, p. 72, pis. 9, il, 13 & 14.

Disseta palumboi Farran, 1908, p. 67.

Heterorhabdus grandis van Breemen, 1908, p. 126, fig. 145.

Four females and four males apparently identical with Giesbrecht's species were found
in the plankton collected with the Hensen vertical net at the following stations.

Stat. 141 (1500 metres to surface), 3 specimens. — Stat. 230 (2000 metres to surface), 4 spe-
cimens. — Stat. 243 (1000 metres to surface), 2 specimens.

Length — female 8 mm., male 7,75 mm.

With the exception of the difference in size I see nothing to separate the 'Siboga'
females from the description and figures given by Giesbrecht.

The male was unknown when the original description was given but it has been found
within recent years by Wolfenden in the plankton collected by the 'Gauss' and by Esterly
in the Pacific. Wolfenden described the female and male as Heterorhabdus grandis. Esterly
recognised the identity of his specimens with the genus Disseta, and named the form Disseta grandis.

With the exception of an apparent difference in the proportional length of the abdominal
segments of the female, and an asymmetrical genital segment, the specimens from the Pacific
are identical with those obtained by the 'Siboga'. The abdominal segments of the Copepoda
are apt to become telescoped at death, and an unnatural shortening may, therefore, easily take
place, which will give rise to incorrect proportional lengths. The asymmetry of the genital
segment of Esterly's specimens may be due to accident. The genital segment of the 'Siboga'
females is quite symmetrical as shevvn in the illustration.

The last abdominal segments, and the furcal joints of the male, are similar to those
of the female. Esterly's figure of the male left fifth foot, shews the apical spine on the third
joint of the exopodite to be short and stout, but the more slender distal portion may easily
have been damaged. Wolfenden's figure of the fifth pair of the male of Heterorhabdus grandis
is identical with the one given in this report.

Difference in size unless accompanied by some other decided feature is of little or no
specific value.

Disseta palumboi appears to have a fairly wide distribution.

2. Disseta seopularis (Brady). Plate XLII, figs. 1 — 9.

Leuckartia seopularis Brady, 1883, p. 51, pi. XIV, figs. 1 — 5.
Leuckartia seopularis Giesbrecht & Schmeil, 1898, p. 125.

A single male specimen, evidently identical with Brady's Leuckartia seopularis, was
found in the plankton collected with the Hensen vertical net at Station 250, 2000 metres to
the surface.

The specimen was rather mutilated. The antennules, antennae, mandible palps and
second maxillipedes were incomplete. The more important characters, however, were intact.
The biting edge of the mandible (Plate XLII, fig. 4) clearly shews that this Calanoid is not,
as stated by Wolfenden in 'Plankton Studies' part I, page 23, a Heterorhabdus. The biting

134

*35

edge of the mandible is of the Lucia/ /ia and Disseta type. The furcal joints are asymmetrical,
and are similar to those of Disseta and Heterorhabdus. The true place of this 'Incerti Generis'
GlESBRECHT and ScHMEIL, is in the genus Disseta.

The minor differences between the figure of the fifth pair of feet given by Brady, and
the illustration given in this report, are probably due to the 'Challenger' specimen having been
more mutilated than the one captured by the 'Siboga'. The curious apical joint of the exopodite
of the right fifth foot, and the long, stout, sinuous terminal spine on the exopodite of the left
fifth foot are quite sufficiënt to make the identity of the 'Siboga' form with Brady's Leuckartia
scopularis a matter of very little doubt.-

Length of 'Siboga' male 9,75 mm.

The long furcal joints, and the character of the fifth pair of feet, readily separate this
male from the male of Disseta • palumboi.

Brady's type specimen was found in a surface collection taken in the Pacific between
Japan and Honolulu.

15. Family Augaptilidae.
Genus Augaptilus Giesbrecht, 1889.

The members of this genus are closely allied to Haloptilus, but the females can readily
be recognised by the segmentation of the abdomen. The abdomen of the females of this genus
is composed of three segments.

Seven species belonging to this genus were represented in the plankton collected in the
Malay Archipelago by the 'Siboga'. Two of the species appear to be undescribed.

1. Augaptilus bullifer Giesbrecht.

Augaptilus bullifer Giesbrecht, 1889, p. 813.

Augaptilus bullifer Giesbrecht, 1893, p. 400, pis. 28 & 39.

Augaptilus bullifer Giesbrecht & Schmeil, 1898, p. 122.

Augaptilus bullifer Sars, 1905 (b), p. 4.

Augaptilus bullifer Farran, 190S, p. 75.

Specimens of this species were obtained from the plankton collected with the Hensen
vertical net at the following stations.

Stat. 141 (1500 metres to surface), 2 specimens. — Stat. 276 (750 metres to surface).

Augaptilus bullifer resembles Augaptilus filigerus in general appearance, but it is
more robust and the genital segment of the female is quite symmetrical.

Giesbrecht's specimens of this form were obtained from the Pacific. Farrax has recently
recorded it from the North Atlantic. Sars obtained it from the plankton collected by the Prince
of Monaco.

135

136

2. Augaptihis filigerus (Claus).

Hemicalanus filigerus Claus, 1863, p. 179.

Augaptilns filigerus Giesbrecht, 1893, p. 400, pis. 3, 27, 28, 29 & 39.

Augaptihis filigerus Giesbrecht & Schmeil, 1898, p. 121.

Augaptilns filigerus I. C. Thompson, 1903, p. 28.

Augaptilus filiger Sars, 1905 (b), p. 4.

Augaptilns filigerus Farran, 190S, p. jj.

Augaptilns filigerus van Breemen, 1809, p. 133, fig. 150.

One specimen belonging to this species was found in the plankton collected with the
Hensen vertical net at each of the following stations.

Stat. 118 (900 metres to surface). — Stat. 141 (1500 metres to surface). — Stat. 143 (1000
metres to surface). ■ — Stat. 148 (1000 metres to surface). — Stat. 276 (750 metres to surface).

Augaptilus filigerus can be separated from the other members of the genus, by the
proportional length of the abdominal segments and furcal joints. The second and third segments
of the abdomen are of about equal length. The furcal joints are slightly longer than broad.
They are as long as the anal segment.

This species was originally obtained from the Mediterranean by Claus. It has since
been recorded from the Xorth Atlantic.

3. Augaptilus hecticus Giesbrecht.

Augaptilus hecticus Giesbrecht, 1889, p. 814.

Augaptilus hecticus Giesbrecht, 1893, p. 400, p!s, 1, 27, 28, 29 & 39.

Augaptilus hecticus Giesbrecht & Schmeil, 1898, p. 122.

Augaptilus hecticus I. C. Thompson, 1903, p. 29.

Augaptilus hecticus van Breemen, 1908, p. 135, fig. 153.

One specimen of this Augaptilus was found in the plankton collected with the Hensen
vertical net at each of the two following stations.

Stat. 141 (1500 metres to surface). — Stat. 276 (750 metres to surface).

This species is a comparatively small one. It can be distinguished by the proportional
length of the abdominal segments and furcal joints. The second and third segments of the
abdomen are of about equal length. The furcal joints are as long as the anal segment. They
are three times longer than broad.

Augaptilus hecticus has a moderately wide distribution. It has been recorded from the
Atlantic and Pacific Oceans and from the Mediterranean.

4. Augaptilus longicaudatus (Claus).

Hemicalanus longicaudatus Claus, 1863, p. 179, pi. XXIX.
Augaptilus longicaudatus Giesbrecht, 1893, p. 400, pis. 27, 28, 29 & 39.
Augaptilus longicaudatus T. Scott, 1893, p. 34, pis. I & II.
Augaptilus longicaudatus Giesbrecht & Schmeil, 1898, p. 123.
Augaptilus longicaudatus I. C. Thompson, 1903, p. 29.

1*6

137

Augaptilus longicaudatus Wolfenden, 1904, p. 112.

Augaptilus longicaudatus Sars, \c)0^{l>], p. 4.

Augaptilus longicaudatus Esterly, 1905, p. 188, fig. 41.

Augaptilus longicaudatus Pcarson, 1906, p. 28.

Augaptilus longicaudatus Farran, 190S, p. 78.

Augaptilus longicaudatus van Breemen, 1908, p. 135, fig. 154.

Six specimens of this form were found in the plankton collected with the Hensen vertical
net at the following stations.

Stat. 185 (1536 metres to surface), 3 specimens. — Stat. 203 (1500 metres to surface), 2 spe-
cimens. — Stat. 276 (750 metres to surface), 1 specimen.

Augaptilus longicaudatus can be distinguished from the other members of the genus,
by its moderately long abdomen and furcal joints. It is closely related to Augaptilus kecticus
and Augaptilus megalurus. It differs from the former species, by the furcal joints being five
times longer than broad, and from the latter, by the equal length of the second and third
abdominal segments. In Augaptilus hecticus the furcal joints are three times longer than broad.
The third abdominal segment of Augaptilus megalurus is distinctly shorter than the second segment.

This species appears to have a moderately wide distribution.

5. Augaptilus palumboi Giesbrecht.

Augaptilus palumboi Giesbrecht, 1889, p. 813.

Augaptilus palumboi Giesbrecht, 1893, p. 400, pis. 27, 28 & 39.

Augaptilus palumboi Giesbrecht & Schmeil, 1898, p. 122.

Augaptilus palumboi I. C. Thompson, 1903, p. 28.

Augaptilus palumboi Sars, 1905^), p. 4.

Augaptilus palumboi Farran, 1908, p. 75.

Augaptilus palumboi van Breemen, 1908, p. 134, fig. 151.

Eight specimens of this species were found in the plankton collected with the Hensen
vertical net at the following stations.

Stat. 118 (900 metres to surface), 1 specimen. — Stat. 128 (700 metres to surface), 1 spe-
cimen. — Stat. 141 (1500 metres to surface), 1 specimen. — Stat. 143 (1000 metres to
surface), 2 specimens. — Stat. 148 (1000 metres to surface), 1 specimen. — Stat. 203 (1500
metres to surface), 2 specimens.

Augaptilus palumboi is readily distinguished by its small size, by the short second
abdominal segment, and by the anal segment being twice the length of the second segment.

This species was originally found in the Pacific Ocean. It has been recorded within
recent years from the North Atlantic.

6. Augaptilus placitus nov. sp. Plate XLII, figs. 10 — 19.

Female — length 10 mm.

Seen from above, the body is elongate ovate, and rather slender. The last thoracic
segment is contracted posteriorly, and the distal ends are somewhat narrowly rounded. Viewed

i37

SIBOGA-EXPEDITIE XXIXa. l8

133

from the side, the cephalic segment appears slightly vaulted. The forehead is decidedly truncate
in outline. The distal end of the last thoracic segment is narrowly rounded below, then slopes
steeply forward till it joins the almost straight dorsal line (Plate XLII, fig. 12). The rostral
filaments are slender and of moderate. length (Plate LXII, fig. 13).

The combined length of the abdomen and fnrca is contained nearly four times in the
total length of the cefihalotkorax, from the frontal margin to the distal end of the last thoracic
segment. The genital segment is distinctly longer than the combined length of the next two
segments. It is not quite symmetrical. The left side is slightly more inflated than the right.
The ventral surface of the segment is produced near the middle into a rounded knob-like process.
The second segment is short. It is about half the length of the third segment. The third
segment is equal to half the length of the genital segment. The furcal joints are slightly longer
than broad. The joints are rather shorter than the anal segment.

The antennules are composed of twenty-five joints and extend beyond the furca by the
last three joints.

The exopodite of the antennae is eight-jointed. It is distinctly less than half the length
of the endopodite (Plate XLII, fig. 15).

The teeth on the biting edge of the mandible are arranged in three sets. The two
inner sets are each represented by two teeth. The outer set is composed of three teeth (Plate
XLII, fig. 16).

The exopodite of the maxillae is furnished with six setae. Three of the setae are long
and stout. The other three are short and very slender.

The two pairs of maxillipedes are of the normal Augaptilus type.

The first four pairs of feet are also of the usual Augaptilus form.

The outer edge spine on the first joint of the exopodite of the first pair of feet extends
to the middle of the third joint.

The terminal spine on the exopodite of the fifth pair of feet is as long as the third
joint. The inner edge spine on the second joint of the exopodite is comparatively short and
straight. It extends to the base of the third inner edge spine on the third joint.

Male unknown.

This species is closely related to Augaptilus squamatus Giesbrecht, but it can be separated
by the difference in the proportional length of the abdominal segments and furcal joints, and
by the exopodite of the maxillae being furnished with three long and three short setae.

Occurrence. — One specimen was found in the plankton collected with the Hensex
vertical net at each of the following stations.

Stat. 143 (1000 metres to surface). ■ — Stat. 148 (1000 metres to surface).

7. Augaptilus validus nov. sp. Plate XLIII, figs. 1 — 10.

Female — length 8,77 mm.

Seen from above, the body is ovate and very robust. The last thoracic segment is
contracted posteriorly, and the distal ends are broadly rounded. Viewed from the side, the

138

139

cephalic segment is seen to be very much depressed. The forehead is extremely narrow (Plate
XLIII, fig. 2). The distal end of the last thoracic segment is broadly rounded below, then
slightly emarginate as it rises to join the dorsal line. The rostrum consists of a bifurcate papilla
without iïlaments (Plate XLIII, hg. 4).

The combined length of the abdomen and furca is contained three and one-half times
in the total length of the cephalothorax \ from the frontal margin to the end of the last
thoracic segment. The genital segment is very slightly asymmetrical. It is fully one and a half
times longer than the combined length of the next two segments. The ventral surface of the
segment is produced into a rounded knob. The second segment is equal to two-thirds of the
length of the third segment. The third segment is equal to one-third of the length of the
genital segment. The furcal joints are small. They are rather longer than broad, and are nearly
as long as the anal segment (Plate XLIII, fig. 1).

The antennules are composed of twenty-five joints and reach to the end of the furca.

The exopodite of the antennae is eight-jointed. It is distinctly less than half the length
of the endopodite.

The biting edge of the mandible is furnished with three pairs of teeth (Plate XLIII, fig. 6).

The exopodite of the maxillae is furnished with two moderately long setae.

The two pairs of maxillipedes are similar to those of the previous species.

The five pairs of feet are also similar to those of Aiigaptilus placittis. The outer edge
spine on the first joint of the exopodite of the first pair of feet does not reach the middle of
the third joint.

Male — length 7,6 mm.

The male resembles the female in general appearance. The abdomen is composed of
five segments. The rostral papilla is more bifurcate, and the apex of each ramus is pointed
(Plate XLIII, fig. 8). The left antennule is prehensile.

The antennae, mandibles, maxillae and maxillipedes are similar to those of the female.

The first four pairs of feet are similar to the first four pairs of the female.

The joints of the exopodite of the fifth pair are very short. The last joint of the right
exopodite is somewhat narrowly rounded at the apex. The inner distal end is furnished with
a short curved spine. The joint is also furnished with one outer margïnal, and one inner marginal
spine. The last joint of the exopodite of the left foot is broadly rounded at the apex. The
distal end bears two spines. The joint is also furnished with one outer marginal setae. The
proximal end of the inner margin of the second joint of the left exopodite, bears a small
spiniform process which is distinctly bifurcate at the apex (Plate XLIII fig. 10).

This species is easily identified by the very depressed cephalic segment, and by the
pointed forehead when seen from the side. The rather feebly bifurcate papilla of the female
rostrum, and the more pointed rami of the male, along with the spiniform process on the inner
margin of the second joint of the exopodite of the left fifth foot, are also characters that help
to separate this species from any of the others.

Occurrence. — Two males and one female were founcl in the plankton collected
with the Hexsex vertical net at the following stations.

139

140

Stat. 12S (700 metres to surface), 1 male. — Stat. 141 (1500 metres to surface), 1 female. — ■
Stat. 276 (750 metres to surface), 1 male.

My father has obtained specimens of a male form from the plankton collected in the
Faröe Channel, by the Scottish International Fisheries Cruiser 'Goldseeker', that is identical
with the male of the present species.

The two species now described as new, may eventually prove to be the same as some
of. the new Attgaptilns, described by Professor G. O. Sars, in 'Bulletin du Musée Océanographique
de Monaco', part 2, (N° 40) 1905. Only the preliminary descriptions are there given. It is
very difïïcult to identify the members of this genus without illustrations.

Genus Haloptilus Giesbrecht, 1898.

The members of this genus are readily recognised by their transparent and flattened
body. The abdomen is comparatively short. It is composed of four segments in the female.
The endopodite of the antennae is much longer than the exopodite.

Four species belonging to this genus were present in the plankton collected by the 'Siboga'.

1. Haloptilus longicornis (Claus).

Hemicalanus longicornis Claus, 1863, p. 179, pi. XXIX.

Hemicalanus longicornis Brady, 1883, p. 44, pi. IX, figs. 1 & 7.

Hemicalanus longicornis Giesbrecht, 1893, p. 384, pis. 1, 2, 27.

Hemicalanus longicornis T. Scott, 1893, p. 32.

Haloptilus longicornis Giesbrecht & Schmeil, 1898, p. 118.

Haloptilus longicornis Sars, 1902, p. 121, pis. LXXXII & LXXXIII.

Haloptilus longicornis I. C. Thompson, 1903, p. 28.

Haloptilus longicornis Wolfenden, 1904, p. 135.

Haloptilus longicornis Sars, 1905 (b), p. 4.

Haloptilus longicornis Farran, 1905, p. 45.

Haloptilus longicornis Pearson, 1906, p. 27.

Haloptilus longicornis Farran, 1908, p. 67.

Haloptilus longicornis van Breemen, 190S, p. 128, fig. 146.

Twenty-two specimens belonging to this species were obtained from the plankton collected
at the followinor stations.

ö

Stat. 118 (Hensen vertical net, 900 metres to surface), 2 specimens. — Stat. 128 (Hensen
vertical net, 700 metres to surface), 2 specimens. — Stat. 129, 1 specimen. — Stat. 141
(HENSEN vertical net, 1500 metres to surface), 3 specimens. — Stat. 148 (Hensen vertical
net, 1000 metres to surface), 4 specimens. — Stat. 203 (HENSEN vertical net, 1500 metres
to surface), 4 specimens. — Stat. 220 (HENSEN vertical net, 200 metres to surface), 2 spe-
cimens. — Stat. 252, 1 specimen. — Stat. 276 (HENSEN vertical net, 750 metres to surface),
3 specimens.

Haloptilus longicornis is a comparatively small form. It can readily be recognised by the
knob-like projection on the forehead when viewed from above, and by the very long antennules.

This species has a wide distribution in the great oceans. It has been recorded from the
North Atlantic off the Coast of Norway, by Professor G. O. Sars.

140

>4'

2. Haloptilus ornatus (Giesbrecht).

Hemicalanus ornatus Giesbrecht, 1S93, p. 384, pis. 27 & 42.
Haloptilus ornatus Giesbrecht & Schmeil, 1898, p. 120.
Haloptilus ornatus I. C. Thompson, 1903, p. 28.
Haloptilus ornatus Sars, 1905 (b), p. 4.
Haloptilus ornatus van Breemen, 1908, p. 130, fig. 14N.

One specimen of this Haloptilus was found in the plankton collected with the Hénsen
vertical net at each of the followingf stations.

Stat. 118 (900 metres to surface). — Stat. 128 (700 metres to surface).

This species can easily be separated from the other members of the genus by its narrowly
rounded forehead, and by the strong curved spines on the apical lobes of the first pair of
maxillipedes. The antennules extend beyond the end of the furca by about four joints.

Haloptilus ornatus was originally described by Giesbrecht from Mediterranean specimens.
Thompson, Sars and van Breemen have since recorded it from other areas.

3. Haloptilus plumosus (Claus).

Hemicalanus plumosus Claus, 1863, p. 178, pis. XXVIII & XXIX.
Hemicalanus plumosus Giesbrecht, 1893, p. 384.
Hemicalanus plumosus T. Scott, 1893, p. 33, pis. II & VI.
Haloptilus plumosus Giesbrecht & Schmeil, 1898, p. 119.

One specimen belonging to this species was found in the plankton collected with the
Hensen vertical net at Station 141, 1500 metres to the surface.

Haloptilus plumosus resembles Haloptilus ornatus in general appearance. It can be
distinguished by its shorter antennules, and by the endopodite of the maxillae being furnished
with four setae.

This species has hitherto only been known from the Mediterranean and from the Gulf
of Guinea.

4. Haloptilus spiniccps (Giesbrecht).

Hemicalanus spiniceps Giesbrecht, 1893, p. 384, pis. 27 & 42.
Haloptilus spiniceps Giesbrecht & Schmeil, 1898, p. 120.
Haloptilus spiniceps I. C. Thompson, 1903, p. 28.
Haloptilus spiniceps Sars, 1907 (a), p. 19.
Haloptilus spiniceps van Breemen, 1908, p. 130, fig. 149.

One specimen of this Haloptilus was obtained from the plankton collected at each of
the following stations.

Stat. 128 (HENSEN vertical net, 700 metres to surface). — Stat. 185 (HENSEN vertical net,
1536 metres to surface). — Stat. 203 HEXSEX vertical net, 1500 metres to surface). —
Stat. 220 (HENSEN vertical net, 200 metres to surface). — Stat. 315.

This species can readily be separated from the other members of the genus by the short,

141

142

hooked, spiniform projection of the forehead when viewed from the side. It is not always
possible, however, to make out the hooked projection of the forehead. It is easily telescoped
and some care is necessary in identification.

Haloptilus spiniccps has apparently hitherto only been recorded from the Mediterranean
and from the Atlantic Ocean.

16. Family Arietellidae.
Genus ArietelluS Giesbrecht, 1893.

The members of this genus can be recognised by the rather tumid body, and by the
characters of the fifth pair of feet of both sexes.

The female fifth pair is represented by two free joints attached to a basal part. The
male fifth pair is well developed and prehensile. The exopodite of each foot is three-jointed
and asymmetrical. The last joint of the right exopodite is lamelliform, and the apex is rounded.
The last joint of the left exopodite bears two apical claw-like spines. The endopodite of each
foot is lamelliform, asymmetrical and apparently two-jointed. The basiopodite is two-jointed.

The characters that separate the various members of the genus depend almost entirely
on the form of the body, the length of the frontal spine, the shape of the last thoracic segment,
and the length of the furcal joints. Obvious differences can be noticed, however, in the structure
of the fifth pair of feet of both sexes.

Three species were obtained from the plankton collected by the 'Siboga' in the Malay
Archipelago.

1. Arietellus setosus Giesbrecht. Plate XLIV, figs. 8 — 13.

Arietellus setosus Giesbrecht, 1893, p. 415, pis. 29 & 39.

Arietellus setosus Giesbrecht & Schmeil, 1898, p. 124.

Arietellus setosus Sars, 1905 (£), p. 5.

Arietellus setosus Esterly, 1905, p. 1S9, fig. 42.

Arietellus setosus van Breemen, 1908, p. 139, fig. 158.

One adult and one immature male belonging to this species, were found in the plankton
collected with the Hensen vertical net at the following stations.

Stat. 141 (1500 metres to surface). — Stat. 203 (1500 metres to surface).

Length of adult male 4 mm.

Arietellus setosus can readily be separated from the other members of the genus by
the short and slightly hooked frontal spine, and by the strong spiniform projections of the last
thoracic segment. The apical spines on the exopodite of the left fifth foot of the male are of
moderate length. The outer one is longer than the third joint. It has a distinct angular bend
near the middle. Esterly's figure of the female fifth foot, shews that the second free joint is
nearly as long as the first joint. The terminal spine is as long as the second joint. In the

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figure of the entire female given by that author, the spiniform projections of the last thoracic
segment are shewn to be nearly straight, and extend to the end of the second abdominal segment.
This species lias been recorded from the Atlantic and Pacific Oceans and from the
Mediterranean.

2. Arietellus aculeatus (T. Scott). Plate XLIV, fïgs. 4 — 7.

Rhincalanus aculeatus T. Scott, 1893, p. 31, pi. II, fïgs. 11 — 22.
Arietellus setosus Giesbrecht & Schmeil, [898 (pars), p. 124.

One adult female identical with the above species was obtained from the plankton
collected with the Hensen vertical net at Station 148, 1000 metres to the surface.

Length of female 4,56 mm.

This species was originally described by my father from a rather immature male as
Rhincalanus aculeatus. It was afterwards included under Arietellus setosus by Giesbrecht
and Schmeil.

The discovery of the adult female shews that it is apparently quite distinct from the
type of the genus. The frontal spine is very strong, much elongated and directed almost straight
in front (Plate XLIV, fig. 5). The spiniform projections of the last thoracic segment are
slightly asymmetrical and rather divergent. The spine of the right side is slightly longer than
that of the left, but it does not reach the distal end of the genital segment when the animal
is viewed from above. The fifth pair of feet of the female is asymmetrical. The right foot is
obviously longer than the left. The second free joint of each foot is very broad. The distal
end of the inner margin is considerably inflated. The apical spine on the right foot is as long
as the joint. The joint bears an indication near the middle, of an outer marginal spine. The
apical spine on the left foot is decidedly longer than the joint (Plate XLIV, fig. 7).

This Arietellus has hitherto only been known from the Gulf of Guinea.

3. Arietellus simplex Sars. Plate XLIV, figs. 14 — 18.

Anctcltus simplex Sars, 1905 (b), p. 22.

Arietellus major Esterly, 1906, p. 74, pis. 9, 11, 12 & 13.

One male agreeing very well with the preliminary description of the above species
given by Sars, was found in the plankton collected with the Hensen vertical net at Station
141, 1500 metres to the surface.

Length of 'Siboga' male 6,2 mm.

The forehead appears only very slightly produced, when viewed from above. The distal
ends of the last thoracic segment are boldly rounded. A feeble indication of a projection is
visible near the junction of the eephalothorax with the first abdominal segment (Plate XLIV,
fig. 14). The anal segment and furcal joints are decidedly longer than in the previous species.
The furcal joints are nearly three times longer than broad. The fifth pair has a general resem-
blance to the fifth pair of the male of Arietellus setosus, but the outer margin of the apical

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joint of the left exopodite is distinctly notched. The apical spines are short and stout. The
longer one is considerably shorter than the joint (Plate XLIY, fig. 1 7).

The rounded last thoracic segment, and the long furcal joints readily separate this form
from any of the other known species.

The female described by Esterly as Arietellus major appears to be identical with Sars'
Arietellus simplex. The figure of the fifth foot given by Esterly, and reproduced in this
report, shews the apical spine of the second free joint to be very short. It is only about equal
to one-half of the length of the joint.

Genus Paraugaptilus Wolfenden, 1904.

This genus was established by Wolfenden in 1904, for a form found in the warm area
of the North Atlantic, that appeared to be closely related to Augaptilus and Arietellus. Sars
(1907 a) recorded Wolfenden's type species from the plankton collected by the Prince of Monaco,
but placed it under the genus Arietellus. Van Breemen, however, regards the genus as distinct
and restores it in 'Nordisches Plankton' 1908. This genus appears to be more closely related
to Arietellus than to Augaptilus. I have therefore included in under the Family Arietellidae.

The two sexes are readily separated from either Augaptilus or Arietellus, by the structure
of the fifth pair of feet. The fifth pair of the female is rudimentary. Each foot is composed
of a single joint. The male fifth pair is well developed and prehensile. The right and left
feet are not symmetrical. The basiopodite is two-jointed. The exopodite of each foot is two-
jointed. The endopodite is very small. It is apparently two-jointed.

Males and females of a form closely related to the type of the genus were obtained
from the plankton collected by the 'Siboga' in the Malay Archipelago.

1. Paraugaptilus siwilis nov. sp. Plate XLIII, figs. 11 — 19.

Female — length 3,75 mm.

Viewed from above, the body appears ovate and robust. The forehead is considerably
contracted in front. The posterior margins of the last thoracic segment are broadly rounded.
The segment is furnished with a small tooth on each side of the junction with the abdomen.
Seen from the side, the dorsal surface of the cephalic segment is much depressed, and the
forehead is very narrowly rounded. The ventral margin of the last thoracic segment is boldly
rounded. The distal end is hollowed out. It is produced into a small tooth at the upper angle,
where it joins the dorsal line (Plate XLIII, fig. 13). The dorsal and lateral surfaces of the
thoracic segments, are clothed with fine short hairs as shewn in the figures. The rostrum is
represented by two slender filaments.

The abdomen is composed of four segments. The combined length of the abdomen
and furca is contained two and a half times in the total length of the ecphalothorax, from
the frontal margin to the base of the genital segment. The genital segment is moderately large.
It is distinctly inflated on each side. The lateral surface is furnished with a small, dorsally
directed pointed process. The genital opening is provided with a pointed knob (Plate XLIII,

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145

fig. 13). The second and third segments are of a-bout equal length. The anal segment is equal
to two-thirds of the length of the third segment. The furcal joints are one and a half times
longer than broad. They are slightly longer than the third abdominal segment. The second
and third inner setae are each furnished with a dense tuft of dark coloured hairs. The ova are
few in number and are verv larsfe.

The antennules are composed of twenty joints and are of nearly equal length. The
left antennule extends to the end of the fourth abdominal segment. The terminal joint of the
right antennule only is furnished with two densely plumose setae (Plate XLIII, fig. 14).

The antennae, mandibles, maxillae and maxillipedes are somewhat similar to those of
Arietellus setosus.

The first four pairs of feet are also similar to those of that species.

The fifth pair is slightly asymmetrical. Each foot consists of a single joint. There is no
distinctly defined basal part. The proximal portion of the outer margin is furnished with a
moderately long seta. The setae on the right foot is longer than the one on the left foot.
The distal portion of the outer margin bears two very small hairs. The apex is furnished with
one long plumose seta (Plate XLIII, fig. 16).

Male — length 3,37 mm.

The male resembles the female in general appearance, but the abdomen is composed
of five segments. The first and third segments are larger, and the second is smaller than the
others. The fourth and fifth segments are of about equal length.

The left antennule is modified for grasping. It is composed of eighteen joints. The
eleventh, twelfth and thirteenth joints are distinctly enlarged. The fifteenth, sixteenth and
seventeenth joints are furnished on the upper edge with a narrow hyaline plate. The hinge is
situated betueen the sixteenth and seventeenth joints (Plate XLIII, fig. 18).

The mouth organs and swimming feet are nearly similar to those of the female. The
inner margin of the second joint of the endopodite of the antennae is fyrnished with a long
seta (Plate XLIII, fig. 15), which appears to be entirely absent in the female.

The fifth pair is large and prehensile. The second joint of the right exopodite is lamelliform.
It is much dilated at the middle. The apex is narrow and sinuous. The inner margin of the
joint is distinctly notched. The second joint of the left exopodite is broadly triangular in outline.
It is well supplied with muscles. The apex of the joint bears two moderately long curved spines.
The spines are rather shorter than the joint. The distal end of the inner spine is sickle-shaped.
The apex of this spine is distinctly bifurcate (Plate XLIII, fig. 19).

This species appears to come very close to Wolfenden's type species {Paraugaptilus
buchani) and I was inclined at first to regard it as identical. Dr. Wolfendex, to whom I
submitted copies of the figures now given, is of the opinion, however, that it is distinct. The
fifth pair of the female of the present form differs from Wolfexdex's species, in having two
small outer edge hairs near the distal end of the joint. The male of the genus has hitherto
been unknown.

Occurrence. Males and females were found in the plankton collected at the

follouïngr stations.

145

SIROGA-EXPEDITIE XX Xa. 19

146

Stat. 141 (HENSEN vertical net, 1500 metres to surface), 2 females. — Stat. 142, 2 males. - —
Stat. 148 (HENSEN vertical net, 1000 metres to surface), 8 females and five males. — Stat.
185 (HENSEN vertical net, 1536 metres to surface), 2 females and 1 male. — Stat. 203
(HENSEN vertical net, 1500 metres to surface), 2 females and 4 males.

Genus Metacalanus Geve, 1901.

This genus was established in 1901 by the late Professor P. T. Cleve for a small
Calanoid found in plankton collected near the Island of Langkuss, N.W. of Billiton in the Malay
Archipelago. It is nearly related to Arietellns in the structure of some of the appendages. It
also comes remarkably close to the genus Scottula established by Professor G. O. Sars in 1902
in 'Crustacea of Norway'.

The only obvious difference between this genus and Scottula, is in the structure of the
female fifth pair of feet. The fifth pair in Scottula has two free joints and a basal part. Metacalanus
has only one free joint and a basal part.

One species is known. It was well represented in the area investigated by the 'Siboga'.

1. Metacalanus aurivillii Cleve.

Metacalanus aurivillii Cleve, 1901, p. 43, pis. IV & V.
Metacalanus aurivillii Thompson & Scott, 1903, p. 243, pi. II.

Males and females belonging to this species were found in the plankton collected at the

following stations.

Stat. 16. — Stat. 19. — Stat. 35. — Stat. 36. — Stat. 37. — Stat. 40. — Stat. 47''. -
Stat. 66. — Stat. 75. -*- Stat. 93. — Stat. 96 (day). — Stat. 96 (night). — Stat. 98. —
Stat. 99. — Stat. ioó. — Stat. 109. — Stat. 117*. — Stat. 11S (Hexsex vertical net, 900
metres to surface). — Stat. 125 (day). — Stat. 128 (Hexsex vertical net, 700 metres to
surface). Stat. 136. — Stat. 138. — Stat. 141 (HEXSEX vertical net, 1500 metres to

surface). - - Stat. 142. — Stat. 143 (Hexsex vertical net, 1000 metres to surfacej. — Stat.
148 (Hexsex vertical net, 1000 metres to surface). — Stat. 184. — Stat. 203 (Hexsex
vertical net, 1500 metres to surface). — Stat. 205. — Stat. 213. — Stat. 217 (horizontal
cylinder). — Stat. 220 (Hexsex vertical net, 200 metres to surface). — Stat. 252. — Stat.
276 (HEXSEX vertical net, 750 metres to surface). — Stat. 282. — Stat. 304. — Stat. 315.

Metacalanus aurivillii is a very small Calanoid and is easily overlooked. The female
is .65 mm. and the male .5 mm. in length.

The right antennule of the male and female is distinctly shorter than the left. The fifth
pair of feet of the female is composed of one free joint attached to a basal part. The free
joint is broad and lamelliform. It is furnished with ene outer marginal seta, one apical seta,
and one long plumose inner marginal seta. The male fifth pair is quite symmetrical. It consists
of four free joints attached to a basal part. The apical joint of the right and left foot is in
the form of a long slender claw. The second and third free joints are each furnished with one
outer marginal seta. The endopodite is absent.

This species was obtained by Cleve from plankton collected in the Malay Archipelago
in 1899. It was present in the plankton taken at twenty-seven stations round the Island of
<. eylon by Professor Hekdmax in 1903.

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'47

Genus Phyllopus Brady, 1883.

The members of this genus are readily recognised by the structure of the fifth pair of
feet of the two sexes. The female fifth pair has a two-jointed basiopodite, and a three-jointed
exopodite. There is no tracé of an endopodite on either foot. The terminal joint of the exopodite
is leaf-like. The apex is rather deeply and irregularly serrate. The male fifth pair is well
developed and prehensile. The exopodite of each foot is two-jointed. The left foot only is
furnished with a rudimentary lamelliform endopodite.

The genus was established by Brady in 1883 from a single specimen that was undoubtedly
a female. Wolfenden's statement, in the Journal of the Marine Biological Association, April
1904, page 124, that it was a male is a curious error as he describes the male in the same
report. The late I. C. Thompson appears to have been the first observer to give an account
of the male, but he wrongly identifies his species with the type of the genus. Thompson,
Wolfenden and Esterly state that the right foot has a rudimentary endopodite. This is an
error due to an imperfect preparation or a reversal of the right and left sides. Esterly, however,
only found one female and his description of the male was taken from Wolfenden's report.

There appears to be some confusion regarding the type species. Other forms have been
recorded by some writers as Phyllopus bidentatus that are clearly distinct. Farran (1908) has
done much to clear up the difficulty, and has established two additional species.

Four species belonging to this genus were obtained from the plankton collected by the
'Siboga' in the Malay Archipelago.

1. Phyllopus bidentatus Brady. Plate XLV, figs. 1 — 9.

Phyllopus bidentatus Brady, 1883, p. 78, pi. V, figs. 7 — 16.
Phyllopus bidentatus T. Scott, 1893, p. 74, pi. VI, fig. 26.
Phyllopus bidentatus Sars, 1905 (b), p. 5.

Eight males and three females apparently identical with Brady*s type species- were found
in the plankton collected at the following stations.

Stat. 118 (HENSEN vertical net, 900 metres to surface), 1 male. -- Stat. 128 (HENSEN vertical
net, 700 metres to surface), 1 male, 1 female. — Stat. 141 (HENSEN vertical net, 1500
metres to surface), 1 male, 1 female. — Stat. 185 (HENSEN vertical net, 1536 metres to
surface), 2 males. — Stat. 203 (HENSEN vertical net, 1500 metres to surface), 1 male. —
Stat. 2 [6, 1 male. — Stat. 276 (HENSEN vertical net, 750 metres to surface), 1 male and
1 female.

The females although resembling Brady's type in the prolongation of the last thoracic
segment, differ from it by the projection being obliquely truncate at the apex, when seen from
the side, instead of distinctly forked as shewn by that author. The terminations of the last
thoracic segment are asymmetrical, both in length and in shape. The left side extends to the
middle of the genital segment. The apex is pointed (Plate XLY, fig. 3). The right side extends
to near the distal end of the genital segment. The apex is obliquely truncate, with a very
minute point at each extremity (Plate XLV, fig. 4).

The combined length of the abdomen and furca is equal to slightly more than one

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half of the total length of the ceplialothorax, from the frontal margin to the base of the genital
segment. The genital segment is as long as the combined length of the second and third seg-
ments. It is rather cylindrical in outline, and appears slightly asymmetrical when viewed from
above. Seen from the side, the dorsal surface is acutely pointed (Plate XLV, figs. 3 & 4). The
furcal joints are one and a half times longer than broad. They are about a third less than
the length of the anal segment.

The apex of the last joint of the exopodite of the fifth pair of feet is divided into six
teeth. The third outer tooth is rather larger than the others (Plate XLV, fig. 6). Length of
female, 3,2 mm.

The outer margin of the apical joint of the exopodite of the left foot of the male fifth
pair is boldly rounded. The distal end of the joint is produced into a short stout tooth-like
projection. The strong distal outer edge hook is about half the length of the joint (Plate XLV, fig. 9).

Length of male, 3 mm.

The figure of the animal shewn on plate VI in the report 'On Entomostraca from the
Gulf of Guinea' by my father, is identical with the female of the present species. The fifth
pair of feet shewn on the same plate does not belong to that individual. This is due to the
fact that drawings of two forms were prepared for publication, but through an error, the fifth
pair of feet belonging to the form represented by the figure of the copepod was omitted.
The fifth pair of the second form was inserted instead. The number of plates allowed by the
Linnean Society for the illustration of doubtful forms proved insufficiënt, and many figures had
to be suppressed although completed. I have compared the drawings that were intended for
publication with those identified in this report as Phyllopus bidcntalus, and find that the fifth
pairs of feet are identical.

The single specimen described by Brady was obtained from plankton collected by the
'Challenger' in the South Atlantic, between Rio de la Plata, and the Island of Tristan da
Cunha. Sars records this species from the plankton collected by the Prince of Monaco, but as
no illustrations have yet been given one must regard the identity as doubtful.

2. Phyllopus helgae Farran. Plate XLVI, fig. 7 — 14.

Phyllopus bidentatus I. C. Thompson, 1903, p. 29, pi. III, figs. 6 — 9.
Phyllopus bidentatus Wolfenden, 1904, p. 124, pi. IX, fig. 16.
Phyllopus bidentatus Farran, 1905 (pars), p. 45, pi. XI, figs. 18, 19 & 21.
Phyllopus bidentatus van Breemen, [908 (pars), p. 143, fig. i6(</ — e).
Phyllopus helgae Farran, 1908, p. 83, pi. IX, figs. 5 & 6.

One female and one male belonging to this species was found in the plankton collected
with the Hensen vertical net at Station 128, 700 metres to the surface.

The female of this form is reaclilv recognised by the almost symmetrical and only
slightly produced distal ends of the last thoracic segment. The genital segment is asymmetrical.
It has a large protuberance on the right side. The fifth pair of feet is slightly asymmetrical.
The serration at the distal end of the apical joint of the fifth pair of the 'Siboga' female is
rather different from that shewn by Farran (Plate XLVI, fig. 11).

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'4"

The male can readily be separated from the males of the other species, by the elongate
and very pointed apex of the last joint of the exopodite of the left fifth toot, and by the long
curved spine on the outer distal half of the joint (Plate XLVI, fig. 14).

Length — female, 2,6 mm., male 2,45 mm.

The male described by the late I. C. Thompson (1903) as Phyllopus bidentatus, is
identical with the male of the present species. The figures of the male fifth pair given by
Wolfexdex ( 1 904) and vax Breemex (1908) as Phyllopus bidentatus are the same as that of
the male of Phyllopus helgae Farran.

3. Phyllopus impar Farran. Plate XLV, figs. 10 — 18.

Phyllopus bidentatus T. Scott, 1893 (pars), p. 74, pi. VI, fig. 28.
Phyllopus bidentatus Farran, 1905 (pars), p. 45, pi. XI, fig. 20.
Phyllopus impar Farran, 190S, p. 84, pi. IX, fïgs. I — 4.

Three females and two males that are clearly identical with this species were obtained
from the plankton collected with the Hexsex vertical net at the following stations.

Stat. 128 (700 metres to surface), one female and one male. — Stat. 141 (1500 metres to
surface), one female. — Stat. 143 (1000 metres to surface), one female and one male.

The two sexes have a general resemblance to those of Phyllopus bidentatus. The female,
however, is easily separated by the genital segment appearing greatly infiated on each side
when viewed from above, and by the character of the serration of the apical joint of the
exopodite of the fifth pair of feet. The teeth are arranged in pairs. The outer tooth of each
set is decidedly larger than the inner one (Plate XLV, fig. 15). The terminal joint of the left
exopodite of the male fifth pair has the outer margin distinctly angled at the middle. The
outer distal curved spine on this joint is proportionally shorter than in the males of Phyllopus
bidentatus or Phyllopus helgae (Plate XLV, fig. 18).

Length — female 3 mm., male 2,7 mm.

The fifth pair of feet shewn on plate VI in the report 'On Entomostraca from the Gulf
of Guinea', and identified by my father as that of Phyllopus bidentatus Brady, is undoubtedly
identical with the female fifth pair of Phyllopus impar Farran.

This species has hitherto only been known from the Atlantic Ocean.

4. Phyllopus giesbrechti nov. sp. Plate XLVI, figs. 1 — 6.

Phyllopus bidentatus Giesbrecht, 1893, p. 419, pis. 18 & 38.

Phyllopus bidentatus Giesbrecht & Schmeil, 1S98 (pars), p. 124.

Phyllopus bidentatus Esterly, 1905, p. 191. fig. 43.

Phyllopus bidentatus van Breemen, 190S (pars), p. 143, fig. 161 [a — b).

Female — length 2,8 mm.

Viewed from above. this species has a general resemblance to Pliyllopus bidentatus
Brady. The last thoracic segment is considerably produced, but the distal ends are only very
slightly asymmetrical. The distal end of the right side has a small notch. It is not lamelliform.
Seen from the side, the produced ends of the last thoracic segment are narrowly rounded at

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15°

the apex. They are not pointed as in Phyllopus bidentatus or Phyllopus impci7- (Plate XLVI,
figs. 3 and 4).

The combined length of the abdomen and furca is equal to half of the total length
of the cephalothorax, from the frontal margin to the distal end of the last thoracic segment.
The genital segment is slightly longer than the combined length of the second and third seg-
ments. It is somewhat cylindrical in outline, and appears very nearly symmetrical when seen
from above. The dorsal surface is flatly rounded when viewed from the side (Plate XLVI,
figs. 3 and 4). The furcal joints are twice as long as broad. Each joint is slightly longer than
the anal segment.

The antennules are twenty-four-jointed and reach to the middle of the genital segment.

The antennae, mandibles, maxillae and maxillipedes are similar to those of Phyllopus
bidentatus.

The four pairs of swimming feet are also similar to those of that species.

The fifth pair of feet resembles that of Phyllopus bidentatus but the last two joints of
the exopodite are proportionally wider (Plate XLVI, fig. 6).

Male unknown.

This species appears to be identical with the form described and illustrated as Phyllopus
bidentatus by Giesbrecht. It differs from Brady's species, however, by the nearly symmetrical
prolongations of the last thoracic segment, and by their narrowly rounded apex when viewed
from the side. The figure given by Esterly (1905), and also some of those shewn by van
Breemen (1908), evidently represent this Phyllopus.

Occurrence. — Three females were obtained from the plankton collected with the
Hensen vertical net at the following stations.

Stat. 203 (1500 metres to surface), two specimens. — Stat. 276 (750 metres to surface), one
specimen.

17. Family Candaciidae.
Genus Candacia Dana, 1846.

This genus is at present the only known representative of the family, but it contains
a considerable number of species. The species are distinguished chiefly by the form of the last
thoracic segment, and by the structure of the fifth pair of feet of the two sexes.

Twelve species were obtained from the plankton collected by the 'Siboga' during the
investigations conducted in the Malay Archipelago. One of the species does not appear to
have previously been described.

1. Candacia aethiopiea (Dana).

Candace aethiopiea Dana, 1849. p. 23.

Candace melanopus Claus, 1863, p. 191, pi. XXXIII.

Candace aethiopiea Giesbrecht, 1893, p. 424, pis. 4, 21, 22 & 39.

i S i

Candacia aethiopica Giesbrecht & Schmeil, 1898, p. 128.

Candacia aethiopica I. C. Thompson, 1900, p. 281.

Candacia aethiopica A. Scott, 1902, p. 405.

Candacia aethiopica Thompson & Scott, 1903, p. 250.

Candacia aethiopica Cleve, 1903, p. 358.

Candacia aethiopica Sars, 1905 (b), p. 5.

Candacia aethiopica Esterly, 1905, p. 196, fig. 47.

Thirty-three specimens belonging to this species were obtained from the plankton col-
lected at the following stations.

Stat. 36. — Stat. 81.— Stat. 93. — Stat. 96 (day). — Stat. 96 (night). — Stat. 98. — Stat. 1 10. —
Stat. 11;1. — Stat. 118 (HENSEN vertical net, 900 metres to surface). — Stat. I2S(Hensen
vertical net, 700 metres to surface). — Stat. 133. — Stat. 138. — Stat. 141 (HENSEN vertical
net, 1000 metres to surface). - - Stat. 146. — Stat. 148 (HENSEN vertical net, 1000 metres
to surface).

► The males and females can readily be separated from the other members of the genus

by the shape of the terminations of the last thoracic segment, and by the structure of the
fitth pairs of feet. The dorsal surface of the body is usually quite black.

Candacia aethiopica appears to have a moderately wide distribution in tropical seas.

2. Candacia bipinnata (Giesbrecht).

Candace pectinata Brady, 1883 (pars), p. 6j, pi. XXX, figs. 1 & 2.

Candace truncata Brady, 1883 (pars), p. 69, pi. XXIX, fig. 13.

Candace bipinnata Giesbrecht, 18S9, p. 815.

Candace bipinnata Giesbrecht, 1893, p. 424, pis, 22 & 39.

Candacia bipinnata Giesbrecht & Schmeil, 189S, p. 129.

Candacia bipinnata Cleve, 1904, p. 1S6.

Candace bipinnata Sars, 1905 (b), p. 5.

Candacia bipinnata Esterly, 1905, p. 195, fig. 45.

Seven specimens identical with this species were found in the plankton collected at the
following stations.

Stat. 129. — Stat. 203 (HENSEN vertical net, 1500 metres to surface). — Stat. 243 (HENSEN
vertical net, 1000 metres to surface). — Stat. 252. — Stat. 276 (HENSEN vertical net, 750
metres to surface). — Stat. 282. — Stat. 315.

The very spiniform wing-like lateral projections of the genital segment, easily distinguish
the temales from those of the other species. Some of the 'Challenger' specimens that were
identified by Brady as Candace pectinata, and Candace truncata, undoubtedly belong to this
species. This is obvious on comparing the illustrations with Giesbrecht's figures.

Candacia bipinnata has been recorded from the Atlantic and Pacific Oceans.

3. Candacia bispinosa (Claus).

Candace bispinosa Claus, 1S63, p. 191, pis. XXVII & XXXIII.
Candace truncata Brady, 1883 (pars), p. 69, pi. XXIX, fig. tl.
Candace bispinosa Giesbrecht, 1893, p. 424, pis. 21, 22 & 39.

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i52

Candaaa bispinosa Giesbrecht & Schmeil, 1898, p. 129.

Candacia bispinosa A. Scott, 1902, p. 406.

Candaaa bispinosa Thompson & Scott, 1903, p. 250.

Candacia bispinosa Geve, 1903, p. 358.

One female belonging to the above species was found in the plankton collected at each
of the three following stations.

Stat. 110. — Stat. 128 (Heksen vertical net, 700 metres to surface). — Stat. 133.

The genital segment of the female is considerably expanded at the distal end. Each
side of the segment is produced into a small spine. Bradv considered that this form was only
a variety of Candacia truncata, but the spiniform projections of the last thoracic segment, and
the shape of the genital segment of the females clearly shew that it is quite distinct.

Candacia bispinosa has been recorded from the Atlantic and Pacific Oceans, and from
the Mediterranean.

4. Candacia cahila (Giesbrecht).

Candacc truncata Brady, 1883 (pars), p. 69, pi. XXIX, tig. 10.

Candace catula Giesbrecht, 1S89, p. 815.

Candacc catula Giesbrecht, 1893, p. 425, pis. 21 & 22.

Candacia catula Giesbrecht & Schmeil, r 898, p. 1 29.

Candacc catula Cleve, 1901, p. 5.

Candacia catula A. Scott, 1902, p. 405.

Candacia catula Thompson & Scott, 1903, p. 250.

Candacia catula Cleve, 1903, p. 358.

Candacia catula Cleve, 1904, p. 186.

Candacc catula Wolfenden, 1905(17), p. 1012.

This species appeared to be fairly well distributed throughout the area investigated.
Forty specimens were obtained from the plankton collected at the following stations.

Stat. 37. — Stat. 471 . — Stat. 66. — Stat. 75 (Hensen vertical net, 1 1 metres to surface). —
Stat. 93. -- Stat. 96 (day). -- Stat. 96 (night). — Stat. 98. — Stat. 101. -- Stat. 121. —
Stat. 125. — Stat. 138. — Stat. 143 (HENSEN vertical net, 1000 metres to surface). —
Stat. 146. — Stat. 148 (HENSEN vertical net, 1000 metres to surface). -- Stat. 185 (HENSEN
vertical net, 1536 metres to surface). -- Stats. 194 — 7. — Stat. 2 1 5:'. — Stat 217 (horizontal
cylinder). — Stat. 220 (surface). — Stat. 220 (HENSEN vertical net, 200 metres to surface). —
Stat. 225. — Stat. 276 (HENSEN vertical net, 750 metres to. surface). — Stat. 282. —
Stat. 304. — Stat. 315.

The structure of the fifth pair of feet of both sexes readily separates this species from
the other members of the genus.

One of the illustrations given on plate XXIX in the report on the 'Challenger' Copepoda,
as the female fifth pair of Candacc truncata clearly belongs to Candacia catula.

Candacia catula has been recorded from the Atlantic, Indian and Pacific Oceans.

5. Candacia curta (Dana).

Candacc curta Dana, 1849, p. 23.

Candace pectinata Brady, 1883 (pars), p. 67, pi. XXX, figs. 10, 12 & 13.

l52

C andace curta Giesbrecht, 1893, p. 424, pis. 21, 22 & 39.

C andace 'intermedia T. Scott, 1893, p. 61, pi. IV, figs. 30 — 37.

Candacia curta Giesbrecht & Schmeil, 1898, p. 129.

Candacia curta Thompson & Scott, 1903, p. 251.

Candacia curta Geve, 1903, p. 358.

Candacia curta Geve, 1904, p. 186.

Candacia curta Sars, i905(/>), p. 5.

Candacia curta Esterly, 1905, p. 196, fig. 46.

Candace curta Wolfenden, 1905 (a) p. 1013.

Thirty-six specimens of the above species were found in the plankton collected at the
following stations.

Stat. 47''. — Stat. 81. — Stat. 89. — Stat. 98. — Stat. 117'. — Stat. 118 (Hensen vertical
net, 900 metres to surface). — Stat. 124. — Stat. 125. (day). — Stat. 138. — Stat. 141
(Hensen vertical net, 1500 metres to surface) — Stat. 143 (Hensen vertical net, 1000
metres to surface). — Stat. 144. — Stat. 146. — Stat. 148 (HENSEN vertical net, 1000
metres to surface). — Stat. 157. — Stat. 165. — Stat. 169. — Stat. 184. — Stat. 185
(Hensen vertical net, 1536 metres to surface). — Stat. 189". — Stat. 194 — 7. — Stat. 213. —
Stat. 282. — Stat. 304.

Candacia curta has a certain amount of resemblance to Candacia armata (Boeck), but
the two sexes are readily separated from it by the structure of the fifth pairs of feet. The
apical joint of the female fifth pair terminates in three strong teeth.

This species has been recorded from the Atlantic and Pacific Oceans and from the Red Sea.

6. Candacia longimana (Claus).

Candace longimaua Claus, 1S63, p. 190, pis. XXVII & XXXIII.
Candace longimana Giesbrecht, 1893, p. 423, pis. 21, 22 & 39.
Candacia longimana Giesbrecht & Schmeil, 1898, p. 127.
Candacia longimana I. C. Thompson, 1900, p. 281.
Candacia longimana Thompson & Scott, 1903, p. 250.
Candacia longimana Sars, 1905, p. 5.

Two females identical with this species were obtained from the plankton collected at
the following stations.

Stat. 112. — Stat. 128 (Hensen vertical net, 700 metres to surface).

The female of Candacia longimana can be recognised by the apical joint of the fifth
pair of feet terminating in three very short teeth.

This species has only previously been known from the Pacific Ocean and from the
Mediterranean.

7. Candacia pachydactyla (Dana).

Candace pachydactyla Dana, 1849, p. 23.

Candace pachydactyla Brady, 1883, p. 68, pi. XXXI, figs. 2—9.
Candace pachydactyla Giesbrecht, 1893, p. 424, pis. 21, 22 & 39.
Candace pachydactyla T. Scott, 1893, p. 60.
Candacia pachydactyla Giesbrecht & Schmeil, [898, p. 128.

iS3

SIBOGA-EXPELMTIE XXIX<7. 20

'54

Candace pachydactyld Cleve, 1901, p. 5.

Candacia pachydactyla Thompson & Scott, 1903, p. 251.

Candacia pachydactyla Cleve, 1903, p. 358.

Candacia pachydactyla Cleve, 1904, p. 187.

Candacia pachydactyla Sars, (1905/7), p. 5.

Candace pachydactyla Wolfenden 1905(0), p. 1013.

This species proved to be moderately common. It was well distributed throu^hout the
area investigated by the 'Siboga' as shewn by the following records.

Stat. 19. — Stat. 36. — Stat. 37. — Stat. 40. — Stat. 50. — Stat. 66. — Stat. 71. —
Stat. 75 (HENSEN vertical net, 11 metres to surface). — Stat. 81. — Stat. 96 (night). —
Stat. 98. - - Stat. 110. - ■ Stat. 124. - - Stat. 128 (HENSEN vertical net, 700 metres to
surface). - - Stat. 133. — Stat. 136. — Stat. 138. — Stat. 141 (HENSEN vertical net, 1500
metres to surface). — Stat. 142. — Stat. 143 (HENSEN vertical net, 1000 metres to surface). —
Stat. 144. — Stat. 148 (HEXSEN vertical net, 1000 metres to surface). — Stat. 157. —
Stat. 165. — Stat. 168. — Stat. 169. — Stat. 172. — Stat. 1S4. — Stat. 189'. — Stat. 193. —
Stats. 194 — 7. — Stat. 203 (surface). — Stat. 203 (HENSEN vertical net, 1500 metres to
surface). — Stat. 204. — Stat. 205 — Stat. 2io\ — Stat. 213. — Stat. 214. — Stat.
215". - ■ Stat. 216. - - Stat. 217 (horizontal cylinder). — Stat. 220 (HENSEN vertical net,
200 metres to surface). — Stat. 223. — Stat. 224. — Stat. 225. — Stat. 245. — Stat.
252. -- Stat. 271. -- Stat. 276 (HENSEN vertical net, 750 metres to surface). — Stat. 282. —
Stat. 304. — Stat. 315.

The two sexes can readily be separated from the other members of the genus by the
structure of the rïfth pairs of feet. The genital segment of the female has two large ventrally
directed spines. The right side of the last thoracic segment of the male terminates in a slightly
biiurcate prolongation. The distal end of the right side of the male genital segment is greatly
produced.

Candacia pacJiydactyla is widely distributed in tropical seas.

8. Candacia simplex (Giesbrecht).

Candace simplex Giesbrecht, 1889, p. 815.

Candace simplex Giesbrecht, 1893, p. 424, pis. 21, 22 & 39.

Candacia simplex Giesbrecht & Schmeil, 189S, p. 130.

Candace simplex Cleve, 1901, p. 5.

Candacia simplex Thompson & Scott, 1903, p. 250.

Candacia simplex Cleve, 1903, p. 358.

Candacia simplex Sars, 1905 [b), p. 5.

One hundred and twenty specimens belonging to this species were obtained from the
plankton collected at the following stations.

Stat. 16. -- Stat. 35. -- Stat. ^6. -- Stat. 66. -- Stat. 71. — Stat. 93. - - Stat. 96 (day). —
Stat. 98. -- Stat. 99. -- Stat. 101. — Stat. 106. — Stat. 1 10. — Stat. 117'. — Stat. 129. —
Stat. 136. — Stat. 141 (Hexsen vertical net, 1500 metres to surface). — Stat. 143 (Hexsen
vertical net, 1000 metres to surface). — Stat. 144. — Stat. 165. — Stat. 172. — Stat. 174. —
Stat. 1 77 '. • - Stat. 185 (Hexsen vertical net, 1536 metres to surface). • - Stat. 189'. -
Stats. 194—7. - - Stat. 204. — Stat. 205. - - Stat. 210'. — Stat. 213. — Stat. 215*. —
Stat. 252. — Stat. 315.

i54

t55

The fifth pairs of feet of the twu sexes are very sitnilar to those of Candacia bispinosa,
but the females can easily be separated by the quite symmetrical genital segment. The segment
lias no spiniform projection on the sides.

Candacia simplex has been recorded from the Pacific and Indian Oceans, and from the
Mediterranean.

9. Candacia ienuimana (Giesbrecht).

Candace ienuimana Giesbrecht, 1889, p. 8 14.
Candace tenuimana Giesbrecht, 1893, p. 424, pis. 21 & 22.
Candacia tenuimana Giesbrecht & Schmeil, 1898, p. 128.
Candacia tenuimana Cleve, 1904, p. 187.

Two females belonging to this species were found in the plankton collected vvith the
Hensen vertical net at Station 141, 1500 metres to the surface.

Candacia tenuimana is closely related to Candacia longimana, but the female can readily
be separated by the long spiniform termination of the apical joint of the fifth pair of feet.

This species is known from the Pacific Ocean and from the Mediterranean.

10. Candacia truncata (Dana).

Candace truncata Dana, 1849, p. 24.

Candace truncata Brady, 1883 (pars), p. 69, pi. XXIX, tig. 9.

Candace truncata Giesbrecht, 1893, p. 425, pis. 21, 22 & 39.

Candacia truncata Giesbrecht & Schmeil, 1898, p. 130.

Candacia truncata I. C. Thompson, 1900, p. 282.

Candacia truncata A. Scott, 1902, p. 406.

Candacia truncata Thompson & Scott, 1903, p. 250.

Candacia truncata Cleve, 1903, p. ,358.

Candacia truncata Cleve, 1904, p. 187.

Candace truncata Wolfenden, \()0^{a), p. 1013.

This species appeared to be well distributed throughout the area investigated bv the
'Siboga' as shewn by the following records. Eighty-eight specimens were obtained.

Stat. 35. — Stat. 37. — Stat. 66. — Stat. 96 (night). -- Stat. 98. — Stat. 99. — Stat. 101. —
Stat. 106. — Stat. 109. — Stat. 1 10. — Stat. 112. — Stat. wj'\ — Stat. 11S (HENSEN
vertical net, 900 metres to surface). — Stat. 121. — Stat. 125 (night). — Stat. 128
(HENSEN vertical net, 700 metres to surface). • • Stat. 133. ■ Stat. 136. — Stat. 141
(HENSEN vertical net, 1500 metres to surface). — Stat. 142. -- Stat. 143 (HENSEN vertical
net, [OOO metres to surface). — Stat. 144. — Stat. 157. - Stat. 169. — Stat. 172. -
Stat. ijj\ — Stat. [84. — Stat. 186. — Stat. 189'. -- Stat. 203 (surface). — Stat. 203
(HENSEN vertical net, 1500 metres to surface).. — Stat. 204. Stat. 217 (horizontal

cylinder). — Stat. 220 (HENSEN vertical net, 200 metres to surface). — Stat. 229. —
Stat. 252. — Stat. 276 (Hensen vertical net, 750 metres to surface). — Stat. 282.
Stat. 304. — Stat. 315.

The females can readily be separated from any of the other members of the genus,
by the truncate distal ends of the last thoracic segment, and by the small tooth at the posterior
extremity of the ventral margin of this segment.

iS5

156

Candacia truncata has been recorded from the Atlantic, Indian and Pacific Oceans, and
from the Red Sea.

ii. Candacia bradyi A. Scott. Plate XLVII, figs. i — 9.

Candace pectinata Brady, 1883 (pars), p. 67, pi. XXX, fig. 9.

Candacia bradyi A. Scott, 1902, p. 406, pi. I, figs. 9 — 12.

Candacia bradyi Thompson & Scott, 1903, p. 250.

Candace tuberculata Wolfenden, 1905 («), p. 1013, pi. XCVI, figs. 40 — 44.

Fifty-seven specimens of this species were obtained from the plankton collected at the
following stations. Only the males have yet been discovered.

Stat. 16. -- Stat. 98. -- Stat. 99. -- Stat. n;\ -- Stat. 124. -- Stat. 125 (night). -- Stat.
136. -- Stat. 138. -- Stat. 141 (HENSEN vertical net, 1 500 metres to surface. — Stat. 142. —
Stat. 143 (HENSEN vertical net, 1000 metres to surface). — Stat. 144. — Stat. 169. —
Stat. 172. - - Stat. 174. - - Stat. 184. - - Stat. 185 (HENSEN vertical net, 1536 metres to
surface). — Stat. 189'. — Stats. 194 — 7. — Stat. 215". -- Stat. 223. — Stat. 225.— Stat. 315.

This species is easily distinguished from any of the other known males belonging to
the genus, by the toothed tubercle on the right side of the genital segment (Plate XLVII, fig. 2)
and by the structure of the fifth pair of feet. The third free joint of the left foot, is produced
at the outer distal angle into a short stout tooth-like process. The tooth is of a dark colour.
W'hen seen from the side it appears very broad, and the apex is divided into three blunt
points. The apical joint of the left foot appears elongate and narrow when seen from the
posterior aspect. In side view, the joint appears very thin. The apex of the joint is furnished
vvith three small spines (Plate XLVII, figs. 8 and 9).

The left antennule is composed of twenty-three joints and extends to the end of the abdomen.

The middle joint of the first pair of maxillipedes is furnished with three very short
spines. The first proxunal spine on the third joint is much thicker than the second proximal
spine (Plate XLVII, fig. 6).

The terminal spine of the exopodite of the third pair of feet is contained one and a
half times in the length of the last joint (Plate XLVII, fig. 7). The terminal spine of the
exopodite of the second and fourth pairs of feet is similar to that of the third. The endopodite
of the first pair of feet is only one-jointed, and there is no setae on the second joint of the
basiopodite. The endopodite of the second, third and fourth pairs of feet is two-jointed.

Length — 2 mm.

The fifth pair of feet of this species is identical with the fifth pair figured by Brady in
the report on the 'Challenger' Copepoda (Plate XXX, fig. 9), and identified as that of Candace
pectinata (= Candace armata Boeck). The fifth pair of feet of the male of Candacia armata
(Boeck), is very different from the illustration in the 'Challenger' report, and from that now
presented. The genital segment also differs by having a large tooth-like projection on the right side.

The species described by Wolfenden 1905(0), as Candace tuberculata is certainly the
same as the present form. My original figures were rather indifferently reproduced by the
lithographer, but the peculiar characters of the fifth pair are quite obvious. Wolfenden's two

156

I ",

5/

figures of the fifth pair are very little different from the ftgures published by me in 1902. The
small differences mentioned by Wolfenden are due to the preparation being examined from a
slightly different position. My paper was published some three years before the appearance of
Wolfenden's report on the Copepoda collected by J. Stanley Gakdiner around the Maldive Islands.
G. Smith (1909), p. 60, makes the following statement regarding the distribution of the
Candaciidae. "Some species, e. g. C. pectinata Brady, have a practically world-wide distribution,
"this species being recorded from the Shetlands and from the Phillipines". I am unable to tind
any record from the Phillipitie area except the one given by Brady in the report on the
'Challenger' Copepoda. The form illustrated in that report as Candace pectinata represents at
least four distinct species, none of which are identical vvith it. The illustratións on Plate XXX
in the 'Challenger' report represent Candacia èipinnata, C. curta, C varicans and C'. bradyi.
Candace pectinata Brady (1878), was shewn by Sars (1902) to be identical with Candace arniata
Boeck (1872), and the distribution is stated to be British Isles (Brady), Atlantic Ocean, between
Lat. n° and 50D X. (Cleve), Mediterranean (Giesbrecht). Sars records it from the Coast of
Norway and from the East of Iceland. Esterly records and illustrates Candacia pectinata from
the Pacific in the vicinity of San Diego, California. Wheeler (1900) records it from Woods Hole.

12. Candacia discaudata nov. sp. Plate XLVII, figs. 10 — 20.

Female — length 1,94 mm.

Seen from above, the body appears rather short and moderately robust. The frontal
margin is truncate. The distal ends of the last thoracic segment terminate in short spiniform
projections. Viewed from the side, the cephalic segment is considerably vaulted. The spiniform
projection of the last thoracic segment is directed ventrally (Plate XLVII, tig. 11).

The combined length of the abdomen and furca is contained two and a half times in
the total length of the cep halothorax \ from the frontal margin to the base of the genital segment.
The genital segment is slightly asymmetrical when viewed from above. It is without lateral
projections. Lach side is furnished with one short setae. The length of the segment is nearly
equal to the combined length of the next two segments. The second segment is broadly
wedge-shapecl. lts length is equal to fully one-half of the length of the genital segment. The
anal segment is very short. It is distinctly asymmetrical. The furcal joints are twice as long as
broad (Plate XLVII, fig. 10). When viewed from the side, the distal end of the second segment
is seen to be considerably expanded. The distal end is much wider than the proximal end of
the next segment. The anal segment is very narrow. It is only equal to one-half of the width
of the distal end of the second segment (Plate XLVII, fig. 1 1).

The antennules are composed of twenty-three joints, and reach to the middle of the
genital segment.

The antennae. mandibles, maxillae and maxillipedes are similar to those of Candacia
norvegica (Boeck). The middle joint of the first maxillipedes is furnished with two spines. The
proximal spine is slightly longer and thicker than the distal one. The first proximal spine on
the third joint is much thicker than the second proximal spine (Plate XL\ II, fig. 13).

D/

158

The endopodite of the first pair of feet is one-jointed. There is no setae on the second
joint of the basiopodite.

The endopodite of the second, third and fourth pairs of feet is two-jointed. The terminal
spine on the exopodite of the third pair of feet is contained one and a half times in the length
of the last joint. The terminal spine on the exopodite of the second and fourth pairs of feet,
is similar to that on the exopodite of the third pair.

The last joint of the fifth pair of feet is long and slender. The joint of one foot is
distinctly longer than that of the other. This gives the fifth pair an asymmetrical appearance.
The apex of the joint is produced into three closely set teeth. The outer margin is furnished
with two small spines. The inner margin bears two moderately long setae (Plate XLYII, figs.
15 and 16).

Male — length 1,8 mm.

The male resembles the female in general appearance. The abdomen is composed of
five joints. The genital segment is asymmetrical. Yiewed from above, the distal end of the
right side is seen to be much inflated. Seen from the right side, the inflated region bears a
small tooth at each end. The anal segment is asymmetrical as in the female (Plate XLYII,
figs. 17 and 18).

The right antennule is twenty-three-jointed. The hinge is situated between the seventeenth
and eighteenth joints. The upper margin of the sixteenth, seventeenth and eighteenth joints,
is furnished with a row of dark coloured teeth as in Candacia bradyi.

The antennae, mandibles, maxillae and maxillipedes are similar to those of the female.

The four pairs of swimming feet are also similar to those of the female.

The joints of the left exopodite of the fifth pair of feet are moderately long and broad.
The terminal joint is furnished with two outer edge spines and two apical spines. The spines
are very small. The right exopodite is short. The moveable claw has a large projection near
the distal end of the inner margin (Plate XLYII, fig. 20).

The males and females of this species are readily separated from the other members
of the genus, by the structure of the fifth pair of feet. YVhen viewed from the side, the abdomen
of the female is seen to have a general resemblance to that of Candacia chcirura Cleve (1904),
but the fifth pair of feet is quite distinct.

O'ccurrence. — One hundred and eighteen females and fifty-six males were obtained
from the plankton collected at the following stations.

Stat. 35, 3 specimens. — Stat. 36, 4 specimens. — Stat. 47', 3 specimens. — Stat. 66, 6
specimens. — Stat. 71,3 specimens. — Stat. Si, 3 specimens. — Stat. 89, 8 specimens. —
Stat. 93, 8 specimens. — Stat. 98, 7 specimens. — Stat. 99, 6 specimens. — Stat. 1 1 j*^,
12 specimens. — Stat. 118 (HEKSEN vertical net, 900 metres to surface), 10 specimens. —
Stat. 122, 7 specimens. — Stat. 136, S specimens. — Stat. 141 (Hexsex vertical net, 1500
metres to surface), 7 specimens. — Stat. 142, 6 specimens. — Stat. 144, 10 specimens. —
Stat. 148 (Hexsex vertical net, 1000 metres to surface), 12 specimens. — Stat. 157, 5 spe-
cimens. — Stat. 168, 6 specimens. — Stat. 174, 10 specimens. — Stat. 189", 8 specimens. —
Stat. 205, 6 specimens. — Stat. 252, ó specimens. — Stat. 315, 10 specimens.

158

'59

t8. Family PoNTELLIDAE.
Genus Pontella Dana, 1S46.

The members of this genus are separated from the other genera belonging to the family,
by the three-jointed endopodite of the first pair of feet, by the presence of a pair of dorsal
eye-lenses. and by the comparatively short rami of the rostrum. A lens for the ventral eye is
occasionally developed in the base of the rostrum.

Eight species of Pontella were represented in the plankton collected by the 'Siboga'
during the investigations in the Malay Archipelago. Four of the species do not appear to have
previously been described.

1. Pontella danae Giesbrecht.

Pontella danae Giesbrecht, 1889, p. 28.

Pontella danae Giesbrecht, 1893, p. 461, pis. 24 & 40.

Pontellnia Ivellina) danae Claus, 1S93, p. 274.

Pontella danae Giesbrecht, 1S95, p. 260.

Pontella danae Giesbrecht & Schmeil, 1S98, p. 143.

Two females belonging to this species were found in the plankton collected at Station 1 1 7a.

The specimens appeared to be slightly immature, and the abdomen was covered with
the cement for attaching spermatophores to the genital opening. The fifth pair of feet of the
two specimens is not quite symmetrical. The exopodite of the left foot is distinctly longer than
the exopodite of the right foot. The fifth pair of the 'Siboga' specimens is similar to the fifth
pair of Pontella danae var. ceyloniea Thompson and Scott, but the furcal joints are iclentical
with Giesbrecht's figure.

Pontella danae has only been recorded from the Pacific Ocean.

2. Pontella f era Dana.

Pontella f era Dana, 1849 (pars), p. 34.

Pontella f era Giesbrecht, 1893, p. 462, pis. 24 & 40.

Pontellnia ( Eupontellina) f era Claus, 1893, p. 273.

Pontella f era Giesbrecht & Schmeil, 1898, p. 144.

Pontella fera A. Scott, 1902, p. 40S.

Pontella fera Thompson & Scott, 1903, p. 252.

Pontella fera Wolfenden, I905(<?), p. 102 1.

One specimen identical with this species was obtained from the plankton collected at
each of the following twelve stations. Six males and six females were tound.

Stat. 66. — Stat. 71. — Stat. 75 (HEXSEX vertical net, 11 metres to surface). — Stat. 93. —
Stat. 109. — Stat. 110. — Stat. 144. — Stat. 203 (surface). — Stat. 205. — Stat. 213. —
Stat. 215. — Stat. 282.

The last thoracic segment of the female is symmetrical and the abdomen is composed

'59

ïóo

of two segments. The structure of the fifth pair of feet of the tvvo sexes readily distinguishes
this species from any of the other known members of the genus.

Pontella fera has been recorded from the Indian and Pacific Oceans.

3. Pontella princeps Dana.

Pontella princeps Dana, 1849, p. 34.

Pontella princeps Giesbrecht, 1893, p. 461, pis. 24 & 40.
Pontellina (Iva) princeps Claus, 1S93, p. 273.
Pontella princeps Giesbrecht & Schmeil, 1898, p. 142.
Pontella princeps Thompson & Scott, 1903, p. 252.

Two females and two males belonging to this species were obtained from the plankton
collected at the following stations.

Stat. 35, male. — Stat. 66, female. — Stat. 117% female. — Stat. 138, male.

The females are closely allied to Pontella ailantica, but they differ from that species
in the structure of the abdomen.

This Pontella has been recorded from the Indian and Pacific Oceans.

4. Pontella securifer Brady.

Pontella securifer Brady, 1883, p. 96, pi. XLV, figs. 1 — 9.

Pontella securifer Giesbrecht, 1893, p. 461, pis. 24 & 40.

Pontella securifer T. Scott, 1893, p. 86.
Pontellina (Ivellina) securifer Claus, 1893, p. 274.

Pontella securifer Giesbrecht & Schmeil, 1898. p. 142.

Pontella securifer Thompson & Scott, 1903, p. 252.

Pontella securifer Geve, 1904, p. 195.

Pontella securifer Wolfenden, 1905 (a). p. 102 1.

Seventeen females and twenty males belonging to the above species were obtained from
the plankton collected at the following stations.

Stat. 19, 2 specimens. ■ — Stat. 35, 3 specimens. — Stat. 36, t specimen. — Stat. ^-j , 1 spe-
cimen. — Stat. 66, 4 specimens. — Stat. 98, 2 specimens. — Stat. 1 10, 3 specimens. —
Stat. 117", 2 specimens. — Stat. 203 (surface), 2 specimens. — Stat. 229, 2 specimens. —
Stat. 230 (Hexsen vertical net, 2000 metres to surface), 2 specimens. — Stat. 282, 1 spe-
cimen. — Stat. 315. 2 specimens.

This species can readily be recognised by the prominent lens in the base of the rostrum,
and by the structure of the fifth pair of feet of the two sexes.

Pontella securifer has been recorded from the warm parts of the Atlantic and Indian Oceans.

5. Pontella alafa nov. sp. Plate LI, figs. 11 — 15.

Female — length 3,58 mm.

Seen from above, the body is elongate and moderately robust. The cephalic segment
is furnished with side hooks and a pair of dorsal eye-lenses. The last thoracic segment is

160

iói

prodUced into strong and slightly divergent points. The left side is slightly more elongated
than the right side (Plate LI, fig. uj. The points of the rostrum are moderately strong, but
there is no tracé of a rostral lens.

The abdomen is composed of two segments. The combined length of the abdomen and
furca is contained three and a half times in the total length of the cephalothorax, from the
frontal margin to the base of the genital segment. The genital segment is quite asymmetrical.
W'hen viewed from above, the left side is seen to be expanded into a large wing-like projection
with a pointed clistal end. The dorso-lateral surface of the right side is furnished with a strong
spine. The furcal joints are asymmetrical. The joint of the right side is longer and broader than
the one on the left side (Plate LI, fig. i i).

The antennules are composed of twenty-four joints and extend to near the end of the
last thoracic segment.

The antennae, mandibles, maxillae and maxillipedes are similar to those of Pontella princeps.

The endopodite of the first pair of feet is three-jointed.

The other three pairs of feet are of the usual Pontella type.

The exopodites of the fifth pair of feet are asymmetrical. The left exopodite is consi-
derably longer than the right. The exopodites are spiniform, and are drawn out to a single
point at the apex. The left exopodite only is furnished with two outer edge spines. The endo-
podites are asymmetrical and terminate in two spines of medium length (Plate LI, fig. 15).

Male unknown.

This species resembles Pontella danae in the two-jointed abdomen, the asymmetrical
furcal joints, and in the shape of the exopodite of the fifth pair of feet. The large projection
on the left side of the genital segment, and the asymmetrical condition of the fifth pair feet
readily separate it, however, from that species.

Occurrence. — Four specimens were found in the plankton collected at Station \\~a.

6. Pontella dentieanda nov. sp. Plate Lil, figs. 1 — 12.

Female — length 1,1 mm-

Seen from above, the body appears elongate ovate, and rather narrow. The cephalic
segment is furnished with side hooks, and a pair of dorsal eye-lenses. The last thoracic segment
is symmetrical. The posterio-lateral angles are narrowly rounded, and are only very slightly
produced (Plate Lil, fig. 1). The points of the rostrum are moderately strong, and there is a
distinct tracé of a lens in the basal part (Plate LH, fig. 21.

The abdomen is composed of two segments. The combined length of the abdomen and
furca is contained three and one-third times in the total length of the cephalothorax, from the
frontal margin to the base of the crenital segrment. The genital segment is asymmetrical. The
proximal portion of the lateral margin of the left side is produced into a large spiniform process
(Plate Lil, fig. 1). The furcal joints are asymmetrical. The left furcal joint is distinctly broader
than the right.

The antennules are twenty-two-jointed and reach to the end of the third thoracic segment.

161

SIPOGA-EXI'EDITIE XXIX il. 21

IÓ2

The antennae, mandibles, maxillae and maxillipedes are of the usual Pontella type.

The endopodite of the first pair of feet is composed of three joints.

The second, third and fourth pairs of feet are of the usual type.

The fifth pair of feet is symmetrical and somewhat similar to that of Pontella f era.
The apex of the exopodite is spiniform. The distal portion of the inner margin is furnished
with three spines. The outer margin has also three spines, but they are much wider apart. The
endopodite is very slightly bifurcate at the apex (Plate Lil, fig. 5).

Male — length 2,9 mm.

The male resembles the female in general appearance, but the abdomen is composed
of five segments, and the furcal joints are nearly symmetrical. The combined length of the
abdomen and furca is contained nearly three times in the total length of the cepkalothorax,
from the frontal margin to the base of the genital segment. The rami of the rostrum are
asymmetrical, but this may be accidental (Plate Lil, fig. 7).

The right antennule has the middle joints much infiated. The proximal hinge joint is
narrow. It is furnished with a large saucer-shaped process with a serrate upper edge. The
distal hinge joint has a simple lamella terminating in a clistinct tooth (Plate Lil, fig. 9).

The fifth pair is large and well developed. The thumb-like process on the exopodite of
the right foot is large and spiniform. It is greatly curved and the apex is directed outwards. The
middle of the first joint is furnished with a moderately long tube-like process. The last joint is
lamelliform and spoon-shaped. There appears to be a rudimentary endopodite on the right foot,
but this may be abnormal (Plate Lil, fig. 1 2). The last joint of the exopodite of the left foot
terminates in two strong spines. The inner spine is contracted to a fine point. The outer spine
is of nearly equal width throughout its length. The distal end is rather bluntly rounded (Plate
Lil, fig. 1 1). The setae on the second joint of the basiopodite is attached to a tooth-like projection.

This species has a general resemblance to Pontella tenuiremis Giesbrecht, but the female
is easily separated by the large spiniform projection on the left side of the genital segment. The
structure of the male fifth pair readily distinguishes it from any of the known males.

O ecu r re nee. - Thirty-two females and eighteen males were obtained from the plankton
collected at the following stations.

Stat. 66, 5 specimens. — Stat. 81, 6 specimens. — Stat. 93, 2 specimens. — Stat. 98, 2 spe-
cimens. — Stat. 99, 5 specimens. — Stat. 109, iS specimens. — Stat. 110, 2 specimens. —
Stat. 124, 1 specimen. -- Stat. 12S (HENSEN vertical net, 700 metres to surface), 3 speci-
mens. — Stat. 157, 1 specimen. — Stats. 194 — 7, 1 specimen. — Stat. 213, 2 specimens. —
Stat. 282, 2 specimens.

7. Pontella forficula nov. sp. Plate LIII, figs. 1 — 7.

Male — length 3,1 mm.

Yiewed from above, the body appears elongate ovate. and rather slender. The ce'phalic
segment is furnished with side hooks, and a pair of dorsal eye lenses. The last thoracic segment
is symmetrical. The posterio-lateral angles are rounded, and the ends are only slightly produced.
The rami of the rostrum are asymmetrical, but this may be accidental. There is no tracé of a
lens in the basal part of the rostrum (Plate LIII, fig. 2).

162

i63

The abdomen is composed of five segments. The combined length of the abdomen and
furca is contained almost three times in the total length of the cep halothorax, from the frontal
margin to the base of the genital segment. The furcal joints are nearly symmetrical (Plate LUI, fig. i).

The left antennule is composed of nineteen joints, and extends to the end of the second
thoracic segment. The middle joints of the right antennule are much infiated. They are furnished
with three very strong and forked processes. The proximal hinge joint has a large saucerdike
process with blunt teeth. The distal hinge joint is short. The upper margin is furnished with
two simple plates (Plate LUI, fig. 4).

The antennae, mandibles, maxillae and maxillipedes are of the usual Pontella type.

The endopodite of the first pair of feet is three-jointed.

The second, third and fourth pairs of feet are of the normal Pontella structure.

The fifth pair of feet is rather small. The thumbdike process on the first joint of the
exopodite of the right foot is long and spiniform. The distal portion is curved inwards. There
is no process on the middle of the joint. The clawdike joint is long and curved. It is furnished
with one apical and three marginal spines. The end joint of the exopodite of the left foot has no
apical spines. The outer margin of the joint is furnished with three small spines (Plate LUI, fig. 7).

Female unknown.

The male of this species is very similar to the male of Pontella denticanda, but it is
easily separated by the remarkable forked horns on the right antennule, and by the structure
of the fifth pair of feet.

Occurrence. — Two specimens were found in the plankton collected at Station 93.

8. Pontella ccrami nov. sp. Plate LUI, figs. 8 — 15.

Male — length 3,45 mm.

Viewed from above, the bod}- appears elongate and moderately robust. The cephalic
segment is furnished with side hooks, and a pair of dorsal eye lenses. The last thoracic segment
is symmetrical, and both sides terminate in spiniform projections. The points are slightly divergent
(Plate LUI, fig. 8). The rami of the rostrum are short, and the basal part is provided with a
well defined circular lens (Plate LUI, fig. 9).

The abdomen is composed of five segments. The combined length of the abdomen and
furca is contained fully three times in the total length of the cep halothorax, from the frontal
margin to the base of the genital segment. The furcal joints are moderately long, and are nearly
symmetrical.

The left antennule is twenty-four-jointed, and extends to the middle of the third thoracic
segment. The middle joints of the right antennule are greatly swollen. The upper margin of
the first swollen joint is furnished with a strong curved spine. The upper margin of the proximal
hinge joint has a strongly serrate lamella. The second and third teeth are much longer than
any of the others (Plate LUI, fig. 12). The outer part of the upper margin of the distal hinge
joint is furnished with two serrate plates. One of the plates has a doublé row of teeth (Plate
LUI. fig. 13). The end of the joint is produced into a short stout spine.

The antennae, mandibles. maxillae and maxillipedes are of the usual Pontella type.

163

164

The endopodite of the first pair of feet is composed of three joints.

The second, third and fourth pairs of feet are of the normal Pontclla form.

The fifth pair is moderately large. The thumb-like process on the proximal end of the
hrst joint of the right exopodite is very long. It is curved inwards. The middle of the joint is
provided vvith a nearly straight spine. The claw-like joint is long and slender and is much curved.
It is furnished with two inarginal spines and one apical spine. The last joint of the exopodite
of the left foot bears three moderately strong apical spines. The inner margin has a large pad
of fine hairs. The outer dorso-lateral margin is furnished with a small spine (Plate LIII, fig. 15).

Female unknown.

This species may easily be passed over as the male of Pontclla seairifer, as it resembles
it in the possession of a circular lens in the base of the rostrum, and also of a serrate plate
on the proximal hinge joint of the right antennule. The structure of the fifth pair of feet.
however, is quite distinct.

O ecu r re nee. - Two specimens were found in the plankton collected with the Hensen
vertical net at Station 203, 1500 metres to the surface.

Genus Labidocera Lubbock, 1853.

The members of this genus are closely related to Pontclla, but they can readily be
separated by the structure of the first pair of feet. The endopodite of the first pair is two-jointed,
like the endopodites of the second, third and fourth pairs of feet. The cephalic segment is
usually without side hooks. One pair of dorsal eye lenses is present. The basal part of the
rostrum has no lens.

Seven species of Labidocera were represented in the plankton collected by the 'Siboga'
in the Malay Archipelago. Two of the species do not appear to have previously been described.

1 . Labidocera acnta (Dana).

Pontclla acnta Dana, 1849, P- 3°-

Pontellina acnta Dana, 1S52, p. 11 50, pi. 80.

Pontclla acnta Brady, 1883, p. 89, pi. XXXVI, figs. 1 — 12.

Labidocera acutum Giesbrecht, 1893, p. 445, pi. 23, 25 & 41.

Labidocera acnta T. Scott, 1S93, p. 85.

Labidocera acutum Giesbrecht, 1895, p. 259.

Labidocera acnta Giesbrecht & Schmeil. 1898, p. 134.

Labidocera acnta I. C. Thompson, 1900, p. 282.

Labidocera acutum Geve, 1901, p. 7.

Labidocera acnta A. Scott, 1902, p. 407.

Labidocera acnta Thompson & Scott, 1903, p. 251.

Labidocera acutum Geve, 1903, p. 363.

Labidocera acnta Geve, 1904, p. 191.

Labidocera acnta Wolfenden, 1905 (a), p. 1016.

Labidocera acnta van Breemen, 1908, p. 150, fig. 168.

This species proved to be moderately common. It was widely distributed throughout the
area investigated as shewn by the following records.

164

i.6s

Stat. 16. — Stat. 19. — Stat. 35. — Stat. 37. — Stat. 40. ■ Stat. 50. — Stat. 66. —
Slat. ;-; (HENSEN vertical net, 11 metres to surface). - Stat. 81. - Stat. 93. — Stat. 96

(day). — Stat. 96 (night). -- Stat. 98. — Stat. 99. — Stat. 101. - Stat. 106. - Stat. 109.

Stat. 112. — Stat. 117", 200 specimens. — Stat. 122. Stat. 124, 441, specimens.

Stat. 125 (night). Stat. 136. — Stat. 138. — Stat. 141 (Mensen vertical net, 1500

metres to surface). — Stat. 142. — Stat. 144. — St.it. 146. — Stat. 148 (HENSEN vertical

net, 1000 metres to surface). — Stat. 157. — Stat. 165. — Stat. 169. -- Stat. 172.

Stat. 174. - Stat. 177". — Stat. 184. — Stat. 189'1. — ■ Stats. 194 — 7. — Stat. 203 (sur-
face). — Stat. 204. — Stat. 205. — Stat. 213. — Stat. 214. — Stat. 2151. — Stat. 220

(HENSEN vertical net, 200 metres to surface). — Stat. 223. — Stat. 224. - - Stat. 225.

Stat. 229. — Stat. 245. — Stat. 252. — Stat. 276 (HENSEN vertical net, 750 metres to
surface). — Stat. 282. — Stal. 304. — Stat. 315.

Labidocera acuta is readily distinguished by the presence of a median crest on the forehead,
and by the structure of the fifth pair of feet of both sexes.

This species appears to have a fairly wide distribution in the warm regions of all the
great oceans.

2. Labidocera detruncata (Dana).

Pontella detruncata Dana, 1849, p. 29.

Pontellina detruncata Dana, 1852, p. 1 143, pi. 80.

Pontella detruncata Brady, 1883, p. 90,' pis. XXVI & XLV.

Labidocera detruncatum Giesbrecht, 1893, p. 445, pis. 23, 25 & 41.

Labidocera detruncata Giesbrecht & Schmeil, 1898, p. 135.

Labidocera detruncata Thompson & Scott, 1903, p. 251.

Labidocera detruncata Wolfenden, 1905 (a), p. 1017, pi. XCVIII.

This Labidocera appeared to be rather rare and the distribution was very limited in the
area investigated by the 'Siboga'. It was found in the plankton collected at the following
eieht stations.

Stat. 16, 10 specimens. — Stat. 96 (night), 5 specimens. — Stat. 98, 3 specimens. — Stat.
1 10, 20 specimens. — Stat. 111, 10 specimens. — Stat. 203 (surface), 7 specimens. —
Stat. 282, 4 specimens. — Stat. 315, 5 specimens.

Twenty-four females and forty males were obtained.

Labidocera detruncata is only known from the Indian and Pacific Oceans.

3. Labidocera kroycri (Brady).

Pontella kroycri Brady, 1S83, p. 93, pi. XXXIX, figs. 1 — 19.

Labidocera kroyeri Giesbrecht, 1893, p. 446, pis. 23, 25 & 41.

Labidocera kroyeri Giesbrecht & Schmeil, 189S, p. 135.

Labidocera kroyeri Cleve, 1901, p. 7.

Labidocera kroyeri Thompson & Scott, 1903, p. 251.

Labidocera kroyeri Pearson, 1906, p. 30.

Labidocera kroyeri van Breemen, 1908, p. 15 1.

Labidocera kroycri, although represented by fewer specimens, appeared to be more widely
distributed than Labidocera detruncata. Seventeen females and nine males were obtained from
the plankton collected at the following fourteen stations in the area investigated by the 'Siboga'.

165

i6.6

Stat. 35, 2 specimens. — Stat. 37, 3 specimens. — Stat. 81, 3 specimens. — Stat. 98, 1
specimen. -- Stat. 99, 2 specimens. — Stat. 109, 3 specimens. — Stat. 1 10, 1 specimen. —
Stat. lij', 1 specimen. -- Stat. 142, 1 specimen. -- Stat. 144, 2 specimens. -- Stat. 165,
1 specimen. -- Stat. 189% 3 specimens. — Stat. 213, 1 specimen. — Stat. 315, 2 specimens.

This species is readily recognised when mixed with the other members of the genus, by
the following characters. The abdominal segments of the female are furnished with strong spines
and teeth. The right side of the last thoracic segment of the male is produced into a bifid
process. The males appear to be rather variable, both in the form of the right projection of
the last thoracic segment, and in the length of the thumb-like process on the first joint of the
exopodite of the right fifth foot. Two varieties of the male fifth pair are shewn in the report
on the Ceylon Copepoda. By a misprint it is stated in that report that the left side of the last
thoracic segment of Labidocera kroyeri var. gallensis has a trifid projection. It ought to read
right side of course. Only the typical form was obtained from the 'Siboga' plankton.

Labidocera kroyeri has been recorded from the Indian and Pacific Oceans. It has also
been found in the Xorth Atlantic off the West of Ireland.

4. Labidocera lacvidentata (Brady). Plate LI, figs. 1 — 10.

Pontella laevidentata Brady, 1SS3, p. 93, pi. XXXVIII, figs. 1 — 6.

Labidocera laevidentatum Giesbrecht, 1893, p. 446.

Labidocera laevidentata Giesbrecht & Schmeil, 1898, p. 137.

Labidocera laevidentata Wolfenden, 1905 (a), p. 1019, pi. XCVIII, figs. 20, 26, 27, 28, 38 (male).

Labidocera kroyeri var. similis Wolfenden, 1905 («), p. 10 16, figs. 22, 23, 33 (female).

This rare form was found in the plankton collected at the following two stations in the
area traversed by the 'Siboga'.

Stat. 66, 75 females and 76 males. — Stat. 71, 1 male.

Brady described the species from a single male specimen found in plankton collected
off Sibago Island, Philippines, on October 23rd, 1874. The species was not again met with
until Wolfenden recorded the male in 1905, from the plankton collected around the Maldives
by J- Stanley Gardiner. Wolfenden states that only the males are known, but the form he
describes as Labidocera kroyeri var. similis, is undoubtedly the female of Labidocera laevidentata.
The fifth pair of feet has not the slightest resemblance to the fifth pair of the female of
Labidocera kroyeri.

The cephalothorax of the female is very similar to that of the male. The cephalic
segment is furnished with lateral hooks. Seen from above, the forehead is broadly angular in
outline. The side hooks are much nearer the frontal margin than in any of the other members
of this genus that have hooks (Plate LI, fig. 1). The last thoracic segment is symmetrical.
The posterio-lateral angles are produced into spines. The spines are rather divergent. The rami
of the rostrum are stout at the base, and are drawn out to a moderately fine point at the
apex. There does not appear to be any articulation between the rami and the basal part. The
excavation between the rami is wedge-shaped (Plate LI, fig. 3).

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1 67

The abdomen is moderately long. It is composed of three segments. The combined
length ot the abdomen and furca is contained two and one-third times in the total length of
the cephalothorax, from the frontal margin to the base of the genital segment. The oenital
segment is symmetrical. It is as long as the combined length of the next two segments. The
dorso-lateral surface is furnished with a strong spine on each side near the distal end. The
second segment is asymmetrical. The distal end is provided with a doublé pointed process.
The anal segment is asymmetrical. It is much shorter on the right side than on the left. The
distal end of the first and second segments, and the ventro-lateral surface of the second segment,
is fringed with fine spines (Plate LI, figs. i and 2). The furcal joints are asymmetrical. The
right iurcal joint is much broader, and slightly longer than the left furcal joint.

The antennules are composed of twenty-four joints and extend to the end of the anal segment.

The antennae, mandibles, maxillae and maxillipedes are similar to those of the male.
The apical portion of the second maxillipedes is four-jointed.

The exopodites of the four pairs of swimming feet are three-jointed. The endopodites
are two-jointed.

The fifth pair of feet is slightly asymmetrical. The right exopodite is rather shorter and
stouter than the left. Each exopodite is armed with three outer edge spines. The distal part
of the inner margin bears two spines set close together. The proximal spine of this pair is
longer and stouter than the distal one. The apex terminates in a strong and slightly curved
spine. The endopodite of each foot is short. The apex is very feebly bifurcate. The figure
shews the fifth pair in a reversed position (Plate LI, fig. 6).

Length of 'Siboga' specimens, female 1,95 mm., male 1,7 mm.

Professor Brady described the species as a Pontella. Giesbrecht placed it in the o-enus
Labidocera on account of the two-jointed endopodite of the first pair of feet. Brady and
Wolfexdex appear to be the only authors who have hitherto met with this form.

5. Labidocera minuta Giesbrecht.

Labidocera minutum Giesbrecht, 1889, p. 27.

Labidocera minutum Giesbrecht, 1893, p. 446, pi. 23, 25 & 41.

Labidocera minuta Giesbrecht & Schmeil, 1898, p. 137.

Labidocera minutum Cleve, 1901, p. 7.

Labidocera minuta A. Scott, 1902, p. 407.

Labidocera minuta Thompson & Scott, 1903, p. 251.

Labidocera minutum Cleve, 1903, p. 363.

Labidocera minuta Wolfenden, 1905 (a), p. 1018, pi. XCVIII, figs. 18, 24, 25, 29, 32, ^~.

Eighteen females and nine males belonging to this species were obtained from the
plankton collected at the following stations.

Stat. 16. — Stat. 35. — Stat. 37. — Stat. 47''. — Stat. 66. — Stat. 71. - Stat. 81. — Stat. 96
(night). — Stat. 106. — Stat. 109. — Stat. 110. -- Stat. 128 (HENSEN vertical net, 700
metres to surface). — Stat. 136. — Stat. 138. - - Stat. 141 (Hensex vertical net, 1500
metres to surface). — Stat 142. — Stat. 143 (Hexsex vertical net, 1000 metres to sur-
face). — Stat. 144. — Stat. 169. — Stat. 174. -- Stat. 189". -- Stat. 204. -- Stat. 205. -
Stat. 213. — Stat. 216. — Stat. 229. — Stat. 315.

167

i6S

The two sexes can readily be distinguished by the structure of the fifth pairs of feet,
and by the shape of the abdominal segments.

Labidocera minuta has been recorded from the Indian and Pacific Oceans, and from the
Red Sea.

6. Labidocera bataviac nov. sp. Plate L, figs. i — 8.

Female — length 2,3 mm.

Viewed from above, the body appears broadly ovate. The greatest width lies in the middle
of the first thoracic segment. The width is contained nearly two and one-half times in the
total length. The cephalic segment is without side hooks. The last thoracic segment is symmetrical.
The lateral margins are produced posteriorly into short divergent points. The basal part of the
rostrum is wide. The excavation is concave but it is very shallow. The rami are distinctly
articulated to the base (Plate L, fig. 2).

The abdomen is very short. It is composed ot two segments. The combined length of the
abdomen and furca is contained fully six times in the total length of the cep halothorax, from
the frontal margin to the base of the genital segment. The genital segment is asymmetrical.
It is comparatively large, and the distal end, when seen from above, is unequally dilated. The
furcal joints are asymmetrical. The lelt furcal joint is one and a half times broader than long.
It has the appearance of being set at right angles to the abdomen, and its setae placed on
the inner margin. The setae are borne on the side and apex, however, as in the other members
of the genus. The right furcal joint is practically normal. It is one and a half times longer
than broad (Plate L, fig. 1).

The antennules are twentv-three-jointed and extend to the end of the last thoracic segment.

The antennae, mandibles, maxillae and maxillipedes are nearly similar to those of
Labidocera laevideniata. The apical portion of the second maxillipedes is composed of four joints.

The endopodites of the first four pairs of feet are two-jointed. The exopodites are
three-jointed.

The fifth pair of feet is slightly asymmetrical. The left exopodite is rather longer than
the right exopodite. The outer margin is furnished with two spines. The apex terminates in three
unequal spines. The endopodite is small, and is slightly bifurcate at the apex (Plate L, fig. 5).

Male — length 1,96 mm.

The male has a general resemblance to the female, but the abdomen is composed of
five segments. The furcal joints are broad and symmetrical (Plate L, fig. 6).

The middle joints of the right antennule are considerably inflated. The upper margin of
the two proximal hinge joints, and of the distal hinge joint is armed with fine teeth (Plate L, fig. 7).

The thumb-like process at the proximal end of the outer margin of the first joint of the
exopodite of the right fifth foot is long and stout. There is a distinct tooth-like spine close to
the base of the thumb. The middle of the outer margin is furnished with a low broad tooth.
The claw-like second joint has a distinct tooth on the middle of the outer margin. The terminal
joint of the left exopodite is about twice as long as broad. It is provided with one outer edge,
and three apical spines. The inner margin has a pad of fine hairs (Plate L, fig. 8).

168

IÓ9

This species at first sight may easily be mistaken for Labidocera pavo Giesbrecht, of
which only the female is known. The genital segment of the female of Labidocera bataviae is
without the large protuberance that is so conspicuous in Labidocera pavo. The fifth pairs of feet
of the two females are also rather different in shape.

Occurrence. — One hundred and fifty-six females and thirty males were obtained
from the plankton collected at the following stations.

Stat. 16, 29 specimens. — Stat. 66, 22 specimens. — Stat. 71, 60 specimens. — Stat. 81,
26 specimens. — Stat. 98, 22 specimens. — Stat. 282, 27 specimens.

7. Labidocera madurae nov. sp. Plate L, figs. 9 — 16.

Female — length 2,5 mm.

Seen from above, the body appears elongate ovate, and rather narrow. The cephalic
segment is without side hooks, and the forehead is boldly rounded. The last thoracic segment
is symmetrical. The lateral margins are produced posteriorly into pointed processes. The basal
part of the rostrum is wide. There is practically no excavation. The rami are long and are
distinctly articulated to the base (Plate L, fig. 10).

The abdomen is short. It is composed of two segments. The combined length of the
abdomen and furca is contained five times in the total length of the cephalothorax \ from the
frontal margin to the distal end of the last thoracic segment. The genital segment is mode-
rately large. It is quite asymmetrical. The middle of the right side is considerably inflated.
The anal segment is very short. The furcal joints are symmetrical. They are rather longer
than broad (Plate L, fig. 9).

The antennules are composed of twenty-three joints and extend to the end of the abdomen.

The antennae, mandibles, maxillae and maxillipedes are similar to those of the previous
species. The apical portion of the second pair of maxillipedes is composed of four joints.

The endopodites of the four pairs of swimming feet are two-jointed. The exopodites
are three-jointed.

The fifth pair of feet is nearly symmetrical. The exopodite is furnished with two outer
marginal spines. The apex terminates in three subequal spines. The apex of the endopodite
is not bifurcate (Plate L, fig. 1 3).

Male — length 1,9 mm.

The male resembles the female except that the abdomen is composed of five segments.
The fourth and fifth segments are much shorter than any of the others (Plate L, fig. 141.

The middle joints of the right antennule are only slightly swollen. The upper margin of
the proximal hinge joint and of the distal hinge joint is fringed with fine teeth (Plate L, fig. 15).

The thumb-like process on the proximal end of the outer margin of the first joint of
the right exopodite of the fifth pair of feet, is comparatively short and curved. There is no
tooth at the base of the process as in Labidocera bataviae. The palm is simple. The claw-like
joint is long and narrow. The apical joint of the left exopodite is elongate ovate. It is twice
as long as broad. The outer margin is furnished with one spine, and the apex bears three

spines. The inner margin has a pad of fine hairs.

169

SIBOGA-EXPEDITIE XXIX a.

170

This species approaches Labidoccra ncrii (Kroyer) in general appearance, but the structure
of the fifth pair of both sexes readily separates it from that form, and from any of the other
known members of the genus.

The name is derived from Madura Strait, where the series of investigations in the
Malay Archipelago carried out by this expedition began, and finally ended, after a year of
exploring the seas and straits in the area.

Occurrence. — One hundred and sixty females and four males vvere obtained from
the plankton collected at the following stations.

Stat. 16, So specimens. — Stat. 141 (HENSEN vertical net, 1500 metres to surface), 60 spe-
cimens. — Stats. 194 — 7, 5 specimens. — Stat. 203 (surface), 13 specimens. — Stat. 203
(HENSEN vertical net, 1500 metres to surface), 2 specimens. — Stat. 2S2, 2 specimens. —
Stat. 315, 2 specimens.

Genus Pontellopsis Brady, 1883.

The members of this genus are separated from Pontclla and Labidoccra by the complete
absence of dorsal and rostral lenses, and by the long slender rami of the rostrum. The structure
of the fifth pair of feet of the two sexes is something similar to that found in Pontella. The
endopodite of the first pair of feet is three-jointed.

Eight species of Pontellopsis were obtained from the plankton collected by the 'Siboga'.
Two of the species do not appear to have previously been described.

1 . Pontellopsis armata (Giesbrecht).

Monops armatus Giesbrecht, 1889, p. 28

Monops armatus Giesbrecht, 1893, p. 487, pis. 26 & 41.

Pontellopsis armata Giesbrecht & Schmeil, 1898, p. 148.

Monops armatus Cleve, 1901, p. 7.

Pontellopsis armata Thompson & Scott, 1903, p. 253.

Pontellopsis armata Wolfenden, 1905(0), p. 1022, pi. XCIX.

This species proved to be the most abundant and generally distributed member of the
genus, as shewn by the records of its occurrence.

Stat. 35. — Stat. 89. ■ — Stat. 98, 23 females and 17 males. — Stat. 117', 1 specimen. —
Stat. 124, 8 specimens. — Stat. 138, 1 specimen. — Stat. 143 (HENSEN vertical net, 1000
metres to surface), 1 specimen. — Stat. 144. — Stat. 157, 2 specimens. — Stat. 184. —
Stat. 186, 1 specimen. — Stat. 189', 3 specimens. — Stat. 193, 1 specimen. — Stats.
194 — 7, 2 specimens. — Stat. 203 (surface), 9 specimens. — Stat. 213, 20 specimens. —
Stat. 2 1 5a, 2 specimens. — Stat. 216, 2 specimens. — Stat. 217 (surface), 2 specimens. —
Stat. 217 (horizontal cylinder), 2 specimens. — Stat. 222, 3 specimens. — Stat. 223, 2 spe-
cimens. — Stat. 229, 15 specimens. — Stat. 245, 1 specimen.

The female of Pontellopsis armata can readily be recognised by the hirsute body, by
the elongate spiniform projections of the last thoracic segment, and by the structure of the
fifth pair of feet.

This species has been recorded from the Indian and Pacific Oceans.

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2. Pontellopsis krameri (Giesbrecht).

Monops krameri Giesbrecht, 1896, p. 323, pi. V, figs. I — 2.
Pontellopsis krameri Giesbrecht & Schmeil, 1898, p. 147.
Pontellopsis krameri A. Scott, 1902, p. 423, pis. I & II.
Pontellopsis krameri Thompson & Scott, 1903, p. 253.
Pontellopsis kramen Wolfenden, 1905 (a), p. 102 1, pi. XCVIII.

Twenty-two specimens belonging to this distinct species, were obtained from the plankton
collected at the following stations.

Stat. 16, 2 specimens. — Stat. 35, 3 specimens. -- Stat. 71, 1 specimen. — Stat. 109, 3 spe-
cimens. — Stat. 110, 2 specimens. — Stat. 124, 3 specimens. -- Stat. 144, r specimen. —
Stats. 194 — 7, 2 specimens. — Stat. 204, 3 specimens. — Stat. 210', 2 specimens.

The female of this Pontellopsis can readily be recognised by the structure of the fifth
pair of feet, and by the right furcal joint being about doublé the size of the left furcal joint.

Pontellopsis krameri is apparently a rare species. It has hitherto only been known
from the Indian Ocean and from the Red Sea.

3. Pontellopsis perspicax (Dana).

Pontella perspicax Dana, 1849, P- 32-

Pontellina perspicax Dana, 1852, p. 1155, pi. Si,

Pontellina pulchra Dana, 1S52, p. 1157, P^ 81.

Monops perspicax Giesbrecht, 1893, p. 486, pis. 26 & 41.

Pontellopsis perspicax Giesbrecht & Schmeil, 1898, p. 147.

Pontellopsis perspicax Thompson & Scott, 1903, p. 253.

Four females and one male identical with the above species were found in the plankton
collected at Station 35.

This species has a certain amount of resemblance to Pontellopsis artnala, but the two
sexes can readily be separated by the structure of the fifth pair of feet.

Pontellopsis perspicax has only vet been recorded from the Atlantic and Indian Oceans.

4. Pontellopsis regalis (Dana).

Pontella regalis Dana, 1849. p. 31.

Pontellina regalis Dana, 1852, p. 1154, pi. Si.

Monops grandis Lubbock, 1853, p. 122, pis. 5 & 7.

Pontella strenita Brady, 1S83 (pars), p. 95, pi. XLV, fig. 18.

Monops regalis Giesbrecht, 1S93, p. 486, pis. 1, 26 & 41.

Monops grandis Claus, 1S93 (pars), p. 277.

Monops regalis Giesbrecht, 1895, p. 260.

Pontellopsis regalis Giesbrecht & Schmeil, 189S, p. 147.

Pontellopsis regalis I. C. Thompson, 1900, p. 283.

Monops regalis Wheeler, 1900, p. 182, fig. 19.

Monops regalis Cleve, 1901, p. 7.

Pontellopsis regalis Thompson & Scott, 1903, p. 253

Pontellopsis regalis Sars, 1905 i/m. p. 6.

Thirteen specimens of this form were obtained from the plankton collected at the foll-

owing stations.

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172

Stat. 98, 2 specimens. — Stat. 1 17% 1 specimen. — Stat. 124, 2 specimens. — Stat. 144,
3 specimens. — Stat. 157, 1 specimen. — Stat. 213, 4 specimens.

This is the largest known member of the genus. The two sexes can easily be identified
by the structure of the fifth pair of feet.

Pontellopsis regalis has a moderately wide distribution. It has been recorded from the
Atlantic, Indian and Pacific Oceans, and from the Mediterranean.

5. Pontellopsis strenua (Dana).

Pontella strenua Dana, 1849, p. 32.

PoHtellina strenua Dana, 1852, p. 1158, pi. 8i.

Monops strenuus Giesbrecht, 1893, p. 486, pis. 26 & 41.

Monops grandis Claus, 1893 (pars), p. 277.

Pontellopsis strenua Giesbrecht & Schmeil, 1898, p. 147.

Monops strenuus Cleve, 1901, p. 7.

Pontellopsis strenua Thompson & Scott, 1903, p. 253.

Ten specimens were found in the plankton obtained from the following two stations.

Stat. 96 (night), 4 specimens. — Stat. 117", 6 specimens.

This species is closely related to Pontellopsis regalis, but it can easily be distinguished
by its smaller size, and by the structure of the fifth pair of feet of the two sexes.

Pontellopsis strenua appears to be rather limited in its distribution. It has only been
recorded from the Indian and Pacific Oceans.

The figures of Pontella strenua given by Professor Brady in the report on the 'Challenger'
Copepoda evidently represent two forms, but neither of them are identical with Dana's Pontella
strenua. Fig. 17, Plate XLV, seems to be identical with the male fifth pair of Pontella atlantica
(M. Edwards). Fig. 18, Plate XLV, appears to be the abdomen of the male of Pontellopsis regalis.

6. Pontellopsis villosa Brady.

Pontellopsis villosa Brady, 1883, p. 86, pis. XXXIV & XXXV.

Monops pilosus Giesbrecht, 1889, p. 28.

Monops villosus Giesbrecht, 1893, p. 486, pis. 26 & 41.

Monops edwardsü Claus, 1893 (pars), p. 277.

Pontellopsis villosa T. Scott, 1893, p. &J, pi. VI, figs. 29 — 34.

Monops villosus Giesbrecht, 1894, p. 92.

Pontellopsis villosa Giesbrecht & Schmeil, 1898, p. 148.

Pontellopsis villosa Sars, 1905 (ó), p. 6.

One female identical with the above species was found in the plankton collected at
Station 138.

The female of this Pontellopsis is somewhat similar to Pontellopsis armata. The abdomen,
however, is composed of a single joint. The abdomen of the female of Pontellopsis armata
is two-jointed.

Pontellopsis villosa has been recorded from the Atlantic and Pacific Oceans, and from
the Mediterranean.

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'73
~. Pontellopsis pexa nov. sp. l'late LIV, figs. 11 — 14.

Female — length 2,2 mm.

Seen trom above, the body appears of the usual Pontellopsis shape. It is robust, and
the last thoracic segment is produced into bluntly rounded processes (Plate LIV, fig. 11). The
cephalic segment and the first three thoracic segments, have narrow bands of short hairs. The
dorsal surface of the last thoracic segment is covered with short hairs as shewn in the figure.
The rami of the rostum are long and slender (Plate LIV, fig. 1 2).

The abdomen is composed of two segments. The genital segment is long and asymmetrical.
The distal end of the right side is considerably inflated. The furcal joints are comparatively
short and are nearly symmetrical. The abdominal segments are without spines.

The antennules are twenty-jointed. The third to the eighth joints are rather indistinctly
separated.

The antennae, mandibles, maxillae and maxillipedes are similar to those Pontellopsis armata.

The first four pairs of feet are also similar to those of that species.

The fifth pair of feet is quite asymmetrical. The exopodite of the right foot is much
shorter than the exopodite of the left foot. The distal end of the inner margin is produced into
a strong spine. The apex of the right exopodite terminates in three small teeth. The exopodite
of the left foot is moderately long and spiniform. There is no inner edge spine and the apex
terminates in a single point. The endopodites are asymmetrical and the apex is bifurcate
(Plate LIV, fig. 14).

This species has a certain amount of resemblance to Pontellopsis tennicauda (Giesbrecht),
but it can readily be separated from that species, or any of the other known members of the
genus, by the bluntly rounded projections of the last thoracic segment, ancl by the structure
of the fifth pair of feet.

Male unknown.

Occurrence. — One specimen was found in the plankton collected at each of the
following two stations.

Stat. 13S. — Stat. 145.

8. Pontellopsis macronyx nov. sp. Plate LIV, Figs. 1 — 10.

Female — length 1,97 mm.

Viewed from above, the body appears moderately robust. The last thoracic segment is
symmetrical. It is produced posteriorly into pointed processes (Plate LIV, fig. 1). The rami of
the rostrum are long and slender.

The abdomen is composed of two segments. The combined length of the abdomen and
furca is contained two and a half times in the total length of the cephalothorax, from the
frontal margin to the base of the genital segment. The genital segment is moderately long. It
is slightly asymmetrical. The proximal and distal regions of the margin of each side are furnished
with spines. The right distal spine is shorter than the left distal spine. The furcal joints are
short (Plate LVI, fig. 1).

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The antennules are twenty-jointed and extend to the end of the thorax.

The antennae, mandibles, maxillae and maxillipedes are similar to those of Pontellopsis
armata. The apical portion of the second maxillipedes is composed of four joints.

The four pairs of swimming feet are also similar to those of Pontellopsis armata.

The fifth pair of feet is asymmetrical. The inner margin of the right exopodite is produced
into a strong spine. The exopodite of the left foot is distinctly shorter than the exopodite of the
right foot. The inner margin has no spine. The endopodites are nearly symmetrical, and the
apex is bifurcate (Plate LIV, fig. 6).

Male — length 1,67 mm.

The male bears a general resemblance to the female, but the last thoracic segment is
distinctly asymmetrical and the abdomen is five-jointed, The left distal end of the last thoracic
segment is the same as that of the female. The right side is produced into a moderately
strong, curved, spiniform process, that extends to the end of the third abdominal segment. The
right side of the third abdominal segment is expanded into a well defined tooth. The furcal
joints are proportionally longer than those of the female (Plate LIV, fig. 7).

The right antennule is composed of about twelve distinct joints. The three middle joints
are greatly infiated. The upper margin of the second proximal hinge joint is produced distally
into a serrate tooth. The lamina on the upper margin of the proximal hinge joint is also serrate.
The proximal portion of the upper margin of the distal hinge joint is furnished with moderately
long slender spines (Plate LIV, fig. 9).

The antennae, mandibles, maxillae and maxillipedes are similar to those of the female.

The first four pairs of feet are also the same as in the female.

The thumb-like projection of the first joint of the right exopodite of the fifth pair is
slender, and is of very remarkable length. The claw-like terminal joint is comparatively short.
The produced outer distal end of the first joint of the left exopodite extends to near the end
of the second joint. The second joint is short. It is furnished with one outer marginal spine,
two sub-apical spines, and one apical spine (Plate LIV, fig. 10).

The females of this species can readily be separated from any of the other females of
the genus, by the spines on the dorsal surface of the genital segment. The structure of the
fifth pair of feet of the two sexes readily distinguishes this species from any of the other
members of the genus. The remarkably long thumb-like projection of the first joint of the right
exopodite of the male fifth pair, is sufficiënt to separate the male of this species, from any
of the other known males.

Occurrence. — Seven specimens were obtained from the plankton collected at the
following stations.

Stat. 3J, 1 female and 1 male. — Stat. 109, 2 females and 1 male. — Stat. 213, 1 female
and 1 male.

Genus Pontellina Dana, 1852.

Pontellina is closely related to the genus Pontellopsis, but the last thoracic segment of
both the male and female is asymmetrical. The right furcal joint of the two sexes is very

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indistinctly separated frotri the anal segment. The antennae and mandible palps are furnished
with very long and densely plumose setae.

The only known representative of this genus appeared to be well distributed throughout
the area investirated bv the 'Siboea'.

i. Pontellina plumata (Dana).

Pontella plumata Dana, 1849, p. 27.

Pontella turgida Dana, 1849, p. 28.

Pontellina plumata Dana, 1852, p. 1135, pi. 79.

Pontellina turgida Dana, 1852, p. 1136, pi. 79.

Calanops messinensis Claus, 1863, p. 212, pis. XXXVI & XXXVII.

Pontella plumata Brady, 18S3, p. 92, pi. XXXVII.

Pontellina plumata Giesbrecht, 1893, p. 497, pis. 4, 25 & 40.

Pontellina plumata T. Scott, 1893, p. 88.

Pontellina plumata Giesbrecht, 1S95, p. 260.

Pontellina plumata Giesbrecht & Schmeil, 1898, p. 149.

Pontellina plumata I. C. Thompson, 1900, p. 283.

Pontellina plumata Cleve, 1901, p. 8.

Pontellina plumata A. Scott, 1902, p. 408.

Pontellina plumata Thompson & Scott, [903, p. 253.

Pontellina plumata Cleve, 1903, p. 367.

Pontellina plumata Cleve, 1904, p. 195.

Pontellina plumata Wolfenden, 1905 (a), p. 1022.

Pontellina plumata Sars, igo5(/>), p. 6.

This characteristic form, although not common, proved to have a wide distribution in the
Malay Archipelago. The following are the stations where it was noted.

Stat. 19. — Stat. 35. — Stat. 37. — Stat. 40. — Stat. 47''. — Stat. 50. — Stat. 66. — Stat.
71. — Stat. 75 (HENSEN vertical net, 11 metres to surface). — Stat. 81. — Stat. 93. — Stat.
96 (day). — Stat. 96 (night). -- Stat. 98. — Stat. 110. — Stat. 112. — Stat. 117*. — Stat.
118 (HENSEN vertical net, 900 metres to surface). — Stat. 121. — Stat. 122. — Stat. 124. —
Stat. 128 (HENSEN vertical net, 700 metres to surface). — Stat. 129. — Stat. 133. — Stat.
136. — Stat. 138. — Stat. 144. — ■ Stat. 148 (HENSEN vertical net, 1000 metres to surface). —
Stat. 157. — Stat. 172. — Stat. 177a. — Stat. 185 (HENSEN vertical net, 1536 metres to
surface). — Stat. 186. — Stat. 189*. — Stats. 194 — 7. — Stat. 203 (surface). — Stat. 2ioa. —
Stat. 213. — Stat. 2 1 5a. — Stat. 217 (surface). — Stat. 217 (horizontal cylinder). — Stat.
220 (surface). — Stat. 223. — Stat. 224. ■ — Stat. 229. — Stat. 245. — Stat. 271. — Stat.
276 (HENSEN vertical net, 750 metres to surface). — Stat. 282. — Stat. 315.

This species is readily identified by its short robust body, and by the long plumose
setae on the antennae and mandible palps.

Pontellina plumata appears to be generally distributed in all the warm regions of the
great oceans.

Genus Calanopia Dana, 1852.

The members of this genus are readily separated from the other genera, by the structure
of the fifth pair of feet of the two sexes. The fifth pair of the female consists of a two-
jointed basiopodite, and a one or two-jointed exopodite. The endopodite is entirely absent. The

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male fifth pair has a two-jointed basiopodite and exopodite. The exopodite of the right foot
is prehensile as in the other genera belonging to the family.

The members of this genus that are already known have no side hooks on the cephalic
segment. A species that appears to be undescribed was obtained from the 'Siboga* plankton,
and although it agrees quite well with Calanopia in the structure of its appendages, the cephalic
segment is provided with side hooks.

Four species were represented in the plankton collected during the traverse in the Malay
Archipelago. Two of the species do not appear to have previously been describecl.

Illustrations of two other known forms, that were not obtained from the plankton collected
by the 'Siboga', are included in this report, in order that the differences between the six species
of Calanopia now known can clearly be observed.

1. Calanopia elliptica (Dana). Plate XLVIII, figs. 1 — 5.

Pontclla elliptica Dana, 1849, p. 27.

Calanopia elltptica Dana, 1852, p. 1132, pi. 79.

Calanopia elliptica Brady, 1883, p. 85, pi. XXXIV, figs. 1 — 9.

Calanopia elliptica Giesbrecht, 1893, p. 441, pis. 31 & 38.

Calanopia elliptica Giesbrecht, 1896, p. 325, pi. 5, figs. 7 — 9.

Calanopia elliptica Giesbrecht & Schmeil, 1898, p. 132.

Calanopia elliptica I. C. Thompson, 1900, p. 282.

Calanopia elliptica Cleve, 1901, p. 5.

Calanopia elliptica A. Scott, 1902, p. 406.

Calanopia elliptica Thompson & Scott, 1903, p. 251.

Calanopia elliptica Cleve, 1903, p. 356.

Calanopia elliptica Wolfenden, 1905 (a), p. 1023.

This species is the type of the genus. It was well distributed throughout the area
investigated by the 'Siboga', as shewn by the following records

Stat. 16. -- Stat. 35. — Stat. 36. — Stat. 37. — Stat. 47". — Stat. 66. — Stat. 71. — Stat.
75 (HENSEN vertical net, 11 metres to surface). — Stat. 81. — Stat. 96 (day). — Stat. 98. • —
Stat. 99. — Stat. 109. — Stat. 117*. — Stat. 125 (day). — Stat. 128 (HENSEN vertical
net, 900 metres to surface). — Stat. 136. — Stat. 138. — Stat. 141 (HENSEN vertical net,
1500 metres to surface). — Stat. 142. — Stat. 143 (HENSEN vertical net, 1000 metres to
surface). Stat. 144. — Stat. 148 (HENSEN vertical net, 1000 metres to surface). — Stat. 149. —
Stat. 165. - - Stat. 174. -- Stat. 184. — Stat. 185 (HENSEN vertical net, 1536 metres to
surface). -- Stat. 205. — Stat. 213. — Stat. 215". — Stat. 216. — Stat. 223. — Stat. 229. —
Stat. 245. -- Stat. 271 (horizontal cylinder). — Stat. 276 (HENSEN vertical net, 750 metres
to surface). — Stat. 304. — Stat. 315.

Examples of this species were not numerous in any of the collections except the one
from Station 142. This was a night gathering, and 1241 specimens were obtained from the
sample. This number was represented by 268 females and 973 males.

Length of female, 1,9 mm.

The combined length of the abdomen and furca is contained nearly twice in the total
length of the cephalolhorax, from the frontal margin to the base of the genital segment. The
second abdominal segment is about as long as the genital segment. It is three trmes longer
than broad. The furcal joints are nearly three times longer than broad.

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1 //

The fïfth pair of feet is asymmetrical. The exopodite is composed of tvvo joints. The joints
of the left exopodite are distinctly longer than the joints of the right exopodite (Plate XLVIII, fig. 3).

Length of male, 1,8 mm.

The distal end of the right side of the second abdominal segment is produced into a
well defined tooth (Plate XLVIII, fig. 4).

The inner margin of the last joint of the left exopodite of the fïfth pair of feet is furnished
with a pad of fine hairs. The palm-Iike margin of the first joint of the right exopodite is
produced into three strong blunt teeth. The claw-like second joint has three small pointed
teeth (Plate XLVIII, fig. 5).

The apical portion of the second maxillipedes of both sexes is composed of five joints.

Calanopia clliptica appears to be generally distributed in the warm regions of the Indian
and Pacific Oceans. It has also been found in the Red Sea.

2. Calanopia minor A. Scott. Plate XLVIII, figs. 6 — 10.

Calanopia minor A. Scott, 1902, p. 406, pi. I, figs. 1 — 5.
Calanopia minor Thompson & Scott, 1903, p. 251.
Calanopia minor Cleve, 1903, p. 356.
Calanopia minor Wolfenden, 1905 (a), p. 1023.

This form may easily be passed over as a small variety of Calanopia elliptica. On
careful examination it is seen to be very distinct. This small form was not so widely distributed
as Calanopia elliptica, but it was rather more plentiful in the samples where it was noted.
Calanopia minor was found in the plankton collected at the following stations.

Stat. 35. — Stat. 36. — Stat. 4jh. — Stat. 66. — Stat. 71. — Stat. Si.— Stat. 96 (day). —
Stat. 99. - - Stat. 109. — Stat. 117». — Stat. 118 (HENSEN vertical net, 900 metres to
surface). — Stat. 128 (HENSEN vertical net, 700 metres to surface). — Stat. 138. — Stat.
141 (HENSEN vertical net, 1500 metres to surface). — Stat. 142. — Stat. 143 (Hensen
vertical net, 1000 metres to surface). — Stat. 148 (HENSEN vertical net, 1000 metres to
surface). — Stat. 168. — Stat. 184. — Stat. 203 (Hensen vertical net, 1500 metres to
surface). — Stat. 205. — Stat. 213. — Stat. 217 (horizontal cylinder). — Stat. 282. — Stat.
304. — Stat. 315.

The collection taken at Station 142 yielded 1850 specimens. This number was repre-
sented by 983 females and 867 males.

Length of female, 1,4 mm.

The combined len<nh of the abdomen and furca is contained one and three-fourth times
in the total length of the ceplialot/wrax, from the frontal margin to the base of the genital
segment. The second abdominal segment is distinctly longer than the genital segment. The
furcal joints are twice as long as broad.

The fifth pair of feet is quite symmetrical. The exopodite is one-jointed. It terminates
in one long spine and one short spine. The long spine is on the inside. The distal part of
the outer margin is furnished with one short spine (Plate XLVIII, fig. 8).

Length of male, 1,2 mm.

The second abdominal segment has no spiniform process on the right side.

i77

SIROGA-EXPEDITIE XXIXn. 2T,

i78

The second joint of the left basiopodite of the fifth pair of feet is considerably swollen
at the proximal end of the inner margin. The swollen part is produced into a small curved
tooth. The length of the second joint of the left exopodite is contained two aad a half times
in length of the first joint. The palm-like margin of the first joint of the right exopodite is
simple, but it is furnished with a thumb-like projection at the proximal end. The claw-like
second joint is spoon-shaped, and it is without teeth (Plate XLVIII, fig. 10).

The apical portion of the second maxillipedes of both sexes is composed of four joints.

The males and females of Calanopia minor are similar in general appearance to Calanopia
americana, and Calanopia anrivillii, but the structure of the fifth pair of feet of the two
sexes readily distinguish.es them from either Dahl's or Cleve's species. The exopodite of the
female fifth pair is furnished with three spines only. The inner apical spine is long and com-
paratively stout. The second joint of the left basiopodite of the male fifth pair has a small
but quite distinct tooth on the inflated portion of the inner margin. The fifth pairs of the two
sexes are very different from those of Calanopia clliptica.

This species has hitherto only been recorded from the Red Sea, and from the northern
area of the Indian Ocean.

3. Calanopia thompsoni nov. sp. Plate XLIX, figs. 1 — 8.

Female — length 2,6 mm.

Seen from above, the body appears elongate ovate, and rather slender. The forehead
is angular in outline. The cephalic segment is furnished with side hooks. The last thoracic
segment is produced posteriorly on each side into strong spiniform projections. The rami of
the rostrum are moderately stout. The distal end of the inner margin of each ramus is barbed
(Plate XLIX, fig. 3). The excavation is rather broadly rounded.

The abdomen is composed of two segments. The combined length of the abdomen and
furca is contained two and one-third times in the total length of the cephalothorax, from the
frontal margin to the base of the genital segment. The genital segment is nearly twice the
length of the second segment. The ventral surface is produced posteriorly at the distal end
into a rounded knob (Plate XLIX, fig. 2). The length of the second segment is equal to
rather less than twice the width. The furcal joints are twice as long as broad.

The antennules are composed of nineteen joints and extend to near the midclle of the
genital segment. The third joint is very small (Plate XLIX, fig. 4).

The antennae, mandibles, maxillae and maxillipedes are almost similar to those of
Calanopia elliptica. The apical portion of the second pair of maxillipedes is composed of five joints.

The four pairs of swimming feet are also similar to those of that species.

The fifth pair of feet is symmetrical. The exopodite is composed of two joints. The
first joint is moderately long. The distal portion of the outer margin is furnished with two
very strong spiniform projections. The second joint is narrow and spiniform. It terminates in a
moderately long and stout spine. The proximal end of the outer margin is furnished with two
spines. The: inner margin bears one spine (Plate XLIX, fig. 5).

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179

Male — length 2,4 mm.

The male resembles the female in general appearance, but the abdomen is composed
of live segments. The second segment has 110 spiniform process on the right side.

The middle joints ot the right antennule are considerably inflated. The upper margin
of the proximal and distal hinge joints is fringed with fine spines (Plate XLIX, fig. 7).

The antennae, mandibles, maxillae, maxillipedes and lïrst four pairs of swimming feet
are similar to those of the female.

The exopodite of the left fifth foot is moderately broad. The second joint is short. It
is equal to two-thïrds of the length of the first joint. The apex is furnished with two spines,
and a broad, flat, finely denticulated process. The distal end of the posterior surface of the
joint bears a curved spine, like a small chela. This spine is almost invisible when the preparation
is reversed and the anterior surface placed uppermost. The claw-like joint of the right exopodite
is spoon-shaped. It is furnished with one small basal tooth (Plate XLIX, fig. 8).

This species is easily separated from any of the other members of the genus, by the
presence of distinct side hooks on the cephalic segment of both sexes. It is a true Calanopia
and is larger than any of the other species.

Occurrence. — Seventy-two females and eighty-eight males were obtained from the
plankton collected at the following stations.

Stat. 16, twenty-two females and ten males. — Stat. 142, twenty-nine females and sixty-nine
males. — Stat. 205, twelve females and five males. — Stat. 213, mne females and four males.

This species is dedicated to the memory of my friend the late I. C. Thompson of
Liverpool, a well known worker amongst the Copepoda. He was the first to seriously investigate
the pelagic and littoral forms of the Irish Sea. He also did a considerable amount of valuable
research in the plankton of the great oceans.

4. Calanopia herdinani nov. sp. Plate XLIX, figs. 9 — 16.

Female — length 1,8.

Viewed from above, the body appears elongate ovate, and moderately robust. The
forehead is narrowly rounded. The cephalic segment is without side hooks. The last thoracic
segment is produced posteriorly into spiniform processes. The rami of the rostrum are rather
stout. The distal end of the inner margin of each ramus is slightly barbed. The excavation is
wedge-shaped (Plate XLIX, fig. 11).

The abdomen is composed of two segments. The combined length of the abdomen and
furca is contained nearly two and one-third times in the total length of the cephalothorax, from
the frontal margin to the base of the genital segment. The genital segment appears short and
tumid in dorsal view. The ventral surface is furnished with a small spine near the anterior end,
but it is not produced into a knob at the distal end as in Calanopia thompsoni. The genital
segment is very slightly longer than the second segment. The second segment is about twice
as long as broad. The furcal joints are two and a half times longer than broad (Plate XLIX,
figs. 9 and 10).

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The antennules are eighteen-jointed and extend to the end of the genital segment. The
third joint is very small (Plate XLIX, fig. 12).

The antennae, mandibles, maxillae, maxillipedes and the four pairs of swimming feet
are almost similar to those of Calanopia elliptica. The apical portion of the second pair of
maxillipedes is composed of five joints.

The fifth pair is symmetrical. The first joint of the exopodite is comparatively long and
slender. The distal portion of the outer margin is furnished with two moderately stout spines.
The second joint is narrow and spiniform. It terminates in a moderately long and slender spine.
The outer margin of the joint is furnished with two small spines. There is no inner edge spine
as in Calatiopia thompsoni (Plate XLIX, fig. 1 3).

Male — length 1,7 mm.

The male resembles the female in general appearance, but the abdomen is composed
of five segments. The second segment has no spiniform process on the right side.

The middle joints of the right antennule are slightly inflated. The upper margin of the
proximal and distal hinge joints is fringed with fine spines.

The antennae, mandibles, maxillae, maxillipedes and first four pairs of swimming feet
are similar to those of the female.

The exopodite of the left fifth foot is slender and rather cylindrical. The second joint
is equal to two-fifths of the length of the first joint. The apex terminates in two moderately
long spines. The outer one is distinctly longer and stouter than the inner one. The outer
margin is furnished with one slender spine. The first joint of the right exopodite is nearly oval
in outline, and the palm is simple. The claw-like second joint is spoon-shaped, but it has no
basal tooth (Plate XLIX, fig. 16).

This species has a general resemblance to Calanopia elliptica, but the two sexes can
readily be separated by the difference in the proportional length of the abdominal segments, by
the absence of a tooth on the right side of the second segment of the male abdomen, and by
the structure of the fifth pairs of feet.

Occurrence. — One female and five males were obtained from the plankton collected
at the following stations.

Stat. 109, one male. — Stat. \\J'\ one male. — Stat. 141 (Hensen vertical net, 1500 metres
to surface), one male. - - Stat. 142, one female and one male. — Stat. 143 (HENSEN ver-
tical net, 1000 metres to surface), one male.

This species is named in compliment to Professor W. A. Herdman, F. R.S., whose
enthusiasm and example have done so much to encourage the systematic investigation of the
fauna of the Irish Sea, that has been carried on during the last twenty years by the Liverpool
Marine Biology Committee. His Oceanic Researches have also been extensive. The reports on
the 'Challenger' Ascidians and the Investigation of the Ceylon Pearl Oyster Beds are well
known works. The late I. C. Thompson and the present writer have had many facilities to
study Oceanic Copepoda by the examination of collections of plankton obtained by him at
various times.

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5. Calanopia americana Dahl. Plate XLVIII, figs. 11 — 15.

Calanopia americana Dahl, [894, p. 21, pi. 1, figs. 23 — 26.
Calanopia americana Giesbrccht & Schmeil, 189S, p. 132.

The two sexes of this species are easily separated from the other smal! forms of Calanopia
by the structure of the fifth pairs of feet.

The combined length of the abdomen and furca of the female is slightly less than one-
half of the total length of the ccplialothorax, from the frontal margin to the base of the crenital
segment. The second joint of the abdomen is nearly as long as the genital segment. It is
twice as long as broad. The furcal joints are two and a half times longer than broad. The
spiniform projections of the last thoracic segment are comparatively short.

The fifth pair of the female is symmetrical. The exopodite is one-jointed. The ape\ of
the joint terminates in three moderately strong spines. The middle spine is considerably longer
than either of the other two spines. This spine is proportionally much shorter than the long
spine on the apex of the exopodite of the female fifth pair of Calanopia minor, or Calanopia
aurivillii. It does not appear to be plumose (Plate XLVIII, "fig. 13).

Length of female, 1,3 mm.

The inner margin of the second joint of the basiopodite of the left side of the male
fifth pair is inflated at the proximal end. The swollen part is produced into a prominent tooth-
like process. The second joint of the left exopodite is comparatively long. It is equal to two-
thirds of the length of the first joint. The claw-like second joint of the right exopodite is
furnished with a distinct tooth. The first joint is very different in shape from that of the male
of Calanopia minor, or Calanopia aurivillii. There is also a deep incision at the base of the
thumb-like process that is not present in the other two species (Plate XLVIII, fig. 15).

Length of male, 1,23 mm.

The apical portion of the second pair of maxillipedes of both sexes is composed of four joints.

Dahl's type specimens were fonnd in plankton collected at the mouth of the Tocantins
River, a branch of the Amazon Estnary. The illustrations given in this report are from specimens
obtained from plankton collected in 1903 at Hamilton, in the Bermuda Islands, by a brother
of Professor Herdmax.

6. Calanopia aurivillii Cleve. Plate XLVIII, figs. 16 — 20.

Calanopia aurivillii Cleve, 1901, p. 37, pis. II & III.
Calanopia aurivillii Thompson & Scott, 1903, p. 251.

This species bears a close resemblance to Calanopia minor and to Calanopia americana ,
but it is quite distinct from either of these forms.

The spiniform projections of the last thoracic segment are moderately long. The combined
length of the abdomen and furca of the female is distinctly longer than one-half of the total
length of the cephalothorax, from the frontal margin to the base of the genital segment. The
second segment is slightly longer than the genital segment. It is nearly three times longer than
broad. The furcal joints are almost twice as long as broad.

182

The fifth pair of feet of the female is symmetrical. The exopodite is one-jointed. The
: of the joint terminates in three spines. The inner spine is distinctly longer than the other
two. It is distinctly plumose. The distal portion of the outer margin of the joint is furnished
with one outer edge spine (Plate XLVIII, fig. 18).

Length of female, 1,34 mm.

The inner margin of the second joint of the basiopodite of the left side of the male
fifth pair is much inflated. The inflated part is broadly rounded and is fringed with fine spines.
There is no tooth as in Calanopia minor, or Calanopia americana. The second joint of the
left exopodite is equal to two-fifths of the length of the first joint. The first joint of the
exopodite of the right foot is moderately broad. The thumb-like projection is well developed.
The palm is simple. The claw-like second joint is spoon-shaped. It has no marginal tooth
(Plate XLVIII, fig. 20).

Length of male, 1,12 mm.

The apical portion of the second pair of maxillipedes of both sexes is composed of four joints.

Calanopia aurivillii approaches Calanopia americana in the structure of the female
fifth pair of feet, but there is a noteworthy difference in the proportional length of the spines
on the apex of the exopodite. The distinctions between the female fifth pair of Calanopia
americana, Calanopia aurivillii, and Calanopia minor, are readily seen on comparing the figures
given on Plate XLVIII.

Cleve's type specimens were obtained from plankton collected in the Malay Archipelago
in 1 899. The illustrations given in this report are from specimens found in plankton collected
by Professor Herdman in the vicinity of Galle, Ceylon, in 1903.

19. Family Parapontellidae.
Genus Bathypontia Sars, 1905 (£).

This genus was established by Professor G. O. Sars in 1905 from a female specimen,
and placed provisionally in the family Parapontellidae owing to the similarity in the structure
of the first pair of maxillipedes with that of the genus Parapontella. The other appendages,
however, are quite distinct, and the abdomen of the female is composed of four segments.

G. P. Farran (1908), gives a very short description of the male, with an illustration
of the right antennule and of the fifth pair of feet.

The rostrum is a moderately strong, cylindrical, and slightly curved process. There is a
very slight tracé of bifurcation at the apex. The exopodites of the four pairs of swimming feet
are three-jointecl. The endopodite of the first pair of feet is two-jointed. The endopodites of the
second, third and fourth pairs of feet are three-jointed. The fifth pair of the female is small.
There is no endopodite. Each foot consists of two free joints attached to a one-jointed basal
part. The right antennule of the male is modified for grasping. The distal hinge joint is strongly
arched. The male fifth pair is very indistinctly prehensile.

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The fifth pairs of feet of the two sexes are quite distinct from the definition given by
Sars for the family Parapontellidae, in 'Crustacea of Norway' vol. IV, Calanoida, and it may
he found necessary at some future period to establish a new family for the reception oi the
members of this genus.

One species, apparently distinct trom the type. was obtained from the plankton collected
by the 'Siboga'.

i. Baihypontia spinifera nov. sp. Plate III, figs. i — 16.

Female — length 3,3 mm.

Seen from above, the body appears considerably elongated, and of nearly cylindrical
form. The head is separated from the first thoracic segment. The fourth and fifth thoracic
segments are completely segmented. The last thoracic segment is symmetrical. It is produced
on each side into wing-like expansions with pointed ends. Seen from the side, the last thoracic
segment is broadly triangular in outline. It terminates in small, bluntly rounded, posteriorly
directed points. The rostrum is represented by a moderately strong cylindrical filament with
a very slight tracé of bifurcation at the apex.

The abdomen is composed of four segments. The combined length of the abdomen and
furca is contained nearly three and one-third times in the total length of the cep halothorax,
from the frontal margin to the base of the genital segment. The genital segment is longer
than the others. It appears considerably inflated in the region of the genital opening, when
viewed from the side. The posterior margin of the first, second and third segments is fringed
with fine spines. The furcal joints are very small (Plate III, fig. 3). The illustration shews the
segments in a rather telescoped condition.

The antennules are composed of twenty-three joints and extend to the middle of the
fourth thoracic segment.

The endopodite and exopodite of the antennae are of nearly equal length. The exopodite
is composed of seven joints. The intermediate joints are very small and indistinct.

The mandible and palp are quite distinct from those of Parapontella. The upper end of
the biting part of the mandible is armed with two spiniform teeth. The lower end is furnished
with a short, stout and densely spinulose seta. The upper half of the intermediate part of the
cutting edge is finely serrate. The lower half is fringed with short hairs. The basal part of the
palp is short and broad. The exopodite is four-jointed. It is distinctly longer and stouter than
the two-jointed endopodite (Plate III, fig. 7). The maxillae are rather more highly developed
than in Parapontella (Plate III, fig. 8).

The first pair of maxillipedes is very strong and resembles slightly that of Parapontella.
The spines on the apical portion are long and curved. The distal portion of the spines is slightly
flatteneel, and the inner margin is fringed with fine short hairs (Plate III, fig. 9).

The second pair of maxillipedes is of the ordinary Calanoid type. The basal part is two-
jointed. The distal part is composed of five joints (Plate III, fig. 10).

The exopodites of the four pairs of swimming feet are three-jointed. The endopodite of

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184

the first pair is two-jointed. The endopodites of the second, third and fourth pairs are three-
jointed. The outer edge spine on the first joint of the exopodite of the third pair of feet is
considerably elongated, and extends to the end of the outer edge spine on the second joint.
The outer edge spine on the first joint of the exopodites of the second and fourth pairs of
feet is normal (Plate III, fig. 12).

The fifth pair of feet is symmetrical and is without any tracé of an endopodite. Each
foot is composed of two free joints attached to a one-jointed basal part. The second free joint
is rather long and slender. The apex is furnished with one long and one very small spine.
The long spine is on the inner edge of the apex (Plate III, fig. 16).

Male — length 3 mm.

Seen from above, the male appears somewhat shorter and more robust than the female.
The last thoracic segment is produced similar to that of the female. When seen from the side,
the terminations appear bluntly rounded and are directed ventrally (Plate III, figs. 1 and 2).

The abdomen is composed of five segments.

The right antennule is twenty-jointed. The middle joints are very little inflated. The
distal hinge joint is boldly arched (Plate III, fig. 5).

The antennae, mandibles, maxillae and maxillipedes are similar to those of the female.

The first, third and fourth pairs of feet are also similar to those of the female. The
outer edge spine on the first joint of the exopodite of the third pair of feet extends to the
end of the outer edge spine on the second joint

The outer edge spine on the first joint of the exopodite of the second pair of feet is
moderately long and stout. It reaches to the base of the spine on the second joint. The outer
edge spine on the second joint is very long and stout. It is slightly curved, and extends
distinctly beyond the distal end of the third joint (Plate III, fig. 13).

The fifth pair of feet is asymmetrical. The basiopodite is two-jointed. The exopodite of
the right foot is composed of two joints. The first joint is nearly twice the length of the second
joint. The second joint is somewhat spiniform. The distal end is furnished with one long and
one very short spine. There is 110 tracé of an endopodite on the right foot. The exopodite of
the left foot is composed of three short and nearly equal joints. The third joint is narrower
than the first or second joints. It is furnished with one long and one short apical spine. The
long spine is on the inner angle of the apex. The inner distal angle of the second joint of
the basiopodite of the left foot is furnished with a long, stout and densely plumose spine. This
may represent a rudimentary endopodite (Plate III, fig. 15).

The female of this species is apparently very closely related to the form described by
Professor Sars as Batliypontia e/ongata, but until figures are given by that author it is per-
haps better to regard it as distinct, especially as the male is evidently different. The male
fifth pair is quite distinct from the figure given by Farran. This author states "The fifth feet
"are almost symmetrical, and consist on each side of four elongate tapering joints, the last
"joint terminated by a small spine". The figure does not agree very well with the description.
The end joint of one of the exopodites is shewn as spiniform, but there is 110 small terminal
spine. This slight defect, however, is probably due to an error in lithographing the plate. The

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second joint of the left basiopodite apparently does not possess the strong spine that is
present in the 'Siboga' male, and no reference is made to the long outer edge spine on the
second joint of the exopodite of the second pair of feet.

Occurrence. - Two females and one male were obtained from the plankton collected
with the Hensen vertical net at Station 143, 1000 metres to the surface.

Genus Neopontella nov.

This genus is very closely related to Parapontella, and at first sight I was inclined to
regard its representative to be a trne member of that genus. A closer examination of the two
sexes, however, shewed that it is clearly distinct.

The generic differences between this genus and Parapontella, are in the structure of
the fifth pair of feet of the female, and in the segmentation of the abdomen of the male.

The female fifth pair of feet has no tracé of an endopodite. The abdomen of the male
is composed of four segments.

The antennules, antennae, mandibles, maxillae and maxillipedes are almost identical
with those of Parapontella brevicornis (Lubbock). The four pairs of swimming feet are also
similar to those of that species.

One species belonging to this new genus was obtained from the plankton collected
during the traverse of the 'Siboga'.

1. Neopontella typica nov. sp. Plate LV, figs. 1 — 15.

Female — length 1,13 mm.

Seen from above, the body appears elongate ovate in outline. The greatest width is
in the middle. The width is contained two and a half times in the total length of the body.
The head is distinctly separated from the first thoracic segment. The frontal margin is rather
broadly rounded. The fourth and fifth thoracic segments are completely fused. The last thoracic
segment is very slightly produced. The posterior margin of the segment is narrowly rounded.
Viewed from the side, the apex of the last thoracic segment is seen to be evenly and rather
bluntly rounded. The rostrum is almost similar to that of Parapontella brevicornis, but the
filaments appear to be rather shorter (Plate LV, fig. 3).

The abdomen is composed of three segments. The combined length of the abdomen
and furca is contained fully twice in the total length of the cep halothorax, from the frontal
margin to the base of the genital segment. The genital segment is considerably swollen. It is
nearly equal to the combined length of the next two segments. Seen from the side, the segment
appears greatly inflated in the region of the genital opening. The second and third segments
are of nearly equal length. The second segment is not armed with spines. The furcal joints
are nearly twice as long as broad, and are almost as long as the anal segment (Plate LV,
figs. 1 and 2).

The antennules are composed of eighteen joints. The third and fourth joints are very
small. The last joint is indistinctly segmented at the distal end.

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SIEOGA-EXPED1TIE XXIXtf. 24

i86

The antennae, mandibles, maxillae and maxillipedes are al most similar to those of
Parapontella brevicornis.

The four pairs of swimming feet are also nearly similar to those of Parapontella. The
exopodites are three-jointed. The endopodite of the first pair is three-jointed. The endopodites
of the second, third and fourth pairs are two-jointed. The outer edge spines on the joints of
the exopodite of the second, third and fourth pairs of feet are coarsely spinulose. The terminal
spine on the last joint of the exopodites of the second, third and fourth pairs of feet is coarsely
serrate (Plate LV, fig. 11).

The fifth pair is symmetrical. Each foot is composed of a two-jointed basiopodite, and
a one-jointed exopodite. The apex of the exopodite is armed with three strong spines. The
middle spine is considerably longer than the other two spines. The inner spine is short and
very stout. It is equal to nearly twice the length of the outer spine. The inner margin is
fringed with a few short hairs. There is no outer edge spine as in Parapontella brevicornis.
The fifth pair of feet has no tracé of an endopodite (Plate LV, fig. 12).

Male — length 1 mm.

The male differs very little in general appearance from the female. The abdomen is
composed of four segments. The segments are without armature of any kind (Plate LV, fig. 13).

The right antennule is somewhat similar to that of Parapontella brevicornis, but the
last joint is not produced into a tooth-like process as in that species. The proximal hinge joint
has no serrated lamina (Plate LV, fig. 14).

The antennae, mandibles, maxillae, maxillipedes and first four pairs of swimming feet
are similar to those of the female.

The fifth pair of feet is asymmetrical. The last joint of the right and left foot is
lamelliform. The last joint of the right foot has a claw-like appearance, but there is no articulation
between the inner thumb-like process and the palm. The outer margin of the last joint of each
foot is furnished with two spines. The apex is spiniform (Plate LV, fig. 15).

This species is easily recognised by the structure of the fifth pairs of feet of the two sexes.

Occurrence. - - Four females and one male were obtained from the plankton collected
with the Hensen vertical net at Station 143, 1000 metres to the surface.

20. Family Acartiidae.
Genus Acartia Dana, 1846.

This was the only member of the family obtained from the plankton collected during
the traverse of the 'Siboga' in the Malay Archipelago.

Representatives of the closely allied genus Paracartia have been found in the plankton
of the Gulf of Guinea, the Antarctic, and from off the coast of Norway. Future research may
reveal the presence of this genus in the plankton of the Indian and Pacific Oceans. Wolfenden,
in the results of the British 'National Antarctic Expedition' Natural History, Vol. IV, Zoology,

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British Museum, 1908, lias described a new genus and species of Copepod as Paralabidocera
hodgsoni. This form is undoubtedly identical with Paracartia aniarctica described by the late
I. C. Thompsox some ten years earlier, in 'Transactions of the Liverpool Biological Society',
Vol. XII, 1898, page 295.

The members of the genus Acartia are easily identified by their slender and almost
transparent body, and by the structure of the various appendages.

Four species were represented in the plankton collected by the 'Siboga'.

1. Acartia danac Giesbrecht.

Acartia danac Giesbrecht, 1889, p. 26.

Acartia danac Giesbrecht, 1893, p. 508, pis. 30 & 43.

Acartia danac Giesbrecht & Schmeil, 1898, p. 154.

Acartia danac Cleve, 1903, p. 355.

Acartia danac Cleve, 1904, p. 184.

Acartia danae Wolfenden, 1905 (a), p. 1023.

Acartia danac van Breemen, 1908, p. 159, fig. 176.

This species is closely related to Acartia negligens, but the last thoracic segment is produced
into strong spines. It was obtained from the plankton collected at the following two stations.

Stat. 203 (HENSEN vertical net, 1500 metres to surface), 4 specimens. — Stat. 217, horizontal
cylinder, 1 specimen.

Acartia danac appears to be rather limited in its distribution. It has been recorded
from the Atlantic and Pacific Oceans, and from the Mediterranean.

2. Acartia erythraca Giesbrecht.

Acartia erythraca Giesbrecht, 1889, p. 26.

Acartia erythraea Giesbrecht, 1893, p. 508, pis. 30 & 43.

Acartia erythraca Giesbrecht & Schmeil, 1898, p. 155.

Acartia erythraea I. C. Thompson, 1900, p. 284.

Acartia erythraea Cleve, 1901, p. 4.

Acartia erythraca A. Scott, 1902, p. 408.

Acartia erythraca Thompson & Scott, 1903, p. 254.

Acartia erythraea Cleve, 1903, p. 355.

Acartia erythraea Wolfenden, 1905 (a), p. 1023.

This proved to be the most common member of the genus in the plankton collected
by the 'Siboga'. It was present at the following stations.

Stat. 16. — Stat. 35. — Stat. 40. — Stat. 471'. — Stat. 71. — Stat. 96 (night). —
Stat. 99. — Stat. 101. — Stat. 106. — Stat. 109. - - Stat. 117". -■ Stat. 118 (HENSEN
vertical net, 900 metres to surface). — Stat. 121. -- Stat. 136. -- Stat. 141 (HENSEN vertical
net, 1500 metres to surface). — Stat. 142. — Stat. 143 (HENSEN vertical net, 1000 metres
to surface). — Stat. 144. — Stat. 148 (HENSEN vertical net, 1000 metres to surface). —
Stat. 149. — Stat. 165. — Stat. 168. — Stat. 169. - - Stat. 174. — Stat. 177». — Stat.
185 (HENSEN vertical net, 1536 metres to surface). -- Stat. 203 (HENSEN vertical net, 1500
metres to surface). — Stat. 205. -- Stat. 2io\ -- Stat. 213. — Stat. 230 (HENSEN vertical
net, 2000 metres to surface). — Stat. 252. -- Stat. 276 (HENSEN vertical net, 750 metres
to surface). — Stat. 282. — Stat. 315.

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The female can readily be recognised by the long naked claw-like spine on the fifth

pair of feet.

This species was first recorded from the Red Sea, but it has since been obtained from

various parts of the Indian Ocean.

3. Acartia negligens Dana.

Acartia negligens Dana, 1849, p. 26.

Acartia negligens Giesbrecht, 1S93, p. 508, pis. 30 & 43.

Acartia negligens Giesbrecht & Schmeil, 1898, p. 154.

Acartia negligens Cleve, 1901, p. 4.

Acartia negligens A. Scott, 1902, p. 408.

Acartia negligens Thompson & Scott, 1903, p. 254.

Acartia negligens Cleve, 1903, p. 355.

Acartia negligens Wolfenden, 1905(0), p. 1023,

Acartia negligens Sars, 1907(0), p. 27.

The spine on the fifth pair of feet of the female of this species is somewhat similar to
that on the fifth pair of Acartia danae. The two forms can readily be separated, however, by
the form of the last thoracic segment. In the present species the posterior margins of the last
thoracic segment are rounded and the distal ends are each furnished with a very small spine.
The last thoracic segment of Acartia danac is produced on each side into a strong spine.

Acartia negligens appeared to have a fairly wide distribution in the area traversed by
the 'Siboga'. It was found at the following stations.

Stat. 36. — Stat. 40. — Stat. 47''. — Stat. 71. — Stat. 96 (day). — Stat. 110. — Stat. 125 (day). —
Stat. 128 (HENSEN vertical net, 700 metres to surface). — Stat. 133. — Stat. 138. —
Stat. 141 (HENSEN vertical net, 1500 metres to surface). — Stat. 142. — Stat. 148 (Hensen
vertical net, 1000 metres to surface). — Stat. 165. — Stat. 168. — Stat. 174. — Stat. 185
(HENSEN vertical net, 1536 metres to surface). — Stat. 203 (HENSEN vertical net, 1500
metres to surface). — Stat. 205. — Stat. 213. — Stat. 217 (horizontal cylinder). — Stat.
Stat. 245. — Stat. 252. — Stat. 276 (HENSEN vertical net, 750 metres to surface). ■
Stat. 282. — Stat. 304.

This Acartia has been recorded from the Mediterranean, Arabian and Red Seas, Indian
and Pacific Oceans, and from the Malay Archipelago.

4. Acartia sfiinicattda Giesbrecht.

Acartia spinicauda Giesbrecht, 1889, p. 25.

Acartia spinicauda Giesbrecht, 1893, p. 508, pis. 30 & 43.

Acartia spinicauda Giesbrecht & Schmeil, 1898, p. 155.

Acartia spinicauda Cleve, 1901, p. 4.

Acartia spinicauda Cleve, 1903, p. 355.

This Acartia resembles Acartia centrura in general appearance, but it can readily be
separated by the form of the spine on the fifth pair of feet of the female. The spine is long
and slender. It appears to be articulated to a short stout basal part attached to the end of
the free joint.

189

One specimen was obtained from the plankton collected at each of the following ten stations.

Stat. 93. — Stat. 99. — Stat. 110. — Stat. 142. — Stat. 169. — Stat. 174. — Stat. 203
(HENSEN vertical net, 1500 metres to surface). — Stat. 225. — Stat. 229. — Stat. 315.

Acartia spinicauda has been recorded from the Chinese Coast, the Arabian Sea, and
the Malay Archipelago.

2 1 . Family Tortanidae.
Genus Tortanus Giesbrecht, 189S.

The members of this genus are readily separated from the other Calanoids by the
peculiarly twisted form of the anal segment, and by the very large eye that gives the head,
when seen from the side, an appearance very similar to some of the Cladocera.

Four species were found in the plankton collected by the 'Siboga'. Two of the species
appear to be undescribed.

1. Tortanus barbatus (Brady). Plate LV, figs. 16 — 18.

Corynura barbata Brady, 1883, p. 71, pi. XXXI, figs. 10 — 12.

Corynura denticulata Giesbrecht, 1889, p. 26.

Corynura denticulata Giesbrecht, 1893, p. 525, pis. 31 & 42.

Corynura barbata, Giesbrecht, 1893, p. 525.

Tortanus barbatus Giesbrecht & Schmeil, 1S9S, p. 158.

Tortanus denticulatus Giesbrecht & Schmeil, 1898, p. 15S.

Four females belonging to the above species were found in the plankton collected with
the Hensex vertical net at Station 185, 1536 metres to the surface.

The abdomen is composed of three segments. The anal segment is long and narrow.
The fifth pair of feet consists of two free joints attached to a basal part. The second free joint
of the left foot is long and comparatively stout. The middle of the inner margin is furnished
with a tuft of five curved lamelliform teeth. The second free joint of the right foot is scarcely
equal to half the length of the second free joint of the left foot. The inner margin has 110
tuft of teeth (Plate LV, fig. 18).

The difference between Tortatms barbatus and Tortanus denticulatus appears to be so
very slight that I am inclined to regard the two forms as identical. The tuft of teeth on the
second free joint of the left foot is more compact than in Tortanus denticulatus. That appears
to be the only difference, except that Tortanus denticulatus has 110 whip-like ends to the teeth
as shewn in Bradv's figure. The tuft of teeth in the 'Siboga' specimens is compact, but the
ends are not whip-like.

I have specimens of Tortanus barbatus from plankton collected in Patani Bay, Siam,
with the whip-like ends of the teeth reaching to midway between the tuft and the distal end
of the joint. The whole of the teeth in these specimens have whip-like ends. The thin ends

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190

appear to be very flexible and are easily damaged or entirely destroyed. This may account
for their absence in the 'Siboga' specimens and in Giesbrecht's Tortanus denticulatus.

Length of 'Siboga' females, 1,6 mm.

Brady's species was described from a single female found in the plankton collected by
the 'Challenger' in Zebu Harbour, Philippine Islands. The form described by Giesbrecht as
Corynura denticulata was taken in the Red Sea.

2. Tortanus gracilis (Brady).

Corynura gracilis Brady, 1883, p. 71, pi. XXXIII, figs. 1 — 14.

Corynura gracilis Giesbrecht, 1893, p. 525.

Tortanus gracilis Giesbrecht & Schmeil, 1898, p. 258.

Tortanus gracilis Cleve, 1901, p. 51, pi. VII, figs. 11 — 14.

Tortanus gracilis Thompson & Scott, 1903, p. 254.

Tortanus gracilis Cleve, 1903, p. 369.

Tortanus gracilis Wolfenden, 1905(0), p. 1026.

Females and males of this species were obtained from the plankton collected at the

following stations in the area traversed by the 'Siboga'.

Stat. 16. — Stat. 50. — Stat. 66. — Stat. 71. — Stat. 142. — Stat. 213, 42 specimens.

The female can easily be recognised by the comparatively long abdomen and furcal
joints, and by the structure of the fifth pair of feet. The fifth pair of the female of this species
is symmetrical or only very slightly asymmetrical. In some cases the second free joint of the
left foot is a little longer than the right foot, but this appears to be due to age. The 'Siboga'
females measured 1,52 mm. to 1,68 mm. The fifth pair of the small form is quite symmetrical,
but in the larger specimens there is a very slight difference between the length of the left
and right sides.

Wolfenden has foliowed Cleve in doubtino- the distinction between Tortamis gracilis
(Brady), and Tortamis forcipatus (Giesbrecht). Cleve says "Fifth pair of legs nearly symme-
trical still, the left leg slightly longer than the right". I regard the asymmetry between the
figure of Tortamis forcipatus given by Giesbrecht and that of Tortamis gracilis shewn by
Cleve, as well as what prevails in the 'Siboga' specimens, to be too great to justify any doubt
regarding the distinctness of the two forms. Giesbrecht's figure shews the terminal joint of
the left foot to be twice the length of the terminal joint of the right foot. The inner margin
of the long joint is comparatively straight and it is fringed with fine spines. There is no tracé
of spines on the inner margin of the last joint of either foot of the 'Siboga' females of Tor-
tanus gracilis.

I have specimens of Tortanus forcipatus from Patani Bay, Siam. The fifth pair of the
female agrees with Giesbrecht's figure, except that there does not appear to be any fine
spines on the inner margin of the last joint of the left foot. These specimens are quite distinct
from those of Tortamis gracilis obtained during the traverse of the 'Siboga', and also from
the plankton collected by Professor Herdman in the Gulf of Suez in 1903.

This species has been recorded from the Arabian and Red Seas, Indian and Pacific
Oceans, and from the Malay Archipelago.

190

3- Tortanus murrayi nov. sp. Plate LVI, figs. i — 8.

Female — length 2,65 mm.

Seen from above, the body appears elongate and rather slender. The length is slightly
less than three times the width. The head is separated from the first thoracic segment. The
fourth and fifth thoracic segments are completely fused together. The last thoracic segment is
symmetrical. It is slightly produced posteriorly and the distal margins are rounded. The eye
is large and conspicuous. A small triangular spine is visible under each eye when the Copepod
is vievved from the side (Plate LVI, fig. 2).

The abdomen is composed of tvvo segments. The combined length of the abdomen and
furca is contained three times in the total length of the cephalothorax, from the frontal margin to
the base of the genital segment. The genital segment is almost symmetrical in outline. The distal
end of the left side is furnished with a distinct tubercle. The anal segment and furcal joints are
fused together. The furcal joints are asymmetrical and comparatively short. The joints appear to
be almost as long as the anal segment. The left furcal joint is much broader than the right joint.
The setae are placed at the apex of each joint. The lateral margins are naked (Plate LVI, fig. 1).

The antennules are composed of seventeen joints and extend to about the middle of
the furcal joints.

The antennae, mandibles, maxillae, maxillipedes and first four pairs of feet are similar
to those of Tortanus o-racilis.

The fifth pair is composed of two free joints attached to a basal part. The second free
joint is long and comparatively slender. The distal end of this joint is produced into three
very strong spines. The last joint of the right foot is as long as the last joint of the left
foot, but is slightly wider (Plate LVI, fig. 5).

Male — length 2,25 mm.

The male is similar in general appearance to the female, but the abdomen is composed
of five segments. The middle joints of the right antennule are considerably inflated. The proximal
hinge joint is furnished with a fringe of fine spines on the upper margin. The distal hinge
joint is armed with a comparatively strong spine and a slender seta at the distal end of the
upper margin (Plate LVI, fig. 6).

The antennae, mandibles, maxillae, maxillipedes and first four pairs of feet are similar
to those of the female.

The fifth pair is large and prehensile. The right foot is cheliform and is much shorter
than the left foot. It is composed of two free joints. The proximal end of the inner margin
of the first joint is produced into two strong tooth-like processes. The second joint is claw-like.
The left foot is composed of three free joints. The second joint has a well defined tubercle
on the middle of the inner surface. The third joint is nearly as long as the second joint, but
it is slightly narrower. The apex is furnished with two slender curved spines (Plate LVI, fig. 7).

This species is quite distinct from any of the known members of the genus. The female
is easily identified by the left furcal joint being broader than the right, and by the three large
spines at the apex of the second free joint of the fifth pair of feet.

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192

Occurrence. — Six females and two males were obtained from the plankton collected
at the following stations.

Stat. 16, one female and one male. — Stat. 118 (HENSEN vertical net, 900 metres to surface),
one female. ■ — Stat. 185 (HENSEN vertical net, 1536 metres to surface), two females. —
Stat. 213, two females and one male.

This species is so named in compliment to Sir John Murray, K.C.B., the well known
hydrographer, one of the pioneers of oceanic research, whose name is inseparably connected
with the Scientific Results of the Exploring Voyage of H. M. S. 'Challenger', 1873 — 1876.

4. Tortanus brevipes nov. sp. Plate LVI, figs. 9 — 1

ó-

Female — length 2,3 mm.

Viewed from above, the body appears elongate ovate, and moderately robust. The
length is distinctly less than three times the width. The head is separated from the first
thoracic segment. The fourth and fifth thoracic segments are completely fused together. The
last thoracic segment is quite asymmetrical. The right side is produced posteriorly into a wing-
like process that reaches to the middle of the genital segment. The left side is also produced,
but the prolongation is much shorter, and it is directed at almost right angles to the body
(Plate LVI, fig. 9). The eye is large and conspicuous. A small triangular spine is visible under
each eye when the Copepod is viewed from the side.

The abdomen is composed of two segments. The combined length of the abdomen and
furca is contained three times in the total length of the ceplialothorax, from the frontal margin
to the base of the genital segment. The genital segment is asymmetrical. lts length exceeds
the combined length of the anal segment and furcal joints. The anal segment is not separated
from the furcal joints. It is comparatively short. The furcal joints are slender and of moderate
length. The joints are twice the length of the anal segment and are asymmetrical. The right
furcal joint is distinctly shorter and more slender than the left furcal joint. The second inner
seta on each furcal joint is long and stout. The furcal joints are furnished with one outer
marginal seta (Plate LVI, fig. 9).

The antennules are composed of sixteen joints and extend slightly beyond the end of
the furcal joints.

The antennae, mandibles, maxillae, maxillipedes and first four pairs of feet are similar
to those of Tortanus ^racilis.

The fifth pair is very small. Each foot is composed of a single free joint attached
to a basal part. The free joints are short and broad and slightly asymmetrical (Plate
LVI, fig. 13).

Male unknown.

This species is rather different from the typical members of the genus. It is easily
cognised by the asymmetrical last thoracic segment, and by the abnormal structure of the fifth
pair of feet. The apparent abnormality does not arise from any accident to the preparation.
The peculiar structure of the fifth pair was quite obvious before the dissection was made.

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193

Occurrence. — Two females were found in the plankton collected at Station 213.
The fifth pairs of feet of the two specimens were identical.

The triangular spine under each eye in the two species now described is readily seen
when the Copepod is so placed that it rests midway between the dorsal and lateral positions.

Tribe AMPHARTHRANDRIA.

22. Family Mormonillidae.

Genus Mormonilla Giesbrecht, 1891.

The members of this genus are readily distinguished by their transparent, elongate
narrow body, by the slender abdomen, and by the long furcal joints. The antennules are
composed of three or four joints, and are furnished with very long setae. The structure of the
other appendages is also characteristic of the genus.

One species was represented in the plankton collected by the 'Siboga'.

1 . Mormonilla phasma Giesbrecht.

Mormonilla phasma Giesbrecht, 1891, pp. 474 & 475.
Mormonilla phasma Giesbrecht, 1893, p. 532, pi. 43.
Mormonilla phasma T. Scott, 1893, p. 64, pi. VII, figs. ir — 21.
Mormonilla phasma I. C. Thompson, 1903, p. 31.
Mormonilla phasma Farran, 1908, p. 88.
Mormonilla phasma van Breemen, 1908, p. 166, fig. 181.

Six females belonging to this species were obtained from the plankton collected at the
following stations.

Stat. 1 18 (HENSEN vertical net, 900 metres to surface), 2 specimens. — Stat. 143 (Hensen vertical
net, 1000 metres to surface), 2 specimens. — Stat. 203 (HENSEN vertical net, 1500 metres
to surface), 1 specimen. — Stat 205, 1 specimen.

The last joint of the antennules of this species is equal to very little more than half
the length of the second last joint. In Mormonilla minor Giesbrecht, the last joint of the
antennules is as long as the second last joint.

Mormonilla phasma has been recorded from the Atlantic and Pacific Oceans.

23. Family Oithonidae.
Genus Oithona Baird, 1S43.

The members of this well known genus are readily recognised by the very elongate ovate
and transparent body, and by the moderately long abdomen. The structure of the mandible
palp and of the second pair of maxillipedes is quite distinct from that found in Cyclops. This

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51BOGA-EXPEDITIE XXIX (7.

194

difference appears to be worthy of more than generic rank. Oithona ought, I think, to be
separated from the Cyclopidae and form the type of a distinct family.

Three species of Oithona were obtained from the plankton collected by the 'Siboga'
in the Malay Archipelago.

i. Oithona rigida Giesbrecht.

Oitliona rigida Giesbrecht, 1896, p. 324, pi. 5, figs. 10 — 15.

Oithona rigida Cleve, 1901, p. 45, pi. V, figs. 7 — 18.

Oithona rigida Thompson & Scott, 1903, p. 255.

Oitliona rigida Cleve, 1903, p. 365.

Oithona rigida Cleve, 1904, p. 193.

Oitliona rigida Wolfenden, 1905 (a), p. 1023, pi. XCIX, fig. 42.

This characteristic form appeared to have a moderately wide distribution in the area
investigated by the 'Siboga'. It was present in the plankton collected at the following stations.

Stat. 47''. -- Stat. 50. -- Stat. 71. -- Stat. 142. — Stat. 165. -- Stat. 168. — Stat. 174. —
Stat. 205. — Stat. 213, 27 specimens. — Stat. 230 (HENSEN vertical net, 2000 metres to
surface).

Oithona rigida is closely related to Oithona nana Giesbrecht, but it can readily be
distinguished by the structure of the fifth pair of feet of the female, and also by the difference
in the proportional length of the abdominal segments.

This species has been recorded from the Red Sea, from the Indian Ocean, and from
off the coast of South Africa.

2. Oitliona pliunifcra Baird.

Oithona plumifera Baird, 1843, p. 193.

Oithona plumifera Dana, 1852, p. 1 100, pi. /6.

Oithona plumifera I. C. Thompson, 18S8, p. 151.

Oithona plumifera Giesbrecht, 1893, p. 537, pis. 4, 34 & 44.

Oithona plumifera T. Scott, 1893, p. 89.

Oithona plumifera Giesbrecht, 1895, p. 260.

Oithona plumifera I. C. Thompson, 1900, p. 284.

Oithona plumifera Wheeler, 1900, p. 186, fig. 22.

Oithona plumifera Cleve, 1901, p. 8.

Oithona plumifera A. Scott, 1902, p. 408.

Oithona plumifera Thompson & Scott, 1903, p. 255.

Oithona plumifera Cleve, 1903, p. 365.

Oithona plumifera Cleve, 1904, p. 193.

Oithona plumifera Wolfenden, 1905 (a), p. 1023.

Oithona plumifera Farran, 1905, p. 46.

Oithona plumifera Esterly, 1905, p. 207, fig. 50.

Oithona plumifera Norman & T. Scott, 1906, p. 185.

Oithona plumifera Pearson, 1906, p. 32.

Oithona plumifera Williams, 1906, p. 651.

Oithona plumifera Farran, 1908, p. 89.

Oithona plumifera van Breemen, 1908, p. 167, fig. 183.

This Oithona proved to be moderately common. It was widely distributed throughout
the area investigated by the 'Siboga', as shewn by the following records.

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195

Stat. 16. -- Stat. 35. — Stat. 36. — Stat. 37. — Stat. 40. — Stat. 47''. -- Stat. 71. — Stat.
75 (HENSEN vertical net, 11 metres to surface). — Stat. 81. -- Stat. 96 (day). — Stat. 99. —
Stat. 110. — Stat. 118 (HENSEN vertical net, 900 metres to surface). — Stat. 121. — Stat. 125
(day). — Stat. 128 (HENSEN vertical net, 700 metres to surface). — Stat. 133. — Stat. 136. —
Stat. 138. — Stat. 141 (Hensen vertical net, 1500 metres to surface). - - Stat. 142. —
Stat. 143 (HENSEN vertical net, 1000 metres to surface). — Stat. 146. — Stat. 148 (HENSEN
vertical net, 1000 metres to surface). — Stat. 157. -- Stat. 165. — Stat. 168. — Stat. 169.
Stat. 184. — Stat. 185 (HENSEN vertical net, 1536 metres to surface). — Stat. 203 (surface). —
Stat. 203 (Hensen vertical net, 1500 metres to surface). — Stat. 205. — Stat. 213. -- Stat.
214.. — Stat. 217 (horizontal cylinder). — Stat. 220 (HENSEN vertical net, 2000 metres to
surface). -*- Stat. 230 — Stat. 243 (HENSEN vertical net, 1000 metres to surface). — Stat.
252. — Stat. 271. - Stat. 276 (HENSEN vertical net, 750 metres to surface). — Stat.
2S2. — Stat. 315.

This species is a moderately large form with a pointed forehead. It appears to be
generally distributed throughout the great oceans.

3. Oithona minuta T. Scott.

Oithona minuta T. Scott, 1893, p. 90, pi. IX, figs. 14 — 25.

Oithona minuta A. Scott, 1902, p. 409.

Oithona minuta Thompson & Scott, 1903, p. 255.

Twenty specimens belonging to this small form were obtained from the plankton collected
at Station 142.

This species is very readily overlooked and requires some care in its determination.
Van Breemen (1908) states that Oithona minuta Kriczagin is identical with Oithona nana
Giesbrecht, but not with Oithona minuta T. Scott.

Oithona minuta has only hitherto been recorded from the Gulf of Guinea, from the
Red Sea, and from the Indian Ocean round Ceylon.

24. Family Longipediidae.
Genus Longipedia Claus, 1863.

The members of this genus are readily separated from all the other Harpacticoida by
the very long endopodite of the second pair of feet.

Three species were represented in the material collected by the 'Siboga' in the Malay
Archipelago. One of the species does not appear to have previously been described.

1. Longipedia coronata Claus. Plate LIX, figs. 5 — 8.

Longipedia coronata Claus, 1863, p. m, pi. XIV, figs. 14—24.

Longipedia coronata Sars, 1903(0), p. 10, pis. III & IV.

Longipedia coronata Thompson & Scott, 1903, p. 257.

Longipedia coronata T. Scott, 1905, p. 143.

Two females that agree fairly well with the illustrations of the above species given by

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196

Professor G. O. Sars, in 'Crustacea of Norway' Vol. V, were found in the washings from
dredged invertebrata collected at Station 164, at a depth of 32 metres.

The 'Siboga' specimens measured .8 mm. in length. This is considerably less than the
size of the European examples of the species and may be due to some unfavourable condition
in the particular area where they were living. The outer edge spine on the endopodite of the
second pair of feet is placed behind the proximal spine on the inner margin. The distal joint
of the fifth pair of feet is distinctly narrower than in Sars' figure, and agrees better with the
illustration given by Claus. The central spiniform elongation of the anal operculum is moderately
stout and of considerable length. Two secondary spines are present on each side of the central
one. The 'Siboga' specimens have a certain amount of resemblance to Longipcdia minor T. and
A. Scott (1893), especially in the size, in the arrangement of the spines on the margin of the
endopodite of the second pair of feet, and in the elongate distal joint of the fifth pair of feet,
but no very small spines are present on the anal operculum.

Longipcdia coronata has been recorded from the Coast of Norway, Heligoland, from the
Gulf of Naples and Ceylon.

2. Longipedia scotti G. O. Sars. Plate LIX, figs. 1 — 4.

Longipcdia coronata Brady, 1880 (non Claus), vol. II, p. 6, pis. XXXIV & XXXV.

Longipcdia coronata T. & A. Scott, 1893 (non Claus), p. 91, pi. II, figs. 4 — 6.

Longipedia coronata T. Scott, 1893 (a), (non Claus), p. 198, pi. II, figs. 1 — 13.

Longipcdia scotti G. O. Sars, 1903 (a), p. il, pi. V, fig. 1.

Longipcdia scotti Pearson, 1905, p. 5.

Longipcdia scotti T. Scott, 1906 (a), p. 305.

Longipedia scotti Norman & T. Scott, 1906, p. 134.

One female apparently identical with the above species described by Professor G. O. Sars,
was found in the washings from dredged invertebrata collected at Station 273, at a depth of
1 3 metres.

This species is readily separated from the other known mernbers of the genus, by the
outer edge spine on the endopodite of the second pair of feet being placed in front of the
proximal spine on the inner margin. The anal operculum terminates in a very stout and elongate
spiniform projection. The margin of the operculum on each side of the median spine is furnished
with one large and three small teeth. Length of the 'Siboga' specimen 1,5 mm.

Longipcdia scotti has hitherto only been recorded from the British and Norwegian Coasts.

3. Longipedia weberi nov. sp. Plate LIX, figs. 9 — 12.

Female — length .95 mm.

This species resembles Longipedia coronata in general appearance. The lateral spine on
each sicle of the genital segment is comparatively strong. The distal margin of the first and
second abdominal segments is fringed with fine short spines. The anal operculum is provided
with two rather strong teeth on each sicle of the median terminal spine. The median spine is
short and slcncler. It is not very much longer than the lateral teeth (Plate LIX, fig. 12).

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i97

The outer marginal spine on the endopodite of the second pair of feet is placed
distinctly behind the proximal spine on the inner margin. The inner sub-apical spine is longer
than the two apical spines (Plate L1X, fig-. 10).

The distal joint of the fifth pair of feet is considerably expanded at the middle and
bears a close resemblance to the distal joint of the fifth pair of Longipedia scotti. The curved
spine on the basal joint is furnished with a moderately long secondary spine near the base of
the inner margin (Plate LIX, lig. i i).

Male unknown.

This species resembles Longipedia corouata, in the number of spines on the distal end
of the anal operculum, but it can readily be separated from that species by the much shorter
median terminal spine. This spine is very little longer than the lateral spines. In Longipedia
coronata the median terminal spine is much longer and thicker than the lateral spines. The
absence of very small secondary spines on the anal operculum renders the separation of this
species from Longipedia scotti, and Longipedia rosea Sars, a matter of simplicity.

Occurrence. — One specimen was found in the washings from dredged invertebrata
collected at Station 273 from a depth of 13 metres.

Genus Canuella T. & A. Scott, 1S93.

This genus is closely related to Longipedia and Sunaristes. It can be distinguished from
the former genus by the nearly equal length of the exopodite and endopodite of the second
pair of feet. It differs from Sunaristes by the presence of a well defïned suture traversing the
dorso-lateral surface of the genital segment of the female, by the exopodite of the mandible
palp being composed of a single large joint, and by the presence of a strong tooth on the
surface of the first joint of the endopodite of the second pair of feet of both sexes.

One species was represented in the material collected by the 'Siboga' in the Malay
Archipelago.

1. Canuella curticaudata (Thompson & A. Scott). Plate LXIV, figs. 1—6.
Sunaristes curticaudata Thompson & Scott, 1903, p. 256, pi. III, figs. 12—17.
Five females and one male were obtained from the washings from dredged invertebrata
collected at the following stations.

Stat. 164, 32 metres, three females and one male. — Stat. 273, 13 metres, two females.

The illustrations given in the Supplementary Report VII 'On The Copepoda', in Professor

Herdman's 'Report to the Government of Ceylon, on the Pearl Oyster Fisheries of the Gulf

of Manaar', were taken from a single immature specimen and are obviously rather unsatisfactory.

The 'Siboga' females were quite adult, and the figures now given shew the perfect condition.

The most conspicuous character that separates this species from any of the other known

members of the genus, is the very short furcal joints. The inner marginal spine on each joint

in Canuella curticaudata is placed very near the apex. Length -- female 1,27 mm., male .94 mm.

The three species of Sunaristes that were described as new in the Report on the Ceylon

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198

Copepoda, have proved on re-investigation to belong to the genus Canuella. They are quite distinct
from the type of the genus, and also from the species described by Professor G. O. Sars in
'Crustacea of Norvvay' Vol. V.

Genus Sunaristes Hesse, 1867.

The female of this genus is readil)' separated from Canuella by the entire absence of
a subdivision of the genital segment, and by the normal structure of the endopodite of the
second pair of feet. There is no spine on the first joint of the endopodite of this pair of feet.

The male antennules are developed into powerful prehensile appendages and are
furnished with a very strong terminal claw. The outer distal end of the first and second joints
of the endopodite of the second pair of feet is produced into a strong spine. The exopodite
of the mandible palp of both sexes is three jointed.

One species was represented in the material collected by the 'Siboga'.

[ . Sunaristes paguri Hesse.

Sunaristes paguri Hesse, 1867, p. 205, pi. IV, figs. 11 — 25.
Longipedina paguri W. Muller, 1884, p. 19, pi. XIII.
Sunaristes paguri A. Scott, 1896, p. 11.
Sunaristes paguri -I. C. Thompson, 1896, p. 24.
Sunaristes paguri T. & A. Scott, 1897, p. 490, pis. XI & XII.
Sunaristes paguri Thompson & Scott, 1903, p. 255.
Sunaristes paguri Sars, I903(«), p. 15, pis. VI & VII.
Sunaristes paguri Norman & T. Scott, 1906, p. 135.

A single male identical with the above species was found in the washings from dredged
invertebrata collected at Station 164, at a depth of 32 metres.

The terminal claw of the antennules and the strong spiniform projection of the first and
second joints of the endopodite of the second pair of feet are of a very dark colour, and were
easily visible in the 'Siboga' specimen.

Hesse's type specimen was obtained from a molluscan shell inhabited by a hermit crab.
I occasionally find both males and females by simply washing the molluscan shells containing
hermit crabs [Pagurus bernhardus) in dilute methylated spirit, and examining the residue.
Hermit crabs caught in the fish trawl in the Mersey estuary invariably yield one or two
specimens of Sunaristes paguri when submitted to the treatment mentioned. I have not found
this Copepod anywhere else in the Irish Sea.

Sunaristes paguri has been recorded from various parts of the British coast, from the
coasts of France and Norway, and from Ceylon.

25. Family Ectinosomidae.

Genus Microsetella Brady and Robertson, 1873.

The members of this genus are readily recognised by their small size, by the cylindrical

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199

body and rounded forehead when seen from the side, and by the rather swollen middle joint
of the second pair of maxillipedes.

Two species were represented in the plankton collected by the 'Siboga' in the Malay
Archipelago.

i. Microsetella norvegica (Boeck).

Setella norvegica Hoeck, 1864, p. 281.

Microsetella atlanticum Brady & Robertson, 1873, p. 130, pi. IX, figs. 11 — 16.

Ectinosoma atlanticum Brady, 1880, vol. II, p. 13, pi. XXXVIII.

Ectinosoma atlanticum Brady, 1883, p. 100, pi. IV, figs. 10 — 14.

Microsetella atlantica Giesbrecht, 1893, p. 550, pi. 44.

Microsetella atlantica T. Scott, 1893, p. 91.

Microsetella atlantica Giesbrecht, 1S95, p. 261.

Ectinosoma atlanticum I. C. Thompson, 1896, p. 24.

Ectinosoma atlanticum T. & A. Scott, 1896, p. 437, pis. 36, 27 & 3^-

Microsetella atlantica I. C. Thompson, 1900, p. 285.

Microsetella atlantica Cleve, 1901, p. 7.

Ectinosoma atlanticum T. Scott, 190 1 (a), p. 352.

Microsetella atlantica I. C. Thompson, 1903, p. 31.

Microsetella atlantica Cleve, 1903, p. 364.

Ectinosoma atlanticum Thompson & Scott, 1903, p. 257.

Microsetella norvegica Sars, 1904, p. 44, pi. XXIV.

Ectinosoma atlantica Wolfenden, 1905 (a), p. 1030.

Ectinosoma atlanticum Pearson, 1905, p. 6.

Microsetella atlantica Farran, 1905, p. 46.

Microsetella norvegica T. Scott, 1906(0), p. 309.

Microsetella norvegica Norman & T. Scott, 1906, p. 137.

Microsetella norvegica Williams, 1906, p. 652.

Microsetella norvegica van Breemen, 1908, p. 173, fig. 188.

Microsetella norvegica Sars, 1909, p. 18.

This species although very limited in its distribution in the area investigated, was not

uncommon in one of the collections. It was found at the following stations.

Stat. 99. — Stat. 217, 277 specimens. — Stat. 271. — Stat. 304.

The comparatively short furcal setae and the distinctly narrow form of the fifth pair of
feet readily separate this species from Microsetella rosea.

Microsetella norvegica appears to be widely distributed in all the great oceans.

2. Microsetella rosea (Dana).

Harpacticus roseus Dana, 1847, p. 153.

Canthocamptus roseus Dana, 1852, p. 1189, pi. 183, figs. I — 10.
Microsetella rosea Giesbrecht, 1893, p. 550, pi. 44.
Microsetella rosea I. C. Thompson, 1900, p. 284.
Microsetella rosea I. C. Thompson, 1903, p. 32.
Ectinosoma roseum Thompson & Scott, 1903, p. 257.
Microsetella rosea Cleve, 1903, p. 364.
Microsetella rosea Esterly, 1905, p. 211, fig. 52.
Microsetella rosea Farran, 1908, p. 91.
Microsetella rosea van Breemen, 1908, p. 174, fig. 189.

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200

Seventeen specimens of this species were obtained from the plankton collected at the
following stations.

Stat. 16, 3 specimens. — Stat. 35, 4 specimens. ■ — Stat. 217, 3 specimens. — Stat. 271,
4 specimens. — Stat. 304, 3 specimens.

Microsetella rosca is readily distinguished from Microsetella atlantica by its larger size,
by the very long furcal setae, and by the form of the fifth pair of feet.

This Microsetella has a moderately wide distribution in all the great oceans.

26. Family Harpacticidae.
Genus Harpacticus M. Edwards, 1S38.

The feature that separates this genus from the other members of the family is the
peculiar transformation of the exopodite of the third pair of feet of the male. The exopodite
of this pair forms a powerful prehensile appendage.

Three species were obtained from the plankton collected by the 'Siboga' in the Malay
Archipelago. Two of the species do not appear to have previously been described.

1. Harpacticus cristatus nov. sp. Plate LXI, figs. 1 — 8.

Female — length .49 mm.

Seen from above, the bod)- appears rather slender and depressed. It resembles a Laophoutc
in general appearance. The cephalic segment is large and is provided vvith a distinct crest
traversing the whole of the middle line. The crest is quite obvious both in the lateral and
dorsal positions (Plate LXI, figs. i & 2). The anterior portion of the ventral margin is considerably
expanded as shewn in the illustration. The rostrum is moderately wide. The apex is bluntly
rounded. The ventral margins of the thoracic segments are distinctly pointed at the distal ends.

The abdomen is composed of four segments. The combined length of the abdominal
segments and furcal joints is contained fully twice in the total length of the ccphalothorax,
from the apex of the rostrum to the end of the last thoracic segment. The genital segment
is moderately large. It is equal to the combined length of the next two segments- The ventral
surface is traversed by a distinct suture. The second and third segments are of nearly equal
length, but the lateral margins of the third segment appear rather hollowed out. The furcal
joints are longer than broad (Plate LXI, fig. 8).

The antennules are composed of eight joints. The first four joints are long and narrow.
The last four joints are very short The combined length of the last four joints is only about
one-seventh of the combined length of the first four joints.

The antennae, mandibles, maxillae, and first pair of maxillipedes resemble those of
Harpacticus chelifer (Muller). The second joint of the second pair of maxillipedes is long and very
slender. The terminal claw is also long and slender. It is much longer than the second joint.

The first pair of feet is rather slender. The exopodite is much longer than the endopodite.
1 hc first joint of the exopodite is short. lts length is contained two and onedialf times in the

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total length of the second joint. The third joint is very small. The endopodite is equal to
twice the length of the first joint of the exopodite. The second joint is small and shews no
tracé of division to indicate a third joint. The terminal claws of the exopodite and endopodite
are of the normal Harpacticus type (Plate LXI, fig. 6).

The second, third and fourth pairs of feet are nearly similar to those of Harpacticus chelifer.

The fifth pair of feet is rather slender. The inner portion of the basal joint is very
little expanded. It is furnished with three marginal and two apical setae. The distal joint is
comparatively narrow and elongate. The distal portion of the outer margin is furnished with
two rather strong spines. The joint is also provided with one outer marginal seta, one apical
seta, and one inner marginal seta (Plate LXI, fig. 7).

Male unknown.

This species is quite distinct from any of the known members of the genus. It can
readily be recognised by the well defined dorsal crest on the cephalic segment. The second pair
of maxillipedes is not of the normal Harpacticus type, but in the absence of a male it is
perhaps well for the present to regard the species as a member of the genus Harpacticus.

Occurrence. — One specimen was obtained from the plankton collected at Station
35 (Paternoster Islands), on March 2 8th.

2. Harpacticus clausi nov. sp. Plate LXI, figs. 9 — 14A.

Female — length .67 mm.

Seen from above, the body appears rather slender and slightly depressed, with a moderately
prominent rostrum. Viewed from the side, the distal ends of the ventral margin of the cephalic
and thoracic segments appear narrowly rounded.

The abdomen is composed of four segments. The combined length of the abdominal
seo-ments and furcal joints is contained fully twice in the total length of the ccphalothorax,
from the apex of the rostrum to the end of the last thoracic segment. The genital segment
is as long as the combined length of the next three segments. lts ventral surface is traversed
by a distinct suture. The second segment is as long as the combined length of the third and
fourth segments. The fourth segment is short. The furcal joints are only half as long as broad.

The antennules are composed of nine joints and are of moderate length. The combined
lenoth of the last five joints is equal to one-third of the combined length of the first four
joints. The second last joint is very small.

The antennae, mandibles, maxillillae and maxillipedes are of the normal Harpacticus
type. The second pair of maxillipedes is very similar to that of Harpacticus unircmis Kroyer.

The four pairs of swimming feet are similar to those of Harpacticus gracilis. The second
joint of the exopodite of the first pair of feet is rather shorter than the first joint. The endopodite
is very little longer than the first joint of the exopodite (Plate LXI, fig. 14).

The fifth pair of feet is moderately large. The inner portion of the proximal joint is
considerably expanded. The distal end of the expansion is broadly rounded. It is furnished with
two subapical spines and one outer marginal spine. There is a considerable space between the
inner marginal spine and the inner subapical spine. The surface of the expansion is furnished

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SinOGA-EXPEDITIE XXIXtf. 20

202

with two small setae near the distal end of the inner margin. The distal joint is elongate and
rather narrow. The distal end of the joint is furnished with five spines of various degrees of
stoutness (Plate LXI, fig. 13).

Note. — In the explanation of this plate, fig. 13, is given as fivst foot and fig. 14, the fifth foot. Fig. 13, should be read fifth
foot and fig. 14, first foot.

Male unknown.

This species appears to be closely related to Harpactiats gracilis Claus, but it can
readily be separated by the quite distinct shape and armature of the inner expansion of the
proximal joint of the fifth pair of feet.

Occurrence. — One specimen was obtained from the plankton collected at the surface
at Station 35 (Paternoster Islands), on March 2 8th.

3. Harpacticus glaber Brady. Plate LXI, Figs. 15 — 21.
Harpacticus glaber Brady, 1899, p. 44, pi. XII, figs. 6 — 11.

One female apparently identical with the above species was obtained from the plankton
collected at the surface at Station 35 (Paternoster Islands), on March 2Sth.

The apex of the expanded portion of the proximal joint of the fifth pair of feet is
armed with three moderately strong setae. The distal joint is oval in outline and is comparatively
short. The antennules are not so elongate as in Harpacticus clausi. Brady's single specimen
is described as having eight-jointed antennules, but the antennules of the present specimen
are nine-jointed. The eighth joint is short and agrees fairly well with the length of the last
joint of Harpacticus glaber. It is quite possible that the antennules of Brady's specimen may
have been imperfect. The shape and armature of the inner expansion of the proximal joint of
the fifth pair of feet is quite distinct from any of the other known members of the genus
Harpactiats, or its closely related ally Tigriopus. Hapacticus glaber is the only known species
with three setae arranged closely together on the apex of the inner expansion of the basal
joint of the fifth pair of feet. The distal ends of the ventral margin of the thoracic segments
of this species are broadly rounded.

Length of 'Siboga' female — .56 mm.

Brady's single specimen was found in surface plankton collected in Otago Harbour,
New Zealand.

27. Family Peltidiidae.
Genus Peltidium Philippi, 1839.

The conspicuous anastomosing chitinous bands that traverse every segment of the animal,
assist very considerably in the separation of the members of this genus from any of the other
genera belonging to the family. The endopodite of the first pair of feet is comparatively broad
and two-jointed. The fifth pair of feet is two-jointed and is entirely obscured, when viewed from
above, by the very wide genital segment.

The genus Oniscidiuin Claus (1860) and the genus Reticulina Cleve (1901) are both

203

identical with Philippt's genus Peltidiunï. The description of the exopodite and endopodite of
the first pair of feet in the report on the Ceylon Copepoda is erroneous. The endopodite
should be exopodite and vice versa.

Four species, all apparently undescribed, were obtained from the material collected by
the 'Siboga' in the Malay Archipelago.

i. Peltidium falcatum nov. sp. Plate LXIV, figs. 7 — 11.

Female — length i,i mm.

Seen from above, the body appears very broad and considerably depressed. It is oblong
ovate in outline. The greatest width is at the posterior end of the cephalic segment and is
contained one and two-third times in the total length of the animal. The distal ends of the
cephalic and thoracic segments are pointed. The segments are produced dorsally in the median
line into triangular projections. The rostrum is very large and prominent. The frontal margin
is broadlv rounded. The genital segment is very large and much produced posteriorly. The
distal ends of the segment project slightly bevond the end of the furcal joints. The furcal
joints are two and one-third times longer than broad. The outer margin of each joint is furnished
near the middle with a short seta (Plate LXIV, fig. 7).

The antennules are composed of seven joints. The fifth and sixth joints are very short.

The antennae, mandibles, maxillae and first pair of maxillipedes are nearly similar to
those of Peltidium purpureum Philippi. The terminal claw of the second pair of maxillipedes
is nearly as long as the second joint. It is moderately stout at the base and contracts gradually
to point at the distal end (Plate LXIV, fig. 9).

The exopodite of the first pair of feet is very slender. The second joint is distinctly
longer than the first joint. The third joint is very short. It is armed with one stout and one
slender curved claw. The endopodite is shorter than the exopodite. The joints are of equal
length, but the first joint is much wider than the second joint. The apex of the second joint
is furnished with two stout blunt pointed spines, and two setae (Plate LXIV, fig. 10).

The second, third and fourth pairs of feet are similar to those of Peltidium purpureum .

The fifth pair of feet is very small. The second joint is furnished with four outer
marginal setae and one apical seta. The fourth outer marginal seta is short (Plate LXIV, fig. 11).

Male unknown.

This species can readily be recognised by the very wide body, by the slender exopodite
of the first pair of feet, and by the short second joint of the fifth pair of feet.

Occurrence. — One specimen was found in the washings from dredged invertebrata
collected at Station 226, from a depth of 1595 metres.

2. Peltidium intermedium nov. sp. Plate LXV, figs. 6 — 10.

Female — length .Sj mm.

Seen from above, the body appears moderately broad and rather depressed. It is somewhat
quadrangular in outline. The greatest width is near the posterior end of the cephalic segment
and is contained one and three-fourth times in the total length of the animal. The distal ends

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204

of the cephalic and thoracic segments are pointed. The segments are produced dorsally in the
middle line into triangular projections. The rostrum is large and prominent. The frontal margin is
truncate. The genital segment is large and much produced posteriorly. The distal ends of the
genital segment extend to about the middle of the furcal joints. The furcal joints are three times
longer than broad. The outer margin of the joints is not furnished with a seta (Plate LXV, fig. 6).

The antennules are composed of seven joints. The fifth ancl sixth joints are very small.

The antennae, mandibles, maxillae and maxillipedes are similar to those of the previous
species.

The exopodite of the first pair of feet is slender. The first joint is distinctly longer than
the second joint. The third joint is very short. It is armed with one stout ancl one slender
curved claw. The endopodite is much shorter than the exopodite. The joints are of nearly
equal length, but the first joint is wider than the second joint. The apex of the second joint
is furnished with two pointed spines and two seta (Plate LXV, fig. 9).

The second, third and fourth pairs of feet are similar to those of Pcltidium purpureum.

The fifth pair of feet is moderately stout. The second joint is furnished with two outer
edge setae, two apical setae, and one inner edge seta (Plate LXV, fig. 10).

Male unknown.

This species can readily be separated from the other members of the genus by the
comparatively slender furcal joints which have no median outer marginal seta, and by the
arrangement of the setae on the fifth pair of feet.

Occurrence. - - One specimen was found in the surface plankton collected at Station
2 1 3, Saleyer Island.

3. Pcltidium exiguum nov. sp. Plate LXV, figs. 11 — 15.

Female — length .98 mm.

Seen from above, the body appears moderately broad and rather depressed. It is oblong
ovate in outline. The greatest width is at the distal end of the cephalic segment and is equal
to rather less than half the length of the entire animal. The distal ends of the cephalic and
thoracic segments are pointed. The segments are produced dorsally in the median line into
triangular projections. The rostrum is rather wide but it is not very prominent. The frontal
margin is broadly rounded. The genital segment is large and broad. The pointed distal ends
of the segment scarcely reach to the end of the anal segment. The furcal joints are moderately
broad and fully twice as long as wide. The middle of the outer margin of the joints is furnished
with a short seta (Plate LXV, fig. 11).

The antennules are composed of six joints. The fifth joint is very small.

The antennae, mandibles, maxillae and maxillipedes are similar to those of Pcltidium
intermedium. The terminal claw on the second joint of the second pair of maxillipedes is
comparatively stout and is blunt pointed.

The exopodite of the first pair of feet is moderately stout. The first and second joints
are of nearly equal length. The third joint is very small and is furnished with three curved
claws. The outer one is smaller than the others. The middle claw is comparatively stout. The

204

endopodite is rather shorter than the exopodite. The joints are of nearly equal length, but
the first joint is slightly wider than the second joint. The apex of the second joint is furnished
with two finely pointed spines and two setae (Plate LXV, fig. 14).

The second, third and fonrth pairs of feet are nearly similar to those oï Peltidium intermedium.

The fifth pair of feet is short and moderately robust. The second joint is furnished
with two marginal and three apical setae. The distal marginal seta is moderately stout and
the distal portion is clothed with short spines (Plate LXY, tig. 15).

Male unknown.

This species can readily be recognised by its oblong ovate body, by the six-jointed
antennules, by the arrangement of the setae on the fifth pair of feet, and by one of these setae
being stouter than the others.

Occurrence. — One specimen was found in the washings from dredged invertebrata
collected at Station 273, at a depth of 13 metres.

4. Pcltidium minulum nov. sp. Plate LXY, figs. 16 — 20.

Female — length .8 mm.

Seen from above, the body appears comparatively narrow. It is elongate ovate in outline.
The greatest width is at the distal end of the cephalic segment and is contained fully one and
two-third times in the total length of the animal. The distal ends of the cephalic and thoracic
segments are pointed. The segments are produced dorsally in the middle line into triangular
projections. The rostrum is moderately large and prominent. The frontal margin is broadly
rounded. The genital segment is large and broad. The pointed distal ends of the segment
reach to near the middle of the furcal joints. The furcal joints are short and moderately stout.
Each joint is twice as long as broad and the middle of the outer margin is furnished with
a short seta (Plate LXY, fig. 16).

The antennules are composed of seven joints. The fifth and sixth joints are very short.

The antennae, mandibles, maxillae and maxillipedes are nearly similar to those of
Peltidium exiguum. The second joint of the second pair of maxillipedes is broad. The terminal
claw is comparatively short and is bluntly pointed.

The exopodite of the first pair of feet is moderately stout. The first joint is much shorter
than the second joint. The third joint is very short and is furnished with two rather stout
curved claws. The endopodite is considerably shorter than the exopodite. The joints are of
nearly equal length but the second joint is much narrower than the first joint. The apex of
the second joint is furnished with four setae (Plate LXV, fig. 19).

The second, third and fourth pairs of feet are similar to those of Peltidium exiguum.

The fifth pair of feet is comparatively long and slender. The second joint is furnished
with two outer marginal. and three apical setae (Plate LXY, fig. 20).

Male unknown.

This species can be distinguished from the other members of the genus by the comparatively
short and stout furcal joints, by the rather slender fifth pair of feet, and by the arrangement
of the setae on the second joint of this pair of feet.

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20Ö

Occurrence. - - One specimen was found in the washings from dredged invertebrata
collected at Station 273, from a depth of 13 metres.

Genus Eupeltidium nov.

The body is rather short and somewhat depressed. The exoskeleton is dense and has
no tracé of anastomosing chitinous bands. The lateral margins of the thoracic segments are
considerably expanded. The abdomen is short and broad. The genital segment is much larger
and wider than the other abdominal segments. The antennules are composed of six joints. The
endopodite of the antennae is indistinctly three-jointed. The exopodite is short and two-jointed.
The mandibles are moderately strong and are furnished with a small one-branched palp. The
first pair of maxillipedes is similar to that of the genus Alteutha Baird (1845). The terminal
joint is produced into a short stout claw. The second pair of maxillipedes is similar to that of
the genus Alteutha and Peltidium. The five pairs of feet are similar to those of Pcltidium.

This genus appears to be somewhat intermediate between Alteutha and Peltidium. It
resembles Alteutha in the general appearance of the animal and in the structure of the first
pair of maxillipedes. The five pairs of feet are nearly similar to those of Peltidium, The biting
edgfe of the mandible is distinct from that found in either of the two genera.

One species belonging to this genus was found in the material collected by the 'Siboga'
in the Malay Archipelago.

1. Eupeltidium glabrum nov. sp. Plate LXIV, figs. 12 — 19.

Female — length 1,2 mm.

Seen from above, the body appears moderately robust. It is elongate ovate in outline.
The greatest width is near the posterior end of the cephalic segment and is equal to half the
entire length of the animal. The distal ends of the cephalic and thoracic segments are narrowly
rounded. The rostrum is moderately large but it is not very prominent. The frontal margin is
broadly rounded. The genital segment is large and broad. It is marked by a distinct suture
traversing the dorsal surface. The distal ends of the segment are very narrowly rounded and
are only very slightly produced. The furcal joints are somewhat cylinclrical in shape. Each joint
is two and a half times longer than broad and the middle of the outer margin is furnished
with a short seta. The principal terminal seta is long and moderately stout (Plate LXIV, fig. 12).

The antennules are composed of six joints. The fifth joint is very short. The fourth and
fifth joints each carry one long sensory organ.

The antennae are similar to those of Alteutha depressa Baird, but the apical spines on
the last joint of the endopodite are rather stronger (Plate LXIV, fig. 14).

The cutting edge of the mandible is provided with seven short and moderately stout
teeth. The palp is comparatively small, one-branched, and two-jointed (Plate LXIV, fig. 15).

The first and second pairs of maxillipedes are nearly similar to those of Alteutha depressa.

The exopodite of the first pair of feet is short, comparatively stout, and three-jointed.
The second joint is longer than the other two joints. The third joint is small. It is furnished
with one stout and one slender curved claw. The endopodite is two-jointed and is nearly as

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2o;

long as the exopodite. The first joint is broad and is distinctly longer than the second joint.
The second joint is much contracted at the apex. It is furnished with one apical and two
subapical setae (Plate LXIY, hg. 18).

The second. third and fourth pairs of feet are similar to those of Peltidium purpurêum.

The hfth pair of feet is small and slender. The inner margin of the second joint is
produced into a small tooth at the distal end. The outer margin is furnished with three moderately
strong setae. The apex bears a single stout seta (Plate LXIV, hg. 19).

Male unknown.

Occurrence. — One specimen was found in the washings from dredged invertebrata
collected at Station 226, between the Lucipara and Schildpad Islands, from a depth of 1595 metres.

Genus Eupelte Claus, 1860.

This genus was established by Claus in 1860 for a Harpacticoid with a broad depressed
body and closely related to Alteutha, but having the endopodite of the first pair of feet composed
of two joints. The mandible palp is one-branched and two or three-jointed. The fifth pair of
feet is biarticulate. The species described by Claus have not, so far, again been met with, and
owing to the rather imperfect illustrations given by that author much doubt has existed reo-ardino-
the true character of the first pair of feet.

One species agreeing with Eupelte in possessing a slender two-jointed endopodite to
the first pair of feet, but differing in the antennules being seven-jointed, in the mandible palp
being distinctly two-branched, and in the fifth pair of feet being only one-jointed, was obtained
from the material collected by the 'Siboga' in the Malay Archipelago.

The difference of the jointing of the antennules is not of very great importance in a
generic distinction. The presence of a small secondary branch to the mandible palp may have
been overlooked by Claus. The two-jointed appearance of the fifth pair of feet may have been
due to some defect in the preparation. The possession of a two-jointed endopodite by the first
pair of feet is a very important character and is the chief reason for placing the 'Siboga' species
in the genus Eupelte.

1. Eupelte oblivia nov. sp. Plate LXVI, figs. 1 — 12.

Female — length .74 mm.

Seen from above, the body appears short, wide and depressed. It is broadly oval in
outline. The greatest width lies near the distal end of the cephalic segment and is equal to
three-fourths of the length of the entire animal. The cephalic segment is large and represents
one-half of the length of the Copepod. The distal ends are slightly produced and pointed. The
distal ends of the first three thoracic segments are also pointed. The rostrum is large and
moderately prominent. The frontal margin is somewhat truncate.

The abdomen is composed of four segments. The genital segment is very large and is
broadly triangular in outline. The distal ends of the segment are produced into small points
that extend to the end of the anal segment. The second, third and fourth segments are short
and narrow. The furcal joints are very short. The joints are about as broad as long. The outer

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angle of the apex of the joints is produced internally into a small tooth-like process. It is also
furnished with a short seta. The inner portion of the apex is slightly produced. It bears one
moderately long and four short setae. The animal is very transparent (Plate LXVI, fig. i).

The antennules are composed of seven joints. The last three joints are much shorter
than the others. The fourth joint is furnished with a moderately long sensory filament.

The antennae are comparatively small. The apex of the last joint of the endopodite is
furnished with one very strong spine provided with a rhinute secondary spine near the base,
and three very slender setae. The endopodite is small and one-jointed. It is furnished with
four setae (Plate LXVI, fig. 3).

The mandible is slender and its biting edge is very feeble. The palp is two-branched
and each branch is one-jointed (Plate LXVI, fig. 4).

The maxillae and first pair of maxillipedes are similar to those of Altcutlia depressa.

The second pair of maxillipedes is comparatively powerful. The second joint is long
and rather narrow. The terminal claw is short and stout (Plate LXVI, fig. 7).

The exopodite of the first pair of feet is composed of three joints. The first and second
joints are of nearly equal length. The third joint is very small. It is furnished with one short
stout curved claw and two very small setae. The endopodite is two-jointed. The second joint
is considerably shorter than the first joint (Plate LXVI, fig. 8).

The exopodite and endopodite of the second, third and fourth pairs of feet are three-
jointed. The outer marginal spine on the first joint of the exopodite of the fourth pair of feet
is distinctly longer, and stouter, than the outer marginal spine on the first joint of the exo-
podite of the second and third pairs of feet (Plate LXVI, fig. 9).

The fifth pair of feet is composed of a single moderately large lamelliform joint. It
is rather wide at the base. The apex is very narrow. The joint is furnished with four outer
marginal and two apical setae. The proximal end of the inner margin bears a small tubercle
carrying two slender setae (Plate LXVI, fig. 10).

Male — length .64 mm.

The male resembles the female is general appearance, but the antennules are rather
stouter and prehensile. The abdomen is composed of live segments. The genital segment is
produced posteriorly and terminates in a short moveable spine. The outer angle of the furcal
joints has a short spine instead of the seta in the female.

The antennae, mandibles, maxillae and maxillipedes are similar to those of the female.

The five pairs of feet are somewhat similar to those of the female. The fifth pair of
feet is proportionally shorter than that of the female (Plate LXVI, fig. 12).

The female differs from the species described by Claus in the external appearance, in
the shape of the rostrum, and in the structure and armature of the fifth pair of feet.

Occurrence. — Five females and four males were found in the washingrs from dredeed
material collected at Station 164, at a depth of 32 metres.

Genus Alteuthella nov.

The body is comparatively short and depressed. The exoskeleton is thin and moderately

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transparent. The antennules are short and seven-jointed. The antennae, mandibles, maxillae and
maxillipedes are similar to those of Altcutha interrupta (Goodsir). The exopodite of the antennae
is two-jointed. The mandible palp is two-branched. The exopodite is very much shorter than
the endopodite. The terminal claw of the second pair of maxillipedes is shorter than the second
joint. The first four pairs of feet are very slender. The exopodite and endopodite are three-
jointed. The exopodite of the first pair of feet is prehensile. The third joint is very small
and is furnished with a single curved claw. The fifth pair of feet is one-jointed and rather
foliaceous. The fifth pair shews no tracé of segmentation to indicate a proximal and distal joint.

This genus is closely related to Alteutha Baird in general appearance, but its members
can readily be separated by the seven-jointed antennules, by the single curved claw on the
apex of the third joint of the exopodite of the first pair of feet, and by the absence of a
division between the proximal and distal portions of the fifth pair of feet.

Three species belonging to this genus were obtained from the material collected by the
'Siboga' in the Malay Archipelago.

i. Alteuthella pellitcida nov. sp. Plate LXYI, figs. 13 — 20.

Female — length .63 mm.

Seen from above, the body appears short and depressed. It is broadly oval in outline
and very transparent. The greatest width is at the distal end of the cephalic segment and is
equal to two-thirds of the entire length of the animal. The cephalic segment is large and
represents one-half of the length of the Copepod. The distal ends are slightly produced and
pointed. The distal ends of the first three thoracic segments are also pointed. The rostrum is
large and prominent. The frontal margin is broadly rounded (Plate LXVI, fig. 13).

The abdomen is composed of four segments. The genital segment is very large and
is somewhat quadrangular in outline. It bas no tracé of a suture on the dorsal surface. The
lateral margins are produced posteriorly into well defined points. The second, third and fourth
segments are short and narrow. The furcal joints are very short and broad. The apex of each
segment is deeply notched, but there is no tooth on the outer angle (Plate LXVI, fig. 13 A).

The antennules are short and seven-jointed. The last three joints are small.

The antennae, mandibles, maxillae and first pair of maxillipedes are similar to those
of Alteutha depressa Baird.

The second pair of maxillipedes is rather slender. The second joint is moderately long
and narrow. The terminal claw is short and curved. It is much shorter than the second joint
(Plate LXVI, fig. 15).

The first pair of feet is moderately slender. The third joint of the exopodite is small
and is furnished with a short curved claw. The endopodite is three-jointed and is considerably
shorter than the exopodite. The first and second joints have each one inner marginal seta.
The apex of the third joint is furnished with three setae (Plate LXVI, fig. 16).

The exopodite and endopodite of the second, third and fourth pairs of feet are three-
jointed and very slender.

The fifth pair of feet is moderately wide at the base and contracts uniformly to a

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SIBOGA-EXPEUITIE XXIXa. 27

2 IO

rather narrow apex. The outer margin is furnished with three slender setae and one spine.
The apex bears one sharp pointed spine and one small seta (Plate LXVI, fig. iS).

Male — length .61 mm.

The male resembles the female in general appearance, but the antennules are stouter
and prehensile. The abdomen is composed of five segments. The distal ends of the genital
segment are furnished with a moveable terminal spine. The principal furcal seta has a mode-
rately stout basal portion and terminates in a whip-like hair. The fifth pair of feet is less
contracted than that of the female and the terminal spines less pointed (Plate LXVI, fig. 20).

The comparatively broad and transparent body, and the shape of the fifth pair of feet,
readily separate this species from the other two members of the genus.

Occurrence. — Three females and one male were found in the washings from
dredged invertebrata collected at Station 164, from a depth of 32 metres.

This species has a superficial resemblance to Eupcltc oölivia, but the endopodite of the
first pair of feet is quite different.

2. Altcuthclla spinicattda nov. sp. Plate LXVI, figs. 21 — 29.

Female — length .75 mm.

Seen from above, the body appears considerably depressed. It is oblong ovate in outline.
The greatest width is at the distal end of the cephalic segment and is equal to slightly less
than half the length of the entire animal. The cephalic segment is moderately large and is
equal to three-fourths of the rest of the body. The distal ends are slightly produced and
pointed. The distal ends of the first three thoracic segments are bluntly rounded. The rostrum
is prominent. The frontal margin is narrowly rounded (Plate LXVI, fig. 21).

The abdomen is composed of four segments. The genital segment is large and is divided
into two portions by a well defined suture. The anterior portion is very wide and the distal
ends are produced posteriorly into blunt points. The posterior portion is much contracted and
its distal ends are also pointed. The second, third and fourth segments are very short and
narrow. The furcal joints are very short and broad. The outer portion of the apex is furnished
with a short stout spine. The base of the principal seta on the inner portion is considerably
thickened. The distal end is whip-like (Plate LXVI, fig. 26).

The antennules are seven-jointed and of moderate length. The last three joints are
comparatively short.

The antennae, mandibles, maxillae and maxillipedes are similar to those of AltcutJiella,
pellucida.

The first four pairs of feet are also similar to those of that species.

The fifth pair of feet is moderately broad at the base, but considerably narrowed
towards the apex. The distal end of the outer margin is furnished with one short, stout, blunt
pointed spine. The apex bears two short blunt pointed spines (Plate LXVI, fig. 25).

Male — length .61 mm.

The male resembles the female in general appearance, but the antennules are moderately
stout and prehensile. The abdomen is composed of five segments. The furcal joints are short

21 I

and broad. The spine on the outer angle of the apex of the joints is stouter than in the
female, and the base of the principal seta on the inner portion is not thickened very greatly
(Plate LXVI, fig. 29).

The fifth pair of feet is rather smaller than that of the female, but the shape is almost
the same. The inner apical spine is very short (Plate LXVI, tig. 28).

The shape of the fifth pair of feet, and the presence of a toothdike spine on the outer
angle of the apex of the furcal joints readily distinguish this species from any of the other
members of the genus.

Occurrence. — One female and one male were found in the washings from dredged
invertebrata collected at Station 226, from a depth of 1595 metres.

3. Alteuthella pygmaea nov. sp. Plate LX VII, figs. 1 — 5.

Female — length .56 mm.

Seen from above, the body appears moderately wide and is considerably depressed. It
is oblong ovate in outline. The greatest width is at the distal end of the cephalic segment
and is equal to rather more than half the length of the entire animal. The distal ends are
bluntly rounded. The distal ends of the first three thoracic segments are produced into distinct
points. The rostrum is very prominent. The frontal margin is rather broad and truncate (Plate
LXVII, fig. 1).

The abdomen is composed of four segments. The genital segment is large and is
sub-quadrangular in shape. It it marked by a distinct suture traversing the middle of the dorsal
surface. The distal end is slightly contracted and the lateral margins are produced posteriorly
into distinct points. The second, third and fourth segments are very. short. The furcal joints are
short and wide. The apex of the joints is produced internally into a distinct toothdike process
(Plate LXVII, fig. 1 A).

The antennules are moderately stout and seven-jointed. The last joints are narrower
and shorter than the others.

The antennae, mandibles, maxillae and maxillipedes are similar to those of Altetitliella
pellucida. The second pair of maxillipedes is rather slender. The second joint is moderately
lons: and narrow. The terminal claw is short and curved. It is much shorter than the second
joint (Plate LXVII, fig. 3).

The first four pairs of feet are similar to those of Alteuthella pellucida. The third
joint of the exopodite of the first pair is very short and is furnished with a single curved
claw. The endopodite of this pair is much shorter than the exopodite and the inner margin
of the first joint has no seta (Plate LXVII, fig. 4).

The fifth pair of feet is moderately wide at the base and contracts to a narrow apex.
There is no tracé of segmentation to indicate a proximal and distal joint. The outer margin
is furnished with four short setae. The narrow apex bears two setae and one small toothdike
spine. The proximal portion of the inner margin is distinctly indented and is provided with
two setae (Plate LXVII, fig. 5).

2 I 2

Male unknown.

This small species can readily be identified by the very narrow distal portion of the
fifth pair of feet, and by the slender condition of the whole of the outer marginal setae.

Occurrence. — One specimen was found in the washings from dredged invertebrata
collected at Station 226, at a depth of 1595 metres.

Genus Parapeltidium nov.

The body is comparatively short and greatly depressed. The exoskeleton is highly
chitinised. It is also strengthened with broad anastomosing bands of chitin. The cephalic seg-
ment is very large and expanded. The rostrum is large and moderately prominent. The thoracic
segments are slightly produced. The genital segment is large and strongly chitinised. The other
abdominal segments are short. The antennules are short and five-jointed. The antennae, man-
dibles, maxillae and second pair of maxillipedes are similar to those of Pcltidium purpureum.
The first pair of maxillipedes is similar to that of Altcutha dcpressa. The terminal joint is of
moderate length and ends in a short claw. The exopodite of the first pair of feet is slender
and is three-jointed. The endopodite is two-jointed, but the basal joint is not expanded as in
Pcltidium. The second, third and fourth pairs of feet are similar to those of the genus Pclti-
dium. The fifth pair of feet consists of a single, highly chitinised, spiniform joint.

This genus is closely related to Pcltidium in the possession of the anastomosing chitinous
bands, but the whole exoskeleton is much stronger and more flattened. The slender endopodite
of the first pair of feet and the one-jointed spiniform fifth pair, readily separate this genus
from Pcltidium.

One species was represented in the plankton collected by the 'Siboga' in the Malay
Archipelago.

The absence of a division between the proximal and distal parts of the fifth pair of
feet of the three genera, Eupelte, Altcuthella and Parapeltidium, appears to be of some
importance. This character readily separates these genera from the members of the family
Peltidiidae, as defined by Professor G. O. Sars in 'Crustacea of Norway' Vol. V, page 61. It
may be found necessary, therefore, at some future period to establish a separate family for
their reception.

1. Parapeltidium johnstoni nov. sp. Plate LXV, figs. 1 — 5.

Female — length 1.36 mm.

Seen from above, the body appears very wide and depressed. It is oval in outline. The
cephalic segment is large. The distal ends are expanded and are produced beyond the ends
of the first thoracic segment. The greatest width is at the end of the cephalic segment and
is equal to two-thirds of the entire length of the animal. The distal ends of the cephalic and
thoracic segments are pointed. The segments are produced dorsally in the middle line into
triangular projections. The rostrum is moderately large and prominent. The frontal margin is
truncate. The genital segment is large and is deeply indented in the middle. The distal ends

are cönsiderably produced and extend beyond the end of the furcal joints. The other abdominal
segments are entirelv covered by the genital segment. The furcal joints are moderately long
and cylindrical. The joints are nearly three times longer than broad and are furnished with
an outer marginal seta (Plate LXV, fig. i).

The antennules are short and are composed of five joints. The last joint is small. The
whole of the distal margin of the first joint and the lower half of the distal margin of the
second joint is fringed with short hairs. The third and fourth joints each bear one long
sensory filament.

The antennae, mandibles, maxillae and second pair of maxillipedes are similar to those
of Pcltidium pitrpitretim. The* first pair of maxillipedes is similar to that of Eupeltidium glabrum .

The exopodite of the first pair ot feet is moderately long and slender. It is three-
jointed. The second joint is distinctly longer than the first joint. The third joint is very short.
It bears one stout and one slender curved claw. The endopodite is narrow and two-jointed.
The second joint is furnished with one subapical and two apical setae (Plate LXV, fig. 4).

The second, third and fourth pairs of feet are similar to those of Pcltidium purpureum.

The fifth pair is composed of a single highly chitinised and somewhat spiniform joint.
The outer margin is furnished with three short setae. The inner margin is furnished with two
setae at the base, and one at the middle. The apex is furnished with a short curved claw
(Plate LXV, fig. 5).

Male unknown.

Occurrence. — One specimen was obtained from the surface plankton collected at
Station 142, when the 'Siboga' was at anchor at Laiwui, on the coast of Obi Major. This species
is named in compliment to my colleague Mr. James Johnstone, B.Sc. His investigations and
reports on the endoparasites of fishes have done much to revive the study and add to the
knowledge of the British forms.

28. Family Porcellidiiae.
Genus Porcellidium Claus, 1860.

The members of this genus are readily recognised by the very depressed body, and by
the large flattened triangular first joint of the endopodite of the first pair of feet. The second
joint is very short. It is furnished with two moderately strong claws that are densely fimbriate
on one side.

One species belonging to this genus was represented in the material collected by the
'Siboga' in the Malay Archipelago.

1. Porcellidium brevicaudatum Thompson & Scott.

Porcellidium brevicaudatum Thompson & Scott, 1903, p. 275, pi. XII, figs. 11 — 14.
A single female belonging to this species was found in the washings from dredged
invertebrata collected at Station 273, at a depth of 13 metres.

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2 14

This species is readily recognised by the shape of the genital segment and furcal joints,
and also by the comparatively slender form of the fifth pair of feet.

Porcellidium brevicaudatum has only previously been recorded from Ceylon.

29. Family Thalestridae.
Genus Phyllothalestris G. O. Sars, 1905. -

Professor G. O. Sars has separated Thalcstris mysis from true Thalestris on account
of the enormous development of the fifth pair of feet of the female, and has established it in
a distinct genus.

One species is knovvn. It was represented in the plankton collected by the 'Siboga' in
the Malay Archipelago.

1. Phyllothalestris mysis (Claus). Plate LXII, figs. 1 — 5.

Thalestris mysis Claus, 1863, p. 130, pi. XVIII, figs. 12 — 16.

Thalestris mysis Brady, 1880, vol. II, p. 121, pi. LVIII, figs. 1 — 3.

Thalestris mysis T. Scott, 1901 (<z), p. 354.

Thalestris mysis Thompson & Scott, 1903, p. 272.

Thalestris mysis Pearson, 1905, p. 13.

Phyllothalestris mysis Sars, 1905, p. 116, pis. LXX & LXXI.

Phyllothalestris mysis T. Scott, \go6(a), p. 314.

Phyllothalestris mysis Norman & T. Scott, 1906, p. 168.

Two females identical with the above species were obtained from the plankton collected
at the surface at Station 142, when the 'Siboga' was at anchor at Laiwui.

The illustration of the fifth pair of feet given on Plate LXII, fig. 5, is similar in shape
to the figure given by Sars in 'Crustacea of Norway' Vol. V. The surface of the fifth pair of
the 'Siboga' specimens is marked by numerous interrupted transverse lines as shewn by the
figure. Length of 'Siboga' specimens 1,9 mm.

The very large foliaceous fifth pair of feet is a conspicuous character and enables the
species to be readily recognised.

Phyllothalestris mysis appears to be rather widely distributed. It has been recorded
from the British and Norwegian Coasts, from the Mediterranean, from the Gulf of Suez, and
from the Island of Ceylon.

Genus Rhynchothalestris G. O. Sars, 1905.

The members of this genus can be distinguished by the unusually sharp division between
the cephalothorax and the abdomen, and by the very large rostrum.

Two species were represented in the material collected by the 'Siboga' in the Malay
Archipelago. One of the species does not appear to have previously been described.

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215

i. Rhynchothalestris rufocincta (Norman). Plate LXII, figs. 12 — 20.

Thalestris rufocincta Norman, (Brady, 1S80, vol. II, p. 125, pi. LVI, figs. 1 — 9).

Thalcstris rufocincta I. C. Thompson, 1S96, p. 25.

Thalestris rufocincta T. Scott, iqoi(a), p. 354.

Thalcstris rufocincta Pearson, 1905, p. 13.

Rhynchothalestris rufocincta Sars, 1905, p. 120, pis. LXXIII & LXXIV.

Rhynchothalestris rufocincta T. Scott, i9o6(«), p. 315.

Rhynchothalestris rufocincta Norman & T. Scott, 1906, p. 168.

Males and females that are perfectly identical with the above species were found in the
plankton, and in the washings from dredged invertebrata collected at the following stations.

Stat. 35, surface, 1 female. — Stat. 40, surface, Pulu Kawassang, Paternoster Islands, 1 female. -
Stat. 164, bottom, 32 metres, 2 females and 2 males. -- Stat. 273, bottom, 13 metres,
1 female and 1 male.

The female can readily be recognised by the shape and armature of the fifth pair of
feet. The last joint of the endopodite of the second and third pairs of feet of the male is
peculiarly modified. The illustrations of the last joint of these feet of the 'Siboga' males (Plate
LXII, figs. iS and 19), are identical with the figures given by Sars in 'Crustacea of Norway'
Vol. V. The upper distal angle of the fifth last joint of the male antennules is produced into
a well defined tooth (Plate LXII, fig. 17). Length of 'Siboga' specimens - - female .98 mm.,
male .7 mm.

Rhynchothalestris rufocincta has been recorded from the coasts of Britain, France, and
Norway.

2. Rhynchothalestris sim i/is nov. sp. Plate LXII, figs. 6 — ri.

Female — length 1,47 mm.

This species bears a very close resemblance to Rhynchothalestris rufocincta, but it can
be separated from it by the following characters. The proportional length of the joints of the
antennules is different. The seventh and eighth joints are of nearly equal length. In Rhyn-
chothalestris rufocincta the eighth joint is distinctly smaller than the seventh joint. The second
joint of the second pair of maxillipedes is moderately large and comparatively narrovv. The
terminal claw exceeds the length of the second joint. The inner expansion of the proximal
joint of the fifth pair of feet is very broad and its apex is rather truncate. The marginal setae
are placed fairly close together round the apex. The distal joint is proportionally narrower than
the distal joint of Rhynchothalestris rufocincta (Plate LXII, fig. 10). The furcal joints are one
and a half times longer than broad.

Occurrence. — One female was found in the washings from dredged invertebrata
collected at Station 273, from a depth of 13 metres.

Genus Idomene Philippi, 1843.

The members of this genus can be recognised by the very depressed body, by the

215

2IÓ

large rounded cephalic segment, by the absence of a rostrum, by the greatly developed mandible
jDalp, and by the structure of the first pair of feet. The joints of the basiopodite of the first
pair of feet are very broad and flattened. The exopodite and endopodite are three-jointed.
The exopodite is comparatively short and narrow. The endopodite is longer than the exopodite.
The first joint is very large and wide.

One species belonging to this genus was represented in the material collected by the
'Siboga' in the Malay Archipelago.

i. Idomene laticaudata (Thompson and Scott).

Dactylopusia la li eau data Thompson & Scott, 1903, p. 271, pi. XI, figs. 1 — 8.

Two females belonging to this species were found in the washings from dredged inver-
tebrata collected at Station 273, from a depth of 13 metres.

The species was originally described as a Dactylopusia, but it undoubtedly belongs to
the genus Idomene described by Philippi in 1843, as suggested by Professor G. O. Sars.
The very short flattened spines on the apex of the proximal joint of the fifth pair of feet
readily separate this species from Idomene forfieata Philippi.

This Idomene has only previously been recorded from Ceylon.

Genus Tydemanella nov.

The body is much dilated and slightly depressed in front, considerably attenuated
behind. The cephalic segment is large and expanded, and provided with a well developed
rostrum. The antennules are eight-jointed. The exopodite of the antennae is composed of a
single joint. The mandibles, maxillae and maxillipedes are of the normal type of the family.
The exopodites of the four pairs of feet are three-jointed. The endopodite of the first pair of
feet is two-jointed and is longer than the exopodite. The first joint is long and moderately
broad. The second joint is short. The endopodites of the second, third and fourth pairs of feet
are three-jointed. The fifth pair is composed of two rather wide joints.

This genus is closely related to Dactylopodella G. O. Sars, but it can readily be separated
by the long slender eight-jointed antennules, and by the one-jointed exopodite of the antennae.

One species belonging to this genus was represented in the material collected by the
'Siboga' in the Malay Archipelago.

The genus is named in compliment to Lieutenant G. F. Tydeman, the Commancler of
H.M.S. 'Siboga' when the investigations were carried out in the Malay Archipelago.

1. Tydemanella typiea nov. sp. Plate LXIII, figs. 15 — 24.

Female — length 1,15 mm.

Seen from above, the body appears rather long and is pyriform in shape. The cephalic
segment is large and broad. It is slightly longer than the combined length of the thoracic
segments. The rostrum is large and well developed.

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2 17

The abdomen is composed of four segments. The genital segment is large. It is much
contracted in the distal half, which is separated from the anterior portion by a distinct suture
traversing the dorsal surface of the segment. The second, third and fourth segments are com-
paratively short. The fnrcal joints are one and a half times longer than broad (Plate LXIII,
fig. 24).

The antennules are moderately long and slender and are eight-jointed. The last four
joints are narrower and shorter than the first four joints (Plate LXIII, fig. 16).

The exopoclite of the antennae is rather long and slender, and one-jointed. It is furnished
with one strong apical seta and one slender marginal seta (Plate LXIII, fig. 1 7).

The mandibles, maxillae and maxillipedes are nearly similar to those of Dactylopodclla
flava (Claus).

The exopodite of the first pair of feet is three-jointed. The endopodite is two-jointed.
The first joint of the endopodite is moderately wide and is nearly as long as the combined
length of the joints of the exopodite. The second joint is short. The apex is furnished with a
long slender, slightly curved claw, and tvvo setae (Plate LXIII, fig. 22).

The second, third and fourth pairs of feet are nearly similar to those of Dactylopodclla.

The fifth pair of feet is somewhat foliaceous. The inner expansion of the proximal joint
is furnished with three strong inner marginal spines, and two apical spines. The distal joint is
short and wide. It is furnished with six setae at the distal end (Plate LXIII, fig. 23).

Male unknown.

Occurrence. — One specimen was found in the surface plankton collected at Station
40, off Pulu Kawassang, Paternoster Islands.

Genus Pseudothalestris Brady, 1883.

This genus was established by Professor G. S. Brady in 1883, in the report on

the 'Challenger' Copepoda. It is closely related to the genus Westwoodia Dana, in the

structure of the appendages, but it differs very considerably in having the exopodite of the

first pair of feet composed of two distinct joints. The exopodite is only one-jointed in true

Weshvoodia .

Professor G. O. Sars 'Crustacea of Norway' Vol. V, disestablished this genus, owing
to the fact that he obtained a species ( Weshvoodia assimilis) with the exopodite of the
first pair of feet composed of two joints, but in all other respects agreeing so closely with
the type of the genus Westwoodia that a very careful examination was required to separate
it from Weshvoodia nobilis (Baird). This reason appears to be scarcely sufficiënt for cancelling
Pseudothalestris especially as it is a common occurrence to find species belonging to different
genera included under one family that possess some character common to all, yet differing
in other points. The two-jointed exopodite of the first pair of feet is evidently not accidental,
and it is surely of as much value in generic distinction as the large fifth pair of feet of
Phxllothalestris, or the greatly developed rostrum of Rhynchothalcstris, which are regarded
by Sars of so much importance, that he separates these forms from typical Thalestris.

217

S1BOOA-EXPED1TIE XXIXfl. 2^

2l8

One species, apparently undescribed, but agreeing with Brady's definition of the genus,
was obtained from the plankton collected by the :Siboga' in the Malay Archipelago.

i. Pseudothalestris sarsi nov. sp. Plate LXIII, figs. i — 7.

Female — length .68 mm.

Seen from the side, the body appears short and moderately robust. The cephalic segment
is large and exceeds the combined length of the thoracic segments. The rostrum is very short
and is triangular in shape.

The abdomen is composed of four segments. The genital segment is longer than the
combined length of the next three segments. The anal segment is much shorter than the other
segments. The furcal joints are shorter than the anal segment. Each joint is one and a half
times broader than long (Plate LXIII, fig. 7).

The antennules are comparatively short and six-jointed. The fifth joint is shorter than
any of the others.

The antennae, mandibles, maxillae and maxillipedes are similar to those of Pseudothalestris
imbricata Brady.

The exopodite of the first pair of feet is short and is distinctly two-jointed. The joints
are sub-equal in length. The endopodite is composed of three joints and is equal to two and
a half times the length of the exopodite. The first joint is very long. The second and third
joints are exceedingly short. The apex of the third joint is furnished with one long and one
very short claw, and a small seta (Plate LXIII, fig. 5).

The second, third and fourth pairs of feet are similar to those of Pseudothalestris
imbricata Brady.

The fifth pair of feet is comparatively large. The proximal joint is greatly expanded.
The apex is armed with five moderately strong spines of unequal length and four small setae.
The distal joint is small and is somewhat quadrangular in outline. It is furnished with one
outer marginal spine, one inner marginal spine, and one apical spine. The distal end of the
inner margin has also two short setae (Plate LXIII, fig. 6).

Male unknown.

This species resembles Pseudothalestris major T. and A. Scott (1895), in general
appearance, but it can readily be distinguished from it or any of the other members of the
genus by the proportional length of the joints of the antennules, and by the shape and armature
of the fifth pair of feet. Sars, 'Crustacea of Norway' Vol. V, p. 143, regards Pseudothalestris
major to be identical with Westwoodia minuta Claus (1863). This view cannot very well be upheld
because Claus in his generic description of Westwoodia defines the exopodite of the first pair of
feet to be short and one-jointed. Pseudothalestris major has the exopodite distinctly two-jointed.
The shape and armature of the fifth pair of feet illustrated by Sars as that of the female of
Westwoodia 'minuta Claus, is quite different from the figure of the same pair of Pseudothalestris
major given by T. and A. Scott in the 'Annals and Magazine of Natural History, Ser. 6,
£V, January 1895. Sars states that Westwoodia minuta Claus, has six-jointed antennules.

218

219

Pseudothalestris major T. and A. Scott, has eight-jointed antennules. Pseudothalestris sarsi
differs distinctly from Saks' illustrations of Westwoodia minuta in the length of the joints of
the antennules, and in the shape and armature of the distal joint of the fifth pair of feet. The
expansion of the proximal joint is also much wider.

Occurrence. — One specimen was obtained from the surface plankton collected at
Station 40, off Pulu Kawassang, Paternoster Islands.

This species is named in compliment to Professor G. O. Sars whose numerous works
on the Crustacea are of the utmost value to every worker who attempts to study almost
any order of that extensive class of animals.

Genus Eudactylopus nov.

The body is moderately stout in front, and rather slender behind. The anterior division
is more or less depressed. The cephalic segment is provided with a well developed and very
motile rostrum. The abdomen of the female is composed of four segments. The antennules
are short, stout and seven-jointed. The exopodite of the antennae is two-jointed. The mandibles,
maxillae and maxillipedes are normal and are similar to those of the genus Dactylopusia
Norman. The exopodite of the first pair of feet is three-jointed, and is considerably shorter
than the endopodite. The terminal joint is short and armed with claws. The endopodite is
two-jointed or very indistinctly three-jointed. The first joint is long. The second joint is very
short and is armed with a very powerful claw. The exopodite and endopodite of the second,
third and fourth pairs of feet are three-jointed and are similar to Dactylopusia. The fifth pair
of feet is large, foliaceous and transparent, and completely covers the ovisac below.

The type of the genus is Dactylopusia latipcs T. Scott (1893). It approaches Dactylo-
pusia in general appearance, but differs conspiciously in the two-jointed exopodite of the
antennae, and in the great development of the fifth pair of feet of the female. It differs from
Dactvlopodclla Sars (1905), in having the exopodite and endopodite of the second pair of feet
composed of three joints, and also in the large fifth pair.

One species at present is known. It was represented in the material collected by the
'Siboga' in the Malay Archipelago.

1. Eudactylopus latipcs (T. Scott). Plate LXIII, figs. 8 — 14.

Dactylopus latipes T. Scott (non Boeck), 1893, p. 99, pi. X, figs. 38 — 43.
Dactylopusia latipes Thompson & Scott, 1903, p. 268.

Female — length 1,4 mm.

Seen from the side, the body appears moderately robust. The cephalic segment is large
and exceeds the combined length of the thoracic segments. The rostrum is well developed and
is very motile.

The abdomen is composed of four segments. The genital segment is rather large and
is almost equal to the combined length of the second and third segments. It is marked by a
distinct suture traversing the middle of the dorsal surface. The second and third segments are

219

220

of nearly equal length. The anal segment is comparatively short. The furcal joints are as long-
as broad, and are equal to two-thirds of the length of the anal segment.

The antennules are short and seven-jointed. The fifth and sixth joints are shorter than
the others. In some positions the seventh joint shews an indication of a sub-division, but this-
is due to the setae becoming folded over the surface of the joint in the preparation of the
mount. The distal end of the fourth joint is furnished with a sensory filament (Plate LXIII, fig. 9).

The antennae are similar to those of Dactylopusia, but the exopodite is distinctly two-
jointed (Plate LXIII, fig. 10).

The mandibles, maxillae and maxillipedes are similar to those of Dactylopusia. The
second joint of the second pair of maxillipedes is long and moderately robust. The upper
margin is fringed with short spines. The terminal claw is long and stout, and is nearly as
long as the second joint (Plate LXIII, fig. 1 1).

The first pair of feet is comparatively short and stout. The exopodite is three-jointed.
The last joint is short and is furnished with three claws and one seta. The endopodite is
two-jointed. The first joint is longer than the exopodite. The second joint is short. It is armed
with one large stout claw, one small claw, ancl a short seta (Plate LXIII, fig. 12).

The exopodites and endopodites of the second, third and fourth pairs of feet are three-
jointed as in the genus Dactylopusia.

The fifth pair of feet is two-jointed and extends to the middle of the second abdominal
segment. The joints are very large and foliaceous. The proximal joint is broadly wedge-shaped.
The distal joint is sub-quadrangular in outline. The margin of the joints is fringed with short
hairs. A few short feeble setae are also present (Plate LXIII, fig. 13).

Male unknown.

Eudactylopus latipes is readily recognised by the two-jointed exopodite of the antennae,
by the structure of the first pair of feet, and by the very large foliaceous and transparent
fifth pair of feet.

This species was described in the report 'On Entomostraca from the Gulf of Guinea'
by my father from a single specimen. It has also been recorded from the Island of Ceylon by
Thompson and A. Scott. Sars points out in 'Crustacea of Norway' Vol. V, p. 131, that
Dactylopus latipes Boeck is identical with Dactylopusia brevicornis (Claus), but is quite distinct
from Dactylopus latipes T. Scott.

Occurrence. — Two specimens were obtained from the washings from dredged
invertebrata collected at Station 273, off Pulu Jedan, East Coast of Aru Islands, at a depth
of 1 3 metres.

30. Family Diosaccidae.
Genus Amphiascus G. O. Sars, 1905 (c).

Sars points out in 'Crustacea of Norway' Vol. V, that many of the species placed under
the genus long known as Dactylopus ought properly to be included under this genus.

2 2 1

The body is rather slender and cylindrical in form. The anterior and posterior portions
of the body are not sharply defined. The exopodite of the antennae is three-jointed. The exopodite
and endopodite of the first pair of feet are three-jointed as in Dactylopusia, but more slender.
The exopodite and endopodite of the second, third and fourth pairs of feet are three-jointed
as in Dactylopusia. The fifth pair of feet is foliaceous and two-jointed.

Three species belonging to this genus were represented in the material collected by the
'Siboga' in the Malay Archipelago.

i. Amphiascus havelocki (Thompson and Scott).

Dactylopusia havelocki Thompson & Scott, 1903, p. 269, pi. IX, figs. 11 — 18.

Four females identical with the above species were found in the washings from dredged
invertebrata collected at Station 273, at a depth of 13 metres.

This species can readily be recognised by the very broad distal joint of the fifth pair
of feet of the female.

Amphiascus havelocki has hitherto only been known from Ceylon.

2. Amphiascus hirsutus (Thompson and Scott).

Dactylopusia hirsuta Thompson & Scott, 1903, p. 269, pi. IX, figs. 19 — 24.

One female belonging to this species was found in the washings from dredged inverte-
brata collected at Station 273, from a depth of 13 metres.

The peculiar pyriform distal joint, and the armature of the proximal joint of the fifth pair
of feet of the female, readily separate this species from any of the other members of the genus.

Amphiascus hirsutus has hitherto only been recorded from Ceylon.

3. Amphiascus ceylonicus (Thompson and Scott).

Dactylopusia ceylonica Thompson & Scott, 1903, p. 269, pi. IX, figs. 25 — 32.

Females identical with the above species were found in the washings from dredged
invertebrata collected at the following two stations.

Stat. 226, 1595 metres, 2 specimens. ■ — Stat. 273, 13 metres, 3 specimens.

Amphiascus ceylonicus is closely related to Amphiascus havelocki in its general appe-
arance, and in the structure of its appendages, but it can be distinguished by the distinct
difference in the proportional length of the joints of the antennules, and by the moderately
narrow distal joint of the fifth pair of feet of the female.

This species has hitherto only been known from Ceylon.

2 2 2

31. Family Canthocamptidae.
Genus Ameira Boeck, 1864.

The members of this genus can be distinguished by the long slender antennules, by
the long slender three-jointed endopodite of the first pair of feet, by the much shorter three-
jointed exopodite, and by the perfectly smooth anal operculum.

One species apparently belonging to this genus as re-defined by Sars in 'Crustacea of
Norway' Vol. V, was obtained from the plankton collected by the 'Siboga' in the Malay Archipelago.

1. Ameira sibogae nov. sp. Plate LX, figs. 1

'/ •

Female — length .43 mm.

Seen from the side, the body appears moderately slender and rather cylindrical. The
cephalic segment is large and is nearly as long as the combined length of the first three thoracic
segments. The rostrum is small and inconspicuous.

The abdomen is composed of four segments. The genital segment is comparatively large
and is equal to the combined length of the second and third segments. It is traversed by a
well defined suture. The anal segment is short. The operculum is very small and is perfectly
smooth. The furcal joints are short. The joints are as long as broad and are equal to about
half the length of the anal segment (Plate LX, fig. 7).

The antennules are long and slender and are composed of eight joints. The last joint
is distinctly smaller than the others. The fourth joint is furnished with a long sensory filament.

The antennae are very small. The exopodite appears to be indistinctly two-jointed (Plate
LX, fig. 3).

The mandibles, maxillae and maxillipedes are nearly similar to those of Ameira
longipes Boeck.

The exopodites and endopodites of the four pairs of feet are three-jointed. The endo-
podite of the first pair of feet is much longer than the exopodite and is distinctly prehensile.
The first joint is equal to twice the combined length of the second and third joints. The inner
marginal seta is placed in the distal third of the joint. The last joint is rather narrow and
linear in shape. It is two and a half times longer than the second joint. The apex is furnished
with one straight claw and a geniculate seta (Plate LX, fig. 5).

The fifth pair of feet is of moderate size and two-jointed. The proximal joint is wide
at the base and only very slightly attenuated towards the apex of the inner expansion. The
apex bears four moderately long setae. The distal joint is narrow and is somewhat pyriform
in shape. It is furnished with three outer marginal setae, one apical seta, and one seta at
the distal end of the inner margin (Plate LX, fig. 6).

Male unknown.

This species can readily be distinguished by its very small size, by the proportional
length of the joints of the endopodite of the first pair of feet, and by the shape and armature
of the fifth pair.

223

Occurrence. — One specimen was obtained from the plankton collected at Station 40,
off Pulu Kawassang, Paternoster Islands.

Genus Phyllopodopsyllus T. Scott, 1896.

The females of this genus can readily be separated from the other members of the
family by the very large, one-jointed, foliaceous fifth pair of feet, and by the strong claw-like
projection of the second joint of the antennules. The male has hitherto been unknown. A single
male specimen belonging to this genus was found in the plankton collected by the 'Siboga'
and some further particulars regarding the genus now become available.

The male resembles the female in general appearance except that the antennules are
prehensile, the fifth pair of feet is two-jointed, and the abdomen is composed of five segments.
The other appendages are quite similar to those of the female.

1. Phyllopodopsyllus loiigicaudatus nov. sp. Plate LX, figs. 17 — -25.

Male — length .5S mm.

Seen from the side, the anterior part of the body appears rather robust and the abdomen
is moderately long and narrow. The cephalic segment is large and inflated, and is equal to
twice the combined length of the first three thoracic segments. The rostrum is very small and
inconspicuous.

The abdomen is composed of five segments. The first four segments are of nearly
equal length. The anal segment is shorter than the others. The anal operculum is broad and
is very slightly rounded. It is fringed with short hairs. The furcal joints are long and slender,
and are slightly curved. The joints are as long as the combined length of the last three
abdominal segments. Each joint is furnished with two small outer edge spines and two apical
setae. The principal apical seta is comparatively short (Plate LX, fig. 25).

The antennules are eight-jointed. The second joint is produced ventrally into a large
well defined tooth. The fifth joint is slightly inflated and cylindrical in shape. It is furnished
with a long slender sensory filament. The hinge is placed between the fifth and sixth joints.
The seventh joint is very small (Plate LX, fig. 18).

The anten nae, mandibles, maxillae and maxillipedes are similar to those of Phyllopodop-
syllus bradyi (T. Scott).

The first pair of feet is moderately long and rather slender. The exopodite is three-jointecl.
The endopodite is two-jointed and is considerably longer than the exopodite. The first joint is
distinctly longer than the combined length of the joints of the exopodite. The inner marginal
seta is situated about one-third from the distal end. The second joint is short and is only one-
fourth of the length of the first joint. The apex is furnished with two setae (Plate LX, fig. 21).

The second, third and fourth pairs of feet are similar to those of Phyllopodopsyllus
bradyi (T. Scott). The exopodites are three-jointed. The endopodites are two-jointed and are
very much shorter than the exopodites. The endopodite of the second and third pairs of feet
is as long as the first joint of the exopodite. The two joints are of nearly equal length. The

224

endopodite of the fourth pair of feet is also as long as the first joint of the exopodite, but
the proximal joint is very short (Plate LX, figs. 22 and 23). The armature of the four pairs
of feet does not appear to differ from that of the females of the genus.

The fifth pair of feet is rather small and is distinctly two-jointed. The proximal joint
is comparatively large and is only slightly expanded internally. The apex is narrow and is
furnished with three setae. The distal joint is narrowly and irregularly wedge-shaped with a
distinctly pointed apex. It is furnished with two outer marginal setae and three inner marginal
setae (Plate LX, fig. 24).

Female unknown.

It is scarcely likely that this can be the male of either Phyllopodopsyllus bradyi (T. Scott)
or Phyllopodopsyllus furcifer G. O. Sars as the size is much too small, and the furcal joints
are so distinctly different in shape and proportional length. It may, however, prove on future
investigation to be the male of Phyllopodopsyllus minor (Thompson and Scott). The type
dissections of Phyllopodopsyllus minor shew no tracé of the tooth-like processes on the inner
expansion of the apex of the second joint of the basiopodite of the second, third and fourth
pairs of feet. I prefer, for this reason, to regard it as distinct in the meantime.

Occurrence. — One specimen was obtained from the plankton collected at Station 40,
off Pulu Kawassang, Paternoster Islands.

32. Family Laophontidae.
Genus Laophonte Philippi, 1840.

The members of this genus are readily distinguished by the very feeble exopodite and
greatly produced endopodite of the first pair of feet. The endopodite is two-jointed and ter-
minates in a very powerful claw.

Two species belonging to this genus were found in the material collected by the 'Siboga'
in the Malay Archipelago.

1. LaopJwnfc cornuta Philippi.

Laophonte cornuta Philippi, 1S40, p. 189, pi. III, fig. 13.

Cleta forcipata Claus, 1866, p. 23, pi. II, figs. 23 — 28.

Laophonte serrata Brady, 1880, vol. II, p. 71, pi. LXXIII, figs. 1 — 14.

Laopliontc serrata T. Scott, 1893, p. 96, pi. XII, figs. 24 — 28.

Laophonte serrata I. C. Thompson, 1S93, p. 24, pi. XX, fig. 6.

Laophonte serrata I. C. Thompson, 1896, p. 25.

Laophonte serrata T. Scott, 1901 (a), p. 353.

Laopliontc serrata Thompson & Scott, 1903, p. 266.

Laophonte serrata Pearson, 1905, p. 9.

Laopliontc serrata Norman & Scott, 1905, p. 157, pis. XIII, XVI & XVII.

Laophonte cornuta Sars, 1907, p. 235, pis. CLVII & CLVIII.

Males and females identical with the above species as re-defined by Professor Sars,

224

were found in the washings from dredged invertebrata collected at the following two stations.
Stat. 226, 1595 metres, 4 females and 1 male. — Stat. 273, 13 metres, 5 females and 1 male.

Laophonte cornuta can readily be recognised by the large size of the animal, by the
very strong tooth-like projection on the second joint of the antennules, and by the shape and
armature of the fifth pair of feet.

This species appears to be widely distributed along the coast of Western Europe. The
form recorded from Ceylon by I. C. Thompson and A. Scott as Laophonte serrata Claus,
has proved on re-examination to be identical with Sars' illustrations of the above species.

2. Laophonte hirsuta Thompson and Scott.

Laophonte hirsuta Thompson & Scott, 1903, p. 266, pi. VIII, figs. 1 — 8.

Specimens belonging to this species were found in the washings from dredged inverte-
brata collected at the following two stations.

Station 226, 1595 metres, 8 female. — Stat. 273, 13 metres, 5 females.

This species is easily recognised by its short, depressed, and very hirsute body, by the
very robust endopodite of the first pair of feet with its very short, stout and curved apical
claw, and by the slender distal joint of the fifth pair of feet.

Laophonte hirsuta has hitherto only been known from Ceylon.

33. Family Cletodidae.
Genus Cletodes Brady, 1872.

The members of this genus are easily recognised by the rather slender body, by the
short stout antennules, by the non-prehensile character of the first pair of feet and by the
absence of a terminal claw on the apex of the endopodite.

Two species belonging to this genus were represented in the material collected by the
'Siboga" in the Malay Archipelago.

1. Cletodes linearis (Claus).

Liljeborgia linearis Claus, 1866, p. 22, pi. II, figs. 1 — 8.

Orthopsyllus linearis Brady & Robertson, 1873, p. 138.

Cletodes linearis Brady, 1S80, vol. II, p. 95, pi. LXXX, figs. 1 — 14.

Cletodes linearis T. Scott, 1893, p. 98, pi. XII, figs. 29 — 32.

Cletodes linearis I. C. Thompson, 1896, p. 25.

Cletodes linearis T. Scott, 1901 (a), p. 354.

Cletodes linearis Thompson & Scott, 1903, p. 267.

Cletodes linearis Fearson, 1905, p. 11.

Cletodes linearis Xorman & T. Scott, 1906, p. 162.

One female identical with the above species was found in the washings from dredged
invertebrata collected at Station 273, at a depth of 13 metres.

Cletodes linearis can readily be identified by the strong teeth that fringe the distal ends

225

SIFOGA-EXFED1TIE XXIX a. 2q

22Ó

of the seo-ments of the body, and by the rather large and somewhat foliaceous fifth pair of

feet of the female.

This species appears to be generally distributed along the coasts of Western Europe.
It has also been recorded from the Gulf of Guinea, and from the coast of Ceylon.

Note. Sars 1909(0) has now restored Brady & Robertson's genus Orlhopsyllus for the reception of this Copepod.

2. Cletodes latipes nov. sp. Plate LX, figs. 8 — 16.

Female — length .57 mm.

Seen from the side, the body appears elongate, cylindrical and considerably arched in
preserved specimens. The various segments are well defined. The cephalic segment is of mode-
rate size and is nearly as long as the combined length of the first three thoracic segments.
The rostrum is short, stout, and slightly recurved.

The abdomen is composed of four segments. The genital segment is moderately large
and rather inflated. It is marked by a well defined suture and is as long as the combined
length of the second and third segments. The second and third segments are sub-equal in length.
The anal segment is short. The anal operculum is moderately wide and the free margin is
boldly rounded. The furcal joints are long and slender. Each joint is fully twice the length of
the anal segment, and is furnished with two short outer marginal setae and one inner marginal
seta. The apex bears a moderately long spine and one small seta. The proximal end of the
joints is somewhat inflated (Plate LX, fig. 16)

The antennules are short and five-jointed. The fourth joint is shorter than the others
and is furnished with a stout sensory filament.

The exopodite of the antennae is small and one-jointed. It is furnished with one inner
marginal seta and one apical seta (Plate LX. fig. 10).

The mandible palp is short and one-jointed (Plate LX, fig. 1 1).

The second joint of the second pair of maxillipedes is elongate ovate in outline. The
terminal claw is rather shorter than the second joint (Plate LX, fig. 12).

The exopodites of the four pairs of feet are three-jointed. The endopodites are two-
jointed and are shorter than the exopodites. The apex of the second joint of the endopodite
of the first pair of feet is furnished with two short stout spines and one seta (Plate LX, fig. 13).
The fifth pair of feet is comparatively small. The proximal joint is expanded internally.
The apex of the expansion is furnished with one stout spine and two rather strong setae.
The distal joint is short and broad. The apex is furnished with four setae. The three outer
setae are short. The innermost seta is very long (Plate LX, fig. 15).
Male unknown.

This species can be distinguished from the other members of the genus by the shortT
five-jointed antennules, by the shape and armature of the fifth pair of feet, and by the rather
long furcal joints.

O c cu r re nee. — One specimen was obtained from the plankton collected at Station 40»
off Pulu Kawassang, Paternoster Islands.

226

34- Family Ceyloniidae nov.

The body is rather slender and cylindrical and resembles Cletodes in general appearance.
The abdomen is four-jointed in the female, and five jointed in the male. The antennules are
comparatively short and seven-jointed in the female. The antennules of the male are prehensile.
The exopodite of the antennae is small and one-jointed. The mandibles, maxillae and first
pair of maxillipedes are similar to those of Cletodes. The second pair of BBRsflTTpedes is
extremely rudimentary and non-prehensile. The first four pairs of feet are very short. The
exopodites are three-jointed. The endopodites are two-jointed and shorter than the exopodites.
The fifth pair of feet of the female is foliaceous and two-jointed. The male fifth pair consists
of a single plate.

The type of this family is Ceylonia armata (Claus). This Harpacticoid is readily
recognised by the very rudimentary mouth organs, but more especially by the non-prehensile
second pair of maxillipedes. This pair consists of flattened triangular plates without articulated claw.

Genus Ceylonia Thompson and Scott, 1903.
= Jurinia Claus, 1866, a name preoccupied by DESVOIDV (Diftera), 1830.

The body is rather slender and cylindrical, with no sharp distinction between the
anterior and postenor divisions. The cephalic segment is of moderate size and is provided
with a small rostrum. The antennules are short and seven-jointed in the female. The last joint
of the endopodite of the antennae is furnished with six short and very stout spines. The
exopodite is small and one-jointed. The mandible has very few teeth. The palp is short and
is indistinctly two-jointed. The maxillae consist of a biting part and one small lobe. The
first pair of maxillipedes is furnished with two digitiform lobes and a terminal claw-bearing
joint. The second pair of maxillipedes is very rudimentary and consists of a thin wedge-shaped
non-prehensile plate which terminates in a rudimentary curved claw. The claw is not articulated.
The exopodite of the first pair of feet is short and three-jointed. The endopodite is two-
jointed and is shorter than the exopodite. It terminates in a moderately strong spine. The
exopodites of the second, third and fourth pairs of feet are slender and three-jointed. The
endopodites are two-jointed and are shorter than the exopodites. The fifth pair of feet of the
female is moderately large and foliaceous, and is two-jointed. The proximal joint has the inner
portion considerably expanded. The male fifth pair is also foliaceous, but there is no tracé of
a division.

This genus was established by the late I. C. Thompson and the writer in the report
on the Ceylon Copepoda collected by Professor Herdman in 1903. We were unaware that
Claus established the genus Jurinia in 1866, for a Copepod identical with the one described
by us as Ceylonia aculeata. The name adopted by Claus, however, had already been used
by Desvoidv in 1830, and must necessarily lapse.

The genus is at present represented by a single species. Specimens belonging to it
were found in the material collected by the 'Siboga' in the Malay Archipelago.

227

228

i. Ceylonia armata (Claus).

Jurinia armata Claus, 1S66, p. 25, pi. II, figs. 15—24.

Ceylonia aculeata Thompson & Scott, 1903, p. 265, pi. VII, figs. 1 1— 23.

Three females identical with the form described by the late I. C. Thompson and the
writer as Ceylonia aculeata were found in the washings from dredged invertebrata collected
at Station 273, off Pulu Jedan, East coast of Aru Islands, from a depth of 11 metres.

The species described by Claus as Jurinia armata although illustrated rather indif-
ferently, is apparently the same Copepod as that found in the washings from dredged inverte-
brata collected off Point de Galle, Ceylon, by Professor Herdman, and named Ceylonia aculeata
by Thompson and Scott. The specific name must, therefore, be discarded.

This species has hitherto only been known from the Mediterranean and from the Indian
Ocean off Ceylon.

35. Family Ilyopsyllidae nov.

The body is short and gibbons. The cephalic segment is very large and is equal to
the combined length of the rest of the animal. The rostrum is moderately strong and pointed.
The abdomen of the female is composed of four segments, The antennules are very short and
five-jointed. The basal joint is greatly expanded and its upper margin is projected forward into
a hood-like process. The endopodite of the antennae is small and three-jointed. There is no
exopodite. The mandibles, maxillae and maxillipedes are very reduced and rudimentary. The
exopodites of the first four pairs of feet are three-jointed. The endopodite of the first pair is
very short, non-prehensile and indistinctly two-jointed. The endopodites of the second, third and
fourth pairs are three-jointed. The fifth pair of feet is very small and one-jointed.

The male resembles the female in general appearance, but the antennules are prehensile
and the abdomen is composed of fïve segments.

The type of the genus is Ilyopsyllus coriaceus Brady and Robertson. The peculiar form
of the body, the greatly inflated and hood-like basal joint of the antennules, and the very
rudimentary mouth organs readily separate this family from any of the other Harpacticoida.

Genus Ilyopsyllus Brady and Robertson, 1873.

The body is very tumid. The antennules are short and five-jointed with a greatly
inflated basal joint. The antennae are short and stout. The endopodite is three-jointed. There
is no exopodite. The mandible is short and the cutting edge is rather coarsely toothed. The
palp is small and one-jointed. The maxillae and maxillipedes are extremely rudimentary. The
second pair of maxillipedes is simple and non-prehensile. The first pair of feet is moderately
short and stout. The exopodite is three-jointed. The joints bear strong outer edge spines.
The last joint is also furnished with two rather long setae. The endopodite is very short and
appears to be indistinctly two-jointed. The first joint is very short. The apex of the second

229

joint is furnished with two short stout spines. The exopodites and cndopodites of the second,
third and fourth pairs of feet are three-jointed. The fifth pair is very small, foliaceous and
one-jointed.

One species belonging to this genus was represented in the plankton collected by the
'Siboga' in the Malay Archipelago.

i. Ilyopsyllus affinis T. Scott.

Ilyopsyllus affinis T. Scott, 1893, p. 101, pi. XI, figs. 4 — 17.
Ilyopsyllus affinis A. Scott, 1902, p. 417.
Ilyopsyllus affinis Thompson & Scott, 1903, p. 275.

Five males and one female identical with the above species were found in the plankton

collected at the following stations.

Stat. 19, 2 males. — Stat. 89, 1 male. — Stat. 213, 1 female and 2 males.

Ilyopsyllus affinis is closely related to Ilyopsyllus coriaceus Brady and Robertson, but
the female can readily be distinguished by the non-spathuiate character of the principal seta
on the furcal joints.

This species has been recorded from the Gulf of Guinea, the Gulf of Suez, and from
the coast of Ceylon.

36. Family Tachidiidae.
Genus Euterpina Norman, 1903.

The only known member of the genus is readily recognised by the slender arched
body, by the prominent sharp pointed rostrum, by the long slender second pair of maxillipedes,
and by the one-jointed foliaceous fifth pair of feet.

This o-enus was represented in the plankton collected by the 'Siboga' in the Malay
Archipelago.

1 . Etitcrpina acutifrous (Dana).

Harpacticus acutifrous Dana, 1847, p. 153.

Harpactuus acutifrous Dana, 1S52, p. 1192, pi. 83, fig. 1 1 a— b.

Euterpe gracilis Claus, 1S63, p. 110, pi. XIV, figs. 1 — 13.

Euterpe gracilis Brady, 1880, vol. II, p. 22, pi. XL, figs. 1 — 16.

Euterpe acutifrous Giesbrecht, 1893, p. 555, pi. 44.

Euterpe acutifrous, var. armata T. Scott, 1893, p. 93, pi. XII, figs. 14—23.

Euterpe acutifrous I. C. Thompson, 1896, p. 25.

Euterpe gracilis Brady, 1899, p. 39.

Euterpe acutifrous I. C. Thompson, 1900, p. 285.

Euterpe acutifrous A. Scott, 1902, p. 409.

Euterpe acutifrous I. C. Thompson, 1903, p. 32.

Euterpina acutifrous Norman, 1903, p. 368.

Euterpina acutifrous Thompson & Scott, 1903, p. 258.

Euterpe acutifrous Cleve, 1903, p. 363.

229

230

Euterpe acutifrons Wolfenden, 1905(0), p. 1034, pi. XCIX, figs. 18 — 20.

Enter pc acutifrons Pearson, 1905, p. 7.

Euterpe acutifrons Esterly, 1905, p. 212, fig. 53.

Euterpina acutifrons Norman & T. Scott, 1906, p. 139.

Euterpe acutifrons van Breemen, 1908, p. 176, fig. 191.

Sixty specimens belonging to this species were obtained from the plankton collected at
the following four stations in the area investigated by the 'Siboga.'

Stat. 35. — Stat. 142. — Stat. 213. — Stat. 304.

Euterpina acutifrons is readly recognised in preserved material by its arched body and
very prominent rostrum, and by the moderately large foliaceous fifth pair of feet of the female.

This Harpacticoid appears to be generally distributed in all the great oceans and appears
to be subject to slight local variations.

37. Family Macrosetf.llidae nov.

The body is very slender and cylindrical. The cephalic segment is large, and is fur-
nished with a prominent beak-like rostrum. The abdomen is composed of four segments in the
female. The furcal joints are rather long and slender. The antennules of the female are slender
and nine-jointed. The last joint is moderately long and claw-like. The endopodite of the antennae
is three-jointed. The exopodite is absent. The mandibles, maxillae and first pair of maxillipedes
are rudimentary. The second pair of maxillipedes is prehensile and two-jointed. The second joint
is furnished with an articulated claw. The exopodites of the first four pairs of feet are three-
jointed. The endopodite of the first pair is two-jointed. The endopodites of the second, third
and fourth pairs are three-jointed. The fifth pair of feet is two-jointed. The male is similar to
the female except that the abdomen is five-jointed and the antennules are prehensile. The endo-
podites of the first and second pairs of feet are two-jointed. The fifth pair is rather smaller.

Genus Macrosetella nov.

= Setella Dana, 1846, a name preoccupied by SCHRANK (Lepidoptera), 1802.

The only known member of this genus is easily identified by its slender body, by the
long furcal joints and by the long antennules.

The entire absence of the exopodite of the antennae, and the rudimentary condition of
the mandibles, maxillae and first pair of maxillipedes indicate that the genus is worthy of more
than generic rank. It is not related to Microsetella or to any of the other members of the
family Ectinosomidae.

The only representative of the genus appeared to be well distributed in the area investigated
by the 'Siboga'.

1. Macrosetella gracilis (Dana).

Setella gracilis Dana, 1852, p, 1 198, pi. 84, fig. ^a — g.
Setella messinensis Claus, 1863, p. 137, pi. XXI, figs. 15 — 16.

230

Setella gracilis Brady, 1883, p. 10S, pi. L, figs. 1 — 10.

Setella gracilis Giesbrecht, 1893, p. 559, pis. 1 & 43.

Setella gracilis T. Scott, 1893, p. 109.

Setella gracilis I. C. Thompson, 1900, p. 285.

Setella gracilis Wheeler, 1900, p. 188, fig. 24.

Setella gracilis Cleve, 1901, p. 9.

Setella gracilis A. Scott, 1902, p. 409.

Setella gracilis I. C. Thompson, 1903, p. 33.

Setella gracilis Thompson & Scott, 1903, p. 257.

Setella gracilis Cleve, 1903, p. 368.

Setella gracilis Wolfenden, 1905 (a), p. 1030.

Setella gracilis van Breemen, 1908, p. 178, fig. 192.

Males and females belonging to this characteristic form were obtained from the plankton
collected at the following stations.

Stat. 19. — Stat. 35. — Stat. 36. — Stat. ^y. - - Stat. 40. -- Stat. 47b. — Stat. 50. -
Stat. 66. — Stat. 75 (11 metres to surface). — Stat. 81. — Stat. 96 (night). — Stat. 98. -
Stat. 99. — Stat. 110. -- Stat. 118 (900 metres to surface). — Stat. 121. -- Stat. 124. —
Stat. 128 (700 metres to surface). — Stat. 138. — Stat. 143 (1000 metres to surface). —
Stat. 146. — Stat. 148 (1000 metres to surface). — Stat. 168. — Stat. 213. — Stat. 216. —
Stat. 217. — Stat. 304. — Stat. 315.

Macroselella gracilis appears to be an entirely pelagic species and has a moderately
wide distribution in the warm regions of the great oceans.

38. Family Clytemnestridae nov.

The body is rather slender and depressed. The distal ends of the cephalic and first
three thoracic segments are considerably expanded and pointed. The thoracic segments are
produced posteriorly. The cephalic segment is large and triangular in outline when seen from
above, and is furnished with a blunt pointed rostrum. The antennules are eight-jointed. The
exopodite of the antennae is short and one-jointed. The mandibles, maxillae and first pair
of maxillipedes are very rudimentary. The second pair of maxillipedes is well developed and
prehensile. The exopodite of the first pair of feet is composed of a single joint. The endopodite
is three-jointed and much longer than the exopodite. The exopodites and endopodites of the
second, third and fourth pairs of feet are three-jointed. The fifth pair of feet is slender and
two-jointed. The female carries a single ovisac.

This family is established for the reception of the genus Clylcmnestra Dana. It differs
very considerably from any of the other Harpacticoida in the long-jointed prehensile second
pair of maxillipedes, and in the structure of the first pair of feet.

Genus Clytemnestra Dana, 1852.

The members of this genus are easily recognised by the form of the body, by the
pointed cephalic and thoracic segments, and by the structure of the various appendages.

231

Two species are at present known. One was represented in the plankton collected by
the 'Siboga' in the Malay Archipelago.

i. Clytemnestra rostrata (Brady).

Goniopsyllus rostratus Brady, 1883, p. 107, pi. XLII, figs. 9 — 16.

Clytemnestra rostrata Giesbrecht, 1893, p. 566, pi. 45.

Clytemnestra rostrata Wheeler, 1900, p. 189, fig. 26.

Clytemnestra rostrata Thompson & Scott, 1903, p 258.

Clytemnestra rostrata Esterly, 1905, p. 214, fig. 54.

Clytemnestra rostrata Norman & T. Scott, 1906, p. 140.

Clytemnestra rostrata Farran, 1908, p. 91.

Clytemnestra rostrata van Breemen, 1908, p. 180, fig. 194.

Four males and one female identical vvith the species clescribed by Professor G. S. Brady
in the report on the 'Challenger' Copepoda, were obtained from the plankton collected at the
following stations.

Stat. 81, 1 male. -- Stat. 142, 1 male. — Stat. 174, 1 female. — Stat. 213, 1 male. —
Stat. 304, 1 male.

Giesbrecht in his great work distinguishes the female of Clytemnestra rostrata (Brady)
from Ciytenniestra scntellata Dana by the proportional length of the joints of the antennules.
The second last joint of the antennules of Clytemnestra rostrata is very distinctly shorter than
the third last joint. lts length is contained nearly six times in the length of the last joint.
The second last joint of the antennules of Ciytenniestra scutellata is slightly longer than the
third last joint. lts length is contained twice in the length of the last joint.

Clytemnestra rostrata appears to have a moderately wide distribution in the great oceans,
but some of the records of its occurrence are perhaps doubtful. The species recorded by mv
father from the Gulf of Guinea as Clytemnestra rostrata is evidently identical with Dana's
species as the illustration of the female antennule is similar to the figure given by Giesbrecht.

39. Family Pontostratiotidae nov.

The body is provided with a well defined sharp pointed rostrum. The principal furcal
seta is in the form of an extremely long slender setiferous spine, with a jointed distal end
carrying a plumose seta. The antennules are six to eight-jointed. The distal end of the upper
margin of the first joint is produced into a knob. The exopodite of the antennae is short and
one to four-jointed. The mandibles, maxillae and maxillipedes are well developed. The second
pair of maxillipedes is not prehensile. The exopodite and endopodite of the four pairs of feet
are three-jointed. The fifth pair of feet is elongate and two-jointed.

The type of this family is Pontostratiotes abyssieola Brady 1883, and it includes the
genus Aegisthus Giesbrecht. The very pointed cephalic segment, and the extraordinary development
of the principal furcal seta are quite sufficiënt to separate the members of this family from any
of the other families belonging to the Harpacticoida.

An examination of the illustrations of the appendages of Pontostratiötes given by Brady
in the 'Challenger' Report shews that there is a close relationship between that genus and Aegisthus,
described and illustrated by Giesbrecht in bis Xaples Monograph. The two genera are distinct
from any of the Harpacticoida and oughjt, I think, to be placed under a separate family. I
have recently had the privilege of examining a specimen of a Copepod identical with Brady's
Pontostratiötes abyssicola and tind that this opinion appears quite reasonable.

The chief differences between the two genera, apart from the presence or absence of
cephalic and thoracic spines, are to be found in the jointing of the exopodite of the antennae
and in the development of the mandible palp. The exopodite of the antennae of Pontostratiötes
is four-jointed. It is only one-jointed in Aegisthus. The mandible palp of Pontostratiötes is well
developed and two-branched. The exopodite is four-jointed. The mandible palp of Aegisthus
is quite rudimentary and unbranched. The antennules, maxillae, first pair of maxillipedes and
the five pairs of feet are nearly identical in the two genera.

The long so-called furcal setae in the two genera may really represent the furcal joints,
because the long setae in perfect examples of Aegisthus terminate in one plumose and two
simple setae. These terminal setae appear to be articulated to the long setae just as in normal
furcal joints.

Genus Aegisthus Giesbrecht, 1891.

The body is slender and of moderate length. The forehead is produced into a sharp
immovable rostrum. The principal furcal seta is of great length. It is in the form of a slender
setiferous spine with a jointed apex that carries a plumose seta. The antennules are rather
slender and six or seven-jointed. The first joint has a distinct knob at the distal end of the
upper margin. The exopodite of the antennae is small and one-jointed. The mandible has
a well developed biting edge and a very rudimentary palp. The maxillae consist of a broad
biting part and one digitiform lobe. The first pair of maxillipedes is rather large and five-jointed.
The two basal joints are moderately long. The three apical joints are short. The distal end
of the upper margin of the second basal joint is furnished with a slender claw. The second
pair of maxillipedes is lamelliform and two-jointed. The second joint is very short. The exopodites
and endopodites of the first four pairs of feet are three-jointed and of nearly equal length.
In some specimens the exopodite and endopodite of the first pair of feet are rather indistinctly
three-jointed. The fifth pair of feet is moderately long and slender. It is indistinctly two jointed.

Two species belonging to this genus were represented in the plankton collected by the
'Siboga' in the Malay Archipelago.

1. Aegisthus aculeatus Giesbrecht.

Aegisthus aculeatus Giesbrecht, 1891, p. 476.

Aegisthus aculeatus Giesbrecht, 1S93, p. 573, pis. 46 & 49.

Aegisthus aculeatus I. C. Thompson, 1903, p. 33.

Aegisthus aculeatus Cleve, 1904, p. 185.

Aegisthus aculeatus van Breemen, 1908, p. 181, fig. 195.

233

SIBOGA-EXI'EDITIE XXIXO. 3°

234
Three specimens belonging to the above species were obtained from the plankton collected
at the following two stations.

Stat. 128 (HENSEN vertical net, 700 metres to surface), 2 specimens. — Stat. 148 (HENSEN
vertical net, 1000 metres to surface), 1 specimen.

Aegisthus aculeatus is much smaller than the next species and the rostrum is not nearly
so prominent. The antennules are seven-jointed. The knob on the upper margin of the lïrst
joint is comparatively short.

This species has only been recorded from the Atlantic and Pacific Oceans.

2. Aegisthus miicronatus Giesbrecht.

Aegisthus mucronatus Giesbrecht, 1891, p. 476.

Aegisthus mucronatus Giesbrecht, 1893, p. 573, pis. 46 & 49.

Aegisthus longirostris T. Scott, 1893, p. 104, pi. XI, figs. 31—34.

Aegisthus mucronatus I C. Thompson, 1903, p. 33.

Aegisthus mucronatus Cleve, 1904, p. 185.

Aegisthus mucronatus Farran, 1905, p. 46.

Aegisthus mucronatus Pearson, 1906, p. 36.

Aegisthus mucronatus Farran, 1908, p. 91.

Aegisthus mucronatus van Breemen, 1908, p. 183, fig. 197.

Twenty specimens of this species were obtained from the plankton collected at the
following stations.

Stat. 109. — Stat. 112. Stat. 118 (HENSEN vertical net, 900 metres to surface). — Stat.

128 (HENSEN vertical net, 700 metres to surface). — Stat. 138. — Stat. 141 (HENSEN vertical
net, 1500 metres to surface). — Stat. 143 (HENSEN vertical net, 1000 metres to surface). —
Stat. 144. — Stat. 148 (HENSEN vertical net, 1000 metres to surface). — Stat. 203 (HENSEN
vertical net, 1500 metres to surface). — Stat. 2151. — Stat. 216. — Stat. 276 (HENSEN
vertical net, 750 metres to surface).

This is a moderately large species with six-jointed antennules. The knob on the distal
end of the upper margin of the first joint is very prominent. The rostrum is long and pointed.

Aegisthus vmcronatus appears to have a wider distribution than the previous species.
It has been recorded from the Atlantic Ocean, off the Coast of Africa and off the West Coast
of Ireland, and from the Pacific. The form described by my father from the Gulf of Guinea
as Aegisthus longirostris appears to be identical with Aegisthus mucronatus Giesbrecht.

40. Family Monstrillidae.
Genus Monstrilla Dana, 1848.

The body is elongate and rather cylindrical. The cephalic segment is of considerable
size and in some cases exceeds the combined length of the thorax and abdomen. There is 110
true rostrum. The abdomen is composecl of three segments in the female and four in the

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235

male. The joints of the antennules are usually indefinite and vary from two to four in number.
The antennae, mandibles and maxillipedes are entirely suppressed. The joints of the basiopo-
dite of the swimming feet are considerably inflated. The exopodites and endopodites of the
first four pairs of feet are three-jointed. The fifth pair of feet is rudimentary and one-jointed.
The male antennules are both prehensile.

The females of this genus are readily identified by the three-jointed abdomen and by
the furcal joints being furnished with five or six setae.

Eight species were obtained from the plankton collected by the 'Siboga' in the Malay
Archipelago. Five of the species do not appear to have previously been described.

i. Monstrilla gracilicauda Giesbrecht. Plate LVII, figs. i and 2.

Monstrilla gracilicauda Giesbrecht, 1893, p. 586, pi. 46.
Monstrilla gracilicauda T. Scott, 1904, p. 245, pis. XIII & XIV.
Monstrilla gracilicauda T. Scott, 1906(0), p. 366.
Monstrilla gracilicauda van Breemen, 1908, p. 206, fig. 217.

One female apparently identical with the above species was found in the plankton
collected at Station 43, off Pulu Kawassang, Paternoster Islands.

Length 3,5 mm.

The antennules are four-jointed and are equal to half the length of the cephalic segment.
The abdomen is composed of three segments. The genital segment is sub-cylindrical in shape
and is equal to twice the combined length of the next two segments. It is as long as the
united length of the next two segments and furcal joints. The segment is marked by a faint
suture traversing the middle. The third abdominal segment of the 'Siboga' specimen is very
little shorter than the second segment. The furcal joints are about one and a half times longer
than the anal segment. Each joint is furnished with one outer marginal seta and five apical
setae. The middle apical seta is much shorter than the others (Plate LVII, fig. 1).

The apex of the fifth pair of feet is rather inflated and is directed at right angles to
the body. The apex is furnished with two long setae, and a short one (Plate LVII, fig. 2).

With the exception of the difference in the length of the third segment of the abdomen
the 'Siboga' specimen agrees well with the illustrations given by Giesbrecht.

Monstrilla gracilicauda has been recorded from the British Coasts and from the
Mediterranean.

2. Monstrilla longicornis I. C. Thompson. Plate LVII, figs. 3 and 4.

Monstrilla longicornis I. C. Thompson, 1890, p. 119. pi. IV.

Monstrilla longiranis Giesbrecht, 1893, p. 586, pi. 46.

Monstrilla longicornis I. C. Thompson, 1896, p. 25.

Monstrilla longicornis T. Scott, 1902, p. 469, pi. XXV, figs. 3 & 4.

Monstrilla longicornis T. Scott, 1904, p. 244, pi. XIII, figs. 1 — 7.

Monstrilla longicornis Pearson, 1906, p. H-

Monstrilla longicornis T. Scott, igo6(a), p. 365.

Monstrilla longicornis Farran, 1908, p. 91.

Monstrilla longicornis van Breemen, 1908, p. 204, fig. 215,

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236

One female apparently belonging to the above species was obtained from the plankton
collected at each of the following two stations.
Stat. 66. — Stat. 121.

Length — 2,8 mm.

The antennules are two-jointed and are equal to two-thirds of the length of the cephalic
segment. The abdomen is composed of three segments. The genital segment is sub-quadrangular
in shape and is equal to nearly twice the combined length of the next two segments. It is
considerably shorter than the united length of the next two segments and furcal joints. The
segment is marked by a well defined suture traversing the middle. The third segment is very
short and is only equal to about half the length of the second segment. The furcal joints are
four times longer than the anal segment. Each joint is furnished with one outer marginal seta
and four apical setae. The second inner seta is shorter than the others (Plate LVII, fig. 3).

The fifth pair of feet is sub-cylindrical in shape with a distinct contraction in the middle.
Each foot is furnished with one inner marginal seta and two apical setae (Plate LVII, fig. 4).

The long antennules with their rather pointed ends, and the shape of the fifth pair appear
to be very characteristic features of this species. The only difference between the 'Siboga'
specimens and the illustrations given by Giesbrecht and by my father, is the absence of a
third seta on the apex of the fifth pair of feet.

Monstrilla longicornis has been recorded from the British Coasts and from the Mediterranean.

3. Monstrilla orcula nov. sp. Plate LVII, figs. 5 and 6.

Female — length 3,8 mm.

Seen from above, the body appears moderately slender. The cephalic segment is greatly
contracted in front and is slightly narrowed behind. It is slightly longer than the posterior part
of the animal. The frontal margin is concave.

The abdomen is composed of three segments. The genital segment is sub-cylindrical in
shape with a distinct constriction at the middle where it is traversed by a well defined suture.
lts length is rather Iess than twice the combined length of the next two segments. It is shorter
than the united length of the next two segments and furcal joints. The second and third
segments are of about equal length. The furcal joints are nearly equal to twice the length of
the anal segment. Each joint is furnished with one marginal seta and five apical setae. The
middle apical seta is distinctly shorter than the others (Plate LVII, fig. 5).

The fifth pair of feet is moderately large and is distinctly bi-lobed. The inner lobe is
narrower than the outer one and extends beyond the end of it. The apex of the inner lobe
is furnished with two setae. The outer lobe is short and stout. The apex is furnished with
three setae (Plate LVII, fig. 6).

This species can readily be separated from the other members of the genus by the
bi-lobed structure of the fifth pair of feet, and by the inner lobe extending beyond the apex
of the outer lobe.

Occurrence. - - One female was obtained from the plankton collected at Station 40,
off Pulu Kawassang, Paternoster Islands.

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237

4. Monstrilla inserta nov. sp. Plate LVII, figs. 7 and S.

bemale — length 3,4 mm.

Seen from above, the body appears modcrately slender. The cephalic segment is evenly
rounded in the frontal portion and is very slightly contracted at the distal end. It is slightly
longer than the posterior part of the animal. The frontal margin is very narrowly rounded
and is slightly cleft.

The abdomen is composed of three segments. The genital segment is sub-quadrangular
in shape and is traversed by a distinct suture rather in front of the middle. lts length is equal
to twice the combined length of the next two segments. It is rather shorter than the united
length of the next two segments and furcal joints. The second and third segments are very
short and are of nearly equal length. The furcal joints are three times longer than the anal seg-
ment. Each joint is furnished with one outer marginal seta and five apical setae (Plate LVII, fig. 7).

The antennules are three-jointed and are equal to one-third of the length of the
cephalic segment.

The hfth pair of feet is rather slender and is distinctly bi-lobed. The inner lobe is
narrower than the outer lobe and does not extend beyond the end of it. The apex is furnished
with one seta. The outer lobe is furnished with three setae (Plate LVII, fig. 8).

This species comes very near Monstrilla grandis in general appearance, and in the
shape of the hfth pair of feet. The chief difference is in the inner lobe of the fifth pair.
Gif.sbrecht's figure shews the inner lobe of the fifth pair of Monstrilla grandis to be furnished
with two setae, instead of one in the 'Siboga' specimens.

O cc ur re nee. — Seven females were obtained from the plankton collected at the
following stations.

Stat. 40, 2 specimens. — Stat. 66, 4 specimens. — Stat. 282, 1 specimen.

5. Monstrilla cymbula nov. sp. Plate LVII, figs. 9 and 10.

Female — length 3 mm.

Seen from above, the body appears rather slender. The cephalic segment is conside-
rably contracted in front and is inrlated in the middle. It is slightly longer than the posterior
part of the animal. The frontal margin is sharply concave.

The abdomen is composed of three segments. The genital segment is sub-cylindrical in
shape with a distinct constriction in the middle where it is traversed by a well defined suture.
It is one and a half times longer than the combined length of the next two segments. lts
length is rather shorter than the united length of the next two segments and furcal joints.
The second and third segments are sub-equal in length. The furcal joints are two and a half
times longer than the anal segment. Each joint is furnished with two outer marginal setae
and four apical setae (Plate LVII, fig. 9).

The antennules are two-jointed and are equal to two-thirds of the length of the
cephalic segment.

The fifth pair of feet is short and broad and is distinctly bidobed. The inner lobe is

237

23§

short and moderately wide. It does not extend beyond the apex of the outer lobe. It is
furnished with two apical setae. The apex of the outer lobe is directed at almost right angles
to the body and is furnished with three setae (Plate LVII, fig. 10).

This species can readily be recognised by the shape and armature of the fvfth pair of feet.

Occurrence. - - One female was obtained from the plankton collected at Station 99,
off North Ubian, Sulu Islands.

6. Monstrilla hclgolandica Claus. Plate LVIII, figs. 1 and 2.

Monstrilla helgolandica Claus, 1863, p. 165, pis. XII & XIII.
Monstrilla helgolandica Timm, 1896, p. 376, pis. 5 & 6.
Monstrilla helgolandica van Breemen, 1908, p. 207, fig. 218.

Female — length 2,07 mm.

Seen from above, the body appears moderately long and slender. The cephalic segment
is contracted in front and is slightly inflated in the middle. It is considerably longer than the
posterior part of the animal. The frontal margin is broadly rounded.

The abdomen is composed of three segments. The genital segment is sub-cylindrical in
shape. It is contracted in the middle but it is not traversed by a suture. The segment is one
and a half times longer than the combined length of the next two segments. It is as long as
the united length of the next two segments and furcal joints. The anal segment is slightly
shorter than the second segment. The furcal joints are as long as the anal segment. Each
joint is furnished with one outer marginal seta and five apical setae. The middle apical seta
is much shorter than the others (Plate LVIII, fig. 1).

The antennules are three-jointed and are equal to one-third of the length of the
cephalic segment.

The fifth pair of feet is very small and divergent. The apex is directed at right angles
to the body and is furnished with two setae (Plate LVIII, fig. 2).

The illustrations given in this report agree very well with the figures by R. Timm (1896).

Occurrence. — One female was obtained from the plankton collected at Station 99,
off North Ubian, Sulu Islands.

Monstrilla helgolandica has only previously been recorded from the North Sea, Skager
Rack, and Eno-lish Channel.

7. Monstrilla longipes nov. sp. Plate LVIII, figs. 3 and 4.

Female — length 1,85 mm.

Seen from above, the body appears rather short and is moderately robust. The cephalic
segment is much inflated just behind the front margin. It is considerably longer than the
posterior part of the animal. The frontal margin is wide and broadly rounded. The exoske-
leton of the cephalic and first three thoracic segments is marked by fine reticulations that are
beset with minute spines.

The abdomen is composed of three segments. The genital segment is sub-quadrangular
in outline. It is slightly contracted at the middle where it is traversed by a distinct suture.

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239

The distal ends are provided with small points. The segment is one and two-third times longer
than the combined length of the next two segments. lts length is rather shorter than the
united length of the next two segments and furcal joints. The second and third segments are
sub-equal in length. The distal end of the third segment is decidedly expanded. The furcal
joints are three times longer than the anal segment. Each joint is furnished with one outer
marginal seta and live apical setae. The middle apical seta is shorter than the others (Plate
LVIII, fig, 3)-

The antennules are four-jointed and are equal to two-fifths of the length of the cephalothorax.

The fifth pair of feet is long and slender and is without apical division. The apex is
furnished with two moderately strong setae (Plate LVIII, fig. 4).

This species is readily recognised by the reticulated exoskeleton and by the long slender
fifth pair of feet.

Occurrence. — One female was found in the plankton collected at Station 142, off
Laiwui, coast of Obi Major.

8. Monstrilla turgida nov. sp. Plate LVIII, figs. 5 and 6.

Female — length 2 mm.

Seen from above, the body appears rather short and is moderately robust. The cephalic
segment is greatly inflated just behind the frontal margin. It is slightly longer than the posterior
part of the animal. The frontal margin is broad and boldly rounded.

The abdomen is composed of three segments. The genital segment is sub-quadrangular
in shape and is traversed near the middle by a distinct suture. It is one and a halt times
longer than the combined length of the next two segments. The segment is nearly as long as
the united length of the next two segments and furcal joints. The second and third segments
are sub-equal in length. The furcal joints are slightly longer than broad and are about one
and a half times longer than the anal segment. Each joint is furnished with one outer marginal
seta and five apical setae. The apical setae are sub-equal in length (Plate LVIII, fig. 5).

The antennules are four-jointed and are equal to one-third of the length of the
cephalic segment.

The fifth pair of feet is moderately long and rather slender. The apex is bi-lobed. The
inner lobe is narrower than the outer lobe and extends beyond the apex of it. It is furnished
with one seta. The outer lobe is furnished with three setae (Plate LVIII, fig. 6).

This species can easily be separated from the other members of the genus by the very
tumid cephalic segment, and by the shape of the fifth pair of feet.

Occurrence. — Two females were obtained from the plankton collected at Station
142, off Laiwui, coast of Obi Major.

Genus Thaumaleus Kroyer, 1849.

The members of this genus are closely related to Monstrilla in general appearance, in
the jointing of the antennules, in the entire suppression of the antennae, mandibles, maxillae

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240

and maxillipedes, and in the structure of the five pairs of feet. The abdomen of the female
is only two-jointed and each furcal joint is furnished with three setae.

The genus was represented in the 'Siboga' collections by two apparently undescribed species.

1. Thaumalcus (ntllatus nov. sp. Plate LYIII, figs. 7 and 8.

Male — length 1,7 mm.

Seen from above, the body appears elongate and is rather slender. The cephalic segment
is considerably inflated at the distal end. It is distinctly shorter than the posterior part of the
body. The frontal margin is broad and rounded with a distinct protuberance in the middle.

The abdomen is composed of three segments. The second segment is shorter and the
anal segment is longer than the others. The distal end of the anal segment is expanded. The
furcal joints are short and broad. Each joint is furnished with four apical setae that are
distinctly swollen at the base (Plate LVIII, fig. 7).

The antennules are five-jointed, prehensile, and equal to three-fifths of the length of
the cephalic segment.

The fifth pair of feet is rudimentary and without setae (Plate LVIII, fig. 8).

This form does not agree with any of the known mal es belonging to the genus. It
can readily be recognised by the proportional length of the abdominal segments, and by the
swollen base of each seta on the furcal joints.

Occurrence. - Thirty specimens were obtained from the plankton collected at Station
142, off Laiwui, Paternoster Islands.

2. Thaumaleus gigas nov. sp. Plate LVIII, figs. 9 and 10.

Female — length 8 mm.

Seen from above, the body appears very elongate and is rather slender. The cephalic
segment is very long. It is two and one-third times longer than the posterior end of the animal.
The segment is contracted in front and is much inflated behind. The frontal margin is narrow
and is slightly concave.

The abdomen is composed of two segments. The genital segment is sub-quadrangular
in shape. The margins slope inwards from the middle to the distal end. The segment is slightly
longer than the anal segment and is traversed by a distinct suture. The anal segment is
rather shorter than the genital segment. It is very narrow in front and is much expanded at
the posterior end. The furcal joints are nearly as long as the anal segment. Each joint is
furnished with one marginal seta and two apical setae (Plate LVIII, fig. 9).

The antennules are comparatively short and four-jointed, and equal to about one-sixth
of the length of the cephalic segment.

The fifth pair of feet is moderately broad. The apex is bi-lobed. The inner lobe is rather
broad but does not extend beyond the apex of the outer lobe. It is without setae. The outer
lobe is furnished with three moderately long setae (Plate LVIII, fig. 10).

This species can readily be separated from the other members of the genus by the

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241

proportional length of the abdominal segments, and by the structure of the fifth pair of feet.
Occurrence. - Three specimens were obtained from die plankton collected at Station
99, off North Ubian, Sulu Islands.

Tribe ISOKERANDRIA.

41. Family Oncaeidai..
Genus Oncaea Philippi, 1843.

The members of this genus can readily be recognised by their rather pyriform body.
The forehead is furnished with a pair of eye-lenses. The abdomen is composed of four segments
in the female. The antennules are six-jointed.

The males resemble the females in general appearance, but the abdomen is composed
of five segments.

Five species belonging to this genus were represented in the plankton collected by the
'Siboga' in the Malay Archipelago.

1 . Oncaea conifera Giesbrecht.

Oncaea conifera Giesbrecht, 1891, p. 477.

Oncaea conifera Giesbrecht, 1892, p. 591, pis. 2 & 47.

Oncaea conifera I. C. Thompson, 1900, p. 287.

Oncaea conifera Cleve, 1901, p. 8.

Oncaea conifera A. Scott, 1902, p. 418.

Oncaea conifera Giesbrecht, 1903, p. 41.

Oncaea conifera Thompson & Scott, 1903, p. 285.

Oncaea conifera Cleve, 1903, p. 365.

Oncaea conifera Cleve, 1904, p. 193.

Oncaea conifera Farran, 1905, p. 47.

Oncaea conifera Esterly, 1905, p. 216, fig. 55.

Oncaea conifera Wolfenden, 1905 (a), p. 1029.

Oncaea conifera Pearson, 1906, p. 25.

Oncaea conifera Farran, 1908, p. 92.

Oncaea conifera van Breemen, 1908, p. 189, fig. 202.

This species appeared to be rather scarce in the area investigated by the 'Siboga'. It
was only noted at the following three stations.

Stat. 47', 11 specimens. — Stat. 141 (HENSEN vertical net, 1500 metres to surface), 2 speci-
mens. — Stat. 143 (HENSEN vertical net, 1000 metres to surface), 24 specimens.

Oncaea conifera can readily be recognised by the evenly contracted and sloping sides
of the genital segment of the female, by the second abdominal segment being distinctly longer
than the third segment, and by the furcal joints being as long as the anal segment.

This species appears to have a wide distribution in all parts of the great oceans. It
has previously been record ed from the Malay Archipelago.

241

SiriOGA-EXPEDITIE XXIX a. 3'

242

2. Oncaea media Giesbrecht.

Oncaea media Giesbrecht, 1891, p. 477.

Oncaea media Giesbrecht, 1893, p. 591, pis. 2 & 47.

Oncaea media Cleve, 190 1, p. 8.

Oncaea media A. Scott, 1902, p. 419.

Oncaea media Thompson & Scott, 1903, p. 284.

Oncaea media Cleve, 1903, p. 366.

Oncaea media Cleve, 1904, p. 193.

Oncaea media Wolfenden, 1905(0), p. 1029.

Oncaea media Pearson, 1906, p. 35.

Oncaea media van Breemen, 1908, p. 187, fig. 200.

This Oncaea appeared to be very scarce in the area investigated by The 'Siboga'. It
was only found in the plankton collected at two stations.

Stat. 148 (HENSEN vertical net, 1000 metres to surface), 3 specimens. — Stat. 203 (HENSEN
vertical net, 1500 metres to surface), 4 specimens.

Oncaea media is closely related to Oncaea mediterranea and Oncaea venusta, but it can
readily be separated by the difference in the proportional length of the last three abdominal
segments and furcal joints.

This species is widely distributed in the great oceans.

3. Oncaea minuta Giesbrecht.

Oncaea minuta Giesbrecht, 1893, p. 591, pi. 57.

Oncaea minuta I. C. Thompson, 1900, p. 287.

Oncaea minuta I. C. Thompson, 1903, p. 34.

Oncaea minuta Thompson & Scott, 1903, p. 284.

Oncaea minuta Esterly, 1905, p. 217, fig. 56.

Oncaea minuta Norman & T. Scott, 1906, p. 197.

Oncaea minuta Farran, 1908, p. 92.

Oncaea minuta van Breemen, 1908, p. 188, fig. 201.

Specimens of this form were found in the plankton from the following five stations.

Stat. 75 (HENSEN vertical net, 11 metres to surface), 1 specimen. — Stat. 93. — Stat. 143
(HENSEN vertical net, 1000 metres to surface). — Stat. 217 (horizontal cylinder), 10 specimens. —
Stat. 304.

Oncaea minuta is a comparatively small species. It can be recognised by the rather
inflated genital segment of the female and by the furcal joints being as long as the anal segment.

This Oncaea has been recorded from the Atlantic, Indian and Pacific Oceans, and from
the Mediterranean.

4. Oncaea tenuimana Giesbrecht.

Oncaea tenuimana Giesbrecht, 1891, p. 477.

Oncaea tenuimana Giesbrecht, 1893, p. 591, pis. 44 & 47.

This species appeared to be very scarce in the area traversed by the 'Siboga'. It was
only present in the plankton collected at two stations.

2 43

Stat. 143 (HENSEN vertical net, 1000 metres to surface), 2 specimens. -- Stat. 148 (HENSEN
vertical net, 1000 metres to surface), 2 specimens.

Oncaea tenuimana can be recognised by the rather long abdomen and comparatively
short furcal juints.

This species is evidently rather limited in its distribution. It does not appear to have
been recorded by any other observer since Giesbrecht described it from specimens found in
plankton collected in the Pacific Ocean.

5. Oncaea venus/a Philippi.

Oncaea venusta Philippi, 1843, p. 62, pi. 4.

Oncaea venusta Giesbrecht, 1893, p. 590, pis. 2, 3 & 47.

Oncaea venusta I. C. Thompson, 1900, p. 286.

Oncaea venusta Wheeler, 1900, p. 190, fig. 27.

Oncaea venusta A. Scott, 1902, p. 418.

Oncaea venusta Thompson & Scott, 1903, p. 284.

Oncaea venusta Cleve, 1903, p. 366.

Oncaea venusta Cleve, 1904, p. 194.

Oncaea venusta Wolfenden, 1905 (a), p. 1029.

Oncaea venusta Pearson, 1906, p. 34.

Oncaea venusta Norman & T. Scott, 1906, p. 197.

Oncaea venusta van Breemen, 1908, p. 186, fig. 198.

This proved to be the most common and widely distributed member of the genus in the

area investigated by the 'Siboga'. It was present in the plankton collected at the following stations.

Stat 16. — Stat. 35. — Stat. 36. Stat. ^. — Stat. 40. Stat. 471'. — Stat. 50. — Stat. 66. —
Stat. 71. — Stat. 75 (HENSEN vertical net, 1 1 metres to surface). — Stat. 81. — Stat. 89. —
Stat. 93. — Stat. 96 (day). — Stat. 98. — Stat. 99. — Stat. 10 1. — Stat. 110. — Stat. 112. —
Stat. 118 (HENSEN vertical net, 900 metres to surface). — Stat. 121. — Stat. 122. -- Stat.
125 (day). — Stat. 128 (HENSEN vertical net, 700 metres to surface). — Stat. 133. — Stat. 136. —
Stat. 138. — Stat. 141 (HENSEN vertical net, 1500 metres to surface). — Stat 142. — Stat. 143
(HENSEN vertical net, 1000 metres to surface). — Stat. 144. — Stat. 148 (HENSEN vertical
net, 1000 metres to surface). — Stat. 157. — Stat. 165. — Stat. 168. — Stat. 169. — Stat.
184. — Stat. 185 (HENSEN vertical net, 1536 metres to surface). ■ — Stat. 186. — Stat. 193. —
Stat. 194 — 7. — Stat. 203 (surface). — Stat. 203 (HENSEN vertical net, 1500 metres to
surface). — Stat. 205. — Stat. 210'. — Stat. 213. — Stat. 216. — Stat. 217 (horizontal
cylinder). — Stat. 220 (surface). — Stat. 220 (HENSEN vertical net, 200 metres to surface. —
Stat. 223. — Stat. 224. — Stat. 229. — Stat. 243 (HENSEN vertical net, 1000 metres to
surface. — Stat. 252. — Stat. 271. — Stat. 276 (HENSEN vertical net, 750 metres to sur-
face. — Stat. 282. — Stat. 304. — Stat. 315.

Oncaea venusta can readily be separated from the other members of the genus by the
comparatively long furcal joints. The furcal joints are longer than the combined length of the
third and fourth abdominal segments.

This species is widely distributed in the warm regions of all the great oceans.

Genus Conaea Giesbrecht, 1891.

This genus is closely related to Oncaea, but it is readily separated by the long end
joint of the antennae with its armature of very long and slender curved spines.
One species was represented in the plankton collected by the 'Siboga'.

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^44

i. Conaea gracilis (Dana).

Antaria gracilis Dana, 1852, p. 1229, pi. 86.

Conaea rapax Giesbrecht, 1891, p. 477.

Conaea rapax Giesbrecht, 1893, p. 605, pis. 5 & 48.

Oncaea gracilis T. Scott, 1893, p. 116, pi. XIII, figs. 4 — 12.

Conaea rapax I. C. Thompson, 1903, p. 34.

Conaea rapax Cleve, 1904, p. 188.

Conaea rapax Farran, 1905, p. 47.

Conaea rapax Pearson, 1906, p. 35.

Conaea rapax Farran, 1908, p. 96.

Conaea rapax van Breemen, 1908, p. 192, fig. 206.

Fifteen specimens of this species were found in the plankton collected at nine stations.

Stat. 118 (HENSEN vertical net, 900 metres to surface), 2 specimens. — Stat. 128 (HENSEN
vertical net, 700 metres to surface), 1 specimen. — Stat. 141 HENSEN vertical net, 1500
metres to surface), 2 specimens. -- Stat. 143 (HENSEN vertical net, 1000 metres to surface),
5 specimens. — Stat. 185 (HENSEN vertical net, 1536 metres to surface), 1 specimen. — Stat.
203 (HENSEN vertical net, 1500 metres to surface), 1 specimen. — Stat. 230 (HENSEN vertical
net, 2000 metres to surface), 1 specimen. - - Stat. 276 (HENSEN vertical net, 750 metres to
surface), 1 specimen.

Conaea gracilis can readily be recognised by its general appearance, by the long third
joint of the antennules, and by the armature of long slender curved spines on the apical joint
of the antennae.

Giesbrecht's Conaea rapax appears to be identical with Antaria gracilis Dana.

This species has been recorded from various parts of the Atlantic and Pacific Oceans.

Genus Lubbockia Claus, 1863.

The members of this genus are readily recognised by the elongate pyriform body and
by the long slender abdomen. The fifth pair of feet is moderately prominent and the terminal
spines are usually lamelliform.

Two species were represented in the plankton collected by the 'Siboga'.

1. Lubbockia aculeata Giesbrecht.

Lubbockia aculeata Giesbrecht, 1891, p. 417.
Lubbockia aculeata Giesbrecht, 1893, p. 606, pi. 48.
Lubbockia aculeata Cleve, 1903, p. 364.

Specimens identical with the above species were obtained from the plankton collected
at the following stations.

Stat. 35, 2 specimens. — Stat. 1 18 (HENSEN vertical net, 900 metres to surface), 3 speci-
mens. - • Stat. 141 (HENSEN vertical net, 1500 metres to surface), 6 specimens. — Stat.
143 (HENSEN vertical net, 1000 metres to surface), 3 specimens. — Stat. 203 (HENSEN
vertical net, 1500 metres to surface), 1 specimen.

Lubbockia aculeata is closely related to Lubbockia squillimaua, but the female can be

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245

separated by the presence of a fringe of small spines on the distal end of die first, second
and third abdominal segments.

The known distribution of this species appears to be very limited. It has been recorded
from the Pacific by Giesbrecht, and from the Red Sea by Cleve.

2. Lubbockia squillimana Clans.

Lubbockia squillimana Claus, 1863, p. 164, pi. XXV, figs. 1 — 5.

Lubbockia squillimana Brady, 1883, p. 118, pis. LUI & LIV.

Lubbockia squillimana Giesbrecht, 1893, p. 606, pis. 4 & 48.

Lubbockia squillimana T. Scott, 1893. p. 115.

Lubbockia squillimana A. Scott, 1902. p. 419.

Lubbockia squillimana Thompson & Scott, [903, p. 285.

Lubbockia squillimana Wolfenden, 1905 (a), p. 1030.

This species appeared to be very rare in the area investigated by the 'Siboga'. One
specimen was obtained from the plankton collected at each of the following four stations.

Stat. 118 (HENSEN vertical net, 900 metres to surface). — Stat. [28 (HENSEN vertical net.
700 metres to surface). — Stat. 143 (HENSEN vertical net, 1000 metres to surface). -- Sta. 315,

Lubbockia squillimana can be distingnished by the absence of small spines on the distal
end of the first, second and third abdominal segments.

This Lubbockia has been recorded from the Atlantic, Indian and Pacific Oceans, and
from the Mediteranean.

42. Family Corvcaeidae.
Genus Corycaeus Dana, 1846.

The members of this genus are readily recognised by their elongate and sub-cylindrical
body, by the one or two-jointed abdomen, and by the presence of a pair of comparatively
large eye-lenses on the frontal margin of the cephalic segment.

Sixteen species belonging to this genus were represented in the plankton collected by
the 'Siboga' during the investigations in the Malay Archipelago.

1 . Corvcaeus alatus Giesbrecht.

Corycaeus alatus Giesbrecht, 1891, p. 480.
Corvcaeus alatus Giesbrecht, 1893, p. 661, pi. 51.
Corycaeus alatus I. C. Thompson, 1900, p. 292.

Twenty specimens were found in the plankton collected at the following three stations.

Stat. 66, 8 specimens. — Station 128 (Hexsex vertical net, 700 metres to surface, 6 speci-
mens. — Stat. 217 (horizontal cylinderi, 9 specimens.

Corycaeus alatus can be clistinguished from the other members of the genus by the

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246

slightly inflated genital segment of the female, by the short anal segment, and by the long
slender furcal joints. The furcal joints are about four times the length of the anal segment.

This species appears to be rather sparsely distributed. It has been recorded from the
Indian and Pacific Oceans.

1. Corycaeus carinatus Giesbrecht.

Corycaeus carinatus Giesbrecht, 1891, p. 481.
Corycaeus carinatus Giesbrecht, 1S93, p. 661. pi. 51.
Corycaeus carinatus I. C. Thompson, 1900, p. 293.
Corycaeus carinatus Wheeler, 1900, p. 192, fig. 30.
Corycaeus carinatus A. Scott, 1902, p. 421.
Corycaeus carinatus Thompson & Scott, 1903, p. 285.
Corycaeus carinatus Wolfenden, (1905 (a), p. 1029.
Corycaeus carinatus Esterly, 1905, p- 226, fig. 62.

One specimen identical with the above species was obtained fröm the plankton collected
with the Hensen vertical net at Station 203, 1500 metres to the surface.

Corycaeus carinatus is closely related to Corycaeus rostrahts. The abdomen of the
female consists of a single segment, but it is distinctly more inflated than in Corycaeus rostrahts
and the furcal joints are moderately long, and slender. The length of the furcal joints is equal
to half the length of the abdomen. The furcal joints of Corycaeus rostrahts are equal to one-
fourth of the length of the abdomen.

This Corycaeus has been recorded from the Atlantic, Indian, and Pacific Oceans.

3. Corycaezts conciwnus Dana.

Corycaeus concinnus Dana, 1847, pp. 150 — 154.

Corycaeus concinnus Dana, 1852, p. 1225, pi. 86.

Corycaeus concinnus Giesbrecht, 1893, p. 661, pi. 51.

Corycaeus concinnus A. Scott, 1902, p. 421.

Corycaeus concinnus Thompson & Scott, 1903, p. 286.

Twenty-two specimens belonging to the above species were obtained from the plankton
collected at the following stations.

Stat. 50, 3 specimens. — Stat. 141 (HENSEN vertical net, 1500 metres to surface), 10 spe-
cimens. ■ — Stat. 148 (Hensen vertical net, 1000 metres to surface), 4 specimens. — Stat
230 (HENSEN vertical net, 2000 metres to surface), 5 specimens.

The female of Corycaeus concinnus can be recognised by the long and rather slender
abdomen. The abdomen consists of a single segment. The proximal end is distinctly inflated,
and the distal end is rather sharply contracted. The furcal joints are moderately slender and
are equal to about one-third of the length of the abdomen.

Corycaeus concinmts has been recorded from the Indian and Pacific Oceans.

4. Corycaeus danae Giesbrecht.

Corycaeus danae Giesbrecht, 1891, p. 480.
Corycaeus danae Giesbrecht, 1893, p. 660, pi. 51.

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^47

Corycacus danae Giesbrecht, 1895, p. 261.
Corycaeus danae I. C. Thompson, 1900, p. 291.
Corycaeus danae Cleve, 1901, p. 6.
Corycaeus danae A. Scott, 1902, p. 420.
Corycaeus danae Thompson & Scott, 1903, p. 285.
Corycaeus danae Cleve, 1903, p. 360.
Corycaeus danae Cleve, 1904, p. 188.
Corycaeus danae Wolfenden, 1905 (a), p. 1026.

This Corycaeus proved to be moderately common in the area investigated by the
'Siboga'. It was present in the plankton collected at the following thirty-two stations.

Stat. 16. — Stat. 36. — Stat. 47''. — Stat. 66. — Stat. 71. — Stat. 75 (Hensen vertical
net, 11 metres to surface). — Stat. 81. — Stat. 96 (day). Stat. 96 (night). — Stat. 98. -
Stat. 99. — Stat. 118 (HENSEN vertical net, 900 metres to surface). — Stat. 128 (HENSEN
vertical net, 700 metres to surface). — Stat. 138. — Stat. 142. — Stat. 143 (HENSEN ver-
tical net, 1000 metres to surface). — Stat. 146. — Stat. 148 (HENSEN vertical net, 1000
metres to surface). — Stat. 165. — Stat. 189". — Stat. 203 (HENSEN vertical net, 1500
metres to surface). — Stat. 204. — Stat. 213. — Stat. 215'. — Stat. 217 (horizontal
cylinder). — Stat. 220 (HENSEN vertical net, 200 metres to surface). — Stat. 225. — Stat.
230 (HENSEN vertical net, 2000 metres to surface). — Stat. 243 (HENSEN vertical net, 1000
metres to surface). — Stat. 276 (HENSEN vertical net, 750 metres to surface). — Stat. 304. —
Stat. 315.

The abdomen of the female of this species is composed of two segments. The genital
segment is narrowly ovate in outline. The furcal joints are two and a half times the length
of the anal segment.

Corycaeus danae has been recorded from the Indian and Pacific Oceans.

5. Corycaeus elongatns Claus.

Corycaeus elongatns Claus, 1863, p. 157, pi. XXIV, figs. 3 & 4.
Corycaeus elongatns Giesbrecht, 1893, p. 659, pis. 49 & 51.
Corycaeus elongatns I. C. Thompson, 1900, p. 292.
Corycaeus elongatns Wheeler, 1900, p. 192, fig. 29.
Corycaeus elongatns Thompson & Scott, 1903, p. 285.
Corycaeus elongatns Cleve, 1903, p. 360.

One specimen was found in the plankton collected at the following four stations.

Stat. 50. — Stat. 118 (HENSEN vertical net, 900 metres to surface). — Stat [85 HENSEN
vertical net, 1536 metres to surface). — Stat. 271.

The abdomen of the female of this Corycaeus is composed of one segment. The
segment is much contracted in front, considerably inflated in the middle, and then slopes
evenly to the rather narrow distal end. The furcal joints are moderately long and slender, and
are equal to fully half the length of the abdomen.

Corycaeus elongatns has been recorded from the Atlantic, Indian and Pacific Oceans,
and from the Mediterranean.

6. Corycaeus Jïaccus Giesbrecht.

Corycaeus flaccus Giesbrecht, 1891, p. 480.
Corycaeus flaccus Giesbrecht, 1S93, p. 659, pi. 51.

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2*48

Corycaeus flaccus Thompson & Scott, 1903, p. 285.
Corycaeus flaccus Geve, 1903, p. 361.

Fourteen specimens of the above species were obtained from the plankton collected
with the Hensen vertical net at the followino- three stations.

Stat. 128 (700 metres to surface), 6 specimens. — Stat. 203 (1500 metres to surface), 3 spe-
cimens. — Stat. 276 (750 metres to surface), 5 specimens.

Corycaeus flaccus resembles Corycacus alatus in general appearance. The abdomen is
composed of two segments. The genital segment is considerably inflated and the distal end
of the dorsal surface is produced in the middle line into a short blunt tooth-like process. The
furcal joints are moderately long and slender, and are about two and a half times longer
than the anal segment. The proximal end of the joints is swollen.

This species has been recorded from the Atlantic, Indian and Pacific Oceans, and from
the Mediterranean.

7. Corycaeus furcifcr Claus.

Corycaeus furcifer Claus, 1863, p. 157, pi. XXIV, figs. 7 — 12.
Corycaeus furcifcr Giesbrecht, 1893, p. 660, pis. 49 & 51.
Corycaeus furcifer I. C. Thompson, 1900, p. 291.
Corycaeus furcifer Cleve, 1901, p. 6.
Corycaeus furcifer A. Scott, 1902, p. 421.
Corycaeus furcifer Thompson & Scott, 1903, p. 285.
Corycaeus furcifer Cleve, 1904, p. 188.

This species appeared to be moderately frequent and fairly well distributed in the area
investigated by the 'Siboga'. It was found in the plankton collected at the following stations.

Stat. 50. — Stat. 98. -- Stat. 118 (HENSEN vertical net, 900 metres to surface). — Stat. 128
(HENSEN vertical net, 700 metres to surface). — Stat. 129. — Stat. 133. — Stat. 141 (HENSEN
vertical net, 1500 metres to surface). — Stat. 144. • ■ Stat. 157. — Stat. 165. — Stats.
194 — 7. — Stat. 203 (HENSEN vertical net, 1500 metres to surface). — Stat. 214. — Stat.
217. — Stat. 217 (horizontal cylinder). — Stat. 220 (HENSEN vertical net, 200 metres to
surface). -- Stat. 223. — Stat. 224. — Stat. 225. — Stat. 276 (HENSEN vertical net, 750
metres to surface). — Stat. 282.

The abdomen of the female of Corycaeus furcifer is composed of two segments. The
furcal joints are long and slender, and are nearly twice as long as the abdomen.

This Corycaeus has been recorded from the Atlantic, Indian and Pacific Oceans, and
from the Mediterranean.

8. Corycaeus gibbulus Giesbrecht.

Corycaeus gibbulus Giesbrecht, 1891, p. 481.
Corycaeus gibbulus Giesbrecht, 1893, p. 660, pi. 51,
Corycaeus gibbulus I. C. Thompson, 1900, p. 293.
Corycaeus gibbulus Cleve, 1901, p. 6.
Corycaeus gibbulus A. Scott, 1902, p. 420.
Corycaeus gibbulus Thompson & Scott, 1903, p. 286.
Corycaeus gibbulus Cleve, 1903, p. 361.
Corycaeus gibbulus VVolfenden, 1905(1-?), p. 1028.

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249

Corycaeus gibbulus although not common, appeared to be well distributed in the area
investigated by the 'Siboga'. It was present in the plankton collected at the following stations.

Stat. 35. — Stat. 36. — Stat. 50. -- Stat. 71. — Stat. 75 (Hensen vertical net, 11 metres
to surface). -- Stat. 96 (day). — Stat. 96 (night). — Stat. 99. -- Stat. 128 (Hensen vertical
net, 700 metres to surface). - - Stat. 142. — Stat. 148 (HENSEN vertical net, 1000 metres
to surface). — Stat. 184. — Stat. 186. — Stat. 203 (HENSEN vertical net, 1500 metres to
surfacej. — Stat. 213. — Stat. 216. — Stat. 217 (horizontal cylinder). -- Stat. 220 (Hensen
vertical net, 200 metres to surface). — Stat. 225. — Stat. 229. — Stat. 276 (Hensen
vertical net, 750 metres to surface). — Stat. 304. — Stat. 315.

The abdomen is composed of two segments. Seen from above, the second segment
appears moderately large and funnel-shaped, with the wide end in front. The furcal joints are
moderately short and stout. The joints are rather shorter than the anal segment.

This Corycaeus has been recorded from various parts of the Indian Ocean, and also
from the Pacific.

9. Corycaeus gracilicaudatus Giesbrecht.

Corycaens gracilicaudatus Giesbrecht, 1891, p. 481.
Corycaeus gracilicaudatus Giesbrecht, 1893, p. 661, pi. 51.
Corycaeus gracilicaudatus Cleve, 1901, p. 6.
Corycaeus gracilicaudatus A. Scott, 1902, p. 421.
Corycaeus gracilicaudatus Thompson & Scott, 1903, p. 286.
Corycaeus gracilicaudatus Cleve, 1903, p. 361.
Corycaeus gracilicaudatus Wolfenden, 1905 (a), p. 1029.

This species appeared to be rather scarce in the area investigated by the 'Siboga'. It
was only observed in the plankton collected at three stations.

Stat. 142. — Stat. 143 (Hensen vertical net, 1000 metres to surface). — Stat. 304.

The abdomen of the female is moderately short and rather slender. It is composed
of two segments. The genital segment is somewhat inflated in the middle. The second seg-
ment is narrow and cylindrical. The furcal joints are comparatively long and slender, and are
slightly longer than the anal segment.

Corycaeus gracilicatidatus has been recorded from various parts of the Indian Ocean
and from the Pacific.

10. Corycaeus longistylis Dana.

Corycaeus longistylis Dana, 1849, pp. 8 — 61.
Corycaeus longistylis Dana, 1852, p. 1212, pi. 85.
Corycaeus longistylis Giesbrecht, 1893, p. 661, pi. 51.
Corycaeus longistylis I. C. Thompson, 1900, p. 293.
Corycaeus longistylis Cleve, 1901, p. 6.
Corycaeus longstylis Thompson & Scott, 1903, p. 286.
Corycaeus longistylis Wolfenden, 1905^), p. 1026.

249

SIBOGA-EXPEDITIE XXIX a.

2=;o

Specimens belonging to this species were founcl in the plankton collected at the
following stations.

Stat. 36. — Stat. 66. - Stat. 71. — Stat. 101. ■ ■ Stat. 112. •- Stat. 121. — Stat. 125

(night). — Stat. 128 (HENSEN vertical net, 700 metres to surface). — Stat. 133. -- Stat.

143 (HENSEN vertical net, 1000 metres to surface). — Stat. 148 (HENSEN vertical net, 1000

metres to surface). — Stat. 271. — Stat. 276 (HENSEN vertical net, 750 metres to surface).

Corycaezcs longistylis resembles Corycaeus furcifer in general appearance. It can easily
be distinguished from that species, however, by the abdomen being composed of a single
segment, and by the rather shorter furcal joints.

This Corycaeus has been recorded from the Indian and Pacific Oceans.

1 1 . Corycaetis lubbocki Giesbrecht.

Corycaeus lubbocki
Corycaeus lubbocki
Corycaeus lubbocki
Corycaeus lubbocki
Corycaeus lubbocki

Giesbrecht, 1891, p. 481.
Giesbrecht, 1893, p. 660, pi. 51.
A. Scott, 1902, p. 421.
Thompson & Scott, 1903, p. 285.
Cleve, 1903, p. 361.

Corycaeus lubbocki appeared to be rather scarce in the Malay Archipelago. It was only
observed in the plankton collected at the following five stations.

Stat. 71. — Stat. 96 (night). — Stat. 213. — Stat. 271. — Stat. 315.

This is a moderately slender form, with the abdomen composed of two segments. The
genital segment is elongate ovate in shape. The second segment is short, narrow and cylindrical.
The furcal joints are rather long and slender, and slightly divergent. The joints are about
three times the length of the anal segment.

Corycaeus lubbocki has been recorded from the Indian and Pacific Oceans, and from
the Red Sea.

12. Corvcaeus obtusus Dana.

Corycaeus obtusus Dana, 1849, pp. 8 — 61.

Corycaeus obtusus Dana, 1852, p. 1214, pi. 85.

Corycaeus obtusus Brady, 1883, p. 116, pi. XLVI.

Corycaeus obtusus Giesbrecht, 1893, p. 659, pis. 3 & 51.

Corycaeus obtusus T. Scott, 1893, p. 112.

Corycaeus obtusus Giesbrecht, 1895, p. 261.

Corycaeus obtusus Cleve, 1901, p. 6.

Corycaeus obtusus A. Scott, 1902, p. 421.

Corycaeus obtusus Thompson & Scott, 1903, p. 286.

Corycaeus obtusus Cleve, 1903, p. 361.

Corycaeus obtusus Wolfenden, 1905 (a), p. 1026.

This species proved to be moderately common and generally distributed in the area
investigated by the 'Siboga', as shewn by the following records of its occurrence.

25i

Stat. 16. — Stat. 35. - - Stat. 36. — Stat. 47''. -- Stat. 71. -- Stat. 75 (HENSEN vertical
net, 11 moties to surface). ■ - Stat. 93. — Stat. 99. ■ - Stat. 121. — Stat. 141 (HENSEN
vertical net, 1500 metres to surface). — Stat. 142. - - Stat. 143 (HENSEN vertical net, 1000
metres to surface). - Stat. 14S (HENSEN vertical net, 1000 metres to surface) — Stat. 149. —
Stat. 165. — Stat. 174. — Stat. 184. — Stat. 185 (HENSEN vertical net, 1536 metres to surface). —
Stat. 203 (HENSEN vertical net, 1500 metres to surface). — Stat. 204. — Stat. 205. —
Stat. 217 (horizontal cylinder). — Stat. 220 (HENSEN vertical net, 200 metres to surface). -
Stat. 229. — Stat. 243 (HENSEN vertical net, 1000 metres to surface). — Stat. 245. — Stat.
271. -- Stat. 276 (HENSEN vertical net, 750 metres to surface). — Stat. 304.. — Stat. 315.

Corycaeus obtusus is a rather small and moderately robust species. The abdomen of the
female is composed of two segments. The second segment is comparatively short and wide.
The furcal joints are slightly divergent and are rather longer than the anal segment.

This Corycaeus has been recorded from various parts of the Indian Ocean and from
the Pacific.

1 3. Corycaeus robust lts Giesbrecht.

Corycaeus robustus Giesbrecht, 1891, p. 4S0.

Corycaeus robustus Giesbrecht, 1893, p. 660, pis. 2 & 51.

Corycaeus robustus Cleve, 1901, p. 6.

Corycaeus robustus Thompson & Scott, 1903, p. 286.

Corycaeus robustus Cleve, 1903, p. 361.

Corycaeus robustus Cleve, 1904, p. 188.

Specimens belonging to this species were obtained frorn the plankton collected at the
following stations in the area investigated by the 'Siboga'.

Stat. 96 (day). — Stat. 98. — Stat. 99. — Stat. 112. -- Stat. 128 (HENSEN vertical net, 700
metres to surface). — Stat. 142. — Stat. 169. — Stats. 194—7. — Stat. 203 (surface). — Stat.
2IO'. — Stat. 215'. — Stat. 216. — Stat. 217 (horizontal cylinder). — Stat. 223. — Stat.
224. — Stat. 225. — Stat. 282. — Stat. 304.

2 :

Corycaeus robustus is a moderately large and stout form. The abdomen of the female
is composed of two segments. The genital segment is large and oval in shape. A distinct
tubercle is present on the dorso-lateral margins. The anal segment is short and wide. The
furcal joints are stout and are slightly divergent. Each joint is about one and a half times
longer than the anal segment.

This Corycaeus has been recorded from the Indian and Pacific Oceans.

14. Corycaeus speciosus Dana.

Corycaeus speciosus Dana, 1849, pp. 8 — 61.
Corycaeus speciosus Dana, 1852 — 55, p. 1220, pi. 86.
Corycaeus speciosus Brady, 1883, p. 115, pi. XLVI.
Corycaeus speciosus Giesbrecht, 1893, p. 660, pi. 51.
Corycaeus speciosus T. Scott, 1893, p. 112.
Corycaeus speciosus I. C. Thompson, 1900, p. 292.
Corycaeus speciosus A. Scott, 1902, p. 420.
Corycaeus speciosus Thompson & Scott, 1903, p. 285.

251

Corycaeus speciosus Cleve, 1903, p. 362.

Corycaeus speciosus Cleve, 1904, p. 189.

Corycaeus speciosus Wolfenden, 1905(0), p. 1026.

Corycaeus speciosus Pearson, 1906, p. 34.

Corycaeus speciosus van Breemen, 1908, p. 199, fig. 212.

This distinct species proved to be widely distributed in the area investigated by the
'Siboga'. It was present in the plankton collected at the following stations.

Stat. 36. — Stat. 40. — Stat. 471.. — Stat. 71. — Stat. 75 (HENSEN vertical net, 11 metres to
surface). — Stat. 81. — Stat. 89. — Stat. 93. — Stat. 96 (day). — Stat. 98. — Stat. 112.-
Stat. 118 (HENSEN vertical net, 900 metres to surface). — Stat. 121. — Stat. 128 (HENSEN
vertical net, 700 metres to surface). — Stat. 133. -- Stat. 138. — Stat. 141 (HENSEN ver-
tical net, 1500 metres to surface). — Stat. 142. — Stat. 143 (HENSEN vertical net, 1000
metres to surface). — Stat. 148 (HENSEN vertical net, 1000 metres to surface). — Stat.
165. -- Stat. 184. — Stat. 185 (HENSEN vertical net, 1536 metres to surface). — Stat. 203
(surface). — Stat. 203 (HENSEN vertical net, 1500 metres to surface). — Stat. 213. —
Stat. 215'. — Stat. 216. - Stat. 217 (horizontal cylinder). — Stat. 220 (HENSEN vertical
net, 200 metres to surface). - - Stat. 223. — Stat. 230 (HENSEN vertical net, 2000 metres
to surface). — Stat. 245. — Stat. 271. -- Stat. 276 (HENSEN vertical net, 750 metres to
surface). — Stat. 282. — Stat. 304.

The moderately long and divergent furcal joints of the female of this species readily
distinguish it from any of the other members of the genus.

Corycaeus speciosus has been recorded from various parts of the Atlantic, Indian and
Pacific Oceans.

15. Corycaeus tenuis Giesbrecht.

Corycaeus tenuis Giesbrecht, 1891, p. 481.
Corycaeus tenuis Giesbrecht, 1893, p. 660, pi. 51.
Corycaeus tenuis Thompson & Scott, 1903, p. 286.

Specimens belonging to the above species were found in the plankton collected at the
following seven stations.

Stat. 47''. — Stat. 142. — Stat. 143 (HENSEN vertical net, 1000 metres to surface). — Stat.
165. — Stat. 203 (HENSEN vertical net, 1500 metres to surface). — Stat. 271. — Stat. 315.

Corycaeus tenuis is a comparatively slender form and resembles Corycaeus lubbocki in
general appearance. The abdomen of the female is composed of tvvo segments. The anal
segment is narrow and cylindrical in shape. The furcal joints are slender and are nearly twice
as longf as the anal segment.

This Corycaeus has been recorded from the Indian and Pacific Oceans.

1 6. Corycaeus venustus Dana.

Corycaeus venustus Dana, 1849, pp. 8 — 61.
Corycaeus venustus Dana, 1852, p. 1222, pi. 86.
Corycaeus venustus Brady, 1883, p. 115, pi. LIV.
Corycaeus venustus Giesbrecht, 1893, p. 674, pis. 4 & 51.
Corycaeus venustus T. Scott, 1893, p. III»

252

253

Corycaeus venustus I. C. Thompson, 1900. p. 290.

Corycaeus venustus A. Scott, 1902, p. 420.

Corycaeus venustus I. C. Thompson, 1903, p. 35.

Corycaeus venustus Thompson & Scott, 1903, p. 285.

Corycaeus venustus Cleve, 1903, p. 362.

Corycaeus venustus Wolfcnden, 1905 («), p. 1026.

Corycaeus venustus Esterly, 1905, p. 225, fig. 61.

Corycaeus venustus Pearson, 1906, p. 34.

Corycaeus venustus van Breemen, 1908, p. 200, fig. 213.

This species although widely distributed in the area appeared to be rather rare. It was
found in the plankton collected at the following fifteen stations.

Stat. 47''. — Stat. 50. — Stat. 75 (HENSEN vertical net, 11 metres to surface). — Stat. 93. —
Stat. 101. — Stat. 118 (HENSEN vertical net, 700 metres to surface). — Stat. 125. —
Stat. 141 (HENSEN vertical net, 1500 metres to surface). — Stat. 185 (HENSEN vertical
net, 1536 metres to surface). — Stat. 203 (HENSEN vertical net, 1500 metres to surface). —
Stat. 205. -- Stat. 213. — Stat. 217 (horizontal cylinder). - Stat. 220 (Hensen vertical
net, 200 metres to surface). — Stat. 229.

Corycaeus venustus resembles Corycaeus tenuis in general appearance, except that it is
more robust. The abdomen is composed of two segments. The furcal joints are slightly lono-er
than the anal segment.

This species appears to be widely distributed in the Atlantic, Indian and Pacific Oceans.
It has also been recorded from the Mediterranean.

43. Family Sapphirinidae.
Genus Sapphirina J- V. Thompson, 1829.

The members of this genus are easily recognised by the semi-transparent, ovate or sub-
ovate depressed body, by the comparatively short lamelliform furcal joints, and by the presence
of a pair of eyedenses on the frontal margin of the cephalic segment.

Fifteen species belonging to this genus were represented in the plankton collected
during the investigations of the 'Siboga', in the Majay Archipelago. One of the species does
not appear to have previously been described.

1 . Sappliirina angusta Dana.

Sapphirina angusta Dana, 1849, p. 41.

Sapphirina angusta Dana, 1S52, p. 1240, pi. 87.

Sapphirina angusta Giesbrecht, 1893, p. 619, pis. 52, 53 & 54.

Sapphirina angusta Giesbrecht, 1S95, p. 261.

Sapphirina angusta Cleve, 1903, p. 368.

Sapphirina angusta Cleve 1904, p. 196.

Sapphirina angusta Esterly, 1905, p. 221, fig. 58.

One specimen of the above species was found in the plankton collected at each of the
following nine stations.

253

254

Stat. 96 (day). — Stat. 96 (night). — Stat. 98. — Stat. 1 10. -- Stat. 136. — Stat. 141 (Hensen
vertical net, 1500 metres to surface). — Stat. 144. — Stat. 185 (HENSEN vertical net,
1536 metres to surface). — Stat. 282.

The furcal joints of this species are nearly three times longer than broad. The distal
end of the inner margin terminates in a moderately strong tooth.

Sapphirina angusta has been recorded from the Atlantic, Indian and Pacific Oceans,
and from the Mediterranean.

2. Sapphirina auronitens Claus.

Sapphirina auronitens Claus, 1863, p. 153.

Sapphirina auronitens Giesbrecht, 1893, p. 619, pis. 4, 52 & 54.

Sapphirina auronitens Steuer, 1898, p. 4.

Sapphirina auronitens Cleve, 1901, p. 8.

Sapphirina auronitens A. Scott, 1902, p. 419.

Sapphirina auronitens Thompson & Scott, 1903, p. 287.

Specimens of this species were obtained from the plankton collected at the following
stations in the area traversed by the 'Siboga'.

Stat. 93. - - Stat. 98. — Stat. 117'. — Stat. 172. — Stat. 185 (Hensen vertical net, 1536
metres to surface). Stat. 193. — Stat. 203 (HENSEN vertical net, 1500 metres to sur-

face. — Stat. 215'.

Sapphirina auronitens is a moderately wide species with broadly oval furcal joints. Each
joint is one and a half times longer than broad. The apex is rather pointed.

This species has been recorded from the Mediterranean and Red Sea, and from various
parts of the Indian Ocean.

3. Sapphirina bicuspidata Giesbrecht.

Sapphirina bicuspidata Giesbrecht, 1891, p. 479.

Sapphirina bicuspidata Giesbrecht, 1893, p. 620, pis. 52 & 54.

Sapphirina bicuspidata Steuer, 1898, p. 5.

Sapphirina bicuspidata Thompson & Scott, 1903, p. 287.

This species was represented in the plankton collected at the following stations in the
Malay Archipelago.

Stat. 16. — Stat. 165. — Stat. 172. — Stat. 184. — Stat. 185 (Hensen vertical net, 1536
metres to surface). — Stat. 186. — Stat. 204. ■ — Stat. 217 (horizontal cylinder). — Stat.
220 (surface). — Stat. 225. — Stat. 271. — Stat. 315.

Sapphirina bieuspidata is a rather broadly oval species with wide furcal joints. The
joints are about one and two-third times longer than broad.

This Sapphirina has been recorded from the Indian and Pacific Oceans, from the
Mediterranean, and from the Red Sea.

4. Sapphirina darwini Haeckel.

Sapphirina darwini Haeckel, 1864, p. 105, pis. 2 & 3.
Sapphirina darwini Giesbrecht, 1893. p. 619, pis. 52 & 54.

254

255

This characteristic species appeared to be vcry limited in its distribution in the area
investigated. It was present in the plankton collected at the following six stations.

Stat. 125 (night). — Stat. 1S5 (HENSEN vertical net, 1536 metres to surface. -- Stat. 189".-
Stats. 194 — 7. — Stat. 203 (HENSEN vertical net, 1500 metres to surface). -- Stat. 282.

The furcal joints are moderately broad. The apex is rather truncate. The distal end of
the inner margin terminates in a small tooth.

This species has apparently only been recorded from the Mediterranean, and from \hr.
Pacific Ocean.

5. Sapphirina gastrica Giesbrecht.

Sapphirina gastrica Giesbrecht, 1891, p. 478.

Sapphirina gastrica Giesbrecht, 1893, p. 620, pis. 52 — 54.

Sapphirina gastrica I. C. Thompson, 1900, p. 288.

Sapphirina gastrica Thompson & Scott, 1903, p. 286.

Specimens belonging to this species were found in the plankton collected at the following
stations in the area traversed by the 'Siboga'.

Stat. 16. — Stat. 106. — Stat. 118 (HENSEN vertical net, 900 metres to surface). — Stat.
136. — Stat. 144. — Stat. 169. — Stat. 185 (HENSEN vertical net, 1536 metres to sur-
face). — Stat. 104. — Stat. 224. — Stat. 225. -- Stat. 276 (HENSEN vertical net, 750
metres to surface).

The furcal joints are elongate ovate in shape and are about twice as long as broad.
The distal end of the inner margin of each joint terminates in a small tooth.

Sapphirina gastrica has been recorded from the Indian and Pacific Oceans.

6. Sapphirina intestinata Giesbrecht.

Sapphirina intestinata Giesbrecht, 1891, p. 478.

Sapphirina intestinata Giesbrecht, 1893, p. 619, pis. 52 & 54.

Sapphirina intestinata Thompson & Scott, 1903, p. 287.

Sapphirina intestinata Wolfenden, 1905 (tf), p. 1029.

This Sapphirina was present in the plankton collected at the following ten stations.

Stat. 129. — Stat. 136. — Stat. 141 (HENSEN vertical net, 1000 metres to surface). — Stat.
165. — Stat. 172. — Stat. 184. — Stat. 185. — Stat. 252. -- Stat. 282.

Sapphirina intestinata is a rather small and moderately broad species. The furcal joints
are somewhat elongate ovate in shape and are fully twice as long as broad. The middle of
the outer margin is distinctly expanded. The apex is rather narrow and truncate. The inner
margin terminates in a small tooth.

This species has been recorded from the Indian and Pacific Oceans.

7. Sapphirina metallina Dana.

Sapphirina metallina Dana, 1849, pp. 8 — 61.
Sapphirina metallina Dana, 1S52, p. 1242, pi. 87.

255

256

Sapphirina metallina Brady, 1883, p. 128, pi. L.

Sapphirina metallina Giesbrecht, 1893, p. 620, pi. 54.

Sapphirina metallina T. Scott, 1893, p. 125, pi. XII.

Sapphirina metallina Steuer, 1898, p. 5.

Sapphirina metallina Cleve, 1901, p. 9.

Sapphirina metallina Thompson & Scott, 1903, p. 287.

Sapphirina metallina Wolfenden, 1905 (a), p. 1029.

Specimens of this very characteristic species were found in the plankton collected at
the followine stations.

ö

Stat. 66. — Stat. 99. — Stat. 121. — Stat. 141 (Hensen vertical net, 1500 metres to sur-
face). — Stat. 142. — Stat. 185 (HENSEN vertical net, 1536 metres to surface). — Stat. 220
(HENSEN vertical net, 200 metres to surface). — Stat. 252. — Stat. 276 (HENSEN vertical
net, 750 metres to surface). — Stat. 282.

The furcal joints are narrowly quadrangular in shape and are about twice as long as
broad. Two of the apical setae are leaf-like in structure.

Sapphirina metallina has been recorded from the Atlantic, Indian and Pacific Oceans.

8. Sapphirina mamlosa Giesbrecht.

Sapphirina maculosa Giesbrecht, 1893, p. 619, pis. 52 & 54.
Sapphirina macnlosa A. Scott, 1902, p. 4(9.

One specimen belonging to this species was found in the plankton collected at each
of the follovving five stations.

Stat. 36. — Stat. S7- — Stat. 47'-. — Stat. 66. — Stat. 225.

The furcal joints are elongate ovate in shape and are about twice as long as broad.
The apex is narrowly rounded. The inner margin terminates in a small tooth.

Sapphirina mactilosa has been recorded from the Mediterranean and Red Sea, and
from the Atlantic Ocean.

9. Sapphirina nigromaculata Claus.

Sapphirina nigromaculata Claus, 1863, p. 152, pi. VIII.

Sapphirina nigromaculata Giesbrecht, 1893, p. 619, pis. 52 & 54.

Sapphirina nigromaculata Steuer, 1898, p. 5.

Sapphirina nigromaculata I. C. Thompson, 1900, p. 288.

Sapphirina nigromaculata Cleve, 1901, p. 9.

Sapphirina nigromaculata A. Scott, 1902, p. 419.

Sapphirina nigromaculata Thompson & Scott, 1903, p. 287.

Sapphirina nigromaculata Cleve, 1903, p. 368.

Sapphirina nigromaculata Cleve, 1904, p. 196.

Sappliirina nigromaculata Wolfenden, 1905 [a), p. 1029.

Sapphirina nigromaculata van Breemen, 1908, p. 196, fig. 209.

This species appeared to be fairly well distributed in the area investigated by the
'Siboga'. It was present at twenty stations as shewn.

256

257

Stat. 16. — Stat. 40. — Stat. 47''. — Stat. 96 (night). — Stat. 96 (day). -- Stat. 101. —
Stat. 106. - Stat. 129. — Stat. 13S. — Stat. 141 (HENSEN vertical net, 1500 metres to
surface). — Stat. 146. — Stat. 148 (HENSEN vertical net, IOOO metres to surface). — Stat.
168. - - Stat. 169. ■ ■ Stat. 184. - - Stat. 185 (Hensen vertical net, 1536 metres to sur-
face). — Stat. 217 (horizontal cylinder). — Stat. 220 (surface). — Stat. 223. — Stat. 271.

Sapphirina nigromaculata is a moderately broad species. The furcal joints are elongate
ovate in shape and are fully twice as long as broad. The apex of each joint is rather narrowly
rounded. The inner margin terminates in a small tooth.

This species has been recorded from the Atlantic, Indian and Pacific Oceans, and from
the Mediterranean, and Red Sea.

10. Sapphirina opalina Dana.

Sapphirina opalina Dana, 1849, PP- 8 — 61.
Sapphirina opalina Dana, 1852 — 55, p. 1254, pi. 88.
Sapphirina opalina Brady, 1883, p. 126, pi. XLIX.
Sapphirina opalina Giesbrecht, 1893, p. 620, pis. 52 & 54.
Sapphirina opalina T. Scott, 1893, p. 123.
Sapphirina opalina Steuer, 1898, p. 6.
Sapphirina opalina Cleve, 1904, p. 196.
Sapphirina opalina Wolfenden, 1905 (a), p. 1029.

This species appeared to be moderately frequent and fairly well distributed in the Malay
Archipelago. It was found in the plankton collected at the following stations.

Stat. 36, 32 specimens. — Stat. 37, 4 specimens. — Stat. 93. — Stat. 96 (night). — Stat. 98,
9 specimens. — Stat. 106, 6 specimens. -- Stat. 117', 21 specimens. — Stat. ii8(HentSEN
vertical net, 900 metres to surface), 1 specimen. — Stat. 136. — Stat. 141 (HENSEN ver-
tical net, 1500 metres to surface), 3 specimens. — Stat. 144, 17 specimens. — Stat. 148
(HENSEN vertical net, 1000 metres to surface), 8 specimens. — Stat. 165, 6 specimens. —
Stat. 169. ■ Stat. 172, 13 specimens. ■ ■ Stat. 1771. -- Stat. 185, 5 specimens. — Stat.
189*. — Stat. 203 (HENSEN vertical net, 1 500 metres to surface). — Stat. 204, 5 specimens. —
Stat. 205. — Stat. 220 (surface), 4 specimens. — Stat. 252. — Stat. 276 (HENSEN vertical
net, 750 metres to surface). — Stat. 282. — Stat. 315, 7 specimens.

Sapphirina opalina is a rather broad species with short and very wide furcal joints.
Each joint is about as broad as long. The tooth-like projection of the inner margin extends
beyond the apex of the joint.

This species has been recorded from Atlantic, Indian and Pacific Oceans, and from the
Mediterranean.

1 1 . Sapphirina ovatolanceolata Dana.

Sapphirina ovatolanceolata Dana, 1849, PP- $ — 61.

Sapphirina ovatolanceolata Dana, 1852, p. 1251, pi. Sy.

Sapphirina ovatolanceolata Giesbrecht, 1893, p. 618, pis. 1, 52 & 54.

Sapphirina ovatolanceolata Steuer, 1898, p. 6.

Sapphirina ovatolanceolata Thompson & Scott, 1903, p. 286.

Sapphirina ovatolanceolata Cleve, 1903, p. 368.

Sapphirina ovatolanceolata Wolfenden, 1905 (a), p. 1029.

257

SIBOGA-EXrEDITIE XXIX.;. 33

25S

This species was generally distributed in the Malay Archipelago. It was obtained from
the plankton collected at the following stations.

Stat. 50. — Stat. 93. — Stat. 96 (night). -- Stat. 101. — Stat. 106. — Stat. 117". — Stat.
121. — Stat. 125. — Stat. 133. — Stat. 136. — Stat. 141 (Hensen vertical net, i50ometres
to surface). — Stat. 177". — Stat. 185 (HENSEN vertical net, 1536 metres to surface). —
Stat. 204. — Stat. 213. — Stat. 215'. — Stat. 217, (horizontal cylinder). - - Stat. 220
(HENSEN vertical net, 200 metres to surface). — Stat. 223. — Stat. 225. — Stat. 252. —
Stat. 282.

This is a rather narrow species. The furcal joints are elongate ovate in shape and are
fully twice as long as broad. The apex of each joint is narrowly rounded. The inner margin
terminates in a small tooth.

Sapphirina ovatolanceolata has been recorded from the Atlantic and Indian Oceans, and
from the Mediterranean.

12. Sapphirina scarlata Giesbrecht.

Sapphirina scarlata Giesbrecht, 1891, p. 478.

Sapphirina scarlata Giesbrecht, 1893, p. 620, pis. 25 & 54.

Sapphirina scarlata Cleve, 1903, p. 368.

Sapphirina scarlata Cleve, 1904, p. 197.

Sapphirina scarlata Esterly, 1905, p. 222, fig. 59.

Four specimens belonging to this species were obtained from the plankton collected at
the three following stations.

Stat. 215', 2 specimens. — Stat. 220 (surface), 1 specimen, -- Stat. 229, 1 specimen.

The male and female of this Sapphirina are moderately wide forms. The furcal joints
are narrowly oval in shape. Each joint is rather less than twice as long as broad. The apex
of the joints is broadly rounded. The distal end of the inner margin is produced into a well
defined tooth.

Sapphirina scarlata has been recorded from the Indian and Pacific Oceans, and from
the Mediterranean.

13. Sapphirina sinuicanda Brady.

Sapphirina sinuicauda Brady, 18S3, p. 129, pi. XLIX.

Sapphirina sinuicanda Giesbrecht, 1893, p. 620, pis. 52 & 53.

Sapphirina sinuicauda T. Scott, 1903, p. 125.

Sapphirina sinuicauda Steuer, 1898, p. 6.

Sapphirina sinuicauda Thompson & Scott, 1903, p. 287.

Sapphirina sinuicauda Cleve, 1904, p. 197.

Specimens identical with the above species were found in the plankton collected at the
following stations.

Stat. 16, 1 specimen. -- Stat. 66, 4 specimens. — Stat. 118 (HENSEN vertical net, 900 metres
to surface), 1 specimen. -- Stat. 136, 1 specimen. -- Stat. 138, 1 specimen. — Stat. 184,

258

259

i specimen. — Stat. 185 (HENSEN vertical net, 1536 metres to surface), 2 specimens. — -
Stat. 193, 1 specimen. - Stats. [94 — 7. — Stat. 276 (HENSEN vertical net, 750 metres to
surface), 1 specimen.

The femalc of this species is moderately broad. The furcal joints are oval in shape
and are nearly twice as long as broad. Each joint terminates in a sharp pointed apex which
and readily distinguishes the species from any of the other known members of the genus.

Sapphirina sinuicauda has been recorded from the Atlantic, Indian and Pacific Oceans,
and from the Mediterranean.

14. Sapphirina stcllata Giesbrecht.

Sapphirina stcllata Giesbrecht, 1891, p. 478.

Sapphirina stcllata Giesbrecht, 1S93, p. 620, pis. 52 & 54.

Sapphirina stcllata I. C. Thompson, 1900, p. 288.

Sapphirina stcllata Cleve, 1903, p. 368.

This proved to be the most common and widely distributed member of the genus. It
was represented at the following stations in the area traversed by the 'Siboga'.

Stat. 81. — Stat. 89, 5 specimens. — Stat. 93, 2 specimens. — Stat. 96 (night). — Stat. 98,
5 specimens. — Stat. 99, 1 specimen. — Stat. 101. — Stat. 106. — Stat. 117", 4 speci-
mens. — Stat. 136. — Stat. 141 (HENSEN vertical net, 1500 metres to surface). 2 specimens. — ■
Stat. 144, 2 specimens. — Stat. 165, 3 specimens. — Stat. 172, 1 specimen. — Stat. 184,

2 specimens. — Stat. 185 (HENSEN vertical net, 1536 metres to surface), $6 specimens. —
Stat. 189% 2 specimens. — Stat. 193, 1 specimen. — Stats. 194 — 7, 6 specimens. — Stat.
204, 2 specimens. — Stat. 213, 6 specimens. — Stat. 215", 6 specimens. — Stat. 217
(horizontal cylinder), 23 specimens. — Stat. 220 (HENSEN vertical net, 200 metres to surface),

3 specimens. — Stat. 220 (surface), 6 specimens. — Stat. 222, 1 specimen. — Stat. 224,
12 specimens. — Stat. 225, 57 specimens. — Stat. 282, 1 specimen. — Stat. 304.

The female is moderately broad. The furcal joints are elongate ovate in shape and are
about twice as long as broad. The apex of each joint is rather narrowly rounded. The distal
end of the inner margin is produced into a distinct tooth.

Sapphirina stellata has been recorded from the Atlantic. Indian and Pacific Oceans.

15. Sapphirina longifurca nov. sp. Plate LXIX, figs. 15 — 20.

Female — length 5.5 mm.

Seen from above, the body appears moderately elongate and narrow. lts length, in-
cluding the furcal joints, is three and a half times longer than broad. The abdomen is distinctly
narrower than the thorax. The furcal joints are comparatively long and narrow. Each joint is
three times longer than broad. The outer margin of the joints is nearly straight. The inner
margin is considerably inflated at the proximal end. The distal end of the outer margin is
notched. The inner margin terminates in a small tooth. The outer margin is entirely without
setae. The joints are furnished with a single seta placed at the apex (Plate LXIX, fig. 15).

The antennules are short and five-jointed. The second joint is considerably longer than
any of the others. The fourth joint is short (Plate LXIX, Fig. 16).

259

2ÓO

The antennae, mandibles, maxillae and maxillipedes are of the usual Sapphirina type.

Male unknown.

The female of this species is readily separated from any of the other members of the
genus by the long narrow furcal joints, and by the outer margin of the joints being nearly
straieht and without setae.

Occurrence. — One specimen was obtained from the plankton collected at Station
136, off Ternate Island, Molucca Passage.

Genus Copilia Dana, 1849.

The males of this genus resemble the males of Sapphirina in general appearance, but
they can readily be separated by their very elongate and narrow furcal joints. The females are
easily recognised by the large and somewhat quadrangular cephalic segment, by the moderately
long anal segment, and by the long slender furcal joints.

Three species were represented in the plankton collected by the 'Siboga' in the Malay
Archipelago.

1 . Copilia mirabilis Dana.

Copilia mirabilis Dana, 1852, p. 1232, pi. 86.

Copilia mirabilis Brady, 1883, p. 117, pi. LUI, figs. I — II.

Copilia mirabilis Giesbrecht, 1893, p. 647, pi. 50.

Copilia mirabilis T. Scott, 1893, p. 113.

Copilia mirabilis I. C. Thompson, 1900, p. 289.

Copilia mirabilis Cleve, 1901, p. 6.

Copilia mirabilis A. Scott, 1902, p. 420.

Copilia mirabilis Thompson & Scott, 1903, p. 286.

Copilia mirabilis Cleve, 1903, p. 360.

This species proved to be comparatively common and widely distributed in the area
traversed by the 'Siboga'. It was present in the plankton collected at the following stations.

Stat. 16. — Stat. 56. — Stat. 47'1. - - Stat. 66. - - Stat. 75 (HENSEN vertical net, 1 1 metres
to surface). — Stat. 81. — Stat. 89. -- Stat. 93. — Stat. 96 (day). ' — Stat. 96 (night). —
Stat. 98. • - Stat. 99. - ■ Stat. 101. - - Stat. 106. — Stat. 110. — Stat. 117', 430 speci-
mens. - - Stat. 118 (HENSEN vertical net, 900 metres to surface). — Stat. 121. — Stat.
124. — Stat. 125. -- Stat. 128 (HENSEN vertical net, 700 metres to surface). — Stat. 129. —
Stat. 133. ■ Stat. 136. ■ Stat. 141 (HENSEN vertical net, 1500 metres to surface). ■
Stat. 144. — Stat. 146. — Stat. 157. — Stat. 165. — Stat. 169. — Stat. 172. — Stat.
i/7a. — Stat. 184. — Stat. 185 (HENSEN vertical net, 1536 metres to surface). — Stat. 189*. —
Stats. 194 — 7. — Stat. 203 (HENSEN vertical net, 1500 metres to surface). — Stat. 204. —
Stat. 213. — Stat. 214. — Stat. 215". — Stat. 216. -- Stat. 217 (horizontal cylinder). —
Stat. 220 (HENSEN vertical net, 200 metres to surface). — Stat. 220 (surface). — Stat. 223. ■ —
Stat. 224. • Stat. 225. — Stat. 252. — Stat. 276 (HENSEN vertical net, 750 metres to
surface). — Stat. 282. — Stat. 304.

The female of this species can readily be recognised by the comparatively long and
narrow anal segment, and by the furcal joints being about two and a half times longer than
the anal segment.

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2ÓI

Copilia mirabilis appears to be widely distributed in die warm rcgions of all the

great oceans.

2. Copilia quadrata Dana.

Copilia quadrata Dana, 1849, pp. 8 — 61.

Copilia quadrata Dana, [852, p. 1232, pi. 86.

Copilia quadrata Giesbrecht, 1893, p. 647, pis. 2 & 50.

Copilia quadrata T. Scott, 1893, p. 113.

Copilia quadrata I. C. Thompson, 1900, p. 289.

This species although widely distributed in the Malay Archipelago, proved to be much
scarcer than Copilia mirabilis. It was present in the plankton collected at the following stations.

Stat. 16. — Stat. 37. — Stat. 66. - - Stat. 89. — Stat. 93. -- Stat. 98. -- Stat. \\y\ -
Stat. 128 (HENSEN vertical net, 700 metres to surface). — Stat. 129. — ■ Stat. 136. -- Stat.
144. — Stat. 146. — • Stat. 157. — Stat. 165. — Stat. 169. — Stat. 172. — Stat. 184. -
Stat. 185 (HENSEN vertical net, 1536 metres to surface). — Stat. 203 (HENSEN vertical
net, 1500 metres to surface). — Stat. 220 (HENSEN vertical net, 200 metres to surface). —
Stat. 220 (surface). — Stat. 230. — Stat. 252. — Stat. 276 (HENSEN vertical net, 750
metres to surface). — Stat. 282. — Stat. 315.

The cephalic segment of the female is very wide. It is nearly quadrangular in outline.
The furcal joints are four times longer than the anal segment.

Copilia quadrata has been recorded from the Atlantic, Indian and Pacific Oceans, and
from the Mediterranean.

3. Copilia vitrea (Haeckel).

Hyalophyllum vitreum Haeckel, 1864, p. 63, pi. 1.
Copilia vitrea Giesbrecht, 1893, p. 647, pis. 2 & 50.

One female apparently identical with the above species was found in the plankton
collected with the Hensen vertical net at Station 220, from a depth of 200 metres to the surface.

The cephalic segment is rather irregular in shape. It is moderately narrow in front
and is somewhat expanded behind. The furcal joints are five times longer than the anal segment.

This Copilia has been recorded from the Atlantic and Pacific Oceans, and from the
Mediterranean.

44. Family Lichomolgidae.
Genus Pachysoma Claus, 1863.

The members of this genus can be recognised by the broad pyriform body with its
distinctly pointed forehead, by the pointed fourth thoracic segment, and by the short abdomen.
The antennules are seven to eight-jointed. The exopodites and endopodites of the four pairs
of swimming feet are three-jointed.

One species was represented in the plankton collected by the 'Siboga'.

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i. Pachysoma punctatum Claus.

Pachysoma pandata Claus, 1863, p. 163, pi. XXV.

Pachysoma punctatum Brady, 1883, p. 121.

Pachysoma punctatum Giesbrecht, 1893, p. 612, pis. 4 & 48.

Pachysoma punctatum T. Scott, 1893, p. 119, pi. XIII, figs. 18 — 24.

Specimens identical with the above species were found in the plankton collected at the
following four stations.

Stat. 142, 1 specimen. — Stat. 143 (HENSEN vertical net, 1000 metres to surface), 3 speci-
mens. - - Stat. 144, 1 specimen. — Stat. 185 (HENSEN vertical net, 1536 metres to sur-
face), 1 specimen.

Pachysoma punctatum can readily be separated from Pachysoma tuberosum Giesbrecht,
by the second and third abdominal segments being of nearly equal length. The second segment
of the abdomen of Pachysoma tuberosum is distinctly shorter than the third segment.

This species has hitherto only been known from the Atlantic Ocean, and from the
Mediterranean.

Genus Hermannella Canu, 1891.

The members of this genus can be recognised by the stylet-shaped form of the rnandible
and of the fïrst pair of maxilipedes, and by the exopodites and endopodites of the first four
pairs of feet being three-jointed.

The three-jointed exopodite and endopodite of the fourth pair of feet is the principal
char-acter that distinguishes this genus from Lichomolgus and Pscudanthcssius.

One species, apparently undescribed, was represented in the plankton collected by the
'Siboga' in the Malay Archipelago.

1. Hermannella concinna nov. sp. Plate LXVIII, figs. 1 — 10.

Female — length 2,9 mm.

Seen from above, the body appears nearly circular in outline. The frontal margin is
broadly rounded. The fifth thoracic segment is comparatively large and is sub-quadrangular in
shape, with the anterior and posterior ends considerably contracted.

The abdomen is composed of four segments. The combined length of the abdomen
and furcal joints is contained nearly twice in the total length of the cepkalothorax, from the
frontal margin to the distal end of the fifth thoracic segment. The genital segment is rather
large and is moderately expanded in the middle. It is as long as the combined length of the
second and third segments added to half of the length of the anal segment. The second and
fourth segments are sub-equal in length. The third segment is much smaller than the others.
The furcal joints are cylindrical and of moderate length. The joints are slightly longer than
the anal segment and are furnished with one outer marginal seta, and four apical setae
(Plate LXVIII, fig. 1).

The antennules are slender and seven-jointed. The second and fourth joints are long.

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263

The fourth joint is as long as the combined length of the last three joints (Plate LXVIII, fig. 2).

The antennae are short and three-jointed. The apex of the third joint is armed with
three moderately strong claws and tour short setae (Plate LXVIII, fig. 3).

The mandible consists of two long slender stylets. The upper stylet has a scrrated
outer margin. The upper margin of the inner stylet is fringed with short hairs. The mandible
is also furnished with two digitiform processes (Plate LXVIII, fig. 4A).

The maxillae are lamelliform and attached to the base of the mandibles. The apex is
excavated in the middle. The upper part is rounded and bears two short hairs. The lower
portion is toothed and is armed with one moderately strong seta, and two very small setae
(Plate LXVIII, fig. 4B).

The second joint of the first pair of maxillipedes has a stylet-shaped termination which
is armed with strong and slightly curved spines on the upper margin. The basal joint is
moderately large (Plate LXVIII, fig. 5).

The second pair of maxillipedes is small and two-jointed. The second joint is elongate
and terminates in a narrow apex carrying two small spines (Plate LXVIII, fig. 6).

The exopodites and endopodites of the first four pairs of feet are three-jointed.

The fifth pair of feet is elongate ovate in shape. The upper margin is arched. The
distal end is furnished with four setae. The lower margin is nearly straight. The middle of
the upper margin and the distal end of the lower margin, is fringed with fine short spines
(Plate LXVIII, fig. 9).

Male — length 2,45 mm.

The male resembles the female in general appearance, but the abdomen is composed
of five segments. The second pair of maxillipedes is furnished with a very powerful curved claw.
The claw is longer than the second joint (Plate LXVIII, fig. 7).

This species can readily be recognised by the very rounded form of the ccphalothora.x ,
by the shape of the fifth pair of feet, and by the proportional length of the abdominal seg-
ments and furcal joints.

Occurrence. — Two females and eight males were obtained from the plankton col-
lected with the Hexsen vertical net at Station 230, from a depth of 2000 metres to the surface.

Genus Lichomolgus Thorell, 1859.

The mandibles and first pair of maxillipedes of the members of this genus are stylet-
shaped. The endopodite of the fourth pair of feet is composed of two very unequal joints
and is considerably shorter than the exopodite.

The two-jointed endopodite of the fourth pair of feet is the most important character
by which the members of this genus can be recognised.

Five species were represented in the material collected during the traverse of the 'Siboga'.
Two of the species do not appear to have previously been described.

1 . Lichomolgus buddhensis Thompson & Scott.

Lichomolgus buddhensis Thompson & Scott, 1903, p. 279, pi. XV, figs. iS — 24.

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264

Specimens identical with the above species were found in the washings from dredged
invertebrata collected at the following two stations.

Stat. 164, 2 specimens. — Stat. 226, midway between the Lucipara and Schildpad Islands,
nineteen specimens.

Lichomolgus buddhensis can readily be recognised by the very short abdomen and
furcal joints, and by the comparatively large fifth pair of feet.

This species has hitherto only been known from the pearl banks around Ceylon.

2. Lichomolgus elegans Thompson & Scott.

Lichomolgus elegans Thompson & Scott, 1903, p. 280, pi. XVI, figs. 8 — 13.

One specimen belonging to this species was found in the washings from dredged in-
vertebrata collected at Station 226, midway between Lucipara and Schildpad Islands, from a
depth of 1595 metres.

Lichomolgus elegans is easily identified by its rather narrow and elongate form, by the
comparatively long cylindrical genital segment, and by the shape of the fifth pair of feet.

This species has hitherto only been known from Ceylon.

3. Lichomolgus gigas Thompson & Scott.

Lichomolgus gigas Thompson & Scott, 1903, p. 280, pi. XVI, figs. 21 — 26.

One male identical with the above species was found in the washings from dredged
invertebrata collected at Station 226, midway between the Lucipara and Schildpad Islands.

This is a large species. It can readily be separated from the other members of the
genus by the large size of the animal, by the proportional length of the joints of the anten-
nules, by the moderately long cylindrical furcal joints, and by the rather large fifth pair of feet.

Lichomolgus gigas has hitherto only been known from Ceylon.

4. Lichomolgus anomalus nov. sp. Plate LXVII, figs. 6 — 17.

Female — length .67 mm.

Seen from above, the body appears short and very broadly oval. The fourth segment
is short and the distal ends are evenly rounded. The fifth thoracic segment is rather short
and is somewhat funnel-shaped. The distal end is considerably expanded.

The abdomen is short and is composed of four segments. The combined length of the
abdomen and furcal joints is contained fully three times in the total length of the ccphalothorax,
from the frontal margin to the distal end of the fifth thoracic segment. The genital segment
is comparatively large and is slightly inflated. It is traversed by an incomplete suture near
the posterior end of the dorsal surface. The segment is slightly longer than the combined
length of the next three abdominal segments and furcal joints. The second, third and fourth
segments are short and sub-equal in length. The furcal joints are very short. The joints are

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265

furnished witli one outer marginal seta, four apical setae, and one inner marginal seta (Plate
LXVII, fig. 6).

The antennules are moderately long and seven-jointed. The second joint is longer than
any of the others. The third and seventh joints are of nearly equal length (Plate LXVII, fig. 7).

The antennae are comparatively short and four-jointed. The fourth joint is furnished at
the apex with one stout claw and three short setae (Plate LXVII, fig. 8).

The mandible has a stylet-shaped apex. The outer portion of the apical region is some-
what quadrangular in shape. The outer margin is furnished with a strong triangular tooth-like
process. The inner margin is fringed with fine short hairs. The upper surface has a simple
hyaline edge (Plate LXVII, fig. 9A).

The maxillae are rather narrow and the apex is furnished with three setae (Plate LXVII,
fig. qB).

The apical portion of the first pair of maxillipedes is stylet-shaped. The middle portion
of the upper margin is fringed with fine spines. The inner margin is furnished near the base
with a short stout spine (Plate LXVII, fig. 10).

The second pair of maxillipedes is prehensile and three-jointed. The third joint is short
and narrow. The apex is furnished with two moderately stout spines (Plate LXVII, fig. 11).

The exopodites and endopodites of the first three pairs of feet are three-jointed. The
exopodite of the fourth pair of feet is three-jointed. The endopodite is two-jointed.

The fifth pair of feet is comparatively large. The distal end is rather narrow and is
furnished with one moderately long seta (Plate LXVII, fig. 16).

Male — length .67 mm.

The male resembles the female in general appearance, but the abdomen is composed
of five segments and the genital segment is very large and inflated. The second pair oi
maxillipedes is well developed and is prehensile. The terminal claw is long and slightly curved
(Plate LXVII, fig. 12). The endopodite of the first pair of feet is apparently to some extent
prehensile. The second joint is curved, and there is an indication of a hinge between the
second and third joints (Plate LXVII, fig. 14). The fifth pair of feet is smaller than in the female.

This species can readily be recognised by its small size and rounded body, by the very
short furcal joints, and by the shape of the fifth pair of feet. The structure of the endopodite
of the first pair of feet of the male is quite distinct from what is usually found in the males
of this genus.

Occurrence. — Seven females and two males were found in the washings from dredged
invertebrata collected at Station 226, midway between the Lucipara and Schildpad Islands,
from a depth of 1595 metres.

5. Lichomolgus gracilipes nov. sp. Plate LXVIII, figs. 11 — 20.

Female — length 1,53 mm.

Seen from above, the body appears broadly oval in outline. The cephalic segment is
greatly inflated near the middle. The frontal margin is boldly rounded. The fourth thoracic

SIBOGA-EXPEDIT1E XXIX a. 34

266

segment is produced posteriorly and the distal ends are narrowly rounded. The fifth segment
is of moderate size and is broadly funnel-shaped. The distal part is greatly expanded.

The abdomen is composed of four segments. The combined length of the abdomen
and furcal joints is contained two and a half times in the total length of the cephalothorax,
from the frontal margin to the distal end of the fifth thoracic segment. The genital segment
is large and is considerably swollen in the middle. It is distinctly longer than the combined
length of the next three segments and furcal joints. The second, third and fourth segments
are short and are of nearly equal length. The furcal joints are about as long as broad and
are slightly shorter than the anal segment. The joints are furnished with one outer marginal
seta and four apical setae (Plate LXVIII, fig. n).

The antennules are slender and seven-jointed. The fourth and fifth joints are of nearly
equal length (Plate LXVIII, fig. 12).

The antennae are four-jointed. The apex of the fourth joint is furnished with two short
curved claws and three setae. The outer claw is much stouter than the inner claw (Plate
LXVIII, fig. 13).

The apex of the mandible is stylet-shaped. The intermediate region is broadly triangular
in shape and is distinctly cleft. The margins are fringed with short spines (Plate LXVIII,
fig. 14A).

The maxillae are elongate and narrow. They are furnished with one marginal seta and
three apical setae.

The apex of the first pair of maxillipedes is stylet-shaped. The upper margin is pectinate.
A moderately long setiferous spine is attached to near the base of the inner margin. The
basal joint is short and broad (Plate LXVIII, fig. 15).

The second pair of maxillipedes is three-jöinted. The last joint is very small. It is
furnished with one small curved spine and three short setae (Plate LXVIII, fig. 16).

The exopodites and endopodites of the first three pairs of feet are three-jointed. The
exopodite of the fourth pair of feet is three-jointed. The endopodite is two-jointed.

The fifth pair of feet is moderately long and narrow. Each foot is fully three times
longer than broad and is furnished with two apical setae (Plate LXVIII, fig. 19).

Male — length 1,1 mm.

The male resembles the female in general appearance, but the abdomen is composed of
five segments. The genital segment is large and is greatly inflated. The second pair of maxilli-
pedes is strongly prehensile. The terminal claw is long and curved (Plate LXVIII, fig. 17).
The fifth pair of feet is comparatively small.

The females of this species can readily be identified by their shape, by the elongate
and slender fifth pair of feet, and by the short sub-equal second, third and fourth segments of
the abdomen.

Twenty-one females and three males were found attached to a Nudibranch collected at
Station 301, Pepela Bay, East Coast of Rotti Island. The label in the tube was marked 'On
Nudibranch, Fig. 273'.

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26;

Genus ParalichomolgUS Thompson and Scott, 1903.

Tliis genus is closely related to Lichomolgus, but the distal ends of the first three
thoracic segments are produced posteriorly and terminate in distinct points. The exopodite
and endopodite of the fourth pair of feet are of nearly equal length. The endopodite is com-
posed of two sub-equal joints.

One species was represented in the material collected by the 'Siboga' in the Malay
Archipelago.

1 . Paralichomolgus curticaudatus Thompson & Scott.

Paralichomolgus curticaudatus Thompson & Scott, 1903, p. 281, pi. XVI, figs. 1 — 7.

Two females belonging to this species were found in the washings from dredged in-
vertebrata collected at Station 226, midway between the Lucipara and the Schildpad Islands,
from a clepth of 1595 metres.

The female is easily recognised by its large body, and very short abdomen and furcal
joints. The distal ends of the first, second and third thoracic segments are produced posteriorly,
and terminate in blunt points.

Paralichomolgus curticaudatus has only previously been recorded from Ceylon.

Genus Pseudanthessius Claus, 1889.

The mandibles and first pair of maxillipedes of the members of this genus are stylet-
shaped. The endopodite of the fourth pair of feet is shorter than the exopodite and is composed
of a single joint.

The comparatively short one-jointed endopodite of the fourth pair of feet is the prin-
cipal character that separates the members of this genus, from the other genera belonging to
the Lichomolgidae.

Four species of Pseudanthessius were represented in the material collected by the 'Siboga'
during the investigations in the Malay Archipelago. None of the four species appear to have
previously been met with.

1. Pseudanthessius weberi nov. sp. Plate LXVII, figs. 18 — 24.

Female — length 1,16 mm.

Seen from above, the body appears short and broadly oval. The frontal margin is
rather narrowly rounded. The distal ends of the fourth thoracic segment are slightly produced
and are narrowly rounded. The fifth thoracic segment is of moderate length and is slightly
expanded at the distal end.

The abdomen is composed of four segments. The combined length of the abdomen and
furcal joints is contained one and two-third times in the total length of the cephalothorax,
from the frontal margin to the distal end of the fifth thoracic segment. The genital segment
is rather long and is slightly expanded in the middle. The segment is as long as the combined

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268

length of the next three segments added to one-third of the length of the furcal joints. The
second and third segments are of nearly equal length. The anal segment is one and one-third
times the length of the second segment. The furcal joints are rather long and moderately
slender, and are twice as long as the anal segment. The joints are furnished with one outer
marginal seta placed near the distal end, and four apical setae (Plate LXVII, fig. 18).

The antennules are comparatively stout and seven-jointed. The second joint is considerably
longer than the others. The third and seventh joints are short (Plate LXVII, fig. 19).

The antennae are four-jointed. The apex of the fourth joint is furnished with three
slender curved claws and three setae. The inner claw is stouter than the other two (Plate
LXVII, fig. 20).

The apex of the mandible is stylet-shaped and is furnished with a simple lamella (Plate
LXVII, fig. 21A).

The maxillae are very short. The apex is furnished with four setae.

The apex of the first pair of maxillipedes is in the form of a long slender stylet. The
upper margin is fringed with fine spines (Plate LXVII, fig. 22).

The second pair of maxillipedes is prehensile. The basal joint is moderately large and
broad. The second and third joints are very narrow. The distal end of the third joint is
furnished with two short spines (Plate LXVII, fig. 23).

The exopodites and endopodites of the first three pairs of feet are three-jointed. The
exopodite of the fourth pair of feet is three-jointed. The endopodite is one-jointed and is
furnished with two apical spines (Plate LXVII, fig. 24).

The fifth pair of feet is very small. The apex of each foot is provided with one spine
and one seta.

Male unknown.

This species can readily be indentified by the short body and comparatively long and
slender abdomen, and by the elongate furcal joints.

Occurrence. — One specimen was found in the washings from dredged invertebrata
collected at Station 226, midway between the Lucipara and the Schildpad Islands, from a
depth °of 1595 metres.

2. Psciidanthessius pectinahis nov. sp. Plate LXVIII, figs. 21 — 27.

Female — length 1,35 mm.

Seen from above, the body appears elongate and rather narrow. The frontal margin is
narrowly rounded. It is almost angular in outline. The fourth segment is produced posteriorly
and the distal ends are narrowly rounded. The fifth segment is considerably expandecl at the
distal end.

The abdomen is composed of four segments. The combined length ot the abdomen
and furcal joints is contained one and three-fourth times in the total length of the cephalotkorax,
from the frontal margin to the distal end of the fifth thoracic segment. The genital segment
is comparatively long and is equal to the combined length of the next three segments. The

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269

proximal end of the segment is expanded, and the distal end is slightly contracted. The
second segment is one and a half times the length of the third segment. The anal ses/ment
is distinctly Ionger than the third segment. The furcal joints are rather short and ovate in
shape. The joints are as long as the second abdominal segment. They are furnished with two
outer marginal setae and three apical setae (Plate LXVIII, fig. 21).

The antennules are moderately long and seven-jointed. The second joint is Ionger, and
the third joint shorter, than any of the others (Plate LXVIII, fig. 22).

The antennae are slender and four-jointed. The apex of the fourth joint is furnished
with three long slender spines and four setae. The two inner spines are stouter than the outside
spine and are fringed on the exterior margin with short hairs (Plate LXVIII, fig. 23).

The apex of the mandible is stylet-shaped. The basal portion is very broad and its
upper margin is coarsely dentate (Plate LXVIII, fig. 24 A).

The maxillae are rather stout. They are furnished with two marginal setae and two
apical setae.

The apex of the first pair of maxillipedes is produced into a short stout blunt stylet which
terminates in a stout spine. The upper margin is armed with six moderately stout teeth. The
inner margin of the apical joint is furnished near the base with a strong and finely toothed
spine (Plate LXVIII, fig. 25).

The second pair of maxillipedes is three-jointed. The upper margin of the second joint
is furnished with two very stout spines. The outer margin of the proximal spine is armed
with eleven moderately long and slender spinules. The distal spine has a fringe of short hairs
on the inner margin. The third joint is short. It terminates in one long moderately stout
and curved claw and two short spines (Plate LXVIII, fig. 26).

The exopodites and endopodites of the first three pairs of feet are three-jointed. The
exopodite of the fourth pair of feet is three-jointed. The endopodite is one-jointed.

Male unknown.

This species bears a close resemblance to Pseurfaiitliessius propinquus T. Scott (1893),
but the female is easily separated by the quite different armature of the second pair of maxil-
lipedes. The proximal spine on the second joint in Psettdanthessius propinquus has no fringe
of long spinules and there is no long apical claw on the third joint.

Occurrence. — One specimen was obtained from the surface plankton collected at
Station 35.

3. P seudanthessius parvus nov. sp. Plate LXIX, figs. 1 — 7.

Female — length .9 mm.

Seen from above, the body appears elongate and narrowly ovate. The frontal margin
is narrowly rounded. It is almost angular in outline. The fourth thoracic segment is very little
produced and the distal ends are rounded. The fifth thoracic segment is of moderate size with
the distal end considerably expanded.

The abdomen is composed of four segments. The combined length of the abdomen and

269

2 JO

furcal joints is contained nearly twice in the total length of the cephalothorax, from the frontal
maro-in to the distal end of the fifth thoracic segment. The genital segment is moderately
lonor and is considerably inflated at the proximal end. It is equal to the combined length of
the next three segments added to half the length of the furcal joints. The second and fourth
segments are sub-equal in length. The third segment is equal to two-thirds of the length of
the second segment. The furcal joints are slightly longer than the anal segment. The joints
are furnished with two outer marginal setae and three apical setae (Plate LXIX, fig. i).

The antenhules are rather long and seven-jointed. The joints are all of moderate length,
except the first and third, which are shorter than the others. (Plate LXIX, fig. 2).

The antennae are short, stout and four-jointed. The apex of the fourth joint is furnished
with two stout curved claws and four setae (Plate LXIX, fig. 3).

The apex of the mandible is stylet-shaped. The basal portion is of moderate size, but
it is deeply constricted in the middle. The upper margin is finely serrate (Plate LXIX, fig. 4).

The maxillae are short and broad. They are furnished with one marginal and three
apical setae.

The apex of the first pair of maxillipedes is stylet-shaped. The upper margin is coarsely
serrate (Plate LXIX, fig. 5).

The second pair of maxillipedes is small and two-jointed. The second joint terminates
in one very stout claw. The upper surface is provided with two short spines (Plate LXIX, fig. 6).

The exopodites and endopodites of the first three pairs of feet are three-jointed. The
exopodite of the fourth pair of feet is three-jointed. The endopodite is one-jointed. The outer
margin is sharply constricted in the middle. The apex is furnished with two moderately long
spathulate spines (Plate LXIX, fig. 7).

The fifth pair of feet is slender and of moderate length. The apex of each foot bears
two short spines.

Male unknown.

This species is readily recognised by the elongate body, by the moderately long and
inflated genital segment, and by the proportional length of the joints of the antennules.

Occurrence. -- Two specimens were obtained from the plankton collected during the
night at Station 142, when the 'Siboga' was anchored off Lawui, on the Coast of Obi Major.

4. P seudanthessius obscurus nov. sp. Plate LXIX, figs. 8 — 14.

Female — length 1,15 mm.

Seen from above, the body appears elongate and narrowly ovate. The frontal margin
is narrowly rounded. It is almost angular in outline. The fourth thoracic segment is short and
is very slightly produced posteriorly. The distal ends are rounded. The fifth thoracic segment
is broadly triangular in shape with the distal end moderately expanded.

The abdomen is slender and is composed of four segments. The combined length of
the abdomen and furcal joints is contained one and two-third times in the total length of the
cephalothorax, from the frontal margin to the distal end of the fifth thoracic segment. The

270

271

genital segment is long and is only slightly inflated. It is as long as the combined length
of the next three segments added to half of the length of the furcal joints. The second segment
is distinctly longer than the third segment. The third and fourth sègments are of nearly equal
length. The furcal joints are moderately long and slender, and are nearly as long as the
second abdominal segment. The joints are furnished with one outer marginal seta, and four
apical setae (Plate LXIX, hg. 8).

The antennules are short, stout and seven-jointed. The third joint is shorter than any
of the others (Plate LXIX, fig. 9).

The antennae are long and four-jointed. The apex of the fourth joint is furnished with
three moderately long and slender curved claws, and three setae (Plate LXIX, fig. 10).

The mandible is moderately broad and lamelliform with a pointed apex. The lower
margin is fringed with short spines (Plate LXIX, fig. 11).

The first pair of maxillipedes is two-jointed. The distal end of the inner margin is
furnished. with a long, straight, pectinate spine. The apex bears two curved teeth. The proximal
end of the inner margin is also furnished with a long, straight, pectinate spine (Plate LXIX, fig. 1 2 ).

The two pectinate spines are distinctly articulated to the joint and are not simply an
extension of it, as in the other members of the genus.

The second pair of maxillipedes is two-jointed. The joints are short and broad. The
apex of the second joint is furnished with a stout curved claw which is armed near the base
of the upper margin with a short spine (Plate LXIX, fig. 13).

The exopodites and endopodites of the first three pairs of feet are three-jointed. The
exopodite of the fourth pair of feet is three-jointed. The endopodite is one-jointed. The proximal
end of the outer margin has a distinct tooth and the apex is furnished with two spines (Plate
LXIX, fig. 14).

The fifth pair of feet is ■ very rudimentary and is represented by two spines attached
to the expanded portion of the fifth thoracic segment (Plate LXIX, fig. 8).

Male unknown.

This species differs from the typical members of the genus P seudanthessius in the very
short antennules, in the shape of the mandible, and in the rudimentary condition of the fifth
pair of feet.

Occurrence. Four specimens were obtained from the plankton collected during

the night at Station 142, when the 'Siboga' was anchored off Laiwui, on the Coast of Obi Major.

45. Family Clausiidae.

Genus Hersiliodes Canu, 1888.

The members of this genus can readily be separated from the Lichomolgidae by the
comparatively large lamelliform fifth pair of feet, ancl by the structure of the mouth organs.
The mandible has the cutting eclge composed of two or three short stout serrate spines. It is

271

2 7-

not stvliform. The first pair of maxillipedes is non-stylet-shaped and is moderately well developed.
The first joint is furnished with a digitiform process carrying spines. The second joint terminates
in a broad serrated tooth. The exopodites and endopodites of the four pairs of swimming feet
are three-jointed. The abdomen of both sexes is composed of five segments.

The non-stylet-shape of the mandible and of the first pair of maxillipedes, along with
the large lamelliform fifth pair of feet, are the prir»cipal characters that separate the members
of the family from the Lichomolgidae.

One species belonging to Canu's genus Hersiliodcs was represented in the material
collected by the 'Siboga' during the investigations carried out in the Malay Archipelago.

i. Hersiliodcs leggii Thompson & Scott.

Hersiliodcs leggii Thompson & Scott, 1903, p. 283, pi. XVII, figs. 12 — 21.

One male identical with the above species was found in the washings from dredged
invertebrata collected at Station 273, off Pulu Jedan, East Coast of Aru Islands, from a depth
of 1 3 metres.

This species is readily recognised by the short broad fifth pair of feet being armed
along the margins with a dense fringe of short spinules.

Hersiliodcs leggii has hitherto only been known from the Gulf of Manaar, Ceylon.

272

LIST OF LITERATURE

REFERRED TO IN THIS REPORT.

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273

SIllOGA-EXPEDlTIE WIXu. 35

274

Dahl, F., 1S94. — "Die Copepodenfauna des unteren Amazonas". Berichte der Naturforschenden Gesell-
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!77

LIST OF STATIONS

SHEWING NUMBERS AND SPECIES OF COPEPODA TAKEN.

Station 16, March 15 & 16, 1899
Coast of Kangeang. HensEN Vertical net

Acartia erythraea.
Acrocalanus gibber.
Acrocalanus gracilis.
Acrocalanus longicornis.
Calanopia elliptica.
Calanopia thompsoni n. sp.
Calocalanus pavo.
Candacia bradyi.
Candacia simplex.
Canthocalanus pauper.
Centropages furcatus.
Centropages orsinii.
Clausocalanus arcuicornis.
Clausocalanus furcatus.
Copilia mirabilis.
Corycaeus danae.
Corycaeus obtusus.
Eucalanus crassus.
Eucalanus pileatus.
Euchaeta concinna.
Euchaeta marina.
Labidocera acuta.
Labidocera bataviae n. sp.

Station 19, March 19 & 21, 1899.
Coast, Lombok. Surface.

Acrocalanus gibber.
Candacia pachydactyla.
Clausocalanus arcuicornis.
Eucalanus monachus.
Eucalanus pileatus.
Euchaeta concinna.
Euchaeta marina.
Ilyopsyllus afrinis.
Labidocera acuta.
Mecynocera clausi.

Lat. 6°59'.oS., Long. U5°24'.7E. Bay of Kankamaraan, S.
with electric light; 10 metres to surface.

Labidocera detruncata.

Labidocera madurae n. sp.

Labidocera minuta.

Lucicutia flavicornis.

Mecynocera clausi.

Metacalanus aurivillii.

Microsetella rosea.

Oithona plumifera.

Oncaea venusta.

Paracalanus parvus.

Pontellopsis krameri.

Pseudodiaptomus aurivillii.

Pseudodiaptomus clevei n. sp.

Sapphirina bicuspidata.

Sapphirina gastrica.

Sapphirina nigromaculata.

Sapphirina sinuicauda.

Scolecithricella marginata.

Temora discaudata.

Temora turbinata.

Tortanus gracilis.

Tortanus murrayi n. sp.

Undinula vulgaris. 46 Species.

Lat. 8°44'.5 S., Long. n6°2'.5E. Bay of Labuan Tring, West

Macrosetella gracilis.
Megacalanus gracilis.
Metacalanus aurivillii.
Pontella securifer.
Pontellina plumata.
Scolecithrix danae.
Temora discaudata.
Undinula danvini.
Undinula vulsraris.

ip Species.

278

279

Station 35, March 28, 1899. Lat. 8° 0.3 S., Lont
Acartia erythraea.
Acrocalanus gibber.
Acrocalanus longicornis.
Calanopia elliptica.
Calanopia minor.
Calocalanus plumulosus.
Candacia discaudata n. sp.
Candacia simplex.
Candacia truncata.
Clausocalanus arcuicornis.
Centropages furcatus.
Corycaeus gibbulus.
Corycaeus obtusus.
Eucalanus monachus.
Eucalanus pileatus.
Eucalanus subcrassus.
Euchaeta concinna,
Euchaeta marina.
Euterpina acutifrons.
Harpacticus clausi n. sp.
Harpacticus cristatus n. sp.
Harpacticus glaber.
Ilyopsyllus aflïnis.
Labidocera acuta.
Labidocera kroyeri.
Labidocera minuta.

Station 36, March 29, 1899. Lat. 7°38'.oS., Long.

u6°5y'.oE. Bali Sea. Surface.
Lubbockia aculeata.
Lucicutia flavicornis.

Macrosetella gracilis.
Mecynocera clausi.
Megacalanus gracilis.
Metacalanus aurivillii.
Microsetella rosea.
Oithona plumifera.
Oncaea venusta.
Paracalanus aculeatus.
Paracalanus parvus.
Pontella princeps.
Pontella securifer.
Pontellina plumata.
Pontellopsis armata.
Pontellopsis krameri.
Pontellopsis perspicax.
Pseudanthessius pectinatus n. sp.
Rhincalanus cornutus.
Rhynchothalestris rufocincta.
Temora discaudata.
Temora turbinata.
Temoropia mayumbaensis.
Undinula darwini.
Undinula vulkans.

5/ Species.

Acartia negligens.
Acrocalanus gibber.
Acrocalanus gracilis.
Acrocalanus longicornis.
Calanopia elliptica.
Calanopia minor.
Calanus minor.
Candacia aethiopica.
Candacia discaudata n. sp.
Candacia pachydactyla.
Candacia simplex.
Clausocalanus arcuicornis.
Copilia mirabilis.
Copilia quadrata.
Corycaeus danae.
Corycaeus gibbulus.
Corycaeus longistylis.
Corycaeus obtusus.
Corycaeus speciosus.
Eucalanus monachus.
Eucalanus mucronatus.

Station 37, March 30 & 31,
Islands. Close to reef. Surface.
Acrocalanus gibber.
Calanopia elliptica.

sp.

ii7°3i'.oE. Bali Sea. Surface.
Eucalanus pileatus.
Euchaeta concinna.
Euchaeta marina.
Euchaeta wolfendeni n.
Labidocera acuta.
Macrosetella gracilis.
Mecynocera clausi.
Metacalanus aurivillii.
Oithona plumifera.
Oncaea venusta.
Paracalanus parvus.
Pontella securifer.
Rhincalanus cornutus.
Scolecithrix danae.
Sapphirina maculosa.
Sapphrina opalina.
Temora discaudata.
Temora turbinata.
Undinula darwini.
Undinula vulgaris.

.// Species.

1899. Lat. 7°36'.oS., Long. n7°28'.7E. Sailus Ketjil, Paternoster-

Candacia catula.
Candacia pachydactyla.

279

2SO

Candacia truncata.
Canthocalanus pauper.
Centropages furcatus.
Centropages gracilis.
Copilia mirabilis.
Copilia quadrata.
Eucalanus crassus.
Eucalanus monachus.
Eucalanus mucronatus.
Eucalanus pileatus.
Euchaeta concinna.
Euchaeta marina.
Euchaeta wolfendeni n. sp.
Labidocera acuta.
Labidocera kroyeri.
Labidocera minuta.
Lucicutia flavicornis.
Macrosetella gracilis.
Mecynocera clausi.
Megacalanus robustior.

Station 40, April 2, 1899. Lat. 2°2j'.oS.,
noster-Islands. Surface, night.
Acartia erythraea.
Acartia negligens.
Acrocalanus gracilis.
Acrocalanus longicornis.
Ameira sibogae, n. sp.
Calocalanus pavo.
Candacia pachydactyla.
Centropages orsinii.
Clausocalanus furcatus.
Cletodes latipes n. sp.
Corycaeus speciosus.
Euchaeta concinna.
Euchaeta marina.
Labidocera acuta.
Macrosetella gracilis.
Mecynocera clausi.
Megacalanus gracilis.
Megacalanus robustior.
Metacalanus aurivillii.
Monstrilla gracilicauda.
Monstrilla inserta n. sp.

Station 47', April 12, 1899. Lat. 8° 20'. 5
Acartia erythraea.
Acartia negligens.
Acrocalanus gibber.
Acrocalanus longicornis.
Calanopia elliptica.
Calanopia minor.
Calanus minor.
Calocalanus pavo.

Metacalanus aurivillii.
Oithona plumifera.
Oncaea venusta.
Paracalanus aculeatus.
Paracalanus parvus.
Pleuromamma abdominalis.
Pleuromamma gracilis.
Pontella securifer.
Pontellina plumata.
Pontellopsis macronyx n. sp.
Rhincalanus cornutus.
Sapphirina maculosa.
Sapphirina opalina.
Scolecithrix danae.
Temora discaudata.
Temora turbinata.
Undinula caroli.
Undinula darwini.
Undinula vulgaris.

4.3 Species.

Long. ii7°49'.oE. Anchorage off Pulu Kawassang. Pater-

Monstrilla orcula n. sp.
Oithona plumifera.
Oncaea venusta.
Paracalanus aculeatus.
Paracalanus parvus.
Phyllopodopsyllus longicaudatus n. sp.
Pleuromamma abdominalis.
Pleuromamma gracilis.
Pontellina plumata.
Pseudothalestris sarsi n. sp.
Rhincalanus cornutus.
Rhynchothalestris rufocincta.
Sapphirina nigromaculata.
Scolecithricella marginata.
Scolecithrix danae.
Temora discaudata.
Temora turbinata.
Tydemanella typica n. sp.
Undinula darwini.
Undinula vulgaris.

4.1 Species.

S., Long. 11 8° 42'. o E. Flores Sea. Surface.
Calocalanus plumulosus.
Candacia bradyi.
Candacia discaudata n. sp.
Candacia catula.
Candacia curta.
Canthocalanus pauper.
Centropages furcatus.
Centropages orsinii.
280

•8i

Clausocalanus arcuicornis.
Copilia mirabilis.
Corycaeus danae.
Corycaeus obtusus.
Corycaeus spcciosus.
Corycaeus tenuis.
Corycaeus venustus.
Eucalanus monachus.
Eucalanus mucronatus.
Eucalanus pileatus.
Eucalanus subcrassus.
Eucalanus subtenuis.
Euchaeta marina.
Labidocera minuta.
Lucicutia flavicornis.
Macrosetella gracilis.

Station 50, April 16 — 18, 1899. Lat.
Flores, Surface.

Acrocalanus longicornis.
Calocalanus pavo.
Candacia pachydactyla.
Canthocalanus pauper.
Centropages furcatus.
Corycaeus concinnus.
Corycaeus elongatus.
Corycaeus furcifer.
Corycaeus gibbulus.
Corycaeus venustus.
Euchaeta marina.
Labidocera acuta.

Station 66, May 7 & 8, 1899. Lat. 6° 32
and Tambolungan, South of Saleyer. Surface.
Calanopia elliptica.
Calanopia minor.
Candacia catula.
Candacia discaudata n. sp.
Candacia pachydactyla.
Candacia simplex.
Candacia truncata.
Canthocalanus pauper.
Centropages elongatus.
Centropages furcatus.
Centropages gracilis.
Centropages orsinii.
Copilia mirabilis.
Copilia quadrata.
Corycaeus alatus.
Corycaeus danae.
Corycaeus longistylis
Eucalanus crassus.
Eucalanus monachus.
Eucalanus mucronatus.

Mecynocera clausi.
Metacalanus aurivillii.
Oithona plumifera.
Oithona rigida.
Oncaea conifera.
Oncaea venusta.
Paracalanus aculeatus.
Paracalanus parvus.
Pontellina plumata.
Sapphirina maculosa.
Sapphirina nigromaculata.
Scolecithricella marginata.
Scolecithrix danae.
Temora discaudata.
Temora turbinata.
Undinula vulkans.

4.8 Species.

8°3o'.oS., Long. U9°52.oE. Bay of Badjo. West Coast of

Macrosetella gracilis.

Oithona rigida.

Oncaea venusta.

Paracalanus parvus.

Pontellina plumata.

Rhincalanus cornutus.

Sapphirina ovatolanceolata.

Scolecithrix danae.

Temora discaudata.

Temora turbinata.

Tortanus gracilis.

Undinula vulgaris. 2^ Species.

.5 S., Long. 1200 27'. 3 E. Bank between Islands of Bahuluwang

Eucalanus subcrassus.
Eucalanus subtenuis.
Euchaeta concinna.
Euchaeta marina.
Euchaeta wolfendeni n. sp.
Gaidius similis.
Hetcrorhabdus spinifrons.
Labidocera acuta.
Labidocera bataviae n. sp.
Labidocera laevidentata.
Labidocera minuta.
Lucicutia flavicornis.
Macrosetella gracilis.
Mecynocera clausi.
Metacalanus gracilis.
Metacalanus aurivillii.
Monstrilla inserta n. sp.
Monstrilla longicornis.
Oncaea venusta.
Paracalanus aculeatus.

281

SIBOGA- EXPEDITIE XXIX a.

36

-82

Pleuromamma abdominalis.
Pleuromamma gracilis.
Pontella denticauda n. sp.
Pontella fera.
Pontella princeps.
Pontella securifer.
Pontellina plumata.
Rhincalanus cornutus.
Sapphirina maculosa.

Sapphirina metallina.
Sapphirina sinuicauda.
Scolecithricella marginata.
Scolecithrix danae.
Temora discaudata.
Tortanus gracilis.
Undinula darwini.
Undinula vulgaris.

57 Species.

Station 71, May 10, 1899. Lat. 5°9'.oS., Long. ii9°23'.sE. Makassar and Surroundings. Surface.

Acartia erythraea.
Acartia negligens.
Acrocalanus longicornis
Calanopia elliptica.
Calanopia minor.
Candacia discaudata n.
Candacia pachydactyla.
Candacia simplex.
Canthocalanus pauper.
Centropages furcatus.
Centropages orsinii.
Clausocalanus furcatus
Corycaeus danae.
Corycaeus gibbulus.
Corycaeus longistylis,
Corycaeus lubbocki.
Corycaeus obtusus.
Corycaeus speciosus.
Euchaeta marina.

sp.

Euchirella galeata.
Labidocera acuta.
Labidocera bataviae n. sp.
Labidocera laevidentata.
Labidocera minuta.
Oithona plumifera.
Oithona rigida.
Oncaea venusta.
Paracalanus parvus.
Pleuromamma abdominalis.
Pleuromamma gracilis.
Pontella fera.
Pontellina plumata.
Pontellopsis kramen.
Pseudodiaptomus aurivillii.
Temora discaudata.
Temora turbinata.
Tortanus gracilis.
Undinula vulgaris.

38 Species.

Station 75, June 8, 1899. Lat. 4°57'.4S.,
1 metres to surface; electric light in net.

Acrocalanus gracilis.
Acrocalanus longicornis.
Calanopia elliptica.
Calocalanus pavo.
Calocalanus plumulosus.
Candacia catula.
Candacia pachydactyla.
Clausocalanus arcuicornis.
Copilia mirabilis.
Corycaeus danae.
Corycaeus gibbulus.
Corycaeus obtusus.
Corycaeus speciosus.
Corycaeus venustus.
Eucalanus crassus.
Eucalanus monachus.
Eucalanus mucronatus.
Eucalanus subtenuis.
Labidocera acuta.

Long, H9°2'.8E. Makassar Strait. HENSEN Vertical Net,

Lucicutia flavicornis.
Macrosetella gracilis.
Megacalanus gracilis.
Metacalanus aurivillii.
Oithona plumifera.
Oncaea media.
Oncaea venusta.
Paracalanus parvus.
Pleuromamma gracilis.
Pontella fera.
Pontellina plumata.
Scolecithricella marginata.
Scolecithrix danae.
Temora discaudata.
Temora turbinata.
Undinula caroli.
Undinula darwini.
Undinula vulgaris.

37 Species.

2 8

Station Si, June i.|. [899. Lat.
Hensen Vertical Net, 10 metres to surf;
Acrocalanus longicornis.
Calanopia elliptica.

Calanopia minor.
Calanus minor.
Candacia aethiopia.
Candacia curta.
Candacia discaudata n. sp.
Candacia pachydactyla.
Canthocalanus pauper.
Centropages calaninus.
Centropages furcatus.
Centropages gracilis.
Clausocalanus furcatus.
Clytemnestra rostrata.
Copilia mirabilis.
Corycaeus danae.
Corycaeus speciosus.
Eucalanus subcrassus.
Euchaeta concinna.
Euchaeta manna.
Euchaeta wolfendeni n. sp.

2°i2'.oS., Long. ti7°24'.6E. Pulu Sebangkatang. Borneo Bank.
tce; electric light in net. Strong current (about 2 miles).

Labidocera acuta.

Labidocera bataviae n. sp.

Labidocera kroyeri.

Labidocera minuta.

Lucicutia flavicornis.

Macrosetella gracilis.

Oithona plumifera.

Oncaea venusta.

Paracalanus aculeatus.

Paracalanus parvus.

Pleuromamma gracilis.

Pontella denticauda n. sp.

Pontella fera.

Pontellina plumata.

Rhincalanus cornutus.

Sapphirina stellata.

Scolecithrix danae.

Temora discaudata.

Undinula darwini.

Undinula vulgaris.

STATION 89, June 21, 1899. Lat. i°7'.oN., Lont
/Etideus armatus.
Acrocalanus longicornis.
Candacia curta.
Candacia discaudata n. sp.
Centropages furcatus.
Copilia mirabilis.
Copilia quadrata.
Corycaeus speciosus.
Eucalanus crassus.
Eucalanus mucronatus.
Eucalanus subcrassus.

.// Species.

i8°44'.6E. Pulu Kaniungan Ketjil. Surface.
Euchaeta concinna.
Euchaeta marina.
Ilyopsyllus affinis.
Labidocera acuta.
Megacalanus gracilis.
Oncaea venusta.
Pontellopsis armata.
Sapphirina stellata.
Temora discaudata.
Undinula vulgaris.

21 Species.

Station 93, June 24 & 25, 1899.
Islands Sulu Archipelago. Surface, night.
Acartia spinicauda.
Acrocalanus gibber.
Acrocalanus gracilis.
Acrocalanus longicornis.
Candacia aethiopica.
Candacia discaudata n. sp.
Candacia simplex.
Candacia truncata.
Canthocalanus pauper.
Centropages calaninus.
Centropages furcatus.
Centropages gracilis.
Clausocalanus arcuicornis.
Copilia mirabilis.
Copilia quadrata.

Lat. 4°59'.oN. Long. U9°49'.oE. Pulu Sanguisiapo, Tawi-Tawi-

Corycaeus obtusus.
Corycaeus speciosus.
Corycaeus venustus.
Eucalanus crassus.
Eucalanus monachus.
Eucalanus mucronatus.
Eucalanus pileatus.
Eucalanus subcrassus.
Eucalanus subtenuis.
Euchaeta marina.
Labidocera acuta.
Macrosetella gracilis.
Metacalanus aurivillii.
Oncaea minuta.
Oncaea venusta.
283

284

Pontella clenticauda n. sp.
Pontella fera.
Pontella forficula n. sp.
Pontellina plumata.
Sapphirina auronitens.
Sapphirina opalina.
Sapphirina ovatolanceolata.

Station 96, June 27, 1899. Lat. 5°48'.o N., Long.
Sulu Archipelago. Surface, day.
Acartia negligens.
Acrocalanus longicornis.
Calanopia elliptica.
Calanopia minor.
Calocalanus pavo.
Candacia aethiopica.
Candacia catula.
Candacia simplex.
Canthocalanus pauper.
Centropages calaninus.
Centropages elongatus.
Centropages furcatus.
Centropages gracilis.
Centropages orsinii.
Clausocalanus arcuicornis.
Clausocalanus furcatus.
Copilia mirabilis.
Corycaeus danae.
Corycaeus gibbulus.
Corycaeus robustus.

Station 96, June 27, 1899. Lat. 5°48'.o N., Long.
Sulu Archipelago. Surface, night.
Acartia erythraea.
Acrocalanus lo ïgicornis.
Calanus minor.
Calocalanus pavo.
Candacia aethiopica.
Candacia catula.
Candacia pachydactyla.
Candacia truncata.
Centropages calaninus.
Centropages elongatus.
Centropages furcatus.
Centropages gracilis.
Centropages orsinii.
Clausocalanus arcuicornis.
Clausocalanus furcatus.
Copilia mirabilis.
Corycaeus danae.
Corycaeus gibbulus.
Corycaeus lubbocki.
Eucalanus mucronatus.
Eucalanus subcrassus.

284

Sapphirina stellata.
Scolecithrix danae.
•Temora discaudata.
Undinula caroli.
Undinula darwini.
Undinula vulgaris.

43 Species.

ii9°44.o E. South East side of Pearl Bank.

Corycaeus speciosus.
Eucalanus pileatus.
Eucalanus subcrassus.
Euchaeta marina.
Labidocera acuta.
Mecynocera clausi.
Metacalanus aurivillii.
Neopontella typica n. sp.
Oithona plumifera.
Oncaea venusta.
Paracalanus parvus.
Pontellina plumata.
Sapphirina angusta.
Sapphirina nigromaculata.
Scaphocalanus magnus.
Scolecithrix danae.
Temora discaudata.
Undinula darwini.
Undinula vulgaris.

jp Species.

H9°44'.oS. South East side of Pearl Bank.

Euchaeta marina.

Labidocera acuta.

Labidocera detruncata.

Labidocera minuta.

Lucicutia flavicornis.

Macrosetella gracilis.

Mecynocera clausi.

Metacalanus aurivillii.

Paracalanus parvus.

Pleuromamma gracilis.

Pontellina plumata.

Pontellopsis strenua.

Sapphirina angusta.

Sapphirina nigromaculata.

Sapphirina opalina.

Sapphirina ovatolanceolata.

Sapphirina stellata.

Scolecithrix danae.

Temora discaudata.

Undinula darwini.

Undinula vulgaris. y_' Species.

«8ü

Station 98, June 28, 1899. Lat. 6°9'.oN., Long.
Acrocalanus gibber.
Acrocalanus gracilis.
Acrocalanus Iongicornis.
Acrocalanus monachus.
Calanopia elliptica.
Candacia aethiopica.
Candacia bradyi.
Candacia catula.
Candacia curta.
Candacia discaudata n. sp.
Candacia pachydactyla.
Candacia simplex.
Candacia truncata.
Canthocalanus pauper.
Centropages furcatus.
Centropages gracilis.
Clausocalanus arcuicornis.
Clausocalanus furcatus.
Copilia mirabilis.
Copilia quadrata.
Corycaeus danae.
Corycaeus furcifer.
Corycaeus gibbulus.
Corycaeus robustus.
Corycaeus speciosus.
Eucalanus crassus.
Eucalanus monachus.
Eucalanus mucronatus.
Eucalanus subcrassus.

Station 99, June 28 — 30, 1899. Lat. 6°7'.5 N.,
Sulu Archipelago. Surface.

Acartia erythraea.
Acartia spinicauda.
Acrocalanus gracilis.
Acrocalanus Iongicornis.
Acrocalanus monachus.
Calanopia elliptica.
Calanopia minor.
Calocalanus pavo.
Candacia bradyi.
Candacia catula.
Candacia discaudata n. sp.
Candacia simplex.
Candacia truncata.
Canthocalanus pauper.
Centropages furcatus.
Clausocalanus furcatus.
Copilia mirabilis.
Corycaeus clanae.
Corycaeus gibbulus.
Corycaeus obtusus.
Corycaeus robustus.

?S5

sp.

sp.

I20°2i'.oS. Sulu Sca. Surface.
Eucalanus subtenuis.
Euchaeta concinna.
Euchaeta marina.
Euchaeta wolfendeni n
Labidocera acuta.
Labidocera bataviae n.
Labidocera detruncata.
Labidocera kroyeri.
Lucicutia flavicornis.
Macrosetella gracilis.
Mecynocera clausi.
Megacalanus gracilis.
Metacalanus aurivillii.
Oncaea venusta.
Pontella denticauda n. sp.
Pontella securifer.
Pontellina plumata.
Pontellopsis armata.
Pontellopsis regalis.
Rhincalanus cornutus.
Sapphirina angusta.
Sapphirina auronitens.
Sapphirina opalina.
Sapphirina stellata.
Scolecithrix danae.
Temora discaudata.
Undinula caroli.
Undinula darwini.
Undinula vulgaris. 38 Species.

Long. i20°26'.oE. Anchorage off North Ubian,

Eucalanus crassus.
Eucalanus monachus.
Eucalanus mucronatus.
Eucalanus pileatus.
Eucalanus subcrassus.
Euchaeta marina.
Labidocera acuta.
Labidocera kroyeri.
Macrosetella gracilis.
Megacalanus gracilis.
Metacalanus aurivillii.
Microsetella norvegica.
Monstrilla cymbula n. sp.
Monstrilla helgolandica.
Oithona plumifera.
Oncaea venusta.
Paracalanus parvus.
Pontella denticauda n. sp.
Rhincalanus cornutus.
Sapphirina metallina.
Sapphirina stellata.

;86

Temora discaudata.
Thaumaleus gigas n. sp.

Station ioi, June 30, 1899. Lat.

Acartia erythraea.
Acrocalanus gracilis.
Calocalanus pavo.
Candacia catula.
Candacia simplex.
Candacia truncata.
Canthocalanus pauper.
Centropages furcatus.
Copilia mirabilis.
Corycaeus longistylis.
Corycaeus venustus.
Eucalanus monachus.

Station 106, July 4, 1899. Lat.
Archipelago. Surface.

Acartia erythraea.
Candacia simplex.
Candacia truncata.
Canthocalanus pauper.
Centropages furcatus.
Copilia mirabilis.
Eucalanus crassus.
Eucalanus mucronatus.
Eucalanus pileatus.
Eucalanus subcrassus.
Euchaeta concinna.
Euchaeta marina.
Labidocera acuta.

Undinula darwini.
Undinula vulgaris.

4.6 Species.

6°i5'.oN., Long. i20°2i'.oE. Sulu Sea. Surface.

Eucalanus mucronatus.

Eucalanus subcrassus.

Labidocera acuta.

Mecynocera clausi.

Oncaea venusta.

Paracalanus aculeatus.

Paracalanus parvus.

Sapphirina nigromaculata.

Sapphirina ovatolanceolata.

Sapphirina stellata.

Temora discaudata.

Undinula vulgaris. 24. Species.

6°4'.o N., Long. I2i°25'.0 E. Anchorage off Kapul Island, Sulu

Labidocera minuta.

Mecynocera clausi.

Metacalanus aurivillii.

Paracalanus parvus.

Pleuromamma abdominalis.

Rhincalanus cornutus.

Sapphirina nigromaculata.

Sapphirina gastrica.

Sapphirina opalina.

Sapphirina ovatolanceolata.

Sapphirina stellata.

Undinula darwini.

Undinula vulgaris. 26 Species.

Station 109, July 5 & 6, 1899. Lat. 6° 7'. o
Archipelago. Surface, night.
Acartia erythraea.
Acrocalanus gracilis.
Aegisthus mucronatus.
Calanopia elliptica.
Calanopia minor.
Calanopia herdmani n. sp.
Candacia truncata.
Canthocalanus pauper.
Centropages furcatus.
Centropages orsinii.
Eucalanus crassus.
Eucalanus subcrassus.
Euchaeta marina.

Station iio, July 6, 1899. Lat. 4°34'.oN.
Acartia negligens.
Acartia spinicauda.
Acrocalanus longicornis.
Calocalanus pavo.

N. Long. i2i°44'E. Anchorage off Tongkil Island, Sulu

Labidocera acuta.

Labidocera kroyeri.

Labidocera minuta.

Mecynocera clausi.

Metacalanus aurivillii.

Paracalanus parvus.

Pontella denticauda n. sp.

Pontella fera.

Pontellopsis krameri.

Pontellopsis macronyx n. sp.

Scolecithrix danae.

Temora discaudata.

Undinula vulgaris. 26 Species.

Long. 1220 o'.O E. Celebes Sea. Surface, night.

Candacia aethiopica.

Candacia bispinosa.

Candacia pachydactyla.

Candacia simplex.
286

287

Candacia truncata.
Canthocalanus pauper.
Centropages orsinii.
Clausocalanus furcatus.

Copilia mirahilis.
Eucalanus monachus.
Eucalanus mucronatus.

Euchaeta concinna.
Euchaeta marina.
Euchaeta wolfendeni n. sp.
Labidocera detruncata.
Labidocera kroyeri.
Labidocera minuta.
Lucicutia flavicornis.
Macrosetella gracilis.

Station iii, July 7, 1S99. Lat.

Acrocalanus longicornis.
Euchaeta marina.

Megacalanus gracilis.
Megacalanus robustior.
Oithona plumifera.
Oncaea venusta.
Pleuromamma abdominalis.
Pontella denticauda n. sp.
Pontella fera.
Pontella securifer.
Pontellina plumata.
Pontellopsis krameri.
Sapphirina angusta.
Temora discaudata.
Undinula darwini.
Undinula vulgaris.

30 19.0 N. Long. ii2°2.oE. Celebes Sea, Surface.

Labidocera detruncata.

JJ Species.

3 Species.

Station 112, July 7, 1899. Lat. 3°i'.oN. Long. 122° 2.0 E. Celebes Sea. Horizontal Cylinder towed
over a distance of 7 miles.

Acrocalanus gibber.
Acrocalanus longicornis.

Aegisthus mucronatus.
Candacia longimana.
Candacia truncata.
Canthocalanus pauper.
Clausocalanus arcuicornis.
Clausocalanus furcatus.
Corycaeus longistylis.
Corycaeus robustus.
Corycaeus speciosus.
Eucalanus subcrassus.

Station 117', July 12, 1899. Lat.

Acartia erythraea.
Acrocalanus gracilis.
Calanopia elliptica.
Calanopia minor.
Calanopia herdmani n. sp.
Candacia aethiopica.
Candacia bradyi.
Candacia curta.
Candacia discaudata n. sp.
Candacia simplex.
Candacia truncata.
Centropages furcatus.
Centropages orsinii.
Copilia mirabilis.
Copilia quadrata.
Eucalanus monachus.
Eucalanus mucronatus.
Eucalanus subcrassus.

Euchaeta marina.
Euchirella hessei.
Labidocera acuta.
Macrosetella gracilis.
Oncaea venusta.
Paracalanus parvus.
Pleuromamma abdominalis.
Pontellina plumata.
Rhincalanus cornutus.
Temora discaudata.
Undinula darwini.
Undinula vulgaris.

2J. Species.

i° 15'. o N. Long. 1230 37 .0 E. North Coast of Celebes. Surface, night.

Euchaeta concinna.
Euchaeta grandiremis.
Euchaeta marina.
Euchaeta media.
Euchaeta wolfendeni n. sp.
Euchirella hessei.
Euchirella pulchra.
Euchirella venusta.
Labidocera acuta.
Labidocera kroyeri.
Lucicutia flavicornis.
Megacalanus gracilis.
Megacalanus robustior.
Metacalanus aurivillii.
Paracalanus parvus.
Pleuromamma abdominalis.
Pleuromamma gracilis.
Pleuromamma xiphias.
287

288

Pontella alata n. sp.
Pontella danae.
Pontella princeps.
Pontella securifer.
Pontellina plumata.
Pontellopsis armata.
Pontellopsis regalis.
Pontellopsis strenua.
Rhincalanus cornutus.
Sapphirina auronitens.

Station 118, July 13, 1899. Lat.
from 900 metres to surface.
Acartia erythraea.
Acrocalanus gibber.
Acrocalanus gracilis.
Acrocalanus longicornis.
Aegisthus mucronatus.
^Etideus armatus.
yEtideus bradyi n. sp.
^Etideus giesbrechti.
zEtideopsis rostrata.
Augaptilus filigerus.
Augaptilus palumboi.
Calanopia minor.
Calanus minor.
Calocalanus pavo.
Candacia aethiopica.
Candacia curta.
Candacia discaudata.
Candacia truncata.
Canthocalanus pauper.
Centropages gracilis.
Centropages orsinii.
Clausocalanus arcuicornis.
Clausocalanus furcatus.
Conaea gracilis.
Copilia mirabilis.
Corycaeus danae.
Corycaeus elongatus.
Corycaeus furcifer.
Corycaeus speciosus.
Corycaeus venustus.
Eucalanus crassus.
Eucalanus mucronatus.
Eucalanus subtenuis.
Euchaeta marina.
Euchirella curticauda.
Euchirella galeata.
Euchirella hessei.
Euchirella messinensis.
Euchirella pulchra.
Euchirella venusta.
Gaetanus armiger.

Sapphirina opalina.
Sapphirina ovatolanceolata.
Sapphirina stellata.
Scolecithrix danae.
Temora discaudata.
Undeuchaeta plumosa.
Undeuchaeta major.
Undinula darwini.
Undinula vulgaris.

SS Species.

i°38'.oN. Long. I24°28'.2 E. Celebes Sea. HENSEN Vertical Net,

Gaetanus caudani.
Gaetanus kruppii.
Gaetanus miles.
Haloptilus longicornis.
Haloptilus ornatus.
Lophothrix frontalis.
Lubbockia aculeata.
Lubbockia squillimana.
Lucicutia flavicornis.
Lucicutia philyra n. sp.
Macrosetella gracilis.
Megacalanus gracilis.
Metacalanus aurivillii.
Metridia boecki.
Metridia brevicauda.
Metridia princeps.
Metridia venusta.
Mormonilla phasma.
Oithona plumifera.
Oncaea venusta.
Oxycalanus semispinus n. sp.
Paracalanus aculeatus.
Paracalanus parvus.
Phaenna spinifera.
Phyllopus bidentatus.
Pleuromamma abdominalis.
Pleuromamma gracilis.
Pleuromamma xiphias.
Pontellina plumata.
Rhincalanus cornutus.
Rhincalanus gigas.
Sapphirina gastrica.
Sapphirina opalina.
Sapphirina sinuicauda.
Scaphocalanus magnus.
Scolecithricella auropecten.
Scolecithricella ctenopus.
Scolecithricella marginata.
Scolecithricella tenuipes.
Scolecithrix danae.
Scottocalanus persecans.
288

28o

Scuttocalanus securifer.
Scottocalanus setosus n. sp.
Temora discaudata.
Tortanus murrayi n. sp.

Station 121, July 14 — 16, 1899. Lat.
Acartia erythraea.
Acrocalanus longicornis.
Calocalanus pavo.
Calocalanus plumulosus.
Candacia catula.
Candacia truncata.
Canthocalanus pauper.
Clausocalanus arcuicornis.
Clausocalanus furcatus.
Copilia mirabilis.
Corycaeus longistylis.
Corycaeus obtusus.
Corycaeus speciosus.
Eucalanus mucronatus.

Undeuchaeta plumosa.
Undinula darwini.
Undinula vulgaris.
Xanthocalanus agilis.

po Species.

i°33'.o N. Long. 1240 47 .5 E. Menado Anchorage. Surface.
Eucalanus pileatus.
Euchaeta marina.
Euchaeta wolfendeni n. sp.
Macrosetella gracilis.
Mecynocera clausi.
Monstrilla longicornis.
Oithona plumifera.
Oncaea venusta.
Paracalanus parvus.
Pontellina plumata.
Sapphirina metallina.
Sapphirina ovatolanceolata.
Temora discaudata.
Undinula vulgaris. 28 Species.

Station 122, July 17, 1899. Lat. i°58'.5N. Long. i25°o'.5 E. Near Biaru Island. Surface.

Candacia discaudata n. sp.
Centropages orsinii.
Labidocera acuta.
Oncaea venusta.

Station 124, July 18, 1899. Lat. 2°27'.o N. Long.
Calanus minor.
Candacia bradyi.
Candacia curta.
Candacia pachydactyla.
Copilia mirabilis.
Eucalanus crassus.
Eucalanus mucronatus.
Eucalanus subtenuis.
Euchaeta concinna.
Euchaeta marina.
Euchaeta wolfendeni n. sp.
Labidocera acuta.

Pontellina plumata.
Temora discaudata.

Undinula vulgaris.

i25°35'.oE. Celebes Sea. Surface.
Macrosetella gracilis.
Pontella denticauda n. sp.
Pontellina plumata.
Pontellopsis armata.
Pontellopsis krameri.
Pontellopsis regalis.
Scolecithrix danae.
Temora discaudata.
Undinula caroli.
Undinula darwini.
Undinula vulgaris.

7 Speac s.

Station 125, July 18 & 19, 1899. Lat. 2°38'.oN., Lont
Island. Surface, day.

Acartia negligens.
Acrocalanus longicornis.
Calanopia elliptica.
Calanus minor.
Candacia catula.
Candacia curta.
Centropages furcatus.
Copilia mirabilis.
Corycaeus venustus.
Eucalanus crassus.
Eucalanus mucronatus.

23 Species.
I25°26'.5E. Anchorage off Sawan, Siau

Eucalanus subcrassus.
Eucalanus subtenuis.
Euchaeta concinna.
Euchaeta marina.
Euchaeta wolfendeni n. sp.
Megacalanus gracilis.
Metacalanus aurivillii.
Oithona plumifera.
Oncaea venusta.
Paracalanus parvus.
Phaenna spinifera.

SIROGA-EXPED1TIE XXIX ö.

37

!90

Rhincalanus cornutus.
Sapphirina ovatolanceolata.
Scolecithrix danae.

Station 125, July 18 & 19, 1899. Lat. 2° $8'. o N.,
Island. Surface, night.

Candacia bradyi.
Candacia truncata.
Canthocalanus pauper.
Corycaeus longistylis.
Eucalanus crassus.
Eucalanus subcrassus.

Temora discaudata.
Undinula darvvini.
Undinula vulgaris.

?<? Spe

Long. I25°2ó.5 E. Anchorage off Sawan, Siau

Eucalanus subtenuis.
Labidocera acuta.
Megacalanus gracilis.
Rhincalanus gigas.
Sapphirina darwini.
Undinula vulgaris.

12 Species.
Station 128, July 22, 1899. Lat. 4°27'.oN., Long. i25°25'./E. Celebes Sea. Hensen Vertical Net,

from 700 metres to surface.

/

Acartia negligens.
Acrocalanus longicornis.
Acrocalanus monachus.
Aegisthus aculeatus.
Aegisthus mucronatus.
/Etideus armatus.
/Etideus bradyi n. sp.
/Etideus giesbrechti.
Augaptilus palumboi.
Augaptilus validus n. sp.
Calanopia elliptica.
Calanopia minor.
Calanus minor.
Candacia aethiopica.
Candacia bispinosa.
Candacia longimana.
Candacia pachydactyla.
Candacia truncata.
Canthocalanus pauper.
Centropages elongatus.
Centropages furcatus.
Chiridius poppei.
Chirundina streetsi.
Clausocalanus arcuicornis.
Clausocalanus furcatus.
Conaea gracilis.
Copilia mirabilis.
Copilia quadrata.
Corycaeus alatus.
Corycaeus danae.
Corycaeus elongatus.
Corycaeus fiaccus.
Corycaeus furcifer.
Corycaeus gibbulus.
Corycaeus longistylis.
Corycaeus robustus.
Corycaeus speciosus.
Eucalanus mucronatus.
Euchaeta concinna.

sp.

Euchaeta hebes.
Euchaeta manna.
Euchaeta wolfendeni n
Euchirella amoena.
Euchirella curticauda.
Euchirella hessei.
Gaetanus caudani.
Gaetanus miles.
Haloptilus longicornis.
Haloptilus ornatus.
Haloptilus spiniceps.
Heterorhabdus clausi.
Heterorhabdus longicornis.
Heterorhabdus papilliger.
Labidocera minuta.
Lophothrix frontalis.
Lubbockia squillimana.
Lucicutia flavicornis.
Lucicutia pera n. sp.
Macrosetella gracilis.
Megacalanus gracilis.
Megacalanus robustior.
Metacalanus aurivillii.
Metridia princeps.
Metridia venusta.
Oithona plumifera.
Oncaea venusta.
Paracalanus aculeatus.
Paracalanus parvus.
Phyllopus bidentatus.
Phyllopus helgae.
Phyllopus impar.
Pleuromamma abdominalis
Pleuromamma gracilis.
Pleuromamma xiphias.
Pontella denticauda n. sp.
Pontellina plumata.
Rhincalanus cornutus.
Rhincalanus gigas.

290

29 1
Scaphocalanus magnus.
Scolecithricella longifurca.

Scolecithricella marginata.
Scolecithrix danae.
Scottocalanus farrani n. sp.

Station 129, July 22 & 23. 1S99. Lat. 4°37'.oN., Long.
Kamboling Islands, Karkaralong-group. Surface.
Candacia bipinnata.
Candacia simplex.
Copilia mirabilis.
Copilia quadrata.
Corycaeus furcifer.
Eucalanus mucronatus.
Eucalanus subcrassus.
Eucalanus subtenuis.

Scottocalanus persecans.
Scottocalanus securifrons.
Undeuchaeta plumosa.
Undinula darwini.

8j Species.

I25°26'.5 E. Anchorage off Kawio- and

Station 133, July 25 — 27,
Island. Surface.

Acartia negligens.
Calocalanus pavo.
Candacia aethiopica.
Candacia bispinosa.
Candacia pachydactyla.
Candacia truncata.
Canthocalanus pauper.
Centropages orsinii.
Copilia mirabilis.
Corycaeus furcifer.
Corycaeus longistylis.
Corycaeus speciosus.
Eucalanus mucronatus.

1899. Lat. 3°59'.oN., Long.

Euchaeta marina.
Haloptilus longicornis.
Megacalanus gracilis.
Pontellina plumata.
Sapphirina intestinata.
Sapphirina nigromaculata.
Undinula darwini.

ij Species.
126° 42.0 E. Anchorage off Lirung, Salibabu

Eucalanus subcrassus.

Euchaeta marina.

Euchirella messinensis.

Megacalanus gracilis.

Oithona plumifera.

Üncaea venusta.

Paracalanus parvus.

Pontellina plumata.

Pseudodiaptomus aurivillii.

Rhincalanus cornutus.

Sapphirina ovatolanceolata.

Scolecithrix danae.

Undinula darwini. 26 Species.

STATION 136, July 29, 1899. Lat. o°48'.oN., Long. i27°2Ó'.oE. Ternate Anchorage. Surface.

Acartia erythraea.
Calanopia elliptica.
Calanus minor.
Candacia bradyi.
Candacia discaudata n. sp.
Candacia pachydactyla.
Candacia simplex.
Candacia truncata.
Canthocalanus pauper.
Centropages furcatus.
Copilia mirabilis.
Copilia quadrata.
Eucalanus monachus.
Eucalanus mucronatus.
Eucalanus subcrassus.
Eucalanus subtenuis.
Euchaeta concinna.
Euchaeta marina.
Euchaeta wolfendeni n. sp.
Labidocera acuta.
Labidocera minuta.

Metacalanus aurivillii.
Oithona plumifera.
Oncaea venusta.
Paracalanus aculeatus.
Paracalanus parvus.
Pontellina plumata.
Rhincalanus cornutus.
Sapphirina angusta.
Sapphirina gastrica.
Sapphirina intestinata.
Sapphirina longifurca n. sp.
Sapphirina opalina.
Sapphirina ovatolanceolata.
Sapphirina sinuicauda.
Sapphirina stellata.
Scolecithrix danae.
Temora discaudata.
Undinula caroli.
Undinula darwini.
Undinula vulgaris.

4.1 Species.

291

292

Station 138, Augnst 3, 1899.
Kajoa Island. Surface, night.
Acartia negligens.
Acrocalanus gibber.
Acrocalanus gracilis.
Acrocalanus longicornis.
Aegisthus mucronatus.
Calanopia elliptica.
Calanopia minor.
Calocalanus pavo.
Candacia aethiopica.
Candacia bradyi.
Candacia catula.
Candacia curta.
Candacia pachydactyla.
Centropages gracilis.
Clausocalanus furcatus.
Corycaeus danae.
Corycaeus speciosus.
Eucalanus crassus.
Eucalanus monachus.
Eucalanus mucronatus.
Eucalanus pileatus.
Eucalanus subcrassus.
Eucalanus subtenuis.
Euchaeta concinna.

Station 141, August 5, 1899.
Net, from 1500 metres to surface.
Acartia erythraea.
Acartia negligens.
Acrocalanus gibber.
Acrocalanus gracilis.
Acrocalanus longicornis.
Aegisthus mucronatus.
/Etideus armatus.
yEtideus bradyi n. sp.
/Etideus giesbrechti.
/Etideopsis rostrata.
Arietellus setosus.
Arietellus simplex.
Augaptilus bullifer.
Augaptilus filigerus.
Augaptilus hecticus.
Augaptilus palumboi.
Augaptilus validus, n. sp.
Bradyidius armatus.
Calanopia elliptica.
Calanopia minor.
Calanopia herdmani n. sp.
Calanus minor.
( 'alocalanus pavo.
Candacia aethiopica.
Candacia bradyi.

Lat. o°6'.oN., Long. I27°6'.oE. Anchorage on the East-Coast of

Euchaeta marina.

Euchaeta vvolfendeni n. sp.

Labidocera acuta.

Labidocera minuta.

Macrosetella gracilis.

Megacalanus robustior.

Metacalanus aurivillii.

Oithona plumifera.

Oncaea venusta.

Paracalanus parvus.

Pontella princeps.

Pontellina plumata.

Pontellopsis armata.

Pontellopsis pexa n. sp.

Pontellopsis villosa.

Rhincalanus cornutus.

Sapphirina nigromaculata.

Sapphirina sinuicauda.

Scaphocalanus magnus.

Scolecithrix danae.

Temora discaudata.

Undinula caroli.

Undinula darwini.

Undinula vulgaris. j$ Species.

Lat. i°o'.4 S., Long. I27°25'.3E. Molucca Passage. HENSEN Vertical

Candacia curta.
Candacia discaudata n. sp.
Candacia pachydactyla.
Candacia simplex.
Candacia tenuimana.
Candacia truncata.
Canthocalanus pauper.
Centropages furcatus.
Chiridius gracilis.
Chiridius obtusifrons.
Chiridius poppei.
Chirundina streetsi.
Clausocalanus arcuicornis.
Clausocalanus furcatus.
Conaea gracilis.
Copilia mirabilis.
Corycaeus concinnus.
Corycaeus furcifer.
Corycaeus obtusus.
Corycaeus speciosus.
Corycaeus venustus.
Disseta palumboi.
Eucalanus crassus.
Eucalanus dentatus n. sp.
Eucalanus monachus.

292

593

Eucalanus mucronatus.
Eucalanus subcrassus.
Eucalanus subtenuis.
Euchaeta acuta.
Euchaeta concinna.
Euchaeta longicornis.
Euchaeta marina.
Euchaeta tenuis.
Euchaeta wolfendeni n. sp.
Euchirella curticauda.
Euchirella galeata.
Euchirella hessei.
Euchirella messinensis.
Euchirella pulchra.
Euchirella venusta.
Gaetanus hamatus n. sp.
Gaetanus kruppii.
Gaetanus miles.
Gaetanus minor.
Gaidius similis.
Haloptilus longicornis.
Haloptilus plumosus.
Heterorhabdus longicornis.
Heterorhabdus spinifrons.
Labidocera acuta.
Labidocera madurae n. sp.
Labidocera minuta.
Lophothrix frontalis.
Lubbockia aculeata.
Lucicutia clausi.
Lucicutia flavicornis.
?.lecynocera clausi.
Megacalanus gracilis.
Megacalanus robustior.
Metacalanus aurivillii.
Metiidia boecki.
Metridia brevicauda.
Metridia princeps.
Metridia venusta.
Oithona plumifera.
Uncaea conifera.

Station 142, August 5 — 7, 1899.
of Obi Major. HENSEN Vertical Net, 10
Acartia erythraea.
Acartia negligens.
Acartia spinicauda.
Acrocalanus gibber.
Acrocalanus gracilis.
Acrocalanus longicornis.
Calanopia elliptica.
Calanopia minor.
Calanopia herdmani n. sp.
Calanopia thompsoni n. sp.

Oncaea venusta.
( (xycalanus semispinus n. sp.
Paracalanus aculeatus.
Paracalanus parvus.
Paraugaptilus similis n. sp.
Phyllopus bidentatus.
Phyllopus impar.
Pleuromamma abdominalis.
Pleuromamma gracilis.
Pleuromamma xiphias.
Paraeuchaeta californica.
Paraeuchaeta tonsa.
Rhincalanus cornutus.
Rhincalanus gigas.
Sapphirina angusta.
Sapphirina intestinata.
Sapphirina metallina.
Sapphirina nigromaculata.
Sapphirina opalina.
Sapphirina ovatolanceolata.
Sapphirina stellata.
Scaphocalanus magnus.
Scaphocalanus major.
Scolecithricella bradyi.
Scolecithricella abyssalis.
Scolecithricella longicornis.
Scolecithricella obtusifrons.
Scolecithricella profunda.
Scolecithricella tenuipes.
Scolecithrix danae.
Scottocalanus farrani n. sp.
Scottocalanus securifrons.
Scottocalanus setosus.
Temora discaudata.
Temora turbinata.
Undeuchaeta plumosa.
Undeuchaeta intermedia n. sp.
Undeuchaeta major.
Undinula vulgaris.
Xanthocalanus agilis.

131 Species.

Lat. o°24'.oS., Long. i27°36'.oE. Anchorage off Laiwui, Coast
metres to surface, with electric light in net.

Candacia bradyi.

Candacia discaudata n. sp.

Candacia pachydactyla.

Candacia truncata.

Canthocalanus pauper.

Centropages furcatus.

Centropages orsinii.

Chiridius gracilis.

Chiridius poppei.

Chirundina streetsi.

293

'94

Clausocalanus arcuicornis.
Clausocalanus furcatus.
Clytemnestra rostrata.
Corycaeus danae.
Corycaeus gibbulus.
Corycaeus gracilicaudatus.
Corycaeus obtusus.
Corycaeus robustus.
Corycaeus speciosus.
Corycaeus tenuis.
Eucalanus crassus.
Eucalanus mucronatus.
Eucalanus subtenuis.
Euchaeta marina.
Euchaeta wolfendeni, n. sp.
Eucbirella galeata.
Euchirella hessei.
Euchirella pulchra.
Euterpina acutifrons.
Gaidius similis.
Labidocera acuta.
Labidocera kroyeri.
Labidocera minuta.
Metacalanus aurivillii.
Metridia venusta.
Monstrilla longipes n. sp.
Monstrilla turgida n. sp.

STATION 143, August 7, 1899. Lat. i°4'.5 S., Long.
Net, from 1000 metres to surface.
Acartia erythraea.
Acrocalanus gibber.
Acrocalanus gracilis.
Acrocalanus longicornis.
Aegisthus mucronatus.
yEtideus armatus.
yEtideus bradyi n. sp.
/Etideus giesbrechti.
yEtideopsis rostrata.
Augaptilus filigerus.
Augaptilus palumboi.
Augaptilus placitus n. sp.
Bathypontia spinifera n. sp.
Calanopia elliptica.
Calanopia minor.
Calanopia herdmani n. sp.
Calanus minor.
Candacia bradyi.
Candacia catula.
Candacia curta.
Candacia pachydactyla.
Candacia simplex.
Candacia truncata.
Canthocalanus pauper.

294

Neopontella typica n. sp.
Üithona plumifera.
Oithona pygmaea.
Oithona minuta.
Oncaea venusta.
Pachysoma punctatum.
Paracalanus aculeatus.
Paracalanus parvus.
Parapeltidium johnstoni n. sp.
Paraugaptilus similis n. sp.
Phyllothalestris mysis.
Pleuromamma abdominalis.
Pseudanthessius obscurus n. sp.
Pseudanthessius parvus n. sp.
Rhincalanus gigas.
Sapphirina metallina.
Scolecithricella abyssalis.
Scolecithricella bradyi.
Scolecithricella marginata.
Scolecithrix danae.
Temora discaudata.
Temora turbinata.
Thaumaleus bullatus n. sp.
Tortanus gracilis.
Undeuchaeta plumosa.
Undeuchaeta intermedia n. sp.

7./ Species.

Undinula vulgaris.

I27°52'.6 E. Halmahera Sea. HENSEN Vertical

Centropages furcatus.
Clausocalanus arcuicornis.
Clausocalanus furcatus.
Chiridius gracilis.
Chirundina streetsi.
Conaea gracilis.
Cornucalanus simplex.
Corycaeus danae.
Corycaeus gracilicaudatus.
Corycaeus longistylis.
Corycaeus obtusus.
Corycaeus speciosus.
Corycaeus tenuis.
Eucalanus crassus.
Eucalanus mucronatus.
Euchaeta concinna.
Euchaeta marina.
Euchaeta tenuis.
Euchirella galeata.
Euchirella messinensis.
Euchirella pulchra.
Euchirella venusta.
Gaetanus caudani.
Gactanus kruppii.

'95

Gaetanus miles.
Heteramalla dubia.
Heterorhabdus longicornis.
Heterorhabdus spinifrons.
Labidocera minuta.
Lubbockia aculeata.
Lubbockia squillimana.
Lucicutia clausi.
Lucicutia flavicornis.
Macrosetella gracilis.
Mecynocera clausi.
Megacalanus gracilis.
Metacalanus aurivillii.
Metridia brevicauda.
Metridia venusta.
Mormonilla phasma.
Neopontella typica n. sp.
Oithona plumifera.
Oncaea conifera.
Oncaea minuta.
Oncaea tenuimana.
Oncaea venusta.
Oxycalanus semispinus n. sp.
Pachysoma punctatum.
Paracalanus aculeatus.

Station 144, August 7 — 9, 1899. Lat. o°58'.oS., Long.
(Damar) Island.

Acartia erythraea.
Acrocalanus longicornis.
Aegisthus mucronatus.
Calanopia elliptica.
Calanus minor.
Candacia bradyi.
Candacia curta.
Candacia discaudata.
Candacia pachydactyla.
Candacia simplex.
Candacia truncata.
Canthocalanus pauper.
Copilia mirabilis.
Copilia quadrata.
Corycaeus furcifer.
Eucalanus crassus.
Eucalanus mucronatus.
Eucalanus subcrassus.
Eucalanus subtenuis.
Euchaeta concinna.
Euchaeta marina.
Labidocera acuta.
Labidocera kroyeri.

Station 146, August 9, 1899. Lat. o°36'.oS., Long.
Group. Surface.

Calocalanus pavo.

295

Paracalanus parvus.
Paraeuchaeta caüfornica.
Paraugaptilus similis n. sp.
Phaenna spinifera.
Pleuromamma abdominalis.
Pleuromamma gracilis.
Pleurömamma xiphias.
Phyllopus impar.
Pontellopsis armata.
Rhincalanus cornutus.
Rhincalanus gigas.
Scaphocalanus magnus.
Scaphocalanus major.
Scolecithricella abyssalis.
Scolecithricella bradyi.
Scolecithricella longicornis.
Scolecithricella marginata.
Scolecithrix d:nae.
Scottocalanus farrani n. sp.
Scottocalanus securifrons.
Scottocalanus setosus n. sp.
Temoropia mayumbaensis.
Undeuchaeta plumosa.
Undinula vulgaris.

P7 Species.
i28°2i'.oE. Anchorage North of Salomakiëe

Labidocera minuta.
Mecynocera clausi.
Oncaea venusta.
Pachysoma punctatum.
Paracalanus parvus.
Phaenna spinifera.
Pleuromamma abdominalis.
Pleuromamma gracilis.
Pontella fera.
Pontellina plumata.
Pontellopsis armata.
Pontellopsis krameri.
Pontellopsis regalis.
Rhincalanus cornutus.
Sapphirina angusta.
Sapphirina gastrica.
Sapphirina opalina.
Sapphirina stellata.
Scolecithrix danae.
Temora discaudata.
Temora turbinata.
Undinula darwini.
Undinula vulgaris.

I28°32'.7 E.

.1

■ 2

j.6 Species.
miles north of Eastern Widi

Candacia aethiopica.

296

Candacia catula.
Candacia curta.
Candacia pachydactyla.
Centropages furcatus.
Copilia mirabilis.
Copilia quadrata.
Corycaeus danae.
Eucalanus crassus.
Eucalanus mucronatus.
Eucalanus subcrassus.

Station 148, August 10, 1899. Lat. o°i7'.6S., Long.
Net, from 1000 metres to surface.

Acartia erythraea.
Acartia negligens.
Acrocalanus gracilis.
Acrocalanus longicornis.
Aegisthus aculeatus.
Aegisthus mucronatus,
/Etideopsis rostrata.
Amallophora typica.
Augaptilus filigerus.
Augaptilus palumboi.
Augaptilus placitus n. sp.
Arietellus aculeatus.
Bradycalanus typicus n. sp.
Calanopia elliptica.
Calanopia minor.
Calanus minor.
Calocalanus pavo.
Calocalanus plumulosus.
Candacia aethiopica.
Candacia catula.
Candacia curta.
Candacia discaudata n. sp.
Candacia pachydactyla.
Canthocalanus pauper.
Centropages furcatus.
Chiridella macrodactyla.
Chiridius gracilis.
Chiridius poppei.
Chirundina streetsi.
Clausocalanus arcuicornis.
Clausocalanus furcatus.
Conaea gracilis.
Corycaeus concinnus.
Corycaeus danae.
Corycaeus gibbulus.
Corycaeus longistylis.
Corycaeus obtusus.
Corycaeus speciosus.
Eucalanus crassus.
Kucalanus mucronatus.
Eucalanus subcrassus.

296

Euchaeta concinna.

Labidocera acuta.

Macrosetella gracilis.

Mecynocera clausi.

Oithona plumifera.

Pleuromamma abdominalis.

Pleuromamma gracilis.

Rhincalanus cornutus.

Sapphirina nigromaculata.

Undinula darwini. 22 Species.

1290 14'. 5 E. Halmahera Sea. HENSEN Vertical

Euchaeta acuta.
Euchaeta concinna.
Euchaeta marina.
Euchaeta tenuis.
Euchirella galeata.
Euchirella maxima.
Euchirella pulchra.
Euchirella venusta.
Gaetanus miles.
Gaidius notacanthus.
Haloptilus longicornis.
Heterorhabdus clausi.
Heterorhabdus longicornis.
Heterorhabdus spinifrons.
Labidocera acuta.
Lophothrix frontalis.
Lucicutia flavicornis.
Macandrevvella joanae n. sp.
Macrosetella gracilis.
Mecynocera clausi.
Megacalanus gracilis.
Megacalanus princeps.
Metacalanus aurivillii.
Metridia boecki.
Metridia princeps.
Metridia venusta.
Oithona plumifera.
Oncaea media.
Oncaea tenuimana.
Oncaea venusta.
Onchocalanus cristatus.
Oxycalanus semispinus n. sp.
Paracalanus aculeatus.
Paracalanus parvus.
Paraeuchaeta californica.
Paraeuchaeta sibogae n. sp.
Paraugaptilus similis n. sp.
Pleuromamma abdominalis.
Pleuromamma gracilis.
Pleuromamma xiphias.
Pontellina plumata.

?<>7

Rhincalanus c< »rnutus.
Sapphirina nigromaculata.
Sapphirina opalina.
Scaphocalanus elongatus n. sp.
Scolecithricella auropecten.
Scolecithricella curticauda n. sp.
Scolecithricella gracilis.
Scolecithricella longicornis.
Scolecithricella obtusi frons.
Scolecithricella tydemani n. sp.
Scolecithricella valida.
Scolecithrix danae.
Scottocalanus farrani n. sp.

Sri ittocalaiuis helenae.

Scottocalanus longispinus n. sp.

Scottocalanus persecans.

Scottocalanus securi frons.

Scottocalanus setosus n. sp.

Temora discaudata.

Temora turbinata.

Temoropia mayumbaensis.

Undeuchaeta plumosa.

Undeuchacta major.

Undinula caroli.

Undinula darwini.

Undinula vulgaris. 108 Species.

Station 149, August 10 & 11,
of Gebé Island. Surface.

Acartia erythraea.
Calanopia elliptica.
Canthocalanus pauper.
Corycaeus obtusus.

Station 157, August 15 & 16,
North point of Great Fam Island (Jef-
Calanus minor.
Candacia curta.
Candacia discaudata n. sp.
Candacia pachydactyla.
Candacia truncata.
Copilia mirabilis.
Copilia quadrata.
Corycaeus furcifer.
Eucalanus mucronatus.
Eucalanus subcrassus.
Eucalanus subtenuis.
Euchaeta concinna.
Euchaeta marina.
Euchaeta wolfendeni n. sp.

Station 164, August 20, 1899.
dredgcd material depth 32 metres.

Alteuthella pellucida n. sp.
Canuella curticaudata.
Eupelte oblivia n. sp.
Lichomolgus buddhensis.

Station 165, August 20 — 22, i
Side of Daram Island (False Pisangs),
Acartia erythraea.
Acartia negligens.
Acrocalanus longicornis.
Calanoides brevicornis.
Calanopia elliptica.
Calanus minor.
Candacia curta.

SIBOGA-EXPEDITIE XX \\.:.

1899. Lat. o°5'.oS., Long. i29°24'.oE. Fau Anchorage, West Coast

Euchaeta marina.
Scolecithrix danae.
Undinula darwini.
Undinula vulgaris.

8 Species.

1899. Lat. o°32'.9S., Long. 1300 i4'.6 E. 41/., Cables N.N.W. of the
Fam-besar). Surface, night.

Labidocera acuta.

Megacalanus gracilis.

Oithona plumifera.

Oncaea venusta.

Paracalanus aculeatus.

Pontella denticauda n. sp.

Pontellina plumata.

Pontellopsis armata.

Pontellopsis regalis.

Rhincalanus cornutus.

Scolecithrix danae.

Undinula darwini.

Undinula vulgaris.

27 Species.

Lat. i°42.5 S., Long. I30°47'.5 E. near New Guinea. Washings from

Longipedia coronata.
Rhynchothalestris rufocincta.
Sunaristes paguri.

7 Species.

899. Lat. 2°8'.oS., Long. i30°5o'.7E. Anchorage on North East
East Coast of Misool. Surface.

Candacia pachydactyla.

Candacia simplex.

Canthocalanus pauper.

Centropages furcatus.

Copilia mirabilis.

Copilia quadrata.

Corycaeus danae.
297

298

Corycaeus furcifer.
Corycaeus obtusus.
Corycaeus speciosus.
Corycaeus tenuis.
Eucalanus crassus.
Eucalanus monachus.
Eucalanus mucronatus.
Eucalanus pileatus.
Eucalanus subcrassus.
Eucalanus subtenuis.
Euchaeta concinna.
Euchaeta marina.
Euchaeta wolfendeni n. sp.
Labidocera acuta.
Labidocera kroyeri.
Oithona plumifera.

Station 168, August 22 & 23, 1899. Lat.
Island. Surface.

Acartia erythraea.
Acartia negligens.
Acrocalanus longicornis.
Calanoides brevicornis.
Calanopia minor.
Calanus minor.
Candacia discaudata.
Candacia pachydactyla.
Canthocalanus pauper.
Clausocalanus arcuicornis.
Clausocalanus furcatus.
Eucalanus monachus.
Eucalanus mucronatus.
Eucalanus pileatus.
Eucalanus subcrassus.
Euchaeta concinna.

Station 169, August 23 — 25, 1899.
West Coast of New Guinea. Surface.
Acartia erythraea.
Acartia spinicauda.
Acrocalanus longicornis.
Calanoides brevicornis.
Candacia bradyi.
Candacia curta.
Candacia pachydactyla.
Candacia truncata.
Canthocalanus pauper.
Centropages furcatus.
Copilia mirabilis.
Copilia quadrata.
Corycaeus robustus.
Eucalanus crassus.
Eucalanus monachus.
Eucalanus mucronatus.

Oithona rigida.

Oncaea venusta.

Faracalanus aculeatus.

Paracalanus parvus.

Rhincalanus cornutus.

Rhincalanus gigas.

Sapphirina bicuspidata.

Sapphirina intestinata.

Sapphirina opalina.

Sapphirina stellata.

Scolecithrix danae.

Temora discaudata.

Temora turbinata.

Undinula caroli.

Undinula darwini.

Undinula vulgaris. j.6 Species.

38'. o S., Long. 131° 33'. E. Anchorage North of Sabuda

Lophothrix frontalis.
Macrosetella gracilis.
Oithona plumifera.
Oithona rigida.
Oncaea venusta.
Paracalanus aculeatus.
Paracalanus parvus.
Rhincalanus cornutus.
Rhincalanus gigas.
Sapphirina nigromaculata.
Scaphocalanus magnus.
Scolecithrix danae.
Temora discaudata.
Undinula darwini.
Undinula vulgaris.

?/ Species.

Lat. 3°o'.oS., Long. i32°o'.2 E. Anchorage off Atjatuning,

Eucalanus pileatus.
Eucalanus subtenuis.
Euchaeta concinna.
Labidocera acuta.
Labidocera minuta.
Oithona plumifera.
Oncaea venusta.
Paracalanus parvus.
Rhincalanus cornutus.
Sapphirina gastrica.
Sapphirina nigromaculata.
Sapphirina opalina.
Scolecithrix danae.
Temora discaudata.
Undinula darwini.

Undinula vulgaris. 32 Species.

298

299

Station 172, August 26 — 28, 1899. Lat. 3'
tli is Island and Ceram Laut. Surface.
Calanoides brevicornis.
Candacia bradyi.
Candacia discaudata n. sp.
Candacia pachydactyla.
Candacia simplex.
Candacia truncata.
Canthocalanus pauper.
Copilia mirabilis.
Copilia quadrata.
Eucalanus crassus.
Eucalanus dentatus n. sp.
Eucalanus mucronatus.
Eucalanus subcrassus.
Eucalanus subtenuis.
Euchaeta concinna.

Station 174, August 28 & 29, 1899. Lat.
of Ceram. Surface.

Acartia erythraea.
Acartia negligens.
Acartia spinicauda.
Calanopia elliptica.
Candacia bradyi.
Candacia discaudata n. sp.
Candacia simplex.
Centropages furcatus.
Clausocalanus arcuicornis.
Clytemnestra rostrata.

Station 1771, September 1, 1899. Lat.
Acartia erythraea.
Candacia simplex.
Candacia truncata.
Chirundina streetsi.
Copilia mirabilis.
Eucalanus mucronatus
Eucalanus subcrassus.
Euchaeta concinna.
Euchirella hessei.
Labidocera acuta.

54'. o S., Long. i30°5o'.o E. Grisser; Anchorage between

Euchaeta wolfendeni n. sp.

Labidocera acuta.

Phaenna spinifera.

Pontellina plumata.

Rhincalanus cornutus.

Rhincalanus gigas.

Sapphirina auronitens.

Sapphirina bicuspidata.

Sapphirina intestinata.

Sapphirina opalina.

Sapphirina stellata.

Scolecithrix danae.

Temora discaudata.

Undinula darwini.

Undinula vulgaris. 30 Species.

',f.O S., Long. 1 300 39'. O E. Waru Bay, North Coast

Corycaeus obtusus.
Labidocera acuta.
Labidocera minuta.
Oithona rigida.
Pontellopsis armata.
Pseudodiaptomus aurivillii.
Rhincalanus cornutus.

Rhincalanus gigas.
Scolecithrix danae.
Undinula vulsjaris.

20 Species.

2°3o'.oS., Long. i29°2S'.oE. Ceram Sea. Surface.
Megacalanus gracilis.
Paracalanus parvus.
Pleuromamma abdominalis.
Pontellina plumata.
Rhincalanus cornutus.
Sapphirina opalina.
Sapphirina ovatolanceolata.
Scolecithrix danae.
Undinula darwini.
Undinula vulgaris. 20 Species.

Station 184, September 11 & 12, 1899. Lat. 30 20.0 S., Long. i27°33'.oE. Anchorage off Kampong

Kelang, South Coast of Manipa Island. Night.
Acrocalanus gibber.
Acrocalanus longicornis.
Calanopia elliptica.
Calanopia minor.
Calanus minor.
Calocalanus plumulosus.
Candacia bradyi.
Candacia curta.
Candacia pachydactyla.

Candacia truncata.
Canthocalanus pauper.
Centropages furcatus.
Clausocalanus furcatus.
Copilia mirabilis.
Copilia quadrata.
Corycaeus gibbulus.
Corycaeus obtusus.
Corycaeus speciosus.

299

;oo

Eucalanus crassus.
Eucalanus dentatus n. sp.
Eucalanus mucronatus.
Eucalanus subcrassus.
Eucalanus subtenuis.
Euchaeta concinna.
Euchaeta marina.
Euchaeta wolfendeni n. sp.
Labidocera acuta.
Lophothrix frontalis.
Lucicutia clausi.
Lucicutia flavicornis.
Mecynocera clausi.
Metacalanus aurivillii.
Oithona plumifera.
Oncaea venusta.
Paracalanus aculeatus.
Paracalanus parvus.

STATluN 1S5, September 12, 1899. Lat. 3° 2o'.o S.
Net, from 1536 metres to surface.
Acartia erythraea.
Acartia negligens.
Acrocalanus longicornis.
/Etideus bradyi n. sp.
/Etideus giesbrechti.
Augaptilus longicaudatus.
Brachycalanus gigas n. sp.
Calanoides brevicornis.
Calanopia elliptica.
Candacia bradyi.
Candacia catula.
Candacia curta.
Candacia simplex.
Canthocalanus pauper.
Centropages furcatus.
Chiridius poppei.
Chirundina streetsi.
Clausocalanus arcuicornis.
Clausocalanus furcatus.
Conaea gracilis.
Copilia mirabilis.
Copilia quadrata.
Corycaeus elongatus.
Corycaeus obtusus.
Corycaeus speciosus.
Corycaeus venustus.
Eucalanus mucronatus,.
Eucalanus subcrassus.
Enchaeta concinna.
Euchaeta marina.
Euchaeta media.
Euchaeta tennis.
Euchirella curticauda.

300

Pleuromamma xiphias.
Pontellopsis armata.
Rhincalanus cornutus.
Sapphirina bicuspidata.
Sapphirina intestinata.
Sapphirina nigromaculata.
Sapphirina sinuicauda.
Sapphirina stellata.
VScottocalanus farrani n. sp.
Scottocalanus securifrons.
Scottocalanus setosus n. sp.
Scolecithrix danae.
Temora discaudata.
Temora turbinata.
Temoropia mayumbaensis.
Undinula darwini.
Undinula vulgaris.

53 Species.

Long. I27°22'.9 E. Manipa Strait. HENSEN Vertical

Euchirella dentata n. sp.
Euchirella dubia 11. sp.
Euchirella granulata n. sp.
Euchirella hessei.
Euchirella messinensis.
Euchirella pulchra.
Euchirella venusta.
Gaetanus miles.
Haloptilus spiniceps.
Heterorhabdus spinifrons.
Lophothrix frontalis.
Lucicutia flavicornis.
Lucicutia grandis.
Megacalanus princeps.
Megacalanus robustior.
Metridia brevicauda.
Metridia princeps.
Uithona plumifera.
Oncaea venusta.
Onchocalanus cristatus.
Onchocalanus hirtipes.
Uxycalanus semispinus n. sp.
Pachysoma punctatum.
Paracalanus aculeatus.
Paracalanus parvus.
Paraeuchaeta californica.
Paraeuchaeta weberi n. sp.
Paraugaptilus similis n. sp.
Phaenna spinifera.
Phyllopus bidentatus.
Pleuromamma abdominalis.
Pleuromamma gracilis.
Pleuromamma xiphias.

;oi

Pontellina plumata.
Rhincalanus cornutus.
Rhincalanus gigas.

Sapphirina angusta.
Sapphirina auronitens.
Sapphirina bicuspidata.
Sapphirina darwini.
Sapphirina gastrica.
Sapphirina intestinata.
Sapphirina metallina.
Sapphirina nigromaculata.
Sapphirina opalina.
Sapphirina ovatolanceolata.
Sapphirina sinuicauda.
Sapphirina stellata.

Scaphocalanus magnus.
Scolecithricella abyssalis.
Scolecithricella marginata.
Scolecithricella obtusifn ms.
Scolecithrix danae.
Scottocalanus farrani n. sp.
Scottocalanus securifrons.
Scottocalanus setosus n. sp.
Temora discaudata.
Temora turbinata.
Temoropia mayumbaensis.
Tortanus barbatus.
Tortanus murrayi tl. sp.
Undinula darwini.
Undinula vulgaris.

()6 Species.

Station i86, September 12, 1899. Lat. 30 10.5 S., Long. I27°20.5'E. Manipa Strait. Surface.

Calanus minor.
Candacia truncata.
Canthocalanus pauper.
Corycaeus gibbulus.
Eucalanus mucronatus.
Euchaeta concinna.
Oncaea venusta.
Faracalanus aculeatus.

Pontellina plumata.
Pontellopsis armata.
Sapphirina bicuspidata.
Scolecithrix danae.
Temora discaudata.
Undinula caroli.
Undinula darwini.

ij Species.

Station 189", September 12, 1899. Lat. 2°22'.oS., Long. i26°4Ó'.oE. Ceram Sea. Surface, eve

ning.

Candacia bradyi.
Candacia discaudata n. sp.
Candacia curta.
Candacia pachydactyla.
Candacia simplex.
Candacia truncata.
Canthocalanus pauper.
Copilia mirabilis.
Corycaeus danae.
Eucalanus crassus.
Eucalanus mucronatus.
Eucalanus subcrassus.
Eucalanus subtenuis.
Euchaete concinna.
Euchaeta marina.
Euchaeta wolfendeni n. sp.
Labidocera acuta.
Labidocera kroyeri.

Labidocera minuta.
Megacalanus gracilis.
Megacalanus robustior.
Pleuromamma abdominalis.
Pleuromamma gracilis.
Pleuromamma xiphias. '
Pontellina plumata.
Pontellopsis armata.
Rhincalanus cornutus.
Sapphirina darwini.
Sapphirina opalina.
Sapphirina stellata.
Scolecithrix danae.
Temora discaudata.
Undeuchaeta plumosa.
Undinula darwini.
Undinula vulgaris.

35 Species.

Station 193, September 13
of Sulu Besi. Surface.

Candacia pachydactyla.
Eucalanus subcrassus.
Oncaea venusta.
Pontellopsis armata.
Sapphirina auronitens.

& 14, 1899. Lat. 2°4'.7S., Long. I2ÓD4'.5 E. Sanana Bay, East Coast

Sapphirina sinuicauda.
Sapphirina stellata.
Scolecithrix danae.
Temora discaudata.

Undinula darwini. 10 Species.

301

;o2

Stations 194 — 7, September 15, 1899.
I27°8.3 E. Banda Sea. Surface.
Calanus minor.
Candacia bradyi.
Candacia catula.
Candacia curta.
Candacia pachydactyla.
Candacia simplex.
Canthocalanus pauper.
Copilia mirabilis.
Corycaeus furcifer.
Corycaeus robustus.
Eucalanus crassus.
Eucalanus mucronatus.
Eucalanus subcrassus.
Euchaeta marina.
Labidocera acuta.

Station 203, September 19, 1899. Lat.
Candacia pachydactyla.
Candacia truncata.
Clausocalanus furcatus.
Corycaeus robustus.
Corycaeus speciosus.
Eucalanus mucronatus.
Eucalanus subcrassus.
Eucalanus subtenuis.
Euchaeta marina.
Labidocera acuta.
Labidocera detruncata.
Labidocera madurae n. sp.

Station 203, September 19, 1899. Lat. 3°32'.5S.,
Net, from 1500 metres to surface.
Acartia danae.
Acartia erythraea.
Acartia negligens.
Acartia spinicauda.
Acrocalanus gracilis.
Acrocalanus longicornis.
Aegisthus mucronatus.
^Etideus armatus.
yEtideus bradyi n. sp.
yEtideus giesbrechti.
Arietellus setosus.
Augaptilus longicaudatus.
Augaptilus palumboi.
Calanopia minor.
Calocalanus pavo.
Candacia bipinnata.
Candacia pachydactyla.
Candacia truncata.
Canthocalanus pauper.
Centropages furcatus.
Centropages gracilis.

302

Between Lat. i°45'-3 & i°55'.oS. and Long i26°39'o. &

Labidocera madurae n. sp.

Megacalanus gracilis.

Oncaea venusta.

Paracalanus aculeatus.

Pleuromamma abdominalis.

Pontella denticauda n. sp.

Pontellina plumata.

Pontellopsis armata.

Pontellopsis krameri.

Sapphirina darwini.

Sapphirina sinuicauda.

Sapphirina stellata.

Scolecithrix danae.

Temora discaudata.

Undinula vulgaris. jo Species.

'32'.5S., Long. I24°i5'.5 E. Banda Sea. Surface.
Mecynocera clausi.
Oithona plumifera.
Oncaea venusta.
Pontella fera.
Pontella securifer.
Pontellina plumata.
Pontellopsis armata.
Scolecithrix danae.
Temora discaudata.
Undinula darwini.
Undinula vulgaris.

21 Species.

Long. I24°i5'.5 E. Banda Sea. HENSEN Vertical

Chirundina streetsi.
Clausocalanus arcuicornis.
Clausocalanus furcatus.
Conaea gracilis.
Copilia mirabilis.
Copilia quadrata.
Corycaeus carinatus.
Corycaeus danae.
Corycaeus flaccus.
Corycaeus furcifer.
Corycaeus gibbulus.
Corycaeus obtusus.
Corycaeus speciosus.
Corycaeus tenuis.
Corycaeus venustus.
Eucalanus mucronatus.
Eucalanus subcrassus.
Eucalanus subtenuis.
Euchaeta acuta.
Euchaeta marina.
Euchaeta tenuis.

3 O'

Euchirella galeata.
Euchirella hessei.
Euchirella messinensis.
Euchirella pulchra.
Euchirella venusta.
Gaidiopsis crassirostris 11. si
Gaidius similis.
Haloptilus longicornis.
Haloptilus spiniceps.
Heterorhabdus longicornis.
Heterorhabdus spinifrons.
Labidocera madurae n. sp.
Lophothrix frontalis.
Lubbockia aculeata.
Lucicutia clausi.
Lucicutia flavicornis.
Mecynocera clausi.
Megacalanus gracilis.
Metacalanus aurivillii.
Metridia boecki.
Metridia brevicauda.
Metridia princeps.
Metridia venusta.
Monacilla dubia n. sp.
Mormonilla phasma.
Oithona plumifera.
Oncaea media.
Oncaea venusta.

Station 204, September 20, 1899. Lat. 4°2o'.oS.
and Buton, Xorth Entrance of Buton Strait. Surface.

Acrocalanus longicornis.
Calanus minor.
Candacia pachydactyla.
Candacia simplex.
Candacia truncata.
Canthocalanus pauper.
Centropages furcatus.
Clausocalanus furcatus.
Copilia mirabilis.
Corycaeus danae.
Corycaeus obtusus.
Eucalanus crassus.
Eucalanus mucronatus.
Eucalanus subcrassus.
Eucalanus subtenuis.
Euchaeta marina.
Labidocera acuta.

Oxycalanus semispinus n. sp.
Paracalanus aculeatus;
Paraugaptilus similis n. sp.
Phyllopus bidentatus.
Phyllopus giesbrechti n. sp.
Pleuromamma abdominalis.
Pleuromamma gracilis.
Pleuromamma xiphias.
Pontella cerami n. sp.
Rhincalanus cornutus.
Rhincalanus gigas.
Sapphirina auronitens.
Sapphirina darwini.
Sapphirina opalina.
Scaphocalanus magnus.
Scolecithricella abyssalis.
Scolecithricella bradyi.
Scolecithricella marginata.
Scolecithrix danae.
Scottocalanus securifrons.
Scottocalanus thomasi n. sp.
Temora discaudata.
Temoropia mayumbaensis.
Undeuchaeta plumosa.
Undinula darwini.
Undinula vulgaris.
Xanthocalanus agilis.

97 Species.

Long. i22°58'.oE. Betvveen Islands of Wovvoni

Labidocera minuta.

Megacalanus gracilis.

Paracalanus parvus.

Pleuromamma gracilis.

Pontellopsis krameri.

Rhincalanus cornutus.

Rhincalanus gigas.

Sapphirina bicuspidata.

Sapphirina gastrica.

Sapphirina opalina.

Sapphirina ovatolanceolata.

Sapphirina stellata.

Scolecithrix danae.

Temora discaudata.

Temora turbinata.

Undinula darwini.

Undinula vulgaris. ,7 Species.

STATION 205, September 20, 1S99. Lat. 4°57'.4S., Long. [22°43'.oE. Lohio Bay, Buton Strait. Night.

Acartia erythraea.
Acartia negligens.
Acrocalanus longicornis.
Calanopia elliptica.
Calanopia minor.

Calanopia thompsoni n. sp.
Candacia discaudata n. sp.
Candacia pachydactyla.
Candacia simplex.
Canthocalanus pauper.

3°3

)°4

Centropages furcatus.
Clausocalanus arcuicornis.
Clausocalanus furcatus.
Corycaeus obtusus.
( !< irycaeus venustus.
Eucalanus monachus.
Eucalanus subcrassus.
Eucalanus subtenuis.
Euchaeta marina.
Labidocera acuta.
Labidocera minuta.
Lucicutia flavicornis.
Mecynocera clausi.

Mctacalanus aurivillii.
Mormonilla phasma.
Oithona plumifera.
Uithona rigida.
Oncaea venusta.
Paracalanus aculeatus.
Paracalanus parvus.
Pontella fera.
Sapphirina opalina.
Temora discaudata.
Temora turbinata.
Undinula darwini.
Undinula vulgaris.

36 Species.

Station 2ioa, September 24, 1899. Lat. 5° 26'.o S., Long. i2i°i8'.oE. Banda Sea. Surface.

Acartia erythraéa.
Acrocalanus longicornis.
Calanus minor.
Candacia pachydactyla.
Candacia simplex.
Corycaeus robustus.
Eucalanus mucronatus.
Euchaeta marina.

STATION 213, September 26, 1899. Lat. 6°4-7 S-, Long.
Acartia erythraéa.
Acartia negligens.
Acrocalanus gracilis.
Acrocalanus longicornis.
Calanopia elliptica.
Calanopia minor.
Calanopia thompsoni n. sp.
Calocalanus pavo.
Candacia curta.
Candacia pachydactyla.
Candacia simplex.
Centropages furcatus.
Centropages orsinii.
Clausocalanus arcuicornis.
Clausocalanus furcatus.
Clytemnestra rostrata.
Copilia mirabilis.
Corycaeus danae.
Corycaeus furcifer.
Corycaeus gibbulus.
Corycaeus lubbocki.
Corycaeus obtusus.
Corycaeus speciosus.
Corycaeus venustus.
Eucalanus mucronatus.
Euchaeta marina.
Euterpina acutifrons.
Ilyopsyllus affinis.
Labidocera acuta.
Labidocera kroyeri.

3°4

Oncaea venusta.
Pontellina plumata.
Pontellopsis krameri.
Rhincalanus gigas.
Temora discaudata.
Undinula caroli.
Undinula darwini.
Undinula vulgaris.

16 Species.

I20°23'.5E. Saleyer Anchorage. Surface.
Labidocera madurae n. sp.
Labidocera minuta.
Lucicutia flavicornis.
Macrosetella gracilis.
Mecynocera clausi.
Metacalanus aurivillii.
Oithona plumifera.
Oithona rigida.
Oncaea venusta.
Paracalanus aculeatus.
Paracalanus parvus.
Peltidium intermedium n. sp.
Pontella denticauda n. sp.
Pontella fera.
Pontellina plumata.
Pontellopsis armata.
Pontellopsis macronyx n. sp.
Pontellopsis regalis.
Pseudodiaptomus aurivillii.
Rhincalanus cornutus.
Sapphirina ovatolanceolata.
Sapphirina stellata.
Scolecithrix danae.
Temora discaudata.
Tortanus brevipes n. sp.
Tortanus gracilis.
Tortanus murrayi n. sp.
Undinula darwini.
Undinula vulgaris.

jp Species.

305

Station 214, October

v.

Acrocalanus longicornis
Candacia pachydactyla.
Canthocalaiuis pauper.
Centropages furcatus.
Copilia mirabilis.
Corycaeus furcifer.

1899. Lat. 6°3o'.oS., Long. [2i°55#.oE. Banda Sea. Surface.

Eucalaims subtenuis.
Labidocera acuta.
Oithona plumifera.
Scolecithrix danae.
Temora discaudata.

Undinula darwini.

12 Species.

Station 215", October 29, 1899. Lat. 6°48'.9S.,
point of Kabia Island reef. Surface.

Acrocalanus gibber.
Acrocalanus longicornis.
Aegisthus mucronatus.
Calanopia elliptica.
Calocalanus pavo.
Candacia bradyi.
Candacia catula.
Candacia pachydactyla.
Candacia simplex.
Canthocalanus pauper.
Clausocalanus arcuicornis.
Clausocalanus furcatus.
Copilia mirabilis.
Corycaeus danae.
Corycaeus robustus.
Corycaeus speciosus.
Eucalanus monachus.
Eucalanus mucronatus.

Long. 1220 9.0 E. West 1000 M. distant from North

Eucalanus subtenuis.
Euchaeta marina.
Gaetanus armiger.
Labidocera acuta.
Paracalanus aculeatus.
Pontella fera.
Pontellina plumata.
Pontellopsis armata.
Sapphirina auronitens.
Sapphirina ovatolanceolata.
Sapphirina scarlata.
Sapphirina stellata.
Scolecithrix danae.
Temora discaudata.
Undeuchaeta intermedia.
Undinula darwini.
Undinula vulgaris.

35 Species.

Station 216, October 3
from 975 — 415 metres depth.

Acrocalanus longicornis.
Aegisthus mucronatus.
Calanopia elliptica.
Candacia pachydactyla.
Copilia mirabilis.
Corycaeus furcifer.
Corycaeus gibbulus.
Corycaeus obtusus.
Corycaeus speciosus.
Eucalanus crassus.
Eucalanus mucronatus.
Heterorhabdus papilliger
Labidocera minuta.
Macrosetella sracilis.

1899. Lat. 6°49'.oS., Long. 122° 43.0 E. Banda Sea. Fowler closing net

Oncaea venusta.
Paracalanus aculeatus.
Phyllopus bidentatus.
Pleuromamma abdominalis.
Pleuromamma gracilis.
Pleuromamma xiphias.
Pontellopsis armata.
Rhincalanus cornutus.
Scolecithrix danae.
Scottocalanus securifrons.
Temora discaudata.
Undeuchaeta plumosa.
Undinula darwini.
Undinula vulgaris.

28 Species.

Station 217, October 31, 1899. Lat. 6°4o'.6S., Long. I23°I4'.7E. Banda Sea. Surface.

Corycaeus furcifer.
Euchaeta marina.
Euchaeta wolfendeni n. sp.
Metridia princeps.

Station 217, October 31, 1899. Lat. 6°4o'.6S., Long.
Acartia danae.

Pontellina plumata.
Pontellopsis armata.
Sapphirina nigromaculata.

7 Species.

Acartia negligens.

SIBOGA-EXPEDITIE XXIX a.

3°5

3 14 .7 E. Banda Sea. Horizontal Cylinder.
Acrocalanus gibber.
Acrocalanus gracilis.

39

io6

Acrocalanus longicornis.
Acrocalanus monachus.
Calanopia minor.
Calanus minor.
Calocalanus pavo.
Calocalanus plumulosus.
Candacia catula.
Candacia pachydactyla.
Candacia truncata.
Canthocalanus pauper.
Centropages furcatus.
Centropages gracilis.
Calusocalanus arcuicornis.
Calusocalanus furcatus.
Copilia mirabilis.
Corycaeus alatus.
Corycaeus danae.
Corycaeus furcifer.
Corycaeus gibbulus.
Corycaeus obtusus.
Corycaeus robustus.
Corycaeus speciosus.
Corycaeus venustus.
Eucalanus mucronatus.
Eucalanus subcrassus.

Station 220, November 1 — 3, 1899.
jang West Coast of Binongka. Surface.
Acrocalanus longicornis.
Candacia catula.
Candacia pachydactyla.
Copilia mirabilis.
Copilia quadrata.
Eucalanus mucronatus.
Euchaeta marina.
Euchaeta wolfendeni n. sp.
Lucicutia flavicornis.
Megacalanus gracilis.
Oncaea venusta.
Paracalanus aculeatus.

Eucalanus subtenuis.
Euchaeta marina.
Euchaeta wolfendeni n. sp.
Heterorhabdus spinifrons.
Macrosetella gracilis.
Mecynocera _clausi.
Metacalanus aurivillii.
Micrósetella norvegica.
Microsetella rosea.
Oithona plumifera.
Oncaea minuta.
Oncaea venusta.
Paracalanus aculeatus.
Paracalanus parvus.
Pontellina plumata.
Pontellopsis armata.
Sapphirina bicuspidata.
Sapphirina ovatolanceolata.
Sapphirina stellata.
Scolecithrix danae.
Temora discaudata.
Undinula caroli.
Undinula darwini.
Undinula vulgaris.

Species.

Lat. 5°58'.oS., Long. i24°o'.oE. Anchorage off Pasir Pand-

Pontellina plumata.
Rhincalanus cornutus.

Sapphirina bicuspidata.

Sapphirina nigromaculata.

Sapphirina opalina.

Sapphirina scarlata.

Sapphirina stellata.

Scolecithrix danae.

Temora discaudata.

Undinula caroli.

Undinula darwini.

Undinula vulgaris. 2./ Sptxies.

STATION 220, November 1 — 3,
200 metres to surface. Banda Sea.
Acrocalanus longicornis.
/Etideus bradyi n. sp.
/Etideus giesbrechti.
Calocalanus pavo.
Candacia catula.
Candacia pachydactyla.
Candacia truncata.
Centropages furcatus.
Clausocalanus arcuicornis.
Clausocalanus furcatus.
Copilia mirabilis.
Copilia quadrata.

1S99. Lat. 5°58'.oS., Long. i24°o'.oE. Hensen Vertical Net, from

Copilia vitrea.
Corycaeus danae.
Corycaeus furcifer.
Corycaeus gibbulus.
Corycaeus obtusus.
Corycaeus speciosus.
Corycaeus venustus.
Eucalanus crassus.
Eucalanus mucronatus.
Eucalanus subcrassus.
Eucalanus subtenuis.
Euchaeta concinna.
?o6

>07

Euchaeta marina.
Euchaeta wolfendeni n. sp.
I laloptilus Iongicornis.
Haloptilus spiniceps.
Hetero rhabdus spinifrons.
Labidocera acuta.
Lucicutia flavicornis.
Mecynocera clausi.
Megacalanus gracilis.
Metacalanus aurivillii.
Oithona plumifera.
Oncaea venusta.

Paracalanus aculeatus.
Pleuromamma xiphias.
Rhincalanus cornutus.
Sapphirina metallina.
Sapphirina i ivatolanceolata.
Sapphirina stellata.
Scolecithrix danae.
Temora discaudata.
Temora turbinata.
I emoropia mayumbaensis.
Undinula darwini.
Undinula vulgaris.

4.8 Spe

Station 222, November 5, 1899. Lat. 6° 10.0 S., Long. 125° 35'. 5 E. Banda Sea. Surface.

Pontellopsis armata. Sapphirina stellata. _' Species.

Station 223, November 6, 1899. Lat. 5°44'.7
Acrocalanus Iongicornis.
Calanopia elliptica.
Candacia bradyi.
Candacia pachydactyla.
Clausocalanus arcuicornis.
Copilia mirabilis.
Corycaeus furcifer.
Corycaeus robustus.
Corycaeus speciosus.
Eucalanus mucronatus.
Euchaeta marina.
Euchaeta wolfendeni 11. sp.

S., Long. i2C°2j'.^K. Banda Sea. Surface.
Labidocera acuta.
Oncaea venusta.
Paracalanus aculeatus.
Pontellina plumata.
Pontellopsis armata.
Rhincalanus cornutus.
Sapphirina nigromaculata.
Sapphirina ovatolanceolata.
Scolecithrix danae.
Temora discaudata.
Undinula darwini.
Undinula vulgaris. 24 Species.

Station 224, November 7, 1899. Lat. 5°34'.oS., Long.
Acrocalanus gracilis.
Calocalanus pavo.
Candacia pachydactyla.
Canthocalanus pauper.
Centropages furcatus.
Clausocalanus arcuicornis.
Clausocalanus furcatus.
Copilia mirabilis.
Corycaeus furcifer.
Corycaeus robustus.
Eucalanus mucronatus.

STATION 225, November 8, 1899. Lat. S°28'.oS., Long.
Acartia spinicauda.
Acrocalanus gracilis.
Calanoides brevicornis.
Candacia bradyi.
Candacia catula.
Candacia pachydactyla.
Canthocalanus pauper.
Centropages furcatus.
Clausocalanus arcuicornis.
Copilia mirabilis.
Corycaeus danae.

3°7

i27°4'.oE. Banda Sea. Surface.
Euchaeta wolfendeni n. sp.
Labidocera acuta.
Oncaea venusta.
Pontellina plumata.
Pontellopsis armata.
Sapphirina gastrica.
Sapphirina stellata.
Scolecithrix danae.
Undinula darwini.
Undinula vulgaris.

21 Species.

I27°20.4E. Banda Sea. Surface.
Corycaeus furcifer.
Corycaeus gibbulus.
Corycaeus robustus.
Eucalanus mucronatus.
Euchaeta marina.
Euchaeta wolfendeni n. sp.
Labidocera acuta.
Pleuromamma gracilis.
Sapphirina bicuspidata.
Sapphirina gastrica.
Sapphirina maculosa.

3o8

Sapphirina ovatolanceolata.
Sapphirina stellata.
Scolecithrix danae.
Temora discaudata.

Temora turbinata.
Undinula darwini.
Undinula vulearis.

29 Species.

Station 226, November 11 & 12, 1899. Lat. 5°26'.7S., Long. 1270 36'. 5 E. Washings from dredged
material depth 1595 metres. Mid channel between the Lucipara and Schildpad Islands.

Alteuthella pygmaea n. sp.
Alteuthella spinicauda n. sp.
Amphiascus ceylonicus.
Eupeltidium glabrum n. sp.
Laophonte cornuta.
Laophonte hirsuta.
Lichomolgus anomalus n. sp.

Lichomolgus buddhensis.
Lichomolgus elegans.
Lichomolgus gigas.
Paralichomolgus curticaudatus.
Peltidium falcatum n. sp.
Pseudanthessius weberi n. sp.

ij Species.

Sta.ION 229, November 14 1899. Lat. 4°23.oS., Long. I28°45'.5E. Banda Sea. Surface.

Acartia spinicauda.
Acrocalanus gracilis.
Acrocalanus longicornis.
Calanopia elliptica.
Calocalanus pavo.
Candacia truncata.
Canthocalanus pauper.
Corycaeus gibbulus.
Corycaeus obtusus.
Corycaeus venustus.
Eucalanus subcrassus.
Euchaeta marina.
Euchaeta wolfendeni n. sp.
Labidocera acuta.

Station 230, November 14, 1899. Lat. 3°s8'.oS., Long.
2000 metres to surface.

Acartia erythraea.
Acrocalanus longicornis.
Calanoides brevicornis.
Chirundina streetsi.
Clausocalanus arcuicornis.
Clausocalanus furcatus.
Conaea gracilis.
Copilia mirabilis.
Copilia quadrata.
Corycaeus concinnus.
Corycaeus danae.
Corycaeus speciosus.
Disseta palumboi.
Uisseta scopularis.
Eucalanus mucronatus.
Euchaeta concinna.
Euchaeta marina.
Euchaeta media.
Euchaeta tenuis.
Euchirella curticauda.
Euchirella galeata.

308

Labidocera minuta.
Oncaea venusta.
Paracalanus aculeatus.
Paracalanus parvus.
Pontella securifer.
Pontellina plumata.
Pontellopsis armata.
Sapphirina scarlata.
Scolecithrix danae.
Temora discaudata.
Temora turbinata.
Undinula darwini.
Undinula vulgaris.

27 Species.

i28°2o'.oE. HENSEN Vertical Net, from

Euchirella hessei.
Gaetanus caudani.
Gaetanus miles.
Hermannella concinna n. sp.
Lophothrix frontalis.
Lucicutia bicornuta.
Lucicutia clausi.
Lucicutia flavicornis.
Lucicutia longiserrata.
Lucicutia maxima.
Mesorhabdus truncatus n. sp.
Metridia macrura.
Oithona plumifera.
Oithona rigida.
Oxycalanus semispinus n. sp.
Paracalanus aculeatus.
Paracalanus parvus.
Paraeuchaeta barbata.
Paraeuchaeta bisinuata.
Paraeuchaeta californica.
Paraeuchaeta gracilicauda n. sp.

309

Paraeuchaeta propinqua.
Paraeuchaeta sarsi.
Paraeuchaeta sibogae n. sp.
Paraeuchaeta tonsa.
Paraeuchaeta tuberculata n. sp.
Paraeuchaeta weberi n. sp.
Pleuromamma abdoniinalis.
Pleuromamma gracilis.
Rhincalanus comutus.
Rhincalanus gigas.
Scolecithricella abyssalis.

STATION 243, December 2, 1899. Lat. 40 30.2 S.
Net, from IOOO metres to surface.
Acrocalanus gracilis.
Acrocalanus longicornis.
Calocalanus pavo.
Chiridius poppei.
Chirundina streetsi.
Clausocalanus arcuicornis.
Corycaeus danae.
Corycaeus obtusus.
Disseta palumboi.
Eucalanus mucronatus.
Euchaeta concinna.
Euchaeta marina.
Euchaeta tenuis.
Euchirella galeata.
Euchirella messinensis.
Euchirella pulchra.
Euchirella venusta.
Gaetanus kruppii.
Heterorhabdus longicornis.
Heterorhabdus spinifrons.
Lophothrix frontalis.
Lucicutia flavicornis.
Megacalanus gracilis.
Megacalanus princeps.
Oithona plumifera.
Oncaea venusta.
Metridia princeps.

Scolecithricella valida.
Scottocalanus farrani n. sp.
Scottocalanus setosus n. sp.
Temora discaudata.
Teniora turbinata.
Undeuchaeta major.
Undeuchaeta plumosa.
Undinula vulgaris.
Valdiviella brevicornis.
Valdiviella gigas.

6j Species

Long. i29°25'.oE. Randa Sea. HENSEN Vertical

Paracalanus aculeatus.
Paracalanus parvus.
Paraeuchaeta barbata.
Paraeuchaeta bisinuata.
Paraeuchaeta californica.
Paraeuchaeta sibogae n. sp.
Paraeuchaeta tonsa.
Paraeuchaeta tuberculata n.
Paraeuchaeta weberi n. sp.
Pleuromamma gracilis.
Pleuromamma xiphias.
Rhincalanus cornutus.

sp.

Rhincalanus gigas.
Scaphocalanus major.
Scolecithricella abyssalis.
Scolecithricella bradyi.
Scolecithricella marginata.
Scolecithrix danae.
Scottocalanus farrani n. sp.
Scottocalanus securifrons.
Scottocalanus setosus n. sp.
Temoropia mayumbaensis.
Undeuchaeta plumosa.
Undeuchaeta intermedia n.
Undinula darvvini
Undinula vulgaris.

sp.

53 Species.

Station 245, December 3, 1899. Lat. 40 1
Acartia negligens.
Acrocalanus gracilis.
Calanopia elliptica.
Candacia pachydactyla.
Centropages furcatus.
Corycaeus obtusus.
Corycaeus speciosus.
Eucalanus mucronatus.
Eucalanus subtenuis.
Euchaeta concinna.
Euchaeta marina.
Euchaeta wolfendeni n. sp.

5'. 5 S. Long. I30°I5'.8E. Banda Sea. Surface.
Gaidius similis.
Labidocera acuta.
Megacalanus gracilis.
Megacalanus robustus.
Pleuromamma abdoniinalis.
Pleuromamma gracilis.
Pontellina plumata.
Pontellopsis armata.
Pontellopsis macronyx n. sp.
Scolecithrix danae.
Temora discaudata.
Temora turbinata.

3°9

IO

Undeuchaeta plumosa.
Undinula darvvini.

Station 252, December 8 & 9, 1899. Lat.
Island. Night.

Acartia erythraea.
Acartia negligens.
Candacia discaudata n. sp.
Candacia pachydactyla.
Candacia simplex.
Candacia truncata.
Canthocalanus pauper.
Copilia mirabilis.
Copilia quadrata.
Eucalanus crassus.
Eucalanus mucronatus.
Eucalanus subcrassus.
Euchaeta concinna.
Euchaeta marina.
Euchaeta tenuis.
Euchirella hessei.
Gaidius similis.
Haloptilus longicornis.

Undinula vulgaris.

2~] Species.

50 40'. 7 S., Long. i32°7'.o E. West Side of Taam

Labidocera acuta.
Lucicutia flavicornis.
Mecynocera clausi.
Megacalanus gracilis.
Metacalanus aurivillii.
Oithona plumifera.
Oncaea venusta.
Paracalanus aculeatus.
Paraeuchaeta bisinuata.
Paraeuchaeta californica.
Phaenna spinifera.
Sapphirina intestinata.
Sapphirina metallina.
Sapphirina opalina.
Sapphirina ovatolanceolata.
Scolecithrix danae.
Temora discaudata.

Undinula vulgaris.

jó Species.

STATION 271, December 21, 1899. Lat. S°4^>'-7 S., Long.
towed for three hours at a speed of 7 knots.

Acrocalanus longicornis.
Calanopia elliptica.
Calanopia minor.
Calocdlanus pavo.
Calocalanus plumulosus.
Candacia pachydactyla.
Canthocalanus pauper.
Clausocalanus furcatus.
Corycaeus elongatus.
Corycaeus longistylis.
Corycaeus lubbocki.
Corycaeus obtusus.
Corycaeus speciosus.
Corycaeus tenuis.

i34°o'.o E. Arafura Sea. Horizontal Cylinder

Eucalanus mucronatus.

Euchaeta marina.

Microsetella norvegica.

Microsetella rosea.

Oithona plumifera.

Oncena venusta.

Paracalanus parvus.

Pontellina plumata.

Sapphirina bicuspidata.

Sapphirina nigromaculata.

Sapphirina sinuicauda.

Scolecithrix danae.

Temora discaudata.

Undinula vulgaris. 2S Species.

Station 273, December 23 — 26, 1899. Lat. 5°24'.oS., Long. i34°43'.oE. Washings from dredged.
material, depth 13 metres. Anchorage off Pulu Jedan. East West of Aru Islands (Pearl Banks).

Laophonte cornuta.
Laophonte hirsuta.

Longipedia scotti.
Longipedia weberi n. sp.
Peltidium exiguum n. sp.

Amphiascus ceylonicus.

Amphiascus havelocki.

Amphiascus hirsutus.

Canuella curticaudata.

Ceylonia armata.

Cletodes linearis = (Orthopsyllus linearis)

Eudactylopus latipes.

Hersiliodes leggii.

Idomene laticaudata.

Peltidium minutum n. sp.
Porcellidium brevicaudatum.
Rhynchothalestris rufocincta.
Rhynchothalestris similis n. sp.

18 Species.

1 1

Station 276, January 9, 1900. Lat. 6° 47'. 5 S.,
Net, from 750 metres to surface.
Acartia erythraea.
Acartia negligens.
Aegisthus mucronatus.
yEtideus armatus.
/Etideus bradyi n. sp.
/Etideus giesbrecliti.
Augaptilus bullifer.
Augaptilus filigerus.
Augaptilus hecticus.
Augaptilus longicaudatus.
Augaptilus validus n. sp.
Bradyidius armatus.
Calanoides brevicornis.
Calanopia elliptica.
Calocalanus pavo.
Candacia bipinnata.
Candacia catula.
Candacia pachydactyla.
Candacia truncata.
Canthocalanus pauper.
Centropages gracilis.
Chiridius poppei.
Chirundina streetsi.
Clausocalanus arcuicornis.
Clausocalanus furcatus.
Conaea gracilis.
Copilia mirabilis.
Copilia quadrata.
Corycaeus danae.
Corycaeus flaccus.
Corycaeus furcifer.
Corycaeus gibbulus.
Corycaeus longistylis.
Corycaeus obtusus.
Corycaeus speciosus.
Eucalanus mucronatus.
Euchaeta marina
Euchaeta wolfendeni n. sp.
Euchirella curticauda.
Euchirella galeata.
Euchirella hessei.
Euchirella maxima.
Euchirella messinensis.
Euchirella pulchra.
Euchirella venusta.
Gaetanus caudani.
Gaetanus hainatus n. sp.
Gaetanus kruppii.
Gaetanus latifrons.
Gaetanus miles.
Gaetanus minor.
Haloptilus longicornis.

Long. i28°4o'.5 E. Banda Sea. HENSEN Vertical

I [eterorhabdus clausi.

1 [eterorhabdus longicornis.

Heten irhabdus papilliger.

Heterorhabdus spinifrons.

Labidocera acuta.

Lophothrix frontalis.

Lucicutia flavicornis.

Lucicutia pera n. sp.

Mecynocera clausi.

Megacalanus gracilis.

Megacalanus robustior.

Metacalanus aurivillii.

Metridia boecki.

Metridia brevicauda.

Metridia venusta.

Oithona plumifera.

Oncaea venusta.

Oxycalanus semispinus n. sp.

Paracalanus aculeatus.

Paraeuchaeta bisinuata.

Paraeuchaeta californica.

Paraeuchaeta dentata n. sp.

Paraeuchaeta gracilicauda 11. sp.

Paraeuchaeta tonsa.

Paraeuchaeta tuberculata n. sp.

Paraeuchaeta spinifera.

Paraeuchaeta weberi n. sp.

Phaenna spinifera.

Phyllopus bidentatus.

Phyllopus giesbrechti 11. sp.

Pleuromamma abdominalis.

Pleuromamma gracilis.

Pleuromamma xiphias.

Pontellina plumata.

Rhincalanus cornutus.

Rhincalanus gigas.

Sapphirina gastrica.

Sapphirina metallina.

Sapphirina opalina.

Sapphirina sinuicauda.

Scaphocalanus magnus.

Scolecithricella abyssalis.

Scolecithricella bradyi.

Scolecithrix danae.

Scottocalanus farrani n. sp.

Scottocalanus securifrons.

Scottocalanus setosus n. sp.

Temora discaudata.

Temora turbinata.

Undeuchaeta plumosa.

Undinula darwini.

Undinula vulgaris. io.f Species.

311

,12

Station 282, January, 15 — 17, 1900. Lat.
Besi and the N.E. point of Timor. Surface.
Acartia erythraea.
Acartia negligens.
Calanopia elliptica.
Calanopia minor.
Calanus minor.
Calanus tenuicornis.
Calocalanus pavo.
Calocalanus plumulosus.
Candacia bipinnata.
Candacia catula.
Candacia curta.
Candacia pachydactyla.
Candacia truncata.
Canthocalanus pauper.
Centropages calaninus.
Centropages furcatus.
Centropages gracilis.
Centropages orsinii.
Clausocalanus arcuicornis.
Clausocalanus furcatus.
Copilia mirabilis.
Copilia quadrata.
Corycaeus furcifer.
Corycaeus robustus.
Corycaeus speciosus.
Eucalanus crassus.
Eucalanus mucronatus.
Eucalanus pileatus.
Euchaeta concinna.
Euchaeta marina.

'25.2S., Long. I27°iS'.4E. Anchorage between Nusa

Euchaeta wolfendeni n. sp.
Labidocera acuta.
Labidocera bataviae n. sp.
Labidocera detruncata.
Labidocera madurae n. sp.
Lucicutia flavicornis.
Mecynocera clausi.
Megacalanus gracilis.
Metacalanus aurivillii.
Monstrilla inserta n. sp.
Oithona plumifera.
Oncaea venusta.
Pontella denticauda n. sp.
Pontella fera.
Pontella securifer.
Pontellina plumata.
Rhincalanus cornutus.
Rhincalanus gigas.
Sapphirina angusta.
Sapphirina darwini.
Sapphirina intestinata.
Sapphirina metallina.
Sapphirina opalina.
Sapphirina ovatolanceolata.
Sapphirina stellata.
Scolecithrix danae.
Temora discaudata.
Undinula darwini.
Undinula vulgaris.

fjg Species.

Station 301, January 30, 1900. Lat. io° 38' S., Long. 123° 25'. 2 E. Pcpela Bay, East Coast of Rotti Island.
Lichomolgus gracilipes n. sp. (on Nudibranch).

Station 304, February 6 — 8, 1900.
over a distance of 36 miles. Savu Sea.
Acartia negligens.
Calanopia elliptica.
Calanopia minor.
Calanus minor.
Calocalanus pavo.
Calocalanus plumulosus.
Candacia catula.
Candacia pachydactyla.
Candacia truncata.
Centropages calaninus.
Centropages furcatus.
Centropages orsinii.
Clytemnestra rostrata.
Copilia mirabilis.
Corycaeus danae.
Corycaeus gibbulus.
Corycaeus gracilicaudatus.

Lat. 8°35'.5S., Long. 123° 31 '.o E. Horizontal Cylinder towed

Corycaeus obtusus.
Corycaeus robustus.
Corycaeus speciosus.
Eucalanus mucronatus.
Euchaeta marina.
Euterpina acutifrons.
Heterorhabdus spinifrons.
Labidocera acuta.
Lucicutia flavicornis.
Macrosetella gracilis.
Mecynocera clausi.
Metacalanus aurivillii.
Microsetella norvegica.
Microsetella rosea.
Oncaea minuta.
Oncaea venusta.
Paracalanus aculeatus.

312

Paracalanus parvus.
Pleuromamma abdominalis.
Pleuromamma gracilis.
Pleuromamma xiphias.
Sapphirina stellata.

Scolecithrix danae.
Temora discaudata.
I rndinula darwini.
Undinula vulgaris,

4.3 Species.

Station

F

ebruarv

17 & 18, 1900. Lat. 70 28'. 2 S., Long. ii7°28'.7 E. Anchorage Kast of

Sailus Besar, Paternoster Islands. Night.
Acartia erythraea.
Acartia spinicauda.
Acrocalanus gibber.
Acrocalanus gracilis.
Acrocalanus longicornis.
Calanopia elliptica.
Calanopia minor.
Candacia bipinnata.
Candacia bradyi.
Candacia catula.
Candacia curta.
Candacia discaudata n. sp.
Candacia pachydactyla.
Candacia simplex.
Candacia truncata.
Canthocalanus pauper.
Centropages furcatus.
Clausocalanus arcuicornis.
Clausocalanus furcatus.
Conaea gracilis.
Copilia mirabilis.
Copilia quadrata.
Corycaeus danae.
Corycaeus elongatus.
Corycaeus gibbulus.
Corycaeus lubbocki.
Corycaeus obtusus.
Corycaeus tenuis.
Eucalanus crassus.
Eucalanus monachus.
Eucalanus mucronatus.
Eucalanus pileatus.

Eucalanus subcrassus.
Eucalanus subtenuis.
Euchaeta concinna.
Euchaeta marina.
Euchaeta wolfendeni n. sp.
Euchirella venusta.
Haloptilus spiniceps.
Heterorhabdus spinifrons.
Labidocera acuta.
Labidocera detruncata.
Labidocera kroyeri.
Labidocera madurae n. sp.
Labidocera minuta.
Lubbockia squillimana.
Lucicutia flavicornis.
Macrosetella gracilis.
Mecynocera clausi.
Metacalanus aurivillii.
Oithona plumifera.
Oncaea venusta.
Paracalanus aculeatus.
Pleuromamma abdominalis.
Pleuromamma gracilis.
Pontella securifer.
Pontellina plumata.
Rhincalanus cornutus.
Sapphirina bicuspidata.
Sapphirina opalina.
Scolecithrix danae.
Temora discaudata.
Temora turbinata.
Undinula vuljraris.

64. Species.

Sir.OGA-EXPEDITIE XXIX,,'.

313

40

SYSTEMATIC LIST

OF THE SPECIES DESCRIBED IN THIS REPORT.

page

AMPHASCANDRIA

Calanidae

Calanus Leach.

minor (Claus) .

tenuicornis Dana .
Canthocalanus nov. .

pauper (Giesbrecht)
Calanoides Brady.

brevicornis (Lubbock)
Megacalanus Wolfenden.

gracilis (Dana) . . .

robustior (Giesbrecht)

princeps Wolfenden .
Bradycalanus nov. . .

typicus nov.
Undinula nov.

vulgaris (Dana).

darwini (Lubbock). .

caroli (Giesbrecht). .

EUCALANIDAE.

Eucalanus Dana .

crassus Giesbrecht.

monachus Giesbrecht.

mucronatus Giesbrecht

pileatus Giesbrecht .

subcrassus Giesbrecht

subtenuis Giesbrecht .

dentatus nov. .
Rhincalanus Dana

cornutus Dana . . .

gigas Brady ....
Mecynocera I. C. Thomi

clausi I. C. Thompson

pson

7
7
8

8

9
io
io

IO
12

•3

13

14

14

16

16

17
18

19
19

'9
20
20
21
21
21
22

23

23
24

25
25

Paracalanidae

Paracalanus Boeck .

aculeatus Giesbrecht

parvus (Claus) .
Acrocalanus Giesbrecht

longicornis Giesbrecht

gracilis Giesbrecht

gibber Giesbrecht .

monachus Giesbrecht
Calocalanus Giesbrecht

pavo (Dana).

plumulosus (Claus)

PSEUDOCALANIDAE

Clausocalanus Giesbrecht

3'

arcuicornis (Dana). .

32

furcatus (Brady)

32

Oxycalanus Farran .

33

semispinus nov.

33

Monacilla G. O. Sars

34

dubia nov. .

35

tEtideidae

36

/Etideus Brady

36

giesbrechti Cleve .

36

armatus (Boeck)

37

bradyi nov. .

38

Bradyidius Giesbrecht

39

armatus (Brady) .

39

/Etideopsis G. 0 Sars

40

rostrata G. O. Sars

. 40

Chiridius Giesbrecht

• 4'

poppei Giesbrecht

• 4i

gracilis Farran .

■ 42

obtusifrons G. 0. Sa

rs

■ 43

page

26

26
26

27
28
28
29

29

30

30
30
31

3'

Chirundina Giesbrecht .

streetsi Giesbrecht
Gaetanus Giesbrecht

miles Giesbrecht .

armiger Giesbrecht .

caudani Canu .

minor Farran .

kruppii Giesbrecht

lati frons G. O. Sars .

hamatus nov. .
Gaidius Giesbrecht .

similis (T. Scott) . .

notacanthus G. O. Sars
Gaidiopsis nov.

crassirostris nov. .
Euchirella Giesbrecht .

amoena Giesbrecht .

hessei (Brady) .

curticauda Giesbrecht

galeata Giesbrecht

messinensis (Claus)

pulchra (Lubbock)

venusta Giesbrecht .

maxima Wolfenden .

granulata nov. .

dentata nov. . . .

dubia nov

Undeuchaeta Giesbrecht

major Giesbrecht .

plumosa (Lubbock) .

intermedia nov.

EUCHAETIÜAE

Euchaeta Philippi
acuta Giesbrecht
concinna Dana.

43
43
44
44
45
46

47
48

49
50

5'
5i
52
52
53
53
53
54
55
55
56
56
57
57
58

59
60

60
61
62

64

64
65
65

314

3 i 5

longicornis Giesbrecht

media Giesbrecht . .

manna (Prestandrea).

tenuis Esterly .

wolfendeni nov.
Paraeuchaeta nov.

barbata (Brady)

bisinuata (G. O. Sars)

californica (Esterly) .

propinqua (Esterly) .

tonsa (Giesbrecht). .

gracilicauda nov. .

sibogae nov.

weberi nov

spinifera (Esterly). .

sarsi (Farran) . . .

dentata nov. . .

tuberculata nov. .
Valdiviella Steuer .

gigas (Brady) . . .

brevicornis G. O. Sars
Chiridiella G. O. Sars .

macrodactyla G. O. Sars

PhaeKnidae.

Phaenna Claus. . . .

spinifera Claus .
Xanthocalanus Giesbrecht

agilis Giesbrecht .
Brachycalanus Farran .

Onchocalanus G. O. Sars
cristatus (Wolfenden)
hirtipes G. O. Sars .

Cornucalanus Wolfenden
simplex Wolfenden .

Amallophora T. Scott .
typica T. Scott.

Heteramalla G. O. Sars
dubia (T. Scott) . .

SCOLECITRICIDAE

Scolecithrix Brady .
danae (Lubbock) . .

Scolecithricella G. O. Sars
abyssalis (Giesbrecht)
auropecten (Giesbrecht)
bradyi (Giesbrecht) .
longicornis (T. Scott)
longifurca (Giesbrecht)
ctenopus (Giesbrecht)

66
66
67
68

68
69
70
70
7'

7'

72

72
73
74
75
75
76
76

77
77
78
78
79

79

79
80

80
80
81
81
82
82
83
83
83
84
85
86
86

87

87
88

88

89
89
89
90
90
9'

marginata (Giesbrecht)

profunda (Giesbrecht)

obtusifrons (G. ü. Sars)

tenuipes (T. Scott)

valida (Farran) .

gracilis G. O. Sars

tydemani nov.

curticauda nov. .
Scaphocalanus G. O. Sars

magnus (T. Scott) .

major (T. Scott) .

elongatus nov.
Lophothrix Giesbrecht

frontalis Giesbrecht .
Macrandrevvella nov. .

joanae nov.
Scottocalanus G. O. Sars

securifrons (T. Scott)

persecans (Giesbrecht)

farrani nov.

setosus nov. .

longispinus nov. .
thomasi nov. .
helenae (Lubbock)

pnge

9i
91
92
92
92
93
93
94
95
97
97
98

98

99

100

101

103
104
105
106
108
109
109
1 1 1

HETERARTHRANDRIA.

Centkopagidae.

Centropages Kroyer .
calaninus (Dana) . .
elongatus Giesbrecht
furcatus (Dana) . .
gracilis (Dana)
orsinii Giesbrecht .

PSEUDODIAPTOMIDAE

Pseudodiaptomus Herrick
aurivillii Cleve
clevei nov

Temoridae.

Temora Baird

discaudata Giesbrecht

turbinata (Dana) . .
Temoropia T. Scott .

mayumbaensis T. Scott

Metrididae.

Metridia Boeck . . .
boecki Giesbrecht .
brevicauda Giesbrecht
macrura G. O Sars .

3i5

12

12
12
'3
13
14
15

16

16
16
16

18

18
18
18

'9
'9

20

20
20
20

21

princeps Giesbrecht.
venusta Giesbrecht .
Pleuromamma Giesbrecht
abdominalis (Lubbock).
gracilis (Claus) . . .
xiphias (Giesbrecht).

LUCICUTIIDAE .

Lucicutia Giesbrecht .
flavicornis (Claus)
clausi (Giesbrecht) .
bicornuta Wolfenden .
longiserrata (Giesbrecht)
maxima Steuer .
philyra nov ....
pera nov

Heterorhabdidai-

Heterorhabdus Giesbrecht

clausi (Giesbrecht)
spinifrons (Claus),
longicornis (Giesbrecht)
papilliger (Claus).

Mesorhabdus G. O. Sars
truncatus nov.

Disseta Giesbrecht .
palumboi Giesbrecht
scopularis (Brady) .

AUGAPTILIDAE

Augaptilus Giesbrecht.

bullifer Giesbrecht .

filigerus (Claus) . .

hecticus Giesbrecht .

longicaudatus (Claus)

palumboi Giesbrecht

placitus nov. .

validus nov. .
Haloptilus Giesbrecht

longicornis (Claus)

ornatus (Giesbrecht)

plumosus (Claus).

spiniceps (Giesbrecht)

Arietellidae

Arietellus Giesbrecht .

setosus Giesbrecht .

aculeatus (T. Scott).

simplex G. O. Sars.
Paraugaptilus Wolfenden

similis nov.

pnge

121

122
122
122
123

124

125

125
125
126
I2Ó
127
I27
128
I29

'3°

130
130
130

'3i
131
132
132

'33
'33
134

JD

>3^">
136
136
137
l37
138
140
140
141
141
141

142

!42
142

'43
'43
144
144

,16

Mctacalanus Cleve .

aurivillii Cleve
Phyllopus Brady

bidentatus Brady

helgae Farran.

impar Farran .

giesbrechti nov. .

Candaciidae

Candacia Dana . . .
aethiopica (Dana)
bipinnata (Giesbrecht)
bispinosa (Claus) .
catula (Giesbrecht) .
curta (Dana) .
longimana (Claus)
pachydactyla (Dana)
simplex (Giesbrecht)
tenuimana (Giesbrecht)
truncata (Dana) .
bradyi A. Scott . .
discaudata nov. .

PONTELLIDAE

Pontella Dana . .

danae Giesbrecht

fera Dana .

princeps Dana

securifer Brady .

alata nov. .

denticauda nov. .

forficula nov. .

cerami nov.
Labidocera Lubbock

acuta (Dana) . .

detruncata (Dana).

kroyeri (Brady) .

laevidentata (Brady

minuta (Giesbrecht)

bataviae nov. .

madurae nov.
Pontellopsis Brady.

armata (Giesbrecht)

kramen (Giesbrecht)

perspicax (Dana

regalis (Dana)

strenua (Dana)

villosa Brady .

macronyx nov.

pexa nov. .
Pontellina Dana

plumata (Dana)

pago
46
46

47
47
48

49
49

50

So

50
Si
5i

52
52
53
53
54
55
55
56
57

59

59
59
59
60
60
60
61
62
63
64
64
65
65
66
67
68
69
70
70
7'
7i
7i
72

72
73
73
74

75

Calanopia Dana .
elliptica (Dana)
minor A. Scott
thompsoni nov.
herdmani nov.
americana Dahl
aurivillii Cleve

Parapontellidae

Bathypontia G. O. Sars

spinifera nov.
Neopontella nov. .

typica nov.

ACARTIIDAE

Acartia Dana.

danae Giesbrecht
erythraea Giesbrecht
negligens Dana . .
spinicauda Giesbrecht

TORTANIDAE

Tortanus Giesbrecht
barbatus (Brady).
gracilis (Brady) .
murrayi nov. .
brevipes nov. .

page

175
[76
177
I7S
179
l8l
l8l

182

182
183
I85
185

186

l86
187
187
188
l88

189

189
189
igO
19 [
192

AMPHARTHRANDRIA.

MnRMONILLIDAE • 193
Mormonilla Giesbrecht

phasma Giesbrecht .

OlTHONIDAE

Oithona Baird
rigida Giesbrecht
plumifera Baird .
minuta T. Scott .

LONGIPEDIIDAE

Longipedia, Claus . .

coronata Claus

scotti G. O. Sars

weberi nov.
Canuella T. and A. Scott

curticaudata (Thompson &
Scott) . . . %. .
Sunaristes Hesse

paguri Hesse .
316

193

'93

193

193
194
194
'95

195

195
195
196
196

•97

197
198
198

page

ECTINOSOMIDAE . 198

Microsetella Brady and Robert-

son 198

norvegica (Boeck) . . . 199

rosea (Dana) 199

Harpacticidae . 200

Harpacticus M. Edvvards . 200

cristatus nov 200

clausi nov 201

glaber Brady 202

Peltidiidae . . 202

Peltidium Philippi .... 202

falcatum nov 203

intermedium nov. . . . 203

exiguum nov 204

minutum nov 205

Eupeltidiuni nov 206

glabrum nov 206

Eupelte Claus 207

oblivia nov 207

Alteuthella nov 208

pellucida nov 209

spinicauda nov 210

pygmaea nov 211

Parapeltidium nov. . . . 212

johnstoni nov 212

PORCELUDIIDAE . 213

Porcellidium Claus. . . . 213
brevicaudatum Thompson &

Scott 213

Thalestriuae. . 214

Phyllothalestris G. O. Sars. 214

mysis (Claus) 214

Rhynchothalestris G. O. Sars 214

rufocincta (Morman) . . 215

similis nov 215

Idomene Philippi 215

laticaudata (Thompson &

Scott) 216

Tydemanella nov 216

typica nov , 216

Pseudothalestris Brady . . 217

sarsi nov 218

Eudactylopus nov. . . . 219

latipes (T. Scott) . . . 219

1 )h ISACCIDAE.

[joge
220

Amphiascus G. O. Sars .
havelocki (Thompson &

Scott)

hirsutus (Thompson & Scott)
ceylonicus Thompson &
Scott)

Canthocamptidae .

Ameira Boeck

sibogae nov

Phyllopodopsyllus T. Scott .

lonmcaudatus nov. .

220

2 2 1
22 1

22 1

2 22
222
223
223

Laüphoniidae. . 224

Laophonte Philippi . . . 224
cornuta Philippi .... 224
hirsuta Thompson & Scott 225

Cletodidae . . 225

Cletodes Brady ....
linearis (Claus)
latipes nov

22 c
225
226

Cevloxiidae . . 227

Ceylonia Thompson & Scott
armata (Claus)

Ilvopsvllidae. .

Ilyopsyllus Brady & Robert-

son

affinis T. Scott ....

227
228

22S

228
229

Tachidiidae . . 2

29

Euterpina Norman .
acutifrons (Dana).

Macrusetellidae

Alacrosetella nov

gracilis (Dana).

Clvtemnestridae .

Clytemnestra Dana.

rostrata (Brady) ....

PONTOSTRATIOTIDAE .

Aeeisthus Giesbrecht . . .

230

230

231

232

233

■>i7

aculeatus Giesbrecht
mucronatus Giesbrecht

MONSTRILL1DAE
Monstrilla Dana. . . .

gracilicauda Giesbrecht

longicornis I. C. Thompson

orcula nov.

inserta nov.

cymbula nov. .

helgolandica Claus .

longipes nov.

turgida nov. .
Thaumaleus Kroyer

bullatus nov. .

"igas nov. ....

ISOKERANDRIA

Oncaeidae.

Oncaea Philippi .

conifera Giesbrecht .

media Giesbrecht

minuta Giesbrecht .

tenuimana Giesbrecht

venusta Philippi .
Conaea Giesbrecht .

gracilis (Dana).
Lubbockia Claus

aculeata Giesbrecht.

squillimana Claus.

CORYCAEIDAE

Corycaeus Dana.
alatus Giesbrecht
carinatus Giesbrecht
concinnus Dana .
danae Giesbrecht
elongatus Claus .
flaccus Giesbrecht .
furcifer Claus .
gibbulus Giesbrecht.
gracilicaudatus Giesbrecht
longistylis Dana .
lubbocki Giesbrecht.
obtusus Dana .
robustus Giesbrecht.
speciosus Dana .
tenuis Giesbrecht . .
venustus Dana

page

233
234

234
234
235
235
236

237

237
238
238

239
239

240
240

24 [

241

241
242
242
242

243
243
244
244

244
245

245

245
245

246
24Ó
246

247

247
248

248

249

249
250

250

251

251

!52

S wTiiiiUNiHAi-:

pson

Sapphirina J. V. Thom

angusta 1 )ana .

auroniterts ( 'lans .

bicuspidata Giesbrecht

darwini Haeckel .

gastrica Giesbrecht .

intestinata Giesbrecht

metallina Dana .

maculosa Giesbrecht

nigromaculata Claus

opalina Dana .

ovatolanceolata Dana

scarlata Giesbrecht .

sinuicauda Brady.

stellata Giesbrecht .

longifurca nov.
Copilia Dana ....

mirabilis Dana

quadrata Dana .

vitrea (Haeckel) .

LiCHOMOLGIDAE

Pachysoma Claus

punctatum Claus.
Hermannella Canu .

concinna nov..
Lichomolgus Thorell .

buddhensis Thompson
Scott

elegans Thompson & Scott

gigas Thompson & Scott

anomalus nov.

gracilipes nov.
Paralichomolgus Thompson
& Scott . .

curticaudatus Thompson &
Scott ....
Pseudanthessius Claus

weberi nov.

pectinatus nov. .

parvus nov.

obscurus nov. .

&

Clausiidae. .

Hersiliodes Canu

leggii Thompson & Scott

page

253

253
253
254
254
254
255
255
255
256
256
257

257

258

258
2 59
259
260
260
261
261

261

261
262
262

262

263

263
264
264
264
265

267

267
267
267
268
269
270

271
271

Erratum. — 1'aye 213, for Porcellidiiae read Povcellidiidae.
317

INDEX TO GENERA AND SPECIES.

The names in italics are synonyms.

abdominale (Pleur omina).

abdominalis (Diaptomus) .
abdominalis (Pleuromamma
abyssalis (Scolecithricella)
abyssalis (Scolecithrix)
abyssicola (Pontostratiotes)

Acartia

Acrocalanus .
acrocephalus (Scaphocalanus
aculeata (Ceylonia) .
aculeata (Lubbockia) .
aculeatus (Aegisthus) .
aculeatus (Arietellus) .
aculeatus (Paracalanus)
aculeatus [Rhincalanus]
acuta (Euchaeta)
acuta (Labidocera) .
acuta (Pontella) . . .
acuta (Pontellind) .
acutifrons (Euterpe)
acutifrons (Euterpina).
acutifrons (Harpacticus)
acutum (Labidocera) .
acutus (Scottocalanus) .

Aegisthus

/Etideopsis ....

.Etideus

aethiopica (Candace) .
aethiopica (Candacia) .
affinis (Ilyopsyllus) .
agilis (Xanthocalanus) .
alata (Pontella) . . .
alatus (Córycaeus) . .

Alteutha

Alteuthella ....
Amallophora ....
Amallophora ....

206

page
123
122

1 22
S9
89

2 3 2

1S6
28

97
228
224
233
143

26

■43
65
164
164
164
229
229
229
164
104

233
40

36
150
150
229

80
160

245
-212

208
84
97

Ameira

americana (Calanopia).
amoena (Euchirella)

Amphiascus

angulata (Chirundina)
angusta (Sapphirina) . .
anomalus (Lichomolgus) .
antarctica (Paracartia) .

Antaria

arcuicornis (Calanus) .
arcuicornis (Clausocalanus)

Arietellus

armata (Candacia) . . .
armata (Ceylonia) . .
armata (Euchaeta) .
armata f Euterpe acutifrons

var.)

armata (J urinia).
armata (Pontellopsis) .
armatus (/Etideus) .
armatus (/Etideus) . . 36
armatus (E! rad y anus) .
armatus (Bradyidius) .
armatus (Chiridius) .
armatus (Monops) .
armatus (Pseudaetideus) .
armatus (Pseudocalaiius) 37
armiger (Gaetanus).
assimilis (Westwoodia)
atlantica ( Ectinosoma). .
atlantica (Euchirella curti

cauda, var.) ....
atlantica (Microsetella)
atlantica (Pontella) . . .
atlanticum (Ectinosoma) .
atlanticum (Microsetella) .

Augaptilus

.118

page
222
l8l

53

220

61

253

264

187

244

32

32

142

156

228

41

229

228
170

37
& 38
39
39
43
170

4i

& 39

45

217

199

55
199
160
'99
'99
'35

aurita (Lucicutia)
aurivillii (Calanopia)
aurivillii (Metacalanus)
aurivillii (Pseudodiaptomus)
auronitens (Sapphirina) .
auropecten (Scolecithricella
auropecten (Scolecithrix) .
australis (Euchaeta)
australis (Undeuchaeta)
barbata (Corynura)
barbata (Euchaeta).
barbata (Euchaeta).
barbata (Paraeuchaeta
barbatus (Tortanus)
bataviae (Labidocera
Bathycalanus . .
Bathypontia .
bella (Euchirella)
bicornuta (Lucicutia)
bicuspidata (Sapphirina
bidentata (O'óthrix) . .
bidentatus (Phyllopus)
butentatus ( Phyllopus)
bipinnata (CanJace)
bipinnata (Candacia) .
bisinuata (Euchaeta) .
bisinuata (Paraeuchaeta) .
bispinosa (Candace).
bispinosa (Candacia)
boecki (Metridia) . . .
Brachycalanus ....

Bradyauus

Bradycalanus

bradyi (/Etideus) . . .
bradyi (Candacia) .
bradyi (Megacalanus) . II
bradyi (Phyllopodopsyllus)

47
148

page
126

1S1

I46
Il6

254
89
89
62
62

189
70

75

70

189

1Ó8

1 1

182

54
126

254
& 82

'47
& 149

'5'

'5'

70

70

'5'

'5'

120

81

39

'4

38

156

& 1.3

5 1 9

bradyi (Scolecithricella
bradyi {Scolecitkrix)
bradyi \ Undinopsis).
Bradyidius.
brevicauda (Metridia
brevicaudatum (Porcellidi
brevicornis (Calanoides
brevicornis [Calanus] .
brevicornis (Dactylopusia
brevicornis (Gaetanus) .
brevicornis (Parapontella)
brevicornis (Valdiviella)
brevipes (Tortanus).
buchani (Paraugaptilis.
buddhensis (Lichomolgus
bullatus (Thaumaleus) .
bullifer (Augaptilus)
ca la in na (Cyclopsina) .
calaninus (Centropages)

Calanoides

Calanopia

Calanops

Calanus

Calanus 9 —

californica (Euchaeta] .
californica (Paraeuchaeta

Candace

Candacia

Canthocalanus
Canthocamptus .
Calocalanus ....

Canuella

carinata ( Euchirella) .
carinatus (Corycaeus) .
caroli (Calanus) .
caroli (Undinula) . .

Catopia

catula (Candace) . .
catula (Candacia) .
caudani (Gaetanus) .
Centropages ....
centrura (Acartia) . .
cerami (Pontella) . .

Cetoclulus

Ceylonia

ceylonia (Dactylopusia)
ceylonica (Pontella da

var.)

ceylonicus (Amphiascus)
chelifer (Cornucalanus).
chelifer (Harpacticus) .
chelifer [Scolecitkrix] .
chelipes (Macandrewella

um

32

&

150

nae

89
89
39
39
120

213

10

10
220

48
185

73
192

H5
263
240

135
1 12
1 12
10
175
175
7
u8

7'

7i

-156

150

8

199

30
197

43
246

18

18

113
152

i;2
46
1 12
188N
163

7
227

221

159

221

83
201

§3
101

chelipes (Scolecitkrix) .
cheirura (Candacia). .

Chiridiella

Chiridius

Ckiridius

Chirundina ....
( 'hirundina ....
c/arus (Gaetanus) .
clausi (Harpacticus).
clausi (Heterocliaeta). .
clausi (Heterorhabdus).
clausi (Leuckartia) .
clausi (Lucicutia)
clausi (Mecynocera).
Clausocalanus.

Cleta

Cletodes

clevei (Pseudodiaptomus)
Clytemnestra ....
comptus {Calanus) . .

Conaea

concinna (Euchaeta) .
concinna (Hermannella)
concinnus (Corycaeus).
conifera (Oncaea) . .

Copilia

coriaceus (Ilyopsyllus). 2
Cornucalanus ....
cornuta (Laophonte) .
cornutus (Rhincalanus).
coronata (Longipedia) .
coronata (Longipedia) .

Corycaeus

Corynura .

crassirostris (Gaidiopsis)
crassirostris (Paracalanus)
crassus (Eucalanus).
cristata (Scolecitkrix ) .
cristatus (Calanus) .
cristatus (Harpacticus).
cristatus (Unchocalanus)
cristatus (Xantkocalanus)
ctenopus (Scolecithricella
ctenopus (Scolecitkrix).
curta (Candace) .
curta (Candacia) . . .
curticauda (Euchirella)
curticauda (Metridia) .
curticauda (Scolecithricell
curticaudata (Canuella)
curticaudata (Sunaristes)
curticaudatus (Paralicho

28

pnge
IOI
[58

78

4'
5'
43
61
48
201

130

130

126

126

25

3i

224

225

116

231

13

243

65
262

246
241
260
& 229

61

224

23

•95

196

245
189

53
28

•9

& 97

16

200

82

82

9'

9i

152

152

55

121

94

'97
197

216,

molgus) 267

319

Cyclops .
Cyclopsina .
cymbula (Monstrill;
Dactylopodella .
Dactylopus .
Dactylopusia . .
Dactylopusia .
danae (Acartia) .
danae (Corycaeus)
danae (Ivellina) .
danae (Pontella) .
danae (Pontellind]
danae (Scolecithrix^
danae (Undina) .
darwini (Calanus)
darwini (Sapphirina
darwini (Undina)
darwini (Undinula)
dentata (Euchirella)
dentata (Paraeuchaeta)
dentatus (Eucalanus) .
denticauda (Pontella) .
denticulata ( Corynura)
denticulatus (Tortanus)
depressa (Alteutha).
detruncata (Labidocera)
detruncata (Pontella) .
detruncata (Pontellind)
detruncatum (Labidocera
Diaptoinus ....
discaudata (Candacia)
discaudata (Temora)

Disseta

Drepanopus. .
dubia (Aiuallophora)
dubia (Euchirella) .
dubia (Heteramalla)
dubia (Monacilla) .
Ectinosoma.
edwardsi \ Monops) .
elegans (Lichomolgus
elliptica (Calanopia 1
elliptica (Pontella) .
elongata (Bathypontia)
elongatus (Centropages
elongatus (Corycaeus) .
elongatus (Scaphocalanus)
emarginata (Scolecitkrix 1
erythraea (Acartia)
Eucalanus .
Euchaeta .
Euchaeta .
Euchirella .

[12 &

219-

1

67
"4

237
2 1 6
219
219
22 1
187
246
'59
'59

'59

88
88

'7
254
'7
'7
59

161
189
189
206
165
165
165
165
1 22

l57
118

32

S6
60
86

35

'99

172
264

T"
176
184
113
247
9S
92
187

'9
64

41, 69—77

//
53

Euchirella . . . .

Eudactylopus. . .

Eupelte

Eupeltidium .
Eupontellina . .

Enter pe

Euterpina ....
exiguum (Peltidium)
falcatum (Peltidium)
farrani (Scottocalanus)
fera {Eupontellina) .
fera (Pontella) . .
fera {Pontellina) .
filicornis [Leptocalanus
nligerus (Augaptilus)
filigerus {Hemicalanus)
finmarchicus (Calanus)
flaccus (Corycaeus) .
flava (Dactylopodella)
flavicomis (Leuckartia)
flavicornis (Lucicutia)
forcipata (Cleta)
forcipatus (Tortanus)
forficata (Idomene) .
forficula (Pontella) .
front al is {Calanus) .
frontalis (Lophothrix)
frontalis (Scolecitlirix)
furcata (Catopia)
furcatus (Centropages]
furcatus (Clausocalanu
furcatus (Drepanopus)
furcifer (Corycaeus)
furcifer (Phyllopodops
Gaetanus .
Gaidiopsis .
Gaidus ....
galeata (Euchirella
gallensis (Labidocera kro

var)

gastrica (Sapphirina)
gibber (Acrocalanus)
gibbulus (Corycaeus)
giesbrechti (/Etideus)
giesbrechti (Phyllopus
gigas (Brachycalanus)
gigas (Euchaeta)
gigas (Lichomolgus)
gigas (Rhincalanus)
gigas (Thaumaleus)
gigas (Valdiviella) .
glaber (Harpacticus)
glabrum (Eupeltidium

yll

us

yen

page

43
219

207

206

159
229
229
204
203
106
159
159
159
25
136
136

7
247
217
125
125
224
190
216
162
10

99

99

113

113

32

32

248

224

44

52

5>

55

166

255

29

248

36

149

81

77
264

24
240

77
202
206

Goniopsyllus

gracile ( Pleuromma) .
gracilicauda (Monstrilla) .
gracilicauda (Paraeuchaeta
gracilicaudatus (Corycaeus
gracilipes (Lichomolgus)
gracilis (Acrocalanus) .
gracilis (Antaria) . .
gracilis {Calanus)
gracilis (Centropages) .
gracilis (Chiridius) . .
gracilis (Conaea) . .
gracilis {Corynura) . .
gracilis {Cyclopsina) .
gracilis {Euterpe) . .
gracilis (Harpacticus) .
gracilis (Macrosetella) .
gracilis (Megacalanus) .
gracilis {Oncaea) . . .
gracilis (Pleuromamma)
gracilis (Scolecithricella)
gracilis (Setella) . . .
gracilis (Tortanus) . .
grandiremis (Euchaeta)
grandis (Disseta)
grandis • ' Heterorhabdus)
grandis (Lucicutia)
grandis ( Monops) .
grandis (Monstrilla)
grandis (Rhincalanus
granulata (Euchirella'
Haloptilus ....
hamatus (Gaetanus)
Harpaticus
Harpacticus. ... 199
havelocki (Amphiascus)
havelocki (Dactylopusia)
hecticus (Augaptilus) .
helenae (Scottocalanus)
helenae {Undina) . .
helgae (Phyllopus) . .
helgolandica (Monstrilla
Hemicalanus . . 136,
herdmani (Calanopia)
Hermannella .
Hersiliodes
hessei {Euchaeta) .
hessei (Euchirella) .
Heteramalla .
Heterocalanus
Heterochaeta .
Heterorhabdus .
hirsuta (Dactylopusia)
320

17

130

&

&

140 —

page

232
123

235
72

249
265

29
244

12
114

42

244
I9O
114
229
20I
230
12
244
123

93
230
190

68
134
133
128
172

237

24

58

140

50

200

229

221

221

136

1 1 1

1 1 1

148

238

141

179

262

271

54

54

86

14

-131

130

221

hirsuta (Laophonte) . .
hirsutus (Amphiascus).
hirtipes (Onchocalanus) .
hodgsoni ( Paralabidocera)
holti (Gaetanus) ....

Hyaloplivlluiii

Idomene

Ilyopsyllus

imbricata (Pseudothalestris)
impar (Phyllopus) .
indica (Euchaeta) .
indica (Euchirella bello., var.
inserta (Monstrilla)
insignis (Valdiviella) .
inter media ( Candace) .
intermedia (Undeuchaeta)
intermedium (Peltidium) .
interrupta (Alteutha)
intestinata (Sapphirina) .

Iva

I veil ara 159

joanae (Macandrewella) .
johnstoni (Parapeltidium)

■Juriua

koehleri (Neoscolecithrix) 47
krameri {Monops) . . .
krameri (Pontellopsis) .
kroyeri Centropages .
kroyeri (Labidocera) .
kroyeri {Pontella) .
kruppii (Gaetanus) .

Labidocera

laevidentata (Labidocera)
laevidentata {Pontella). .
laevidentatum { Labidocera)

Laophonte

laticaudata {Dactylopusia).
laticaudata (Idomene) .
latifrons (Gaetanus).
latipes (Cletodes) . . .
latipes {Dactylopus).
latipes (Dactylopus). . .
latipes {Dactylopusia) .
latipes (Eudactylopus). .
leggii (Hersiliodes) .

Leptocalanus

Leuckartia . . 125 — 127

Lichomolgus

Liljeborgia

linearis (Cletodes) .
linearis {Liljeborgia)
linearis (Orthopsyllus) . .
longicaudatus (Augaptilus)

page
225
22 I

83
1S7

49
261

215
22S
218
149

67

54
237

78
153

63
203
209

255
160
& 160
101
212

& 82

'7i
i/i
115
165
165
48
164
166
166
166
224
216
216

49
226
219
220
219
219
272

25

& 134

263

22^

225

22^

136

121

longicaudatus [Hemicalanus)
longicaudatus (1'hyllopodop

syllus

longicornis (Acrocalanus).
longicornis (Euchaetai.
longicornis (Haloptilus) .
longicornis [Hemicalanus)
longicornis [Heterochaeta )
longicornis (Hetcrorhabdus)
longicornis (Lucicutia). 127
longicornis f Macrocalanus )
longicornis ( Megacalanus
longicornis (Monstrilla)
longicornis (Scolecithricella
longicornis [Scolecithrix.
longicornis (Temora) .
longifurca (Sapphirina)
longifurca (Scolecithricella)
longifurca [Scolecithrix)
longimana [Candace) .
longimana (Candacia) .
Longipedia ....
Longipedina ....
longipes (Ameira) . .
longipcs (Monstrilla) .
longiremis (Monstrilla).
longirostris (Aegisthus)
longiserrata ( Leuckartia \
longiserrata (Lucicutia)
longispinus (Gaetanus).
longispinus (Scottocalanus
longistylis (Corycaeus).
Lophothrix ....

Lophothrix

lubbocki (Corycaeus) .

Lubbockia

lucens (Metridia) . .

Lucicutia

lucida (Lucicutia) . .
Macandrewella . . .
Macrocalanus ....
macrodactyla (Chiridiella
macronyx (Pontellopsis)
Macrosetella ....
macrura (Metridia) . .
maculosa (Sapphirina).
madurae (Labidocera) .
magna (Amallophora) .
magna (Scolecithrix) .
magnus (Cornucalanus)
magnus (Scaphocalanus) 61
major (Arietellus) .
major (Gaetanus)

page

223

28

66

140

140

131

131

& 128

13
13

235
90
90

119

259
90
90
153
153
195
198
222
238
235
234
127
127

49
109

249

98

104

250

244

120

125

129

100

13

79

i/3

230

121

256

169

97

97

S3

& 97

143
48

major (Scaphocalanus).
major [Scolecithrix)
major (Pseudothalestris)
major (Undcuchaeta) .
marginata (Scolecithriccll
marginata {Scolecithrix)
marina (Euchaeta) . .
manna (Euchaeta) .
marinus (Cyclops) .
maxima (Euchirella) .
maxima (Lucicutia). .
maximus (Bathycalanus)
mayumbaensis (Temorop
Mecynocera ....
media (Euchaeta) . .
media (Oncaea) .
mediterranea (Oncaea)
medius (Heterocalanus)
Megacalanus ....
megalurus (Augaptilus)
melanopus (Candace) .
Mesorhabdus ....
messinensis (Calanops) .
messinensis (Euchirella)
messinensis (Se tel la)
messinensis (Undina) .
Metacalanus ....
metallina (Sapphirina).

Metridia

Microsetella ....
miles (Gaetanus). . .
minor (Calanopia) . .
minor (Calanus) .
minor (Cetochilis) .
minor (Gaetanus)
minor (Longipedia).
minor (Mormonilla)
minor (Phyllopodopsyllus)
minor (Scolecithricella)
minor (Scolecithrix) .
minor (Undeuchaeta) .
minuta (Labidocera) .
minuta (Oithona) . .
minuta (Oithona) . .
minuta (Oncaea) . . .
minuta (Westwoodia) .
minutum (Labidocera).
minutum (Peltidiumi .
mirabilis (Copilia) .
monachus (Acrocalanus
monachus (Eucalanus).

Monacilla

Monops

page

97

97
21S

61

9'

9i

67

68
67

57
127

& '3

119

25

66

242

242

15
10

150
132
175

56
230

56
146

255

120

198

44

177

7

7

47
196

193
224

§7

37

62

167

195

195

242

21S

167

205

260

30

20

34

47

69

SIBOGA-EXPELiITIE XXIX tl.

Monstrilla

Mormonilla ....
mucronatus (Aegisthus)
mucronatus (Eucalanus
murrayi (Tortanus).
mysis (Phyllothalestris
mysis (Thalestris) .
nana (Oithona) . .
nasutus (Rhincalanus
negligens (Acartia) .
Neopontella .
Neoscolecithrix .
nerii (Labidocera) .
nigromaculata (Sapphirina
nobilis (Westwoodia)
normani (Metridia) .
norvegica (Candacia)
norvegica [Euchaeta)
norvegica (Microsetella)
norvegica (Paraeuchaeta)
norvegica (Setel/a) .
notacanthus (Gaidius) .
oblivia (Eupelte).
obscurus (Pseudanthessius)
obtusifrons {Amallophora)
obtusifrons (Chiridius) . .
obtusifrons (Scolecithricella
obtusifrons {Scolecithrix)
obtusus (Corycaeus)

Oithona

oligartha (Valdiviella) .

Oncaea

Oncaea

Onchocalanus.

Oniscidium

Oothrix

opalina (Sapphirina) .
orcula (Monstrilla) .
ornatus (Haloptilus) .
ornatus {Hemicalanus) .
orsinii (Centropages) .
Ortliopsyllus ....
ovatolanceolata (Sapphirina
Oxy calanus ....
pachydactyla {Candace)
pachydactyla (Candacia)
Pachysoma ....
paguri (Longipedina) .
paguri (Sunaristes) .
palumboi (Augaptilus).
palumboi (Disseta) .
papilliger (Heterorhabdus
papilligera {Heterochaeta)

41

47

page

234

'93
234
20
191
214
214
194

24

188

185

& 82

170

256

217

122

158

69

199

& 76

199

52

207

270

92

43
92

92
250

193
78

241

244
82

202
& 82

257
236
141
141

"5
225

257

33

iS3

153
261
19S
198

137

133
L3i
L3i

32:

Paracalanus ....

Paracartia

Paraeuchaeta ....
Paralabidocera .
Paralichomolgus .
Parapeltidium
Parapontella ....
Paraugaptilus.
parvus (Calanus).
parvus (Paracalanus) .
parvus (Paracalanus) .
parvus (Pseudanthessius)
patagoniensis (Calanoides
pauper {Calanus)
pauper (Canthocalanus)
pavo (Calanus) .
pavo (Calocalanus) .
pavo (Labidocera) .
pectinata (Candace).
pectinatus (Pseudanthessi
pellucida (Alteuthella)
Peltidum ....
pera (Lucicutia).
perplexus (Paracalanu

vus var).
persecans (Scolecithrix
per secans ( 'Scolecithrix
persecans (Scottocalan
perspicax (Monops)
perspicax (Pontella)
perspicax (Pontellina)
perspicax (Pontellopsi
pexa (Pontellopsis) .
Phaenna ....
phasma (Mormonilla)
philyra (Lucicutia) .
Phyllopodopsyllus .
Phyllopus ....
Phyllothalestris . .
pileatus (Eucalanus)
pilcatus (Gaetanus) .
pilosus (Monops)
placitus (Augaptilus)
Pleuromamma
Pleuromma
plumata (Pontella) .
plumata (Pontellina)
plumifera (Oithona)
plumosa (Undeuchaeta)
plumosa (Undina) .
plumosus (Haloptilus
plumosus (Hemicalanus
plumulosus (Calanus) .

182

151

us'

par

123

page

26

186

69

187

267

212

-1S6

144

27

27

26

269

10

9

9

3°

30

169

-157
268

209
202
129

26
105
1 1 1
105
171
171
171
171
'73

79
193
128

164
159

&

'47
214
21
46
172
137

122

124
175
175
194
62
62
141
141

1 1

plumulosus (Calocalanus

Pontella

Pontella

Pontellina

Pontellina

Pontellopsis ....
Pontostratiotes .
poppei (Chiridius) .
poppei (Chiridius). .
Porcellidium ....
princeps (Bradycalanus)
princeps (Calanus) .
princeps ( Calanus) .
princeps (Iva)
princeps (Macrocalanus)
princeps (Megacalanus)
princeps (Megacalanus )
princeps (Metridia).
princeps (Pontella) . .
princeps (Pontellina) .
prestandraea (Euchaeta)
profunda (Scolecithricella
profu nda ( Scolecithrix)
propinqua (Euchaeta) .
propinqua (Paraeuchaeta)
propinquus (Pseudanthessius
Pseudaetideus
Pseudanthessius .
Pseudocalauus
Pseudodiaptomus
Pseudothalestris .
pulchra (Euchaeta) .
pulchra f Euchaeta) .
pulchra (Euchirella)
pulchra (Pontellina)
pulchra (Undina)
punctata (Pachysoma)
punctatum (Pachysom
pungens (Gaidius) .
purpureum (Peltidium
pygmaea (Alteuthella
pygmaeus (Paracalanu
quadrata (Copilia) .
rapax (Conaea) . .
regalis (Monops) .
regalis (Pontella)
regalis (Pontellina) .
regalis (Pontellopsis
Reticulina ....
Rhincalanus .
Rkincalanus .
Rhynchothalestris .
richardi (Bathycalanus
322

37

203

pa^e

3'
'59

— 175

'74

-171

170

232

4i
42

213
■4
14
13

160

13

13

& 13

121

160

160

67

9i
9i
7i
71
269

41
267

& 39
116
217

56
62

56
171

56
262

262

Si

-213

21 1
28

261

244
171
171
171
171
202

23
143
214

1 1

rigida (Oithona) . . .
rosea (Longipedia) .
rosea (Microsetella)
roseum ( Ectinosoma) .
roseus ( Canthocamptus )
roseus ( Harpacticus) .
rostrata (/Etideopsis) .
rostrata (Clytemnestra)
rostrata (Euchirella) .
rostrata (Euchirella) .
rostratus (Corycaeus) .
rostratus ( Goniopsyllus)
robustior (Calanus).
robustior (Megacalanus)
robustus (Corycaeus) .
rufocincta (Rhynchothalestri
rufocincta (Thalestris).
salinus (Pseudodiaptomus

Sapphirina

sarsi (Euchaeta) ....
sarsi (Paraeuchaeta). . .
sarsi (Pseudothalestris)
Scaphocalanus ....
scarlata (Sapphirina) .
Scolecithricella ....

Scolecithrix

Scolecithrix ... 86, 88
scopularis (Disseta) . .
scopularis (Heterorhabdus)
scopularis (Leuckartia)
scotti (Longipedia) .
scotti (Scolecithrix) .

Scottocalanus

Scottula

scutellata (Clytemnestra) .
securifer (Ivellina) . . .
securifer (Pontella) . . .
securifer (Pontellina) . .
securifrons (Lophothrix) .
securi frons (Scolecithrix) .
securifrons (Scolecithrix) .
securifrons (Scottocalanus)
semispinus (Oxycalanus) .
serrata (Laophonte) . .
serricaudatus (Pseudodiap

tomus)

Setella 199

setosus (Arietellus) . . .
setosus (Arietellus) . . .
setosus (Scottocalanus)
sibogae (Ameira) . . .
sibogae (Paraeuchaeta)
simplex (Arietellus) . .

page
194
I97
I99
I99
199
I99
40
232

54

54

246

2^2

13

'3
251

215

215
117

253
75
75

218

95

258

88

8/"
-105

'34
134
'34
196
86

103
146
232
160
160
160
104
104
1 1 1
104

33
224

117

& 230

142

'43
108

73
143

j-o

simplex (Candacé) .
simplex (Candacia) .
simplex (Cornucalanus
similis [Euchaeta hessei var.)
similis (Gaidius) .
similis (Labidocera kroyet

var.)

similis (Paraugaptilus
similis ( Rhynchothalestris
sinuicauda (Sapphirina)
speciosus (Corycaeus) .
spinicauda (Acartia)
spinicauda (Alteuthella)
spiniceps (Haloptilus) .
spiniceps (Hetnicalanus)
spinifer (Oxycalanus) .
spinifera (Bathypontia)
spinifera (Euchaeta). .
spinifera (Paraeuchaeta)
spinifera (Phaenna). .
spinifrons ( Heterockaeta)
spinifrons (Heterorhabdu
Spinocalanus ....
squamatus (Augaptilus)
squillimana (Lubbockia)
stellata (Sapphirina)
streetsi (Chirundina)
strenua (Pontclla) .
strenua [Pontclla) .
strenua (Pontellina).
strenua (Pontellopsis)
strenuus (Monops) .
subcrassus (Eucalanus
subtenuis (Eucalanus)
Sunaristes ....
Sunaristes ....
Temora ....
Temoropia.

154

•54

83

5'
5'

166
144
215
258
251
[88
210

'4'
141

34

■83

75

75

80

130

130

33
138

245
259

43
172

171
172
172
172
21
21
198
197
118
119

tenuicauda (Pontellopsis) .
tenuicornis (Calanus) .

tenuimana [Candacé) .
tenuimana (Candacia) .
tenuimana (Oncaea)
tenuipes (Scolecithricella).
tenuipes (Scolecitkrix) . .
tenuiremis (Pontella) .
tenuirostris (.Etideus) .
tenuis (Corycaeus) .
tenuis (Euchaeta) .
tenuispinus (Gaidius)
tenuispinus (Chiridius).

Thai est ris 214

Thaumaleus

thomasi (Scottocalanus) .
thompsoni (Calanopia).

Tigriopus

tonsa (Euchaeta).
tonsa (Paraeuchaeta) .

Tortanus

trigoniceps (Onchocalanus)
truncata (Candacé) .
truncata ( Candacé) . .151
truncata (Candacia).
truncatus (Mesorhabdus) .
tubercnlata (Candacia).
tuberculata (Paraeuchaeta)
tuberosum (Pachysoma) .
tu m ida ( Scolecith rix)
turbinatus ( Calanus)
tubinata (Temora)
turgida (Monstrilla)
turgida {Pontella)
turgida (Pontellina)
Tydemanella .
tydemani (Scolecithricella)
typica (Amallophora) . .

page
173

8

155

155

242

92
92

162

37

2 e 2

68

5i

5'

& 215

239

109

178

202

72

72

189

82

155
& 152

155
132

156

76

262

89
118
118

239
175
175
216

93
85

page

typica (Neopontclla) . .

. 185

typica (Tydemanella) .

. 2l6

typicus (Bradycalanus).

14

typicus (Xanthocalanus) .

• 85

60

1 'ndina . .16, 56, 62, 88

& I I I

• 39

16

unicornis (Gaetanus) .

. 46

. 201

• 77

valgus (Calanus).

7

valida (Scolecithricella) .

. 92

valida {Scolecitkrix)

. 92

validus (Augaptilus)

■ 138

varicans (Candacia).

• 157

venusta (Euchirella)

• 57

venusta (Metridia) .

. 122

venusta (Oncaea)

• 243

venustus (Corycaeus) .

• 252

villosa (Pontellopsis) .

172

villosus (Monops) .

172

violaceus (Centropages) .

• "5

261

vitreum (Hyalophyllum) .

. 261

vittata (Scolecithricella) 8

9 & 91

vulgaris (Calanus) .

16

vulgaris (Undina) .

16

vulgaris (Undinula).

16

weberi (Longipedia) .

196

weberi (Paraeuchaeta) .

■ 74

weberi (Pseudanthessius) .

. 267

Westwoodia

217

wolfendeni (Euchaeta).

. 68

. 80

Xanthocalanus ... 8

2 & 85

xiphias (Pleuromamma) .

. 124

xiphias (Pleuroiiima) . .

. 124

PLATES

PLATE I.

Figs. I — il. Bradycalanus typicus nov. sp.

Fig. I. Female, dorsal view. X 9.

Fig. 2. Female, last thoracic and first abdominal segments, left side. < 18.

Fig. 3. Female, antenna. X 26.

Fig. 4. Female, mandible and palp. X 26.

Fig. 5. Female, maxilla. X 26.

Fig. 6. Female, first maxilliped. X 19, part of a terminal spine. X /O.

Fig. 7. Female, second maxilliped. > 19.

Fig. 8. Female, first foot. X 22,5.

Fig. 9. Female, second foot. • 22,5.

Fig. 10. Female, fourth foot. X 22,5.

Fig. 11. Female, fifth foot. X 22,5.

Figs. 12 — 18. Megacalanus prïnceps Wolfenden.

Fig. 12. Female, dorsal view. X 9,5-

Fig. 13. Female, last thoracic and first abdominal segments, left side. / 33.

Fig. 14. Female, first maxilliped. < 19.

Fig. 15. Female, first foot. X 22,5.

Fig. 16. Female, second foot
Fig. 17. Female, third foot.
Fig. 18. Female, fifth foot. ■

< 22,5.
< 22,5.
22,5.

Siboga-Expeditie XXIX a. A. Scott. Copepoda.

■

PLATE II.

Figs. i — 8. Eucalanus dentatus nov. sp.

Fig. i. Female, dorsal view. X 45.

Fig. 2. Female, head, lateral view. X 60.

Fig. 3. Female, antenna. X 90.

Fig. 4. Female, mandible and palp. X 90.

Fig. 5. Female, maxilla. X 70.

Fig. 6. Female, second maxilliped. • 90.

Fig. 7. Female, first foot. X m.

Fig. 8. Female, fourth foot. X 97.

Figs. 9 — 21. Oxycalanus semispinus nov. sp.

Fig. 9. Female, dorsal view. x 45.

Fig. 10. Female, last thoracic and first abdominal segments. 60.

Fig. 11. Female, rostrum. X 195.

Fig. 12. Female, antenna. X 60.

Fig. 13. Female, mandible and palp. X 60.

Fig. 14. Female, maxilla. X 60.

Fig. 15. Female, first maxilliped. X 60.

Fig. 16. Female, second maxilliped. < 90.

Fig. 17. Female, first foot. X 60.

Fig. 18. Female, second foot. x 60.

Fig. 19. Female, third foot. X 60.

Fig. 20. Female, fourth foot (right side). X 60.

Fig. 21. Female, fourth pair of feet, basal portion. X 90.

Siboera-Expeditie XXIX a. A. Scott. Copepoda.

II.

-A»v<rti**ScoH( d-eA

'O o

PLATE III.

Figs. i — 16. Bathypontia spinifera nov. sp.

Fig. i. Male, dorsal view. ■ 36.

Fig. 2. Male, last thoracic and first abdominal segments. ,< 60.

Fig. 3. Female, abdomen, dorsal view. X 36.

Fig. 4. Female, antennule. x 36.

Fig. 5. Male, right antennule. X 36.

Fig. 6. Female, antenna. X 36.

Fig. 7. Female, mandible and palp. X 90.

Fig. 8. Female, maxilla. X 60.

Fig. 9. Female, first maxilliped. X 60.

Fig. 10. Female, second maxilliped. > 60.

Fig. 11. Female, first foot. > 90.

Fig. 12. Female, second foot. X 60.

Fig. 13. Male, second foot. X 60.

Fig. 14. Female, fourth foot. ;< 60.

Fig. 15. Male, fifth feet. X 90.

Fig. 16. Female, fifth feet. X 90.

Figs. 17 — 29. Monacilla dubia nov. spec.

Fig. 17. Male, dorsal view. X 45.

iS. Male, last thoracic and first abdominal segments. ;• 90.

Male, right antennule. X 45.

Male, left antennule. X 45-

Male, antenna. X 90.

Male, mandible and palp. X 90.

Male, maxilla. ;< 90.

Male, first maxilliped. X 156.

25. Male, second maxilliped. :• 90.

Fig. 26. Male, first foot. X 90.

Fig. 27. Male, second foot. X 90.

Fig. 28. Male, fourth foot. X 90.

Fig. 29. Male, fifth feet. X 90.

Fig.

iS.

Fig.

19.

Fig.

20

Fig.

21,

Fig.

22,

Fig.

23

Fig.

24,

Fig.

25.

Siboga-Expeditie XXIX a. A. Scott. Copepoda.

III.

•

PLATE IV.

Figs. I — 13. jStideus giesbrecliti Cleve.

Fig. 1. Female, dorsal view. X 45-

Fig. 2. Female, head, lateral view. •:. 45.

Fig. 3. Female, last thoracic and first abdominal segments. 45.

Fig. 4. Female, rostrum. X 181.

F'g- 5- Female, antennule. X 45-

Fig. 6. Female, antenna :< 90.

Fig. 7. Female, mandible and palp. : 90.

Fig. 8. Female, maxilla. 90.

Fig. 9. Female, first maxilliped. • 90.

Fig. 10. Female, second maxilliped. ■ 90.

Fig. 11. Female, first foot. X 120.

Fig. 12. Female, second foot. X 120.

Fig. 13. Female, fourth foot. • 120.

Figs. 14 — 25. Aïtideus armatus (Boeck).

Fig. 14. Female, dorsal view. X 45-

Fig. 15. Female, head, lateral view. 45.

Fig. 16. Female, last thoracic and first abdominal segments. 45.

Fig. 17. Female, rostrum. X 1S1.

Fig. 18. Female, antennule. X 45-

Fig. 19. Female, antenna. X 90.

Fig. 20. Female, mandible and palp. 90.

Fig. 21. Female, first maxilliped. • 90.

Fig. 22. Female, second maxilliped. ;< 90.

Fig. 23. Female, first foot. >.; 120.

Fig. 24. Female, second foot. X. 120.

Fig. 25. Female, third foot. X 120.

Siboga-Expeditie XXIX a. A. Scott. Copepoda.

IV.

Av\cWev> ScoH,d«i

PLATE V.

Figs. i — 12. jEtidcus bradyi nov. sp.

Fig. i. Female, dorsal view. X 45.

Fig. 2. Female, head, lateral view. X 45.

Fig. 3. Female, last thoracic and first abdominal segments. • 45.

Fig. 4. Female, rostrum. X 1S1 -

Fig. 5. Female, antennule. X 45-

Fig. 6. Female, antenna, y 90.

Fig. 7. Female, mandible and palp. X 90.

Fig. 8. Female, first maxilliped. X 120.

Fig. 9. Female, second maxilliped. X 120.

Fig. 10. Female, first foot. X 120.

Fig. 11. Female, second foot. X 120.

Fig. 12. Female, fourth foot. x 120.

Figs. 13 — 24. ^Etidcopsis rostrata G. O. Sars.

Fig. 13. Female, dorsal view. X 36.

Fig. 14. Female, head, lateral view. X 36.

Female, last thoracic and first abdominal segments. X 36.

Female, rostrum. X 260.

Female, antennule. X 36.
Fig. 18. Female, antenna. X 90.

Female, mandible and palp. X 90.

Female, first maxilliped. > 60.

Female, second maxilliped. X 60.

Female, first foot. X 90.

Female, second foot. X 90.

Female, fourth foot. X 90.

Fig.

i-5-

Fig.

16.

Fig.

'7-

Fig.

18.

Fig.

19.

Fig.

20.

Fig.

21.

Fig.

22.

Fig.

23-

Fig.

24.

Siboga-Expeditie XXIX a. A. Scott. Copepoda.

V.

■^ü.YejSs.ott,dd

Fig.

i.

Fig.

2.

Fig.

3-

Fig.

4-

Fig.

5-

Fig.

6.

Fig.

7-

Fig.

8.

Fig.

9-

Fig.

IO.

Fig.

1 1.

big.

12.

Fig.

13-

Fig.

14.

Fig.

15-

Fig.

16.

Fig.

•7-

Fig.

18.

Fig.

19.

Fig.

20.

Fig.

21.

Fig.

22.

Fkr.

23.

PLATE VI.

Figs. 1 — n. Bradyidius armatus (Brady).

Female, dorsal view. ■ 45.

2. Female, head lateral view. X 45-

3. Female, last thoracic and first abdominal segments. X 45.

4. Female, rostrum. X 181.
Female, antennule. - 45.
Female, antenna. X 120.
Female, first maxilliped. X 90.
Female, second maxilliped. < 90.
Female, first foot. x 90.
Female, second foot. X 90.
Female, fourth foot. X 90.

Figs. 12 — 23. Macandrewella joanae nov. sp.

Female, dorsal view. X 36.

Female, head, lateral view. X 36.

Female, last thoracic and first abdominal segments, left side. < 36.

Female, last thoracic segment, right side. X 36.

Female, rostrum. • 90.

Female, antennule. X 36.

Female, antenna. • 45.

Female, first maxilliped. > 90.

Female, second maxilliped. X 45-

Female, second foot. >; 45.

Female, fourth foot. • 45.

Female, fifth feet. >( 390.

Siboga-Expeditie XXIX a. A. Scott. Copepoda.

VI.

.-.r.dr^o Stijtt.Hcl.

PLATE VIL

Figs. i — ii. Gaidius sinulis (T. Scott).

Fig. i. Male, dorsal view. X 36.

Male, head, lateral view. X 36.

Male, last thoracic and first abdominal segments. 36.

Male, rostrum. < 520.

Male, antennule. > 36.

Male, antenna. < 60.

Male, second maxilliped. X 120.

Male, first foot. ■ 90.

Male, second foot. x 90.

Male, fourth foot. • 90.

Male, fifth feet. >. 90.

Figs. 12 — 22. Gaidiopsis crassirostris nov. sp.

Fig. 12. Female, dorsal view. X 36.

Fig. 13. Female, head, lateral view. X 36.

Female, last thoracic and first abdominal segments. 36.

Female, rostrum. X 260.

16. Female, antennule. • 36.

Female, antenna. ■ 60.

Female, first maxilliped. 90.

Female, second maxilliped. x 90.

Female, first foot. 90.

Female, second foot. • 90.

Female, third foot. ,< 90.

Fig.

2.

Fig.

3-

Fig.

4-

Fig.

5-

Fig.

6.

Fig.

7-

Fig.

8.

Fig.

9-

Fig.

10.

Fig.

1 1.

Fig.

14.

Fig.

15-

Fig.

16.

Fig.

17-

Fig.

18.

Fig.

19.

Fig.

20.

Fig.

21.

Fig.

22.

Siboga-Expeditie XXIX a. A. Scott. Copepoda.

VII.

-AtUrsuSuttde

Fig.

i.

Fig.

2.

Fig.

3-

Fig.

4-

Fig.

5'

Fig.

6

Fig.

7

Fig.

8.

PLATE VIII.

Figs. I — 8. Gactanus miles Giesbrecht.

Female, dorsal view. X 23,5.
Female, head, lateral view. X 23,5.

Female, last thoracic and first abdominal segments. 23,5.
Female, rostrum. X 260.
Female, second maxilliped. X 60.
Female, first foot. x 60.
Female, second foot. X 60.
8. Female, fourth foot, basal portion only. X 120.

Figs. 9 — 15. Gactanus caudani Canu.

Fig. 9. Female, dorsal view. x 23,5.

Fig. 10. Female, head, lateral view. < 23,5.

Fig. 11. Female, last thoracic and first abdominal segments. X 23,5.

Fig. 12. Female, rostrum. ;• 260.

Fig. 13. Female, second maxilliped, basal portion only. X 45-

Fig. 14. Female, first foot. X 45.

Fig. 15. Female, fourth foot, basal portion only. > 90.

Figs. 16 — 22. Gaetanus armiger Giesbrecht.

Fig. 16. Female, dorsal view. • 23,5.

Fig. 17. Female, head, lateral view. X 23,5.

Fig. 18. Female, last thoracic and first abdominal segments. ■' 23,5.

Fig. 19. Female, rostrum. < 520.

Fig. 20. Female, second maxilliped, basal portion only. X 60.

Fig. 21. Female, first foot. X 90.

Fig. 22. Female, fourth foot, basal portion only. X 120.

Siboga-Expeditie XXIX a. A. Scott. Copepoda.

VI11.

Andyeo Stoft", ciel

PLATE IX.

Figs. i — 8. Gaetanus minor Farran.

Fig. i. Female, dorsal view. x 45-

Fig. 2. Female, head, lateral view. X 45-

Fig. 3. Female, last thoracic and first abdominal segments. x 45-

Fig. 4. Female, rostrum. X 781.

Fig. 5. Female, second maxilliped, basal portion only. ■ 90.

Fig. 6. Female, first foot. X 120.

Fig. 7. Female, second foot, basal portion only. x 181.

Fig. 8. Female, fourth foot, basal portion only. • 1 Si.

Figs. 9 — 15. Gaetanus kruppii Giesbrecht.

Fig. 9. Female, dorsal view. x 23,5.

Fig. 10. Female, head, lateral view. X 23,5.

Fig. II. Female, last thoracic and first abdominal segments. ■ 23,5.

Fig. 12. Female, rostrum. • 260.

Fig. 13. Female, second maxilliped, basal portion only. X 45.

Fig. 14. Female, first foot. > 45.

Fig. 15. Female, fourth foot, basal portion only. X 90.

Figs. 16 — 22. Gaetanus liamatus nov. sp.

Fig. 16. Female, dorsal view. X 23,5.

Fig. 17. Female, head, lateral view. X 23,5.

Fig. 18. Female, last thoracic and first abdominal segments. X 23,5.

Fig. 19. Female, rostrum, x 90.

Fig. 20. Female, second maxilliped, basal portion only. x 45-

Fig. 21. Female, first foot. X 60.

Fig. 22. Female, fourth foot, basal portion only. >, 90.

Siboga-Expeditie XXIX a. A. Scott. Copepoda.

IX.

Atkwci} Ss<**. de'.

PLATE X.

Figs. i — 9. Gaetanus krnppii Giesbrecht.

Fig. 1. Male, dorsal view. / 22,5.

Fig. 2. Male, head, lateral view. x 22,5.

Fig. 3. Male, last thoracic and first abdominal segments. X 22,5.

Fig. 4. Male, rostrum. ■ 390.

Fig. 5. Male, second maxilliped. x 36.

Fig. 6. Male, first foot. < 45.

Fig. 7. Male, second foot. x 45-

Fig. 8. Male, fourth foot, basal portion only. x 90.

Fig. 9. Male, fifth feet. X 60.

Figs. 10 — 17. Gaetanus latifrons G. O. Sars.

Fig. 10. Female, dorsal view. X iS.

Fig. n. Female, head, lateral view. ■ 18.

Fig. 12. Female, last thoracic and first abdominal segments. X 18.

Fig. 13. Female, rostrum.' < 520.

Fig. 14. Female, second maxilliped, basal portion only. X 60.

Fig. 15. Female, first foot. X 60.

Fig. 16. Female, second foot. X 45-

Fig. 17. Female, fourth foot, basal portion only. X 90.

Siboga-Expeditie XXIX a. A. Scott. Copepoda.

X.

./uuiviC 5;

PLATE XL

Figs. I — 9. Chiridius ? gracilis Farran.

Female, dorsal view. X 45-

Female, head, lateral view. X 45-

Female, last thoracic and first abdominal segments. X 45.

Female, antennule. X 60.

Female, mandible and palp. X 90.

Female, second maxilliped. X 120.

Female, first foot. X 181.

8. Female, second foot. >( 181.

Female, fourth foot. X 181.

Figs. 10 — 17. Chiridius poppei Giesbrecht.

Fig. 10. Female, dorsal view. x 60.

Fig. 11. Female, head, lateral view. X 60.

Fig. 12. Female, last thoracic and first abdominal segments. X 60.

Fig. 13. Female, antennule. x 60.

Fig. 14. Female, second maxilliped. X 181.

Fig. 15. Female, first foot. X 181.

Fig. 16. Female, second foot. X 181.

Fig. 17. Female, fourth foot. X 181.

Fig.

1.

Fig.

2.

Fig.

3-

Fig.

4-

Fig.

5-

Fig.

6.

Fig.

7-

Fig.

8.

Fig.

9-

Sibosa-Expeditie XXIX a. A. Scott. Copepoda.

XI.

,AndTtu> £to^",d«l.

PLATE XII.

Figs. i — ii. Chirundina streetsi Giesbrecht.

Fig. i. Male, dorsal view. X 24,5.

Fig. 2. Male, head, lateral view. • 24,5.

Fig. 3. Male, last thoracic and first abdominal segments. X 24,5.

Fig. 4. Male, rostrum. • 390.

Fig. 5. Male, antennule. X 24,5.

Fig. 6. Male, antenna. X 36.

Fig. 7. Male, second maxilliped. ;•; 60.

Fig. 8. Male, first foot. < 60.

Fig. 9. Male, second foot. x 60.

Fig. 10. Male, fifth feet. x 45-

Fig. 11. Female, last thoracic segment and abdomen, dorsal view. > 24,5.

Figs. 12 — 20. Euchirella maxima Wolfenden.

Fig. 12. Female, dorsal view. > 16.

Fig. 13. Female, head, lateral view. X 16.

Fig. 14. Female, last thoracic and first abdominal segments. X 16.

Fig. 15. Female, rostrum. X 190.

Fig. 16. Female, antennule. X 16.

Fig. 17. Female, antenna. ■ 31,5.

Fig. 18. Female, maxilla, endopodite and exopodite. X 90.

Fig. 19. Female, fourth foot, basal portion only. ■ 90.

Fig. 20. Female, spine on first basipodite of the fourth foot. X 181.

Siboga-Expeditie XXIX a. A. Scott. Copepoda.

XII.

-AndireO itofr.dcï

-<&">'

PLATE XIII.

Figs. i — 12. Euchirella granulata nov. sp.

Fig. I. Female, dorsal view. x 23.

Fig. 2. Female, head, lateral view. x 23.

Fig. 3. Female, last thoracic and first abdominal segments. X 23.

Fig. 4. Female, rostrum, x 390.

Fig. 5. Female, portion of the integument highly magnified.

Fig. 6. Female, antennule. x 23.

Fig. 7. Female, antenna. X 45.

Fig. 8. Female, maxilla, endopodite and exopodite. X 90.

Fig. 9. Female, second maxilliped. x 22,5.

Fig. 10. Female, first foot. x 45-

Fig. 11. Female, second foot, basal portion only. X 60.

Fig. 12. Female, fourth foot, basal portion only. X 60.

Figs. 13 — 21. Euchirella dentata nov. sp.

Fig. 13. Female, dorsal view. x 19.

Fig. 14. Female, head, lateral view. X 19.

Fig. 15. Female, last thoracic and first abdominal segments. X 19.

Fig. 16. Female, rostrum, x 120.

Fig. 17. Female, antennule. X 19.

Fig. 18. Female, antenna, x 45.

Fig. 19. Female, second maxilliped. X 45-

Fig. 20. Female, first foot. x 45.

Fig. 21. Female, fourth foot, basal portion only. x 90.

Siboga-Expeditie XXIX a. A. Scott. Copepoda.

XIII.

-AndTeüSto1rt;de|

PLATE XIV.

Figs. I — 7. Euchirella dubia nov. sp.

Fig. 1. Female, dorsal view. X 17.

Fig. 2. Female, head, lateral view. x 17.

Fig. 3. Female, last thoracic and first abdominal segments. x 17.

Fig. 4. Female, rostrum, x 181.

Fig. 5. Female, antennule. x 17.

Fig. 6. Female, maxilla, endopodite and exopodite. x 90.

Fig. 7. Female, fourth foot, basal portion only. X 90.

Figs. 8 — 15. Paraeuchaeta tonsa (Giesbrecht).

Fig. 8. Female, dorsal view. x 17.

Fig. 9. Female, head, lateral view. x 17-

Fig. 10. Female, last thoracic and first abdominal segments. x 17.

Fig. 11. Female, antennule. x 17-

Fig. 12. Female, second maxilliped, part of one of the distal hairs. x 78.

Fig. 13. Female, first foot. X 90.

Fig. 14. Female, second foot. X 90.

Fig. 15. Female, part of terminal spine, exopodite of third foot. X 390.

Siboga-Expeditie XXIX a. A. Scott. Copepoda.

XIV.

.Anchedicott.deL

PLATE XV.

Figs. i — 8. Paraenchaeta califomica (Esterly).

Fig. I. Female, dorsal view. x 18.

Fig. 2. Female, head, lateral view. X 18.

Fig. 3. Female, last thoracic and first abdominal segments. X 18.

Fig. 4. Female, antennule. x 18.

•fig- 5- Female, second maxilliped, part of one of the distal hairs. x 781.

Fig. 6. Female, first foot. x 90.

Fig. 7. Female, second foot. x 90.

Fig. 8. Female, part of teiminal spine, exopodite of third foot. X 390.

Figs. 9 — 16. Paraeuchaeta weberi nov. sp.

Fig. 9. Female, dorsal view. x 14.

Fig. 10. Female, head, lateral view. X 14.

Fig. 11. Female, last thoracic and first abdominal segments. X 14.

Fig. 12. Female, antennule. X 14.

Fig. 13. Female, second maxilliped, part of one of the distal hairs. x 781.

Fig. 14. Female, first foot. X 90.

Fig. 15. Female, second foot. X 90.

Fig. 16. Female, part of terminal spine, exopodite of third foot. X 390.

Siboga-Expeditie XXIX a. A. Scott. Copepoda.

XV.

.AndrevJ ScotT d»l

PLATE XVI.

Figs. i — 9. Paraeuchaeta sibogae nov. sp.

Female, dorsal view. x 23,5.

Female, head, lateral view. x 23,5.

Female, last thoracic and first abdominal segments, left. x 23,5.

Female, last thoracic and first abdominal segments, right. x 23,5.

Female, antennule. X 23,5.

Female, second maxilliped, part of one of the distal hairs. x 781.

Female, first foot. X 90.

Female, second foot. x 90.

9. Female, part of terminal spine, exopodite of third foot. x 390.

Figs. 10 — 17. Paraeuchaeta bisinuata (G. O. Sars).

Fig. 10. Female, dorsal view. X 23,5.

Fig. 11. Female, head, lateral view. x 23,5.

Fig. 12. Female, last thoracic and first abdominal segments. x 23,5.

Fig. 13. Female, antennule. X 23,5.

Fig. 14. Female, second maxilliped, part of one of the distal hairs. X 781.

Fig. [5. Female, first foot. x 90.

Fig. 16. Female, second foot. x 90.

Fig. 17. Female, part of terminal spine, exopodite of third foot. X 390.

Fig.

1,

Fig.

2,

Fig.

3

Fig.

4

F.g.

5'

Fig.

6

Fig.

7

Fig.

8,

Fig.

9'

Siboga-Expeditie XXIX a. A. Scott. Copepoda.

XVI.

JVnd-»«Oiiött.<iel

PLATE XVII.

Figs. i — 12. Eucliaeta wolfendeni nov. sp.

Fig. 1. Female, dorsal view. x 36.

Fig. 2. Female, head, lateral view. x 36.

Fig. 3. Female, last thoracic and first abdominal segments. x 36.

Fig. 4. Female, antennule. x 36.

Fig. 5. Female, second maxilliped, one of the distal hairs. x 781.

Fig. 6. Female, first foot. x 195.

Pig. 7. Female, second foot. x 195.

Fig. 8. Female, part of terminal spine, exopodite of third foot. X 781.

Fig. 9. Male, first foot, exopodite. x 195-

Fig. 10. Male, second foot, part of exopodite. x 195.

Fig. 11. Male, fifth foot, part of left branch. X 195.

Fig. 12. Male, abdomen. x 36.

Figs. 13 — 20. Paraeuchaeta propinqua (Esterly).

Fig. 13. Female, dorsal view. x 1 3,45-

Fig. 14. Female, head, lateral view. X 13,45.

Fig. 15. Female, last thoracic and first abdominal segments. X 13,45.

Fig. 16. Female, antennule. X 13,45.

Fig. 17. Female, second maxilliped, part of one of the distal hairs. x 781.

Fig. 18. Female, first foot. x 60.

Fig. 19. Female, second foot. x 60.

Fig. 20. Female, part of terminal spine, exopodite of third foot. X 390.

Siboga-Expeditie XXIX a. A. Scott. Copepoda.

XVII.

Ar\A*e*J Stolt* dal.

PLATE XVIII.

Figs. I — 8. Paraeucliaeta barbata (Brady).

Fig. i. Female, dorsal view. x 15,7.

Fig. 2. Female, head, lateral view. x 1 5,7-

Fig. 3. Female, last thoracic and first abdominal segments. x 15,7.

Fig. 4. Female, antennule. X 1 5,7-

Fig. 5. Female, second maxilliped, part of one of the distal hairs. X 781.

Fig. 6. Female, first foot. X 90.

Fig. 7. Female, second foot. X 90.

Fig. 8. Female, part of terminal spine, exopodite of third foot. x 390.

Figs. 9 — 16. Paraeucliaeta gracilicauda nov. sp.

Fig. 9. Female, dorsal view. X 15,7.

Fig. 10. Female, head, lateral view. 15,7.

Fig. 11. Female, last thoracic and first abdominal segments. X 15,7.

Fig. 12. Female, antennule. x 15,7.

Fig. 13. Female, second maxilliped, part of one of the distal hairs. X 781.

Fig. 14. Female, first foot. X 90.

Fig. 15. Female, second foot. X 90.

Fig. 16. Female, part of terminal spine, exopodite of third foot. X 390.

Sibosa-Expeditie XXIX a. A. Scott. Copepoda.

XVIII.

AidTtOSto^del.

Fig.

i.

Fig.

2.

Fig.

3-

Fig.

4-

Fig.

5-

Fig.

6.

Fig.

7-

PLATE XIX.

Figs. i—8. Euchaeta tennis Esterly.

Female, dorsal view. x 19.

Female, head, lateral view. x 19.

Female, last thoracic and first abdominal segments. \ 19.

Female, antennule. x 19-

Female, second maxilliped, one of the distal hairs. X 90.

Female, first foot. x 90.

Female, second foot. X 90.

Fig. 8. Female, part of terminal spine, exopodite of third foot. X 390.

Figs. 9 — 20. Eucliaeta marina (Prestandrea).

Fig. 9. Female, head, dorsal view. X 31.

Fig. 10. Female, head, lateral view. X 31.

Fig. 11. Female, last thoracic segment and abdomen, dorsal view. x 31.

Fig. 12. Female, last thoracic and first abdominal segments, left side. y 31.

Fig. 13. Female, last thoracic and first abdominal segments, right side. X 31.

Fig. 14. Female, second maxilliped, end hair. x 90.

Fig. 15. Female, first foot, exopodite only. x 195.

Fig. 16. Female, second foot, outer margin of exopodite. x 135.

Fig. 17. Female, part of terminal spine, exopodite of third foot. X 390.

Fig. 18. Male, first foot, exopodite only. X 195.

Fig. 19. Male, second foot, outer margin of exopodite. x 135.

Fig. 20. Male, fifth foot, part of left branch. x 135.

Figs. 21 — 27. Enchaeta concinna Dana.

Fig. 21. Female, second maxilliped, end hair. x 90.

Fig. 22. Female, first foot, exopodite only. X 195.

Fig. 23. Female, second foot, outer margin of exopodite. x 135.

Fig. 24. Female, part of terminal spine, exopodite of third foot. x 390.

Fig. 25. Male, first foot, exopodite only. X 195.

Fig. 26. Male, second foot, outer margin of exopodite. x 135.

Fig. 27. Male, fifth foot, part of left branch. x 260.

Siboga-Expeditie XXIX a. A. Scott. Copepoda.

XIX.

8.

1

^

ê

17

12

10

\ M

/

^nAvcw -

13

1

11

■s

PLATE XX.

Figs. I- — 9. Enchaeta acuta Giesbrecht.

Fig. 1. Female, dorsal view. x 23,5.

Fig. 2. Female, head, lateral view. X 90.

Fig. 3. Female, last thoracic and flrst abdominal segments. X 46.

Fig. 4. Female, genital segment, dorsal view. X 46.

Fig. 5. Female, antennule. x 31.

Fig. 6. Female, second maxilliped, end hair. X 90.

Fig. 7. Female, first foot. x 120.

Fig. 8. Female, second foot. x 120.

Fig. 9. Female, part of terminal spine, exopodite of third foot. X 390.

Fies. 10 — 18. Euchaeta media Giesbrecht.

o

Fig. 10. Female, dorsal view. x 31.

11. Female, head, lateral view. x 90.

Female, last thoracic and first abdominal segments. X 60.

Female, genital segment, dorsal view. X 60.

Female, antennule. X 31.

Female, second maxilliped, end hair. x 90.

Female, first foot. X 135.

Female, second foot. x 135.

Female, part of terminal spine, exopodite of third foot. x 390.

Fig.

11.

Fig.

12.

Fig.

13-

Fig.

14.

Fig.

15

Fig.

16.

Fig.

17

Fig.

18.

Siboga-Expeditie XXIX a. A. Scott. Copepoda.

XX.

■r

14.

&

18.

d.reü> lacott, dtl .

13.

PLATE XXL

Figs. i — 8. Paraeucliaeta tuberculata nov. sp.

Fig. I. Male, head, dorsal view. x 34-

Fig. 2. Male, head, lateral view. x 34-

Fig. 3. Male, last thoracic and first abdominal segments, dorsal view. x 34-

Fig. 4. Male, last thoracic and first abdominal segments, lateral view. X 34.

Fig. 5. Male, first foot, exopodite only. x 135-

Fig. 6. Male, second foot, outer margin of exopodite. X 60.

Fig. 7. Male, part of terminal spine, exopodite of third foot. x 380.

Fig. 8. Male, fifth foot, part of left branch. x 90.

Figs. 9 — 15. Paraeucliaeta sar si Farran.

Fig. 9. Male, head, dorsal view. X 26.

Fig. 10. Male, head, lateral view. x 26.

Fig. 11. Male, last thoracic and first abdominal segments, dorsal view. x 26.

Fig. 12. Male, last thoracic and first abdominal segments, lateral view. X 26.

Fig. 13. Male, first foot, exopodite only. X 90.

Fig. 14. Male, part of terminal spine, exopodite of third foot. x 380.

Fig. 15. Male, fifth foot, part of left branch. x 90.

Figs. 16 — 23. Paraeucliaeta dentata nov. sp.

Fig. 16. Male, head, dorsal view. x 26.

Fig. 17. Male, head lateral view. X 26.

Fig. 18. Male, last thoracic and first abdominal segments, dorsal view. x 26.

Fig. 19. Male, last thoracic and first abdominal segments, lateral view. x 26.

Fig. 20. Male, first foot, exopodite only. x 90.

Fig. 21. Male, second foot, outer margin of exopodite. x 60.

Fig. 22. Male, part of terminal spine, exopodite of third foot. x 3S0.

Fig. 23. Male, fifth foot, part of left branch. X 90.

Figs. 24 — 33. Gaidius notacanthus G. O. Sars.

Fig. 24. Male, head, dorsal view. x 26.

Fig. 25. Male, head, lateral view. x 26.

Fig. 26. Male, last thoracic and first abdominal segments, dorsal view. x 26.

Fig. 27. Male, last thoracic and first abdominal segments, lateral view. x 26.

Fig. 28. Male, first foot, exopodite only. x 90.

Fig. 29. Male, second foot. x 60.

Fig. 30. Male, part of terminal spine, exopodite of third foot. x 380.

Fig. 31. Male, fifth foot, left branch. x 45-

Fig. 32. Male, fifth foot, right branch. X 45.

Fig. 33. Male, rostrum. X 181.

Sibos:a-Expeditie XXIX a. A. Scott. Copepoda.

XXI.

AndTtu) Sscdtt",^*

PLATE XXII.

Figs. i — 8. Undeucliaeta plumosa (Lubbock).

Fig. r. Male, head, dorsal view. x 45.

Fig. 2. Male, head, lateral view. x 45.

Fig. 3. Male, last thoracic and first abdominal segments, dorsal view. x 45.

Fig. 4. Male, last thoracic and first abdominal segments, lateral view. X 45.

Fig. 5. Male, first foot, exopodite only. X 181.

Fig. 6. Male, second foot, outer margin of exopodite. x 135.

Fig. 7. Male, part of terminal spine, exopodite of third foot. x 390.

Fig. 8. Male, fifth pair of feet. x 60.

Figs. 9 — 16. Paraenchaeta spinifera (Esterly).

Fig. 9. Male, head, dorsal view. X 36.

Fig. 10. Male, head, lateral view. x 36.

Fig. 11. Male, last thoracic and first abdominal segments, dorsal view. X 36.

Fig. 12. Male, last thoracic and first abdominal segments, lateral view. x 36.

Fig. 13. Male, first foot, exopodite only. x 181.

Fig. 14. Male, second foot, outer margin of exopodite. x 90.

Fig. 15. Male, part of terminal spine, exopodite of third foot. x 390.

Fig. 16. Male, fifth foot, part of left branch. x 60.

Figs. 17 — 26. Valdiviella gigas (Brady).

Fig. 17. Male, head, dorsal view. x 19-

Fig. 18. Male, head, lateral view. x 19.

Fig. 19. Male, last thoracic and first abdominal segments, dorsal view. x 19.

Fig. 20. Male, last thoracic and first abdominal segments, lateral view. X 19.

Fig. 21. Male, rostrum, x 181.

Fig. 22. Male, antennule. x 23,5.

Fig. 23. Male, first foot, exopodite only. x 90.

Fig. 24. Male, second foot, outer margin of exopodite. x 60.

Fig. 25. Male, part of terminal spine, exopodite of third foot. x 390.

Fig. 26. Male, fifth feet. X 60.

Figs. 27 — 35. Valdiviella brevicornis G. O. Sars.

Fig. 27. Male, head, dorsal view. x 31.

Fig. 28. Male, head, lateral view. X 31.

Fig. 29. Male, last thoracic and first abdominal segments, dorsal view. X31.

Fig. 30. Male, last thoracic and first abdominal segments, lateral view. X 31.

Fig. 31. Male, rostrum. X 181.

Fig. 32. Male, antennule. X 23,5.

F'g- 33- Male, first foot, exopodite only. x 181.

Fig. 34. Male, second foot, outer margin of exopodite. X 120.

Fig. 35. Male, fifth feet. X 60.

Siboga-Expeditie XXIX a. A. Scott. Copepoda.

XXII.

«Ai\At«ü ScdHjclel

PLATE XXIII.

Figs. i — 8. Undeuchaeta intermedia nov. sp.

Fig. i. Female, dorsal view. x 31.

Fig. 2. Female, head, lateral view. x 31.

Fig. 3. Female, last thoracic and first abdominal segments, left side. X 31.

Fig. 4. Female, last thoracic and first abdominal segments, right side. X 31.

Fig. 5. Female, rostrum, x 390.

Fig. 6. Female, antennule. X 31.

Fig. 7. Female, first foot. X 90.

Fig. 8. Female, second foot. x 90.

Figs. 9 — 15. Macandrezvella joanae nov. sp.

Fig. 9. Male, antennule. X 31.

Fig. 10. Male, rostrum. X 390.

Fig. n. Male, first maxilliped. X 181.

Fig. 12. Male, second foot. x 90.

Fig. 13. Male, fourth foot. X 90.

Fig. 14. Male, fifth feet. X 90.

Fig. 15. Male, abdomen, dorsal view. x 60.

Siboga-Expeclitie XXIX a. A. Scott. Copepoda.

XXIII.

AMreiOS«*-,d*l.

PLATE XXIV.

FigS. i — q. Scottocalanus farrani nov. sp.

Fig. i. Female, dorsal view. X 31.

Fig. 2. Female, head, lateral view. X 31-

Fig. 3. Female, last thoracic and first abdominal segments. x 31-

Fig. 4. Female, rostrum, x 90.

Fig. 5. Female, antennule. y 31.

Fig. 6. Female, first maxilliped, distal portion. X 156.

Fig. 7. Female, second foot. X 90.

Fig. 8. Female, fourth foot. x 9°-

Fig. 9. Female, fifth feet. X 90.

Figs. 10 — 18. Scottocalanus setosus nov. sp.

'ö

Fig. 10. Female, dorsal view. x 31-

Fig. 11. Female, head, lateral view. X 31.

Fig. 12. Female, last thoracic and first abdominal segments. X 31.

Fig. 13. Female, rostrum. X 181.

Fig. 14. Female, antennule. x 31.

Fig. 15. Female, first maxilliped, distal portion. X 156.

Fig. 16. Female, second foot. x 90.

Fi°\ 17. Female, fourth foot. X 90.

Fig. iS. Female, fifth feet. X 90.

Siboga-Expeditie XXIX a. A. Scott. Copepoda.

XXIV

-AluWu) Scott,de\

PLATE XXV.

FjcrS. ! — g. Scottocalanus securifrons (T. Scott).

Fig. I. Female, dorsal view. X 23,5.

Fig. 2. Female, head, lateral view. x 23,5.

Fig. 3. Female, last thoracic and first abdominal segments. x 23,5.

Fig. 4. Female, rostrum, x 135-

Fig. 5. Female, antennule. X 23,5.

Fig. 6. Female, first maxilliped, distal portion. X 156.

Fig. 7. Female, second foot. X 90.

Fig. 8. Female, fourth foot. x 9°-

Fig. 9. Female, fifth feet. X 90.

Figs. 10—18. Scottocalanus longispinus nov. sp.

Fig. 10. Female, dorsal view. X 23,5,

Fig. 11. Female, head lateral view. x 23,5.

Fig. 12. Female, last thoracic and first abdominal segments. x 23,5.

Fig. 13. Female, rostrum. X 181.

Fig. 14. Female, antennule. X 23,5.

Fig. 15. Female, first maxilliped, distal portion. x I56-

Fig. 16. Female, second foot. x 9°-

Fig. 17. Female, fourth foot. x 90.

Fig. 18. Female, fifth feet. X 90.

Siboga-Expeditie XXIX a. A. Scott. Copepoda.

XXV.

•hnd-reO SccVtdel.

,y 0°s *o

:LIBRAR

PLATE XXVI.

Fiers. I — 10. Scottocalanus tlwmasi nov. sp.

Fig. I. Female, dorsal view. >. 19.

Fig. 2. Female, head, lateral view. X 19.

Fig. 3. Female, last thoracic and first abdominal segments. X 19.

Fig. 4. Female, rostrum. X 181.

Fig. 5. Female, antennule. X 19-

Fig. 6. Female, antenna, distal part of exopodite. X 90.

Fig. 7. Female, first maxilliped, distal portion. X 156.

Fig. 8. Female, second foot. X 60.

Fig. 9. Female, fourth foot. ■ 60.

Fig. 10. Female, fifth feet. X 60.

Figs. 11 — 20. Lophothrix frontalis Giesbrecht.

Fig. II. Female, dorsal view. x 13,5-

Fig. 12. Female, head, lateral view. x 1 3,5-

Fig. 13. Female, last thoracic and first abdominal segments. X I3>5-

Fig. 14. Female, rostrum. ■ 135.

Fig. 15. Female, antennule. X 13,5-

Fig. 16. Female, antenna, distal part of exopodite. X 90.

Fig. 17. Female, first maxilliped, distal portion. X 90.

Fig. 18. Female, second foot. X 60.

Fig. 19. Female, fourth foot. < 60.

Fig. 20. Female, fifth feet. X 130.

Sibosa-Expeditie XXIX a. A. Scott. Copepoda.

XXVI.

-AndveO Stolt, dtl

PLATE XXVII.

Figs. i — 9. Scottocalanus helenae (Lubbock).

Fig. 1. Male, dorsal view. X 23,5.

Fig. 2. Male, head, lateral view. x 23,5.

Fig. 3. Male, last thoracic and first abdominal segments. X 23,5.

Fig. 4. Male, rostrum. X 181.

Fig. 5. Male, antennule. X 23,5.

Fig. 6. Male, first maxilliped, distal portion. X 181.

Fig. 7. Male, second foot. X 60.

Fig. 8. Male, fourth foot. X 60.

Fig. 9. Male, fifth feet. X 60.

Figs. 10 — 18. Scottocalanus persecans (Giesbrecht).

Fig. 10. Male, dorsal view. < 23,5.

Fig. n. Male, head, lateral view. X 23,5.

Fig. 12. Male, last thoracic and first abdominal segments. X 23,5.

Fig. 13. Male, rostrum. • 181.

Fig. 14. Male, antennule. ■ 23,5.

Fig. 15. Male, first maxilliped, distal portion X 181.

Fig. 16. Male, second foot. • 60.

Fig. 17. Male, fourth foot. X 60.

Fig. 18. Male, fifth feet. X 60.

Siboga-Expeditie XXIX a. A. Scott. Copepoda.

XXVII.

A\dTto Scott" del

PLATE XXVIII.

Figs. i — 9. Scottocalamis securifrons (T. Scott.).

Fig. 1. Male, dorsal view. < 23,5.

Fig. 2. Male, head, lateral view. 23,5.

Fig. 3. Male, last thoracic and first abdominal segments. X 23,5.

Fig. 4. Male, rostrum. X 181.

Fig. 5. Male, antennule. ;< 23,5.

Fig. 6. Male, first maxilliped, distal portion. X 181.

Fig. 7. Male, second foot. X 60.

Fig. 8. Male, fourth foot. X 60.

Fig. 9. Male, fifth feet. X 90.

Figs. 10 — 17. Scottocalamis thomasi nov. sp.

Fig. 10. Male, dorsal view. X 19-

Fig. 11. Male, head, lateral view. X 19.

Fig. 12. Male, last thoracic and first abdominal segments. x 19-

Fig. 13. Male, rostrum. 181.

Fig. 14. Male, antennule. ■ 19.

Fig. 15. Male, first maxilliped, distal portion. X 181.

Fig. 16. Male, second foot. x 60.

Fig. 17. Male, fifth feet. < 90.

Siboa;a-ExpecUtie XXIX a. A. Scott. Copepoda.

XXVIII.

>»;.'£0 ücott.cUl.

PLATE XXIX.

Figs. i — 10. Lophothrix frontalis Giesbrecht.

Male, dorsal view. X 19-

2. Male, head, lateral view. X 19.

Male, last thoracic and first abdominal segments. X 19.

Male, rostrum. • 181.

5. Male, antennule. 19.

Male, antenna, distal part of exopodite. ■ 90.

Male, first maxilliped, distal portion. 181.

Male, second foot. y 60.

Male, fourth foot. X 60.

Male, fifth feet. ;,; 60.

Figs. 11 — 18. Scottocalanus farrani nov. sp.

Fig. n. Male, dorsal view. X 23,5.

Fig. 12. Male, head, lateral view. X 23,5.

Fig. 13. Male, last thoracic and first abdominal segments. ■ 23,5.

Fig. 14. Male, rostrum. • 18 1.

Fig. 15. Male, antennule. X 23,5.

Fig. 16. Male, first maxilliped, distal portion. • 181.

Fig. 17. Male, second foot. > 90.

Fig. 18. Male, fifth feet. X 90.

Fig.

1.

Fig.

2.

Fig.

3-

Fig.

4-

Fig.

5-

Fig.

6.

Fig.

7-

Fig.

8.

Fig.

9-

Fig.

10.

Siboga-Expeditie XXIX a. A. Scott. Copepoda.

XXIX.

PLATE XXX.

Figs. i — 9. Scolecithricella curticanda nov. sp.

Female, dorsal view. >( 19.

Female, head, lateral view. X 19.

Female, last thoracic and first abdominal segments. X 19.

Female, rostrum. X 181.

Female, antennule. X 19.

6. Female, first maxilliped, distal portion. x 90.

Female, second foot. X 90.

Female, fourth foot. X 45.

Female, fifth feet. X 181.

Figs. 10 — 17. Scolecitliricella tydemani nov. sp.

Fig. 10. Female, dorsal view. X 19-

Fig. 11. Female, head, lateral view. X 19-

Fig. 12. Female, last thoracic and first abdominal segments. X 19.

Fig. 13. Female, rostrum. X 181.

Fig. 14. Female, antennule. • 19.

Fig. 15. Female, first maxilliped, distal portion. • 90.

Fig. 16. Female, second foot. X 60.

Fig. 17. Female, fifth feet. X 181.

Fig.

1,

Fig.

2,

Fig.

3'

Fig.

4

Fig.

5>

Fig.

6.

Fig.

7<

Fig.

8.

Fig.

9<

Sibosa-Expeditie XXIX a. A. Scott. Copepoda.

■<cf^J

-Y?'

10.

.Andrt u> ^ ;

PLATE XXXI.

Figs. i — 9. Scolecithricella obtusifrons (G. O. Sars).

Fig. 'I. Female, dorsal view. ■ 23,5.

Fig. 2. Female, head lateral view. X 23,5.

Fig. 3. Female, last thoracic and first abdominal segments. X 23,5.

Fig. 4. Female, rostrum. X 181.

Fig. 5. Female, antennule. X 23,5.

Fig. 6. Female, first maxilliped, distal portion. X 181.

Fig- 7- Female, second foot. < 60.

Fig. 8. Female, fourth foot. 60.

Fig. 9. Female, fifth feet. X 181.

Figs. 10 — 18. Scolecithricella gracilis G. O. Sars.

Fig. 10. Female, dorsal view. X 23,5.

Fig. 11. Female, head, lateral view. X 23,5.

Fig. 12. Female, last thoracic and first abdominal segments. x 23,5.

Fig. 13. Female, rostrum. ■ i S 1 .

Fig. 14. Female, antennule. ■ 23,5.

Fig. 15. Female, first maxilliped, distal portion. X 181.

Fig. 16. Female, second foot. x 90.

Fig. 17. Female, fourth foot. < 60.

Fig. 18. Female, fifth feet. X 260.

Siboga-Expeditie XXIX a. A. Scott. Copepoda.

XXXI.

AruWeO. S«>-ft. del

PLATE XXXII.

Figs. i- — 9. Scolccitliricella valida (Farran).

Female, dorsal view. v 31,5.

Female, head, lateral view. X 31,5-

Female, last thoracic and first abdominal segments. x 31,5-

Female, rostrum. • 181.

Female, antennule. • 31,5.

Female, first maxilliped, distal portion. x 181.

Female, second foot. X 90.

8. Female, fourth foot. X 90.

9. Female, fifth feet. X 260.

Figs. 10 — 16. Scaplwcalanus elongatus nov. sp.

Fig. 10. Female, dorsal view. X 47.

Fig. n. Female, head, lateral view. X 47.

Fig. 12. Female, last thoracic and first abdominal segments. X 47.

Fig. 13. Female, rostrum. X 390.

Fig. 14. Female, first maxilliped, distal portion. X 181.

Fig. 15. Female, second foot. X 18 1.

Fig. 16. Female, fifth feet. X 390.

Fig.

1.

Fig.

2,

Fig.

3'

Fig.

4>

Fig.

5'

Fig.

6

Fig.

7'

Fig.

8.

Fig.

9

Siboga-Expeclitie XXIX a. A. Scott. Copepoda.

XXXII.

•AiviieJ Stoft, del.

PLATE XXXIII.

Figs. i — 9. Heter amalla dubia (T. Scott).

Fig. 1. Female, dorsal view. v 23,5.

Fig. 2. Female, head, lateral view. ■ 23,5.

Fig. 3. Female, last thoracic and first abdominal segments. • 23,5.

Fig. 4. Female, rostrum. < 181.

Fig. 5. Female, antennule. > 23,5.

Fig. 6. Female, first maxilliped, distal portion. ■ 90.

Fig. 7. Female, second foot. ■ 90.

Fig. 8. Female, part of terminal spine, exopodite of second foot.

Fig. 9. Female, fifth feet. X 390.

Figs. 10 — 18. XantJiocalanus agilis Giesbrecht.

Fig. 10. Female, dorsal view. ■ 45.

Fig. 11. Female, head, lateral view. 45.

Fig. 12. Female, last thoracic and first abdominal segments. X 45.

Fig. 13. Female, rostrum. • 390.

Fig. 14. Female, antennule. X 45-

Fig. 15. Female, first maxilliped, distal portion. 181.

Fig. 16. Female, second foot. 120.

Fig. 17. Female, fourth foot. > 120.

Fig. 18. Female, fifth feet. X 260.

Sibosa-Expeditie XXIX a. A. Scott. Copepoda.

XXXIII.

^■ndTCu>Scött', de

PLATE XXXIV.

Figs. i—8. Onchocalanus cristatus (Wolfenden).

Fig. i. Female, dorsal view. X 19-

Fig. 2. Female, head, lateral view. X 19-

Fig. 3. Female, last thoracic and first abdominal segments. X 19.

Fig. 4. Female, rostrum. ■ 18 1.

Fig. 5. Female, first maxilliped, distal portion. X 9°-

Fig. 6. Female, second foot. ■ 45.

Fig. 7. Female, fourth foot. • 45.

Fig. 8. Female, fifth feet. x 120.

pjgS. g — ij, Onchocalanus hirtipcs G. O. Sars.

Fig. 9. Female, dorsal view. X 23,5.

Fig. 10. Female, head, lateral view. X 23,5.

Fi^. 11. Female, last thoracic and first abdominal segments. X 23,5.

Fig. 12. Female, rostrum. • 181.

Fig. 13. Female, antennule. > 23,5.

Fig. 14. Female, first maxilliped, distal portion. X 9°-

Fig. 15. Female, second foot. X 60.

Fig. 16. Female, fourth foot. ■ 60.

Fig. 17. Female, fifth feet. X 120.

Siboga-Expeclitie XXIX a. A. Scott. Copepoda.

XXXIV

.HnirejScott'.iïl.

PLATE XXXV.

Figs. i — g. Cornucalanus simplex Wolfenden.

Fig. i. Female, dorsal view. X 23,5.

Female, head, lateral view. x 23,5.

Female, last thoracic and first abdominal segments. x 23,5.
Female, rostrum. X 1S1.
Female, antennule. • 23,5.

Female, first maxilliped, distal portion. y 120.
Female, second foot. y 60.
8. Female, fourth foot. X 60.
Female, fifth feet. - 136.

Figs. 10 — 18. Brachycalanus gigas nov. sp.

Fig. 10. Male, dorsal view. X 19.

Fig. 11. Male, head, lateral view. X 19.

Fig. 12. Male, last thoracic and first abdominal segments. X 19-

Fig. 13. Male, rostrum. X 90.

Fig. 14. Male, antennule. 19.

Fig. 15. Male, first maxilliped, distal portion. X 90.

Fig. 16. Male, second foot. y 60.

Fig. 17. Male, fourth foot, endopodite only. X 90.

Fig. 18. Male, fifth feet. X 90.

Fig.

0

Fig.

3'

Fig.

4

Fig.

5'

Fig.

6.

Fig.

7

Fig.

8.

Fig.

9

Siboga-Expeditie XXIX a. A. Scott. Copepoda.

XXXV.

. itöttdel

PLATE XXXVI.

Figs. i — 8. Amallophora typica T. Scott.

Fig. i. Male, dorsal view. X 36.

Fig. 2. Male, head, lateral view. x 36.

Fig. 3. Male, last thoracic and first abdominal segments. ■ 36.

Fig. 4. Male, rostrum. X 90.

Fig. 5. Male, antennule. X 36.

Fig. 6. Male, first maxilliped, distal portion. X 260.

Fig. 7. Male, second foot. x 120.

Fig. 8. Male, fifth feet. X 120.

Figs. 9 — 21. Chiridiella uiacrodactyla G. O. Sars.

Fig. 9. Female, dorsal view. x 36.

Fig. IO. Female, head, lateral view. X 36.

Fig. 11. Female, last thoracic and first abdominal segments. x 36.

Fig. 12. Female, antennule. X 36.

Fig. 13. Female, antenna. X 90.

Fig. 14. Female, mandible and palp. ■: 90.

Fig. 15. Female, maxilla. ■ 60.

Fig. 16. Female, first maxilliped. X 60.

Fig. 17. Female, second maxilliped. ;• 60.

Fig. 18. Female, first foot. x 90.

Fig. 19. Female, second foot. x 90.

Fig. 20. Female, fourth foot. X 90.

Fig. 21. Female, terminal spine, exopodite of fourth foot. X 190.

Siboga-Expeditie XXIX a. A. Scott. Copepoda,

XXXVI.

.Andhre w -3 c ofr, cUl

PLATE XXXVII.

Figs. i — 8. Pseudodiaptomus clevei nov. sp.

Fig. I. Female, dorsal view. x 60.

Fi°f. 2. Female, head, lateral view. X 60.

Fig. 3. Female, last thoracic and first abdominal segments. < 60.

Fig. 4. Female, antennule. X 60.

Fig. 5. Female, fifth foot. ■ 390. ,

Fig. 6. Male, abdomen, dorsal view. X 60.

Fig. 7. Male, antennule, right side. X 60.

Fig. 8. Male, fifth feet. > 260.

Figs. 9 — 11. Mctridia brevicauda Giesbrecht.

Fig. 9. Female, dorsal view. > 45.

Fig. 10. Female, second foot, hooks on basal joint of endopodite. X 3S0.

Fig. II. Female, fifth feet. • 260.

Figs. 12 — 14. Metridia boecki Giesbrecht.

Fig. 12. Female, dorsal view. X 36.

Fig. 13. Female, second foot, hooks on basal joint of endopodite. • 380.

Fig. 14. Female, fifth feet. ■ 260.

Figs. 15 — 20. Metridia venusta Giesbrecht.

Fig. 15. Female, dorsal view. X 36.

Fig. 16. Female, second foot, hooks on basal joint of endopodite. ■ 380.

Fig. 17. Female, fifth feet. X 181.

Fig. 18. Male, abdomen, dorsal view. X 45-

Fig. 19. Male, second foot, hooks on basal joint of endopodite. X 380.

Fig. 20. Male, fifth feet. X 181.

Siboga-Expeditie XXIX a. A. Scott. Copepoda.

XXXVII.

AndTto Stóu7d «\

PLATE XXXVIII.

Figs. I — 7. Metridia princeps Giesbrecht.

Male, dorsal view. • 13.

Male, antennule, right side. X 15,5.

Male, antennule, left side. X 15,5.

Male, second foot, hooks on basal joint of endopodite. X 144.

Male, fifth feet. x 47.
Fig. 6. Female, second foot, hooks on basal joint of endopodite. X 144.
Fig. 7. Female, fifth feet. X 71.

Figs. 8 — 11. Metridia macrura G. O. Sars.

Fig. 8. Female, dorsal view. x 11,75.

Fig. 9. Female, antennule. X 15.

Fig. 10. Female, second foot, hooks on basal joint of endopodite. X 144.

Fig. 11. Female, fifth feet. X 89.

Fig.

I

Fig.

2,

Fig.

3

Fig.

4

Fig.

5

Sibosa-Expeditie XXIX a. A. Scott. Copepoda.

XXXVIII.

PLATE XXXIX.

Figs. i — ii. Liicicutia bicomuta Wolfenden.

Fig. I. Male, dorsal view. X 12,5.

Fig. 2. Male, head, lateral view. X 12,5.

Fig. 3. Male, last thoracic and first abdominal segments. x 12,5.

Fig. 4. Male, rostrum, x 200.

Fig. 5. Male, antennule, right side. x 22.5.

Fig. 6. Male, antennule, left side. x 22,5.

Fig. 7. Male, antenna. X 36.

Fig. 8. Male, mandible and palp. X 36-

Fig. 9. Male, first maxilliped. X 36-

Fig. 10. Male, second maxilliped. x 3^-

»&■

Fig. 11. Male, fifth feet. X 328.

Figs. 12 — 21. Mcsorliabdus truncatus nov. sp.

Fig. 12. Female, dorsal view. x 15.

'S

Fig. 13. Female, head lateral view. x 15.

Fig. 14. Female, last thoracic and first abdominal segments. x 15.

Fig. 15. Female, rostrum. X 96.

Fig. 16. Female, antennule. x 22,5.

Fig. 17. Female, mandible and palp. x 48-

Fig. 18. Female, first maxilliped. x 72.

Fig. 19. Female, second maxilliped. x 36-

Fig. 20. Female, first foot. x 36.

Fig. 21. Female, fifth foot. X 36.

Siboga-Expeditie XXIX a. A. Scott. Copepoda.

XXXIX.

^niY«w

Fig.

i.

Fig.

2.

Fig.

3-

Fig.

4-

Fig.

5-

Fig.

6.

Fig.

7-

Fig.

8.

PLATE XL.

Figs. i — 9. Lucicutia pcra nov. sp.

Female, dorsal view. x 30.
Female, head, lateral view. x 30.

Female, last thoracic and first abdominal segments. X 30.
Female, antennule. X 29.
Female, mandible. X 144.
Female, first maxilliped. x 96.
Female, second maxilliped. X 70.
Female, first foot. X 144.
Fig. 9. Female, fifth foot. x 144.

Figs. 10 — 18. Lucicutia philyra nov. sp.

Fig. 10. Female, dorsal view. X 29.

Fig. 11. Female, head, lateral view. x 29.

Fig. 12. Female, last thoracic and first abdominal segments. x 29.

Fig. 13. Female, antennule. X 29.

Fig. 14. Female, mandible. X 66.

Fig. 15. Female, first maxilliped. X 96.

Fig. 16. Female, second maxilliped. x 70.

Fig. 17. Female, first foot. x 144-

Fig. iS. Female, fifth foot. X 144.

Sibos;a-Expeclitie XXIX a. A. Scott. Copepoda.

XL.

PLATE XLI.

Figs. i — 10. Liicicutia maxima Steuer.

Fig. i. Male, dorsal view. x 13, 5-

Fig. 2. Male, head, lateral view. x 13,5.

Fig. 3. Male, last thoracic and first abdominal segments. x 1 3,5-

Fig. 4. Male, rostrum, x 273.

Fig. 5. Male, antennule, right side. x 15-

Fig. 6. Male, antennule, left side. x IS-

Fig. 7. Male, mandible. X 142.

Fig. S. Male, maxilla. x 48.

Fig. 9. Male, first foot. X 48.

Fig. 10. Male, fifth feet. X 48.

Figs. 11 — 21. Disseta palumboi Giesbrecht.

Fig. 11. Female, dorsal view. x 15,7-

Fig. 12. Female, head, lateral view. X 15,7.

Fig. 13. Female, last thoracic and first abdominal segments. x 1 5,7-

Fig. 14. Female, rostrum. X 108.

Fig. 15. Female, antennule. X 15.

Fig. 16. Female, mandible. x 108.

Fig. 17. Female, second maxilliped. X 48.

Fig. 18. Female, first foot. x 48.

Fig. 19. Female, fifth foot. x 48.

Fig. 20. Male, antennule, left side. x 15.

Fig. 21. Male, fifth feet. X 48.

Sibo°;a-Expeditie XXIX a. A. Scott. Copepoda.

XLI.

-'■««•tv ^CQi|rtel

PLATE XLII.

Figs. i — 9. Disseta scopularis (Brady).

Fig. 1. Male, dorsal view. x 11,5.

Fig. 2. Male, head, lateral view. X 11,5.

Fig. 3. Male, last thoracic and first abdominal segments. X 11,5.

Fig. 4. Male, mandible. X 144.

Fig. 5. Male, maxilla. X 48.

Fig. 6. Male, first maxilliped. X 48.

Fig. 7. Male, first foot. x 36.

Fig. 8. Male, fourth foot, end joint of exopodite. x 36.

Fig. 9. Male, fifth feet. X 48.

Figs. 10 — 19. Augaptilus placitus nov. sp.

Fig. 10. Female, dorsal view. x 1 1 ,5-

Fig. 11. Female, head, lateral view. x 1 1 ,5-

Fig. 12. Female, last thoracic and first abdominal segments. X 11,5.

Fig. 13. Female, rostrum. X 71.

Fig. 14. Female, antennule. x 10.

Fig. 15. Female, antenna. X 10.

Fig. 16. Female, mandible and palp. X 48.

Fig. 17. Female, maxilla, part of one of the hairs. X 400.

Fig. 18. Female, second maxilliped. X 28.

Fig. 19. Female, fifth foot. X 48.

Siboga-Expeditie XXIX a. A. Scott. Copepoda.

XLII.

AntWlU Scotf

PLATE XLIII.

Figs. i — 10. Augaptilus validus nov. sp.

Fig. I. Female, dorsal view. x 13, 5-

Fig. 2. Female, head, lateral view. x I3>5-

Fig. 3. Female, last thoracic, and first abdominal segments. X 13,5.

Fig. 4. Female, rostrum, x 24.

Fig. 5. Female, antennule. x 15-

Fig. 6. Female, mandible. x 71.

Fig. 7. Male, abdomen, dorsal view. x 3°-

Fis. 8. Male, rostrum, x 24.

Fig. 9. Male, antennule, left side. x 15-

Fig. 10. Male, fifth feet. X 48.

Figs. u—.!^. Paraugaptilus similis nov. sp.

Fig. 11. Female, dorsal view. X 36.

Fig. 12. Female, head, lateral view. x 36-

Fig. 13. Female, last thoracic and first abdominal segments. X 36-

Fig. 14. Female, antennule. X 36.

Fig. 15. Female, antenna. X 71.

Fig. 16. Female, fifth feet. x 96-

Fig. 17. Male, abdomen, dorsal view. X 48.

Fig. 18. Male, antennule, left side. X 36.

Fig. 19. Male, fifth feet. X 96.

Siboga-Expeditie XXiX a. A. Scott. Copepoda.

XLIII.

_W»o *<*; a^

PLATE XLIV.

Figs. i — 3. Ckiridius ? obtusifrons G. O. Sars.

Fig. 1. Female, dbrsal view. x 36.

Fig. 2. Female, head, lateral view. x 36.

Fig. 3. Female, last thoracic and first abdominal segments, left side. X 36.

Figs. 4 — 7. Arietellus aculeatus (T. Scott).

Fig. 4. Female, dorsal .view. X 21,6.

Fig. 5. Female, head, lateral view. X 79.

Fig. 6. Female, last thoracic and first abdominal segments, left side. X 53.

Fig. 7. Female, fifth pair of feet. X 144.

Figs. 8 — 13. Arietellus setosus Giesbrecht.

Fig. 8. Male, dorsal view. x 22.

Fig. 9. Male, head, lateral view. x 106.

Fig. 10. Male, last thoracic and first abdominal segments, left side. x 53-

Fig. II. Male, fifth pair of feet. x 72.

Fig. 12. Female, dorsal view, after ESTERLY. x 9-

Fig. 13. Female, fifth foot, after ESTERLY. X 83.

Figs. 14 — 18. Arietellus simplex G. O. Sars.

Fig. 14. Male, dorsal view. X 16.

Fig. 15. Male, head, lateral view. x 79.

Fig. 16. Male, last thoracic and first abdominal segments, left side. X 32.

Fig. 17. Male, fifth feet. X 72.

Fig. 18. Female, fifth foot, after ESTERLY. X 70.

Sibos;a-Expeaitie XXIX a. A. Scott. Copepoda.

XLIV.

7N

7.

\

9.

C\ 8.

10.

3.

-Vr

\

12.

_ /

' PI H

,A«\iireo S-ortT, d*l.

/

\

16.

15.

A

14

/^ i

>«/

Fig.

i.

Fig.

2.

Fig.

3-

Fig.

4-

Fig.

5-

Fig.

6.

Fig.

7-

Fig.

8.

Fig.

9-

Fig
Fig
Fig
Fig
Fig
Fig
Fig
Fig
Fig

PLATE XLV.

Figs. i — 9. P/iyllopns bidentatus Brady.

Female, dorsal view. X 36.
Female, head, lateral view. x 36.

Female, last thoracic and first abdominal segments, left side. x 36.
Female, last thoracic and first abdominal segments, right side. X 36.
Female, antennule. x 48.
Female, fifth feet. x 143.
Male, abdomen, dorsal view. X 48.
Male, antennule, left side. X 48.
9. Male, fifth feet. x 71.

Figs. 10 — 18. Pliyllopus itnpar Farran.

10. Female, dorsal view. x 36.

11. Female, head, lateral view. x 36.

12. Female, last thoracic and first abdominal segments, left side. x 36.

13. Female, last thoracic and first abdominal segments, right side. X 36.

14. Female, antennule. X 48.

15. Female, fifth feet. X 143.

16. Male, abdomen, dorsal view. X 48.

17. Male, antennule, left side. X 48.

18. Male, fifth feet. X 71.

Siboga-Expeditie XXIX a. A. Scott. Copepoda.

XLV.

,Ai«l»«0 Scolt.del

Fig.

i.

Fig.

2.

Fig.

3-

Fig.

4-

Fig.

5-

Fig.

6.

PLATE XL VI.

Figs. i — 6. Phyllopus giesbrechti nov. sp.

I. Female, dorsal view. X 36.

Female, head, lateral view. X 36.

Female, last thoracic and first abdominal segments, left side. X 36.

Female, last thoracic and first abdominal segments, right side. X 36.

Female, antennule. x 48.

6. Female, fifth feet. x 200.

Figs. 7 — 14. Phyllopus lielgae Farran.

Fig. 7. Female, dorsal view. x 36.

Fig. 8. Female, head, lateral view. x 36.

Fig. 9. Female, last thoracic and first abdominal segments, left side. X 36.

Fig. 10. Female, antennule. x 71.

Fig. n. Female, fifth feet. X 273.

Fig. 12. Male, abdomen, dorsal view. x 48.

Fig. 13. Male, antennule, left side. X 71.

Fig. 14. Male, fifth feet. X 95.

Siboga-Expeditie XXIX a. A. Scott. Copepoda.

XLVI.

And.tti> Scott c\el

[ui LIBR<

Fig.

i.

Fig.

2.

Fig.

3-

Fig.

4-

Fig.

5-

Fig.

6.

Fig.

7-

Fig.

8.

Fig.

9-

PLATE XL VIL

Figs. i- — g. Candacia bradyi A. Scott.

Male, dorsal view. x 45-

Male, last thoracic and first abdominal segments, right side. x 45.

Male, antennule, left side. X 71.

Male, antennule, right side. x 71.

Male, antennule, right side, hinge joints. X 273.

Male, first maxilliped. x 71.

Male, third foot, terminal spine on last joint of exopodite. x 164.

Male, fifth feet. X 143.

Male, fifth foot, terminal joints of left side, edge view. X 143.

Figs. 10 — 20. Candacia discaudata nov. sp.

Fig. 10. Female, dorsal view. x 45.

Fig. 11. Female, last thoracic and first abdominal segments. X 45.

Fig. 12. Female, antennule. x 71.

Fig. 13. Female, first maxilliped. x 71.

Fig. 14. Female, third foot, terminal spine on last joint of exopodite. x 164.

Fig. 15. Female, fifth feet. x 143.

Fig. 16. Female, fifth foot, apex of last joint, x 410.

Fig. 17. Male, last thoracic and first abdominal segments, right side. Y 45.

Fig. 18. Male, abdomen, dorsal view. x 71.

Fig. 19. Male, antennule, right side. x 71.

Fig. 20. Male, fifth feet. x 143.

Siboga-Expeditie XXIX a. A. Scott. Copepoda.

XLVII.

JWXYG. W S (JD H\ fa)..

PLATE XLVIII.

Figs. i — 5. Calanopia ellipüca (Dana).

Fig. 1. Female, dorsal view. x 60.

Fig. 2. Female, last thoracic and first abdominal segments. X 60.

Fig. 3. Female, fifth feet. X 250.

Fig. 4. Male, abdomen, dorsal view. X 96.

Fig. 5. Male, fifth feet. X 250.

Figs. 6 — 10. Calanopia minor A. Scott.

Fig. 6. Female, dorsal view. x 60.

Fig. 7. Female, last thoracic and first abdominal segments. X 60.

Fig. 8. Female, fifth feet. X 273.

Fig. 9. Male, abdomen, dorsal view. X 143.

Fig. 10. Male, fifth feet. X 273.

*&•

Figs. 11 — 15. Calanopia americana Dahl.

Fig. U. Female, dorsal view. x 60.

*&■

Fig. 12. Female, last thoracic and first abdominal segments. x 60.

Fig. 13. Female, fifth feet. < 273.

Fig. 14. Male, abdomen, dorsal view. X 143.

Fig. 15. Male, fifth feet. x 273.

pjg. j6 — 20. Calanopia aurivillii Cleve.

Fig. 16. Female, dorsal view. X 60.

Fi<*. 17. Female, last thoracic and first abdominal segments. X 60.

Fig. 18. Female, fifth feet. X 273.

Fig. 19. Male, abdomen, dorsal view. X 143.

Fig. 20. Male, fifth feet. X 273.

Siboeja-Expeditie XXIX a. A. Scott. Copepoda.

XLVIII.

12

-AnArt*-> Stort, dei

PLATE XLIX.

FjgS. i — 8. Calanopïa thompsoni nov. sp.

Fig. I. Female, dorsal view. X 45,5.

Fig. 2. Female, last thoracic and first abdominal segments. X45>5-

Fig. 3. Female, rostrum. X 273.

Fig. 4. Female, antennule. X 57-

Fig. 5. Female, fifth feet. x 250.

Fig. 6. Male, abdomen, dorsal view. X 71.

Fig. 7. Male, antennule, right side. X 57.

Fig. 8. Male, fifth feet. X 250.

FjgS. g — 16, Calanopia herdmani nov. sp.

Fig. 9. Female, dorsal view. x 61,5.

Fig. 10. Female, last thoracic and first abdominal segments. x 61,5.

Fig. 11. Female, rostrum. X 54-6-

Fig. 12. Female, antennule. X 96.

Fig. 13. Female, fifth feet. X 250.

Fig. 14. Male, abdomen, dorsal view. x H2-

Fig. 15. Male, antennule, right side. x 96-

Fig. 16. Male, fifth feet. X 250.

Siboga-Expeditie XXIX a. A. Scott. Copepoda.

XLIX.

!4

A\Aïeu: ^;oft,it\

PLATE L.

Figs. i — 8. Labidocera bataviae nov. sp.

Fig. i. Female, dorsal view. x 47-

Fig. 2. Female, rostrum. X 273.

Fier. 3. Female, antennule. X 48.

Fig. 4. Female, first foot, endopodite. X 273.

Fig. 5. Female, fifth feet. x 144.

Fig. 6. Male, abdomen, dorsal view. x 144-

Fig. 7. Male, antennule, nght side. X 48.

Fig. 8. Male, fifth feet. X 144.

Figs. 9 — 16. Labidocera madurae nov. sp.

Fig. 9. Female, dorsal view. X 47.

Fig. 10. Female, rostrum. X 273.

Fig. 11. Female, antennule. X 48.

Fig. 12. Female, first foot, endopodite. X 273.

Fig. 13. Female, fifth feet. X 144.

Fig. 14. Male, abdomen, dorsal view. X 144.

Fig. 15. Male, antennule, right side. X 48.

Fig. 16. Male, fifth feet. X 144.

Siboga-Expeditie XXIX a. A. Scott. Copopoda.

,~,iU.tc u &c o»] del .

PLATE LI.

Figs. i — io. Labidocera laevidentata (Brady).

Fig. I. Female, dorsal view. x 60.

Fig. 2. Female, last thoracic segment and abdomen, right side. X 60.

Fig. 3. Female, rostrum. X 450.

Fig. 4. Female, antennule. X 72.

Fig. 5. Female, second foot, endopodite. x 273.

Fig. 6. Female, fifth feet. x 144-

Fig. 7. Male, abdomen, dorsal view. X 96.

Fig. 8. Male, antennule, right side. X 72.

Fig. 9. Male, antennule, right side, hinge joints. X 273.

Fig. 10. Male, fifth feet. X 144-

'tv

Figs. 11 — 15. Pontella alata nov. sp.

Fig. 11. Female, dorsal view. X 31,5.

*s

Fig. 12. Female, rostrum. X 273.

Fig. 13. Female, antennule. X 4S.

Fig. 14. Female, first foot, endopodite. X 273.

Fig. 15. Female, fifth feet. x 48-

Siboga-Expeditie XXIX a. A. Scott. Copepoda.

LI.

OD

U-J

'

PLATE LIL

Figs. i — 12. Pontella denticauda nov. sp.

Female, dorsal view. x 31,5.
Female, rostrum. X 250.
Female, antennule. X 72.
Female, second foot, endopodite. X 273.
Female, fifth feet. x 250.
6. Male, dorsal view. X 31,5.
Male, rostrum. X 250.
Male, antennule, left side. X 72.
Male, antennule, right side. X 72.
Male, first foot, endopodite. X 273.
Male, fifth foot, left side. X 164.
Fig. 12. Male, fifth foot, right side. X 164.

Fig.

1.

Fig.

2.

Fig.

3-

Fig.

4-

Fig.

5-

Fig.

6.

Fig.

7-

Fig.

8.

Fig.

9-

Fig.

10.

Fig.

1 1.

Siboga-Expeditie XXIX a. A. Scott. Copepoda.

Lil.

.Ani"»^ Scott. <Ael .

PLATE LUL

Figs. i — 7. Pontella forficula nov. sp.

Fig. 1. Male, dorsal view. X 31,5.

Fig. 2. Male, rostrum. X 288.

Fig. 3. Male, antennule, left side. X 72.

Fig. 4. Male, antennule, right side. X 72.

Fig. 5. Male, antennule, right side, proximal marginal plate. x 450.

Fig. 6. Male, first foot, endopodite. x 410.

Fig. 7. Male, fifth feet. X 108.

Fig
Fig
Fig
Fig
Fig
Fig
Fig
Fig

Figs. 8 — 15. Pontella cerami nov. sp.

8. Male, dorsal view. X 31,5.

9. Male, rostrum. X 144.

10. Male, antennule, left side. x 7~-

11. Male, antennule, right side. X 48.

12. Male, antennule, right side, proximal marginal plate. x 250.

13. Male, antennule, right side, distal marginal plate. X 250.

14. Male, nrst foot, endopodite. X 273.

15. Male, fifth feet. X 96.

Siboga-Expeditie XXïX a. A. Scott. Copepoda.

LUI.

.AiA»*i3 Sictv, del.

14.

aS^

'S

PLATE LIV.

Figs. i — 10. Pontcllopsis ntacronyx nov. sp.

Fis;, i. Female, dorsal view. ;•' 60.

Fig. 2. Female, rostrum. 273.

Fig. 3. Female, antennule. >; 72.

Fig. 4. Female, second maxilliped. • 250.

Fig. 5. Female, first foot, endopodite. < 546.

Fig. 6. Female, fifth feet. • 144.

Fig. 7. Male, last thoracic segment and abdomen, dorsal view. 60.

Fig. 8. Male, antennule, right side. X 72.

Fig. 9. Male, antennule, right side, hinge joints. 273.

Fig. 10. Male, fifth feet. 144.

Figs. 11 — 14. Pontcllopsis pcxa nov. sp.

Fig. 11. Female, last thoracic segments and abdomen, dorsal view. 60.

Fig. 12. Female, rostrum. X 250.

Fig. 13. Female, antennule. . 72.

Fig. 14. Female, fifth feet. X 144-

Siboga-Expeditie XXIX a. A. Scott. Copepoda.

LIV.

.A»A»iïj StoitjAtl

PLATE LV.

Figs. i — 15. Neopontella typica nov. sp.

Fig. 1. Female, dorsal view. ■ 90.

Fig. 2. Female, last thoracic and first abdominal segments. x 90.

Fig. 3. Female, rostrum. X 410.

Fig. 4. Female, antennule. x 144.

Fig. 5. Female, antenna. 273.

Fig. 6. Female, mandible and palp. 273.

Fig. 7. Female, maxilla. 273.

Fig. 8. Female, first maxilliped. X 164.

Fig. 9. Female, second maxilliped. X 450.

Fig. 10. Female, first foot. ' 273.

Fig. 11. Female, third foot. < 273.

Fig. 12. Female, fifth feet. > 410.

Fig. 13. Male, abdomen, dorsal view. X 144.

Fig. 14. Male, antennule, right side. X 144.

Fig. 15. Male, fifth feet. ■ 328.

Figs. 16 — 18. Tortanus barbatus (Brady).

Fig. 16. Female, dorsal view. X 60.

Fig. 17. Female, antennule. X 90.

Fig. 18. Female, fifth foot. • 273.

Sibosa-Expeditie XXIX a. A. Scott. Copepoda.

LV.

^re^ÊtctfjciJ

PLATE LVI.

Figs. i — 8. Tortanus murrayi nov. sp.

Female, dorsal view. X 36.

Female, head, lateral view. > 36.

Female, antennule. ■ 48.

Female, first foot. X 280.

Female, fifth feet. X 273.

Male, antennule, right side. 72.

Male, fifth feet. X 144.

Male, abdomen, dorsal view. • 72.

Figs. 9 — 13. Tortanus brevipes nov. sp.

Fig. 9. Female, dorsal view. X 45.

Fig. 10. Female, head, lateral view. • 45.

Fig. 11. Female, antennule. X 48.

Fig. 12. Female, first foot. 280.

Fig. 13. Female, fifth feet. X 546-

Fig.

1.

Fig.

2

Fig.

3-

Fig.

4-

Fig.

5-

Fig.

6.

Fig.

7-

Fig.

8.

Siboga-Expeditie XXIX a. A. Scott. Copepoda.

LVI.

AvireulScott.aal

PLATE LVII.

Figs. i — 2. Monstrilla gracilicauda Giesbrecht.

Fig. i. Female, dorsal view. X 31, 5-
Fig. 2. Female, fifth foot. X 144.

FigS. 3 — 4. Monstrilla longicornis, I. C. Thompson.

Fig. 3. Female, dorsal view. > 36,3.
Fig. 4. Female, fifth foot. • 144.

Figs. 5 — 6. Monstrilla orcula, nov. sp.

Fig. 5. Female, dorsal view. X 31, 5-
Fig. 6. Female, fifth foot. X 144-

Figs. 7 — 8. Monstrilla inserta nov. sp.

Fig. 7. Female, dorsal view. 31.5.
Fig. 8. Female, fifth foot. . 144.

Figs. 9 — 10. Monstrilla cymbula nov. sp.

Fig. 9. Female, dorsal view. > 31,5.
Fig. 10. Female, fifth foot. 144.

Siboga-Expeditie XXIX a. A. Scott. Copepoda.

LVII.

A\d»eci SootflcUl.

PLATE LVI1I.

Figs. i — 2. Monstrilla Iielgolandica Claus.

Fig. I. Female, dorsal view. X 60.
Fig. 2. Female, fifth feet. X 144.

Fig. 3 — 4. Monstrilla longipes nov. sp.

Fig. 3. Female, dorsal view. x 60.
Fig. 4. Female, fifth feet. X 250.

Figs. 5 — 6. Monstrilla turgida nov. sp.

Fig. 5. Female, dorsal view. . 60.
Fig. 6. Female, fifth feet. ■ 250.

Figs. 7 — 8. Thaumaleus bullatus nov. sp.

Fig. 7. Male, dorsal view. X 60.
Fig. 8. Male, fifth foot. ■ 450.

Figs. 9 — 10. Thaumaleus gigas nov. sp.

Fig. 9. Female, dorsal view. X 19.
Fig. 10. Female, fifth foot. 144.

Siboga-Expeditie XXIX a. A. Scott. Copepoda.

LVIII.

AïiAno Sto\t, J.»l

PLATE LIX.

Figs. i — 4. Longipedia scotti G. O. Sars.

Fig. 1. Female, lateral view. • 60.

Fig. 2. Female, second foot, exopodite incomplete. ■ 144.

Fig. 3. Female, fifth foot. • 273.

Fig. 4. Female, anal segment and furca. 273.

Fig. 5 — 8. Longipedia coronata Claus.

Fig. 5. Female, lateral view. X 90.

Fig. 6. Female, second foot, exopodite incomplete. X 250.

Fig. 7. Female, fifth foot. 410.

Fig. 8. Female, anal segment and furca. ■ 450.

Figs. 9 — 12. Longipedia weberi nov. sp.

Fig. 9. Female, lateral view. X 90.

Fig. 10. Female, second foot, exopodite incomplete. • 250.

Fig. 11. Female, fifth foot. • 410.

Fig. 12. Female, anal segment and furca. • 450.

Siboga-Expeclitie XXIX a. A. Scott. Copepoda.

LIX.

»<*lreuj Stolt, At}

Fig.

i.

Fig.

2.

Fig.

3-

Fig.

4-

Fig.

5

Fig.

6,

Fig.

7

PLATE LX.

Fig. i — 7. Ameira sibogae nov. sp.

Female, lateral view. X 181.

Female, antennule. 410.

Female, antenna. 820.

Female, mandible and palp. 820.

Female, first foot. ■ 820.

Female, fifth foot. X 820.

Female, anal segment and furca. < 820.

Fig. 8 — 16. Cletodes latipes nov. sp.

Fig. 8. Female, lateral view. X 181.

Fig. 9. Female, antennule. X 820.

Fig. 10. Female, antenna. • 820.

Fig. 11. Female, mandible palp. • 820.

Fig. 12. Female, second maxilliped. X 820.

Fig. 13. Female, first foot. X 450.

Fig. 14. Female, fourth foot. x 45°-

Fig. 15. Female, fifth foot. ■ 820.

Fig. 16. Female, anal segment and furca. 273.

pjg. ij — 25. Phyllopodopsyllus longicaudatus nov. sp.

Fig. 17. Male, lateral view. x 181.

Fig. 18. Male, antennule. ■ 410.

Fig. 19. Male, antenna. • 410.

Fig. 20. Male, second maxilliped. • 410.

Fig. 21. Male, first foot. 410.

Fig. 22. Male, third foot. X 410.

Fig. 23. Male, fourth foot. 410.

Fig. 24. Male, fifth foot. • 410.

Fig. 25. Male, anal segment and furca. 144.

Siboga-Expeditie XXIX a. A. Scott. Copepoda.

LX.

-AtvAv*^ Sc»tt;ael

PLATE LXI.

Figs. i — 8. Harpacticus cristatus nov. sp.

Fig. i. Female, lateral view. X 181.

Fig. 2. Female, cephalic segment, dorsal view. X 181.

Fig. 3. Female, antennule. X 410.

Fig. 4. Female, antenna. X 410.

Fig. 5. Female, second maxilliped. X 4to-

Fig. 6. Female, first foot. • 410.

Fig. 7. Female, fifth foot. ■ 410.

Fig. 8. Female, anal segment and furca. x 4IQ-

FigS. g — i^h. Harpacticus clausi nov. sp.

Fig. 9. Female, lateral view. X 120.

Fig. 10. Female, antennule. x 4IG-

Fig. II. Female, antenna, v 410.

Fig. 12. Female, second maxilliped. X 4IG-

Fig. 13. Female, first foot. ■ 410.

Fig. 14. Female, fifth foot. < 410.

Fig. 14A. Female, anal segment and furca. ■ 410.

Figs. 15 — 21. Harpacticus glaber Brady.

Fig. 15. Female, lateral view. X 181.

Fig. 16. Female, antennule. 410.

Fig. 17. Female, antenna, exopodite only. ■ 410.

Fig. 18. Female, second maxilliped. X 410.

Fig. 19. Female, first foot. • 373.

Fig. 20. Female, fifth foot. • 410.

Fig. 21. Female, anal segment and furca. X 4ia

Siboga-Expeditie XXIX a. A. Scott. Copepoda.

LXI.

AniTev> Stott.iitl

PLATE LXIL

Figs. i — 5. Phyllothalestris mysis (Claus).

Fig. 1. Female, lateral view. X 94-

Fig. 2. Female, antennule. X 144-

Fig. 3. Female, second maxilliped. X 144.

Fig. 4. Female, first foot. < 144.

Fig. 5. Female, fifth foot. > 72.

Figs. 6 — n. Rliynclwtlialestris similis nov. sp.

Fig. 6. Female, lateral view. • 60.

Fig. 7. Female, antennule. X 273.

Fig. 8. Female, second maxilliped. ■ 273.

Fig. 9. Female, first foot. ■ 144.

Fig. 10. Female, fifth foot. ■' 144.

Fig. 11. Female, anal segment and furca. X 164.

Figs. 12 — 20. Rhynchothalestris rufocincta (Norman).

Fig. 12. Female, lateral view. X 95.

Fig. 13. Female, antennule. 273.

Fig. 14. Female, second maxilliped. X 410.

Fig. 15. Female, first foot. ■ 273.

Fig. 15A. Female, fifth foot. X 273.

Fig. 16. Female, anal segment and furca. X 164.

Fig. 17. Male, antennule. ■ 273.

Fig. 18. Male, second foot, endopodite only. X 273.

Fig. 19. Male, third foot, end joint of endopodite only. X 410-

Fig. 20. Male, fifth foot. X 273.

Siboga-Expeditie XXIX a. A. Scott. Copepoda.

LXII.

PLATE LXIII.

Figs. i — 7. Pseudothalestris sar si nov. sp.

Fig. 1. Female, lateral view. X 120.

Fig. 2. Female, antennule. < 410.

Fig. 3. Female, antenna, exopodite only. X 410.

Fig. 4. Female, second maxilliped. X 410.

Fig. 5. Female, first foot. X 273.

Fig. 6. Female, fifth foot. ■ 410.

Fig. 7. Female, anal segment and furca. X 410.

Figs. 8 — 14. Eudactylopus latipes (T. Scott).

Fig. 8. Female, lateral view. ;< 60.

Fig. 9. Female, antennule. X 410.

Fig. 10. Female, 'antenna, exopodite only- 4l°-

Fig. 11. Female, second maxilliped. X 410.

Fig. 12. Female, first foot. • 200.

Fig. 13. Female, fifth foot. x 72.

Fig. 14. Female, anal segment and furca. X 144-

Figs. 1 5 — 24. Tydemanella typica nov. sp.

Fig. 15. Female, lateral view. X 60.

Fig. 16. Female, antennule. ■ 205.

Fig. 17. Female, antenna, exopodite and part of endopodite. X 410.

Fig. 18. Female, mandible. X 410.

Fig. 19. Female, mandible palp. 410.

Fig. 20. Female, maxilla. X 273.

Fig. 21. Female, second maxilliped. X 205.

Fig. 22. Female, first foot. ■ 273.

Fig. 23. Female, fifth foot. • 410.

Fig. 24. Female, anal segment and furca. 273.

Siboga-Expeditie XXIX a. A. Scott. Copepoda.

LXIII.

^tniTtjbtitt'.öel.

PLATE LXIV.

Figs. i — 6. Canuella atrticaudata (Thompson and Scott).

Fig. i. Female, lateral view. < 90.

Fig. 2. Female, first foot. • 205.

Fig. 3. Female, second foot. 205.

Fig. 4. Female, fourth foot. < 205.

Fig. 5. Female, fifth foot. • 546.

Fig. 6. Female, anal segment and furca. • 144.

Figs. 7 — 11. Peltidïum falcatum nov. sp.

Fig. 7. Female, dorsal view. ■ 90. A. furca. 410.

Fig. 8. Female, antennule. > 273.

Fig. 9. Female, second maxilliped. X 273.

Fig. 10. Female, first foot. 164.

Fig. 11. Female, fifth foot. X 273.

Figs. 12 — 19. Eupeltidiiim glabrum nov. sp.

Fig. 12. Female, dorsal view. ... 60. A. furca. • 410.

Fig. 13. Female, antennule. ■ 273.

Fig. 14. Female, antenna, y 205.

Fig. 15. Female, mandible and palp. X 273.

Fig. 16. Female, first maxilliped. X 205.

Fig. 17. Female, second maxilliped. X 144-

Fig. 18. Female, first foot. < 205.

Fig. 19. Female, fifth foot. ■ 273.

Siboga-Expeditie XXIX a. A. Scott. Copepoda.

LXIV.

PLATE LXV.

Figs. i — 5. Parapcltuiium johnstoni nov. sp.

Female, dorsal view. 60. A. furcaX3iO.
Female, antennule. • 205.
Female, second maxilliped. v 144.
Female, first foot. X 164.
Female, fifth foot. • 164.

6 — 10. Peltidium intermedium nov. sp.

Female, dorsal view. ■ 90. A. furca. 410.
Female, antennule. 273.
Female, second maxilliped. > 205.
Female, first foot. X 164.
Female, fifth foot. X 410.

Figs. 11 — 15. Peltidium exiguum nov. sp.

Fig. 1 1. Female, dorsal view. X 90. A. furca. X 410.

Fig. 12. Female, antennule. X 273.

Fig. 13. Female, second maxilliped. X 205.

Fig. 14. Female, first foot. • 205.

Fig. 15. Female, fifth foot. 410.

Figs. 16 — 20. Peltidium minutum nov. sp.

Fig. 16. Female, dorsal view. X 90. A. furca. X 410.

Fig. 17. Female, antennule. X 273.

Fig. iS. Female, second maxilliped. X 273.

Fig. 19. Female, first foot. X 205.

Fig. 20. Female, fifth foot. X 410.

Fig.

1.

Fig.

2.

Fig.

3-

Fig.

4-

Fig.

5-

F

igs.

Fig.

6.

Fig.

7-

Fig.

8.

Fig.

9-

Fig.

10.

Siboga-Expeditie XXIX a. A. Scott. Copepoda.

LXV.

Anó-it^ScAr jul

PLATE LXVI.

Figs. I — 12. Eupelte oblivia nov. sp.

Fig. I. Female, dorsal view. x 90. A. furca. X 410.

Fig. 2. Female, antennule. X 273.

Fig- 3- Female, antenna. X 273.

Fig. 4. Female, mandible and palp. X 273.

Fig. 5. Female, maxilla. X 273.

Fig. 6. Female, first maxilliped. X 410.

Fig. 7. Female, second maxilliped. X 273.

Fig. 8. Female, first foot. >; 273.

Fig. 9. Female, fourth foot. X 205.

Fig. 10. Female, fifth foot. X 205.

Fig. 11. Male, antennule. X 273.

Fig. 12. Male, fifth foot. X 205.

Figs. 13 — 20. Alteuthella pellucida nov. sp.

Fig. 13. Female, dorsal view. 120. A. furca. X 410.

Fig. 14. Female, antennule. •' 273.

Fig. 15. Female, second maxilliped. >: 273.

Fig. 16. Female, first foot. 273.

Fig. 17. Female, fourth foot. X 205.

Fig. 18. Female, fifth foot. < 273.

Fig. 19. Male, antennule. X 205.

Fig. 20. Male, fifth foot. • 273.

Figs. 21 — 29. Alteuthella spinicauda nov. sp.

Fig. 21. Female, dorsal view. X 120.

Fig. 22. Female, antennule. X 273.

Fig. 23. Female, second maxilliped. x 273.

Fig. 24. Female, first foot. 273.

Fig. 25. Female, fifth foot. v 273.

Fig. 26. Female, anal segment and furca. X 405.

Fig. 27. Male, antennule. X 273.

Fig. 28. Male, fifth foot. X 273.

Fig. 29. Male, anal segment and furca. v 405.

Siboga-Expeditie XXIX a. A. Scott. Copepoda.

LXVI.

^nirtwStott"^.

PLATE LXVII.

Figs. I — 5. Alteuthella pygmaea nov. sp.

Fig. 1. Female, dorsal view. X 181. A. furca. X 410.

Fig. 2. Female, antennule. ■' 273.

Fig. 3. Female, second maxilliped. X 273.

Fig. 4. Female, first foot. > 273.

Fig. 5. Female, fifth. foot. < 273.

Figs. 6 — 17. Lichomolgus anomalus nov. sp.

Fig. 6. Female, dorsal view. x 120. A. furca. • 410.

Fig. 7. Female, antennule. •' 273.

Fig. 8. Female, antenna. X 273.

Fig. 9. Female, mandible A, maxilla B. x 410.

Fig. 10. Female, first maxilliped. X 410.

Fig. n. Female, second maxilliped. X 410.

Fig. 12. Male, second maxilliped. X 273.

Fig. 13. Female, first foot. .-, 273.

Fig. 14. Male, first foot. ■ 273.

Fig. 15. Female, fourth foot. X 273.

Fig. 16. Female, fifth foot. X 205.

Fig. 17. Male, abdomen. X 205.

Figs. 18 — 24. Pseudanthessius weberi nov. sp.

Fig. 18. Female, dorsal view. ■ 90.

Fig. 19. Female, antennule. :< 210.

Fig. 20. Female, antenna. >; 205.

Fig. 21. Female, mandible A, maxilla B. X 410.

Fig. 22. Female, first maxilliped. X 410.

Fig. 23. Female, maxilliped. • 410.

Fig. 24. Female, fourth foot. X 205.

Siboga-Expeditie XXIX a. A. Scott. Copepoda.

LXVII.

AhJ^-t-u ScJfr. cUl-

PLATE LXVIII.

Figs. i — [o. Hermannella concinna nov. sp.

Fig. I. Female, dorsal view. ■ 30.

Fig. 2. Female, antennule. X 96.

Fig. 3. Female, antenna. X 96.

Fig. 4. Female, mandible A, maxilla B. X 205.

Fig. 5. Female, first maxilliped. X 205.

Fig. 6. Female, second maxilliped. X 205.

Fig. 7. Male, second maxilliped. ■ 72.

Fig. 8. Female, fourth foot. :■■' 72.

Fig. 9. Female, fifth loot. < 205.

Fig. 10. Male, abdomen. 48.

Figs. 11 — 20. Lichomolgus gracilipes nov. sp.

Fig. 11. Female, dorsal view. X 60.

Fig. 12. Female, antennule. • 162.

Fig. 13. Female, antenna. X 205.

Fig. 14. Female, mandible A, maxilla B. 273.

Fig. 15. Female, first maxilliped. X 273.

Fig. 16. Female, second maxilliped. X 273.

Fig. 17. Male, second maxilliped. X 160.

Fig. 18. Female, fourth foot. , 144.

Fig. 19. Female, fifth foot. • 410.

Fig. 20. Male, abdomen. < 72.

Figs. 21 — 27. Pseudanthessius pectinatus nov. sp.

Fig. 21. Female, dorsal view. X 60.

Fig. 22. Female, antennule. X 205.

Fig. 23. Female, antenna. :•( 164.

Fig. 24. Female, mandible A, maxilla B. X 273.

Fig. 25. Female, first maxilliped. X 273.

Fig. 26. Female, second maxilliped. ■ 273.

Fig. 27. Female, fifth foot. 273.

Sibosa-Expeditie XXIX a. A. Scott. Copepoda.

LXVIII.

Fig.

i

Fig.

2.

Fig.

3>

Fig.

4>

Fig.

5>

Fig.

6.

Fig.

7

PLATE LXIX.

Figs. I- — y. Pseudantlies-sius parvus nov. sp.

Female, dorsal view. >( 90.
Female, antennule. X 273.
Female, antenna. X 273.
Female, mandible A, maxilla B. X 410.
Female, first maxilliped. X 410.
6. Female, second maxilliped. X 410.
Female, fourth foot. X 410.

Figs. 8 — 14. Pscudanthessius obsciirus nov. sp.

Fig. 8. Female, dorsal view. x 90.

Fig. 9. Female, antennule. 410.

Fig. 10. Female, antenna. < 273.

Fig. 11. Female, mandible. • 410.

Fig. 12. Female, first maxilliped. X 410.

Fig. 13. Female, second maxilliped. X 410.

Fig. 14. Female, fourth foot. x 410.

Figs. 15 — 20. Sappliirina longifiirca nov. sp.

Fig. 15. Female, dorsal view. • 23.

Fig. 16. Female, antennule. X 144-

Fig. 17. Female, antenna. X 72.

Fig. 18. Female, mandible A, maxilla B. X 205.

Fig. 19. Female, first maxilliped. X 144.

Fig. 20. Female, second maxilliped. X 96.

Siboga-Expeditie XXIX a. A. Scott. Copepoda.

LX1X.

Livr. XLIV.

■

• ■ '■ •".■'"• ■■ ■■■---■■■■

i. ■ ■

«»MS§»tiiH§rj ■

, i

RESULTATS DES EXPLORATIONS
ZOOLOGIQUES, BOTANIQUES, OCEANOGRAPHIQUES ET GEOLOGIQUES

KNTRKI'KISKS AUX
CNDE3 NÉERI.ANDAISES OIUFNTALES en 1899 — 1900,

& bord du ÖIBOÖA

SOUS I.E COMMANDF.MENT DE

G. F. TYDEMAN

PUBLIÉS PAR

MAX W K M K R.

Chef de 1'eipédition.

*I

•11

«111

IV.

*l\6is.

V.

*VI.

*VII.

«vin.

*ix.
*x.

•XI.
•XII.

«xin.

«XIV.

•XV.

«XVI.

«XVII.

XVIII.

XIX.

«XX.

*XX1.

XXII.

XXIII.

«XXI Vi.

XX1V2.

«XXV.

«XXVI.

«XXVIto.

XXVII.

«XXVIII.

•XXIX.

«XXX.

«XXXI.

*\\\Uis.

«XXXII.

XXXIII.

«XXXIV.

•XXXV.

«XXXVI.

«XXXVII.

■XXXVIII.

* XXXIX.

«XL.

XLI.

«XLII.

«XLII1.

«XLIV.

«XLV.

«XLVI.

«XLVII.

«XLVIII.

*XLIX'.

•XMX«

*L.

«LI.

«Lil.

«LUI.

«LIV.

LV.

«LVI.

«LVII.

«LVIII.

*LIX.

«LX.

«LXI.

«LXII.

LXIII.

LXIV.

«LXV.

«LX VI.

Introductiou et description de 1'eïpédition, Max Weber.
. Le bateau et sou équipement scientifique, G. F. Tydeman.
Re'sultats hydrographiques, G. F. Tydeman.
Foramiuifera, J. Hofker.
Xenophyophora, F. E. Sc huize.
Kadiolaria, M. Hartmann.
Porifera, G. C. J. Vosmaer et I. Ijima ').
Hydropolypi, A. Billard1).

Stylasterina, S. J. Hickson et MUe H. M. England.
Siphonophora, Miles Lens et van Riemsdijk.
Hydromedusae, O. Maas.
Scyphomedusae, O. Maas.
Ctenophora, M"e F. Moser.

Gorgonidae, Alcyouidae, J. Versluys, S. J. Hickson,
[C. C. Nuttiog et J. A. Thomson ').
Pennatulidae, S. J. Hickson.
Actiniaria, P. Mc Murrich1).

Madreporaria, A. Alcock, C. J. van der Horst et
Autipatharia, A. J. van Pesch. [H. Boschma').

Turbellaria, E. Reisinger.
Cestodes, (J. W. Sp engel f).
Nematomorpha, H. F. Nierstrasz.
Chaetognatha, G. H. Fowler.

Nemertini, (A. A. W. Hubrech t f) et Mme G. Stiasny.
Myzostomidae, R. R. von Stummer.
Polychaeta errantia, R. Horst').
Polychaeta sedentaria, M. Caullery et F. Mesnil.
Gep'hyrea, C. Ph. Sluiter.
Enteropueusta, J. W. Spengel.
Pterobranchia, S. F. H arm er.
I'rachiopoda, J. F. van Bemmelen.
Polyzoa, S. F. Harmer ').
Copepcda, A. Scott1).
Ostracoda, G. W. Muller.
Cirripedia, P. P. C. Hoek.

Rhizocephalen. P. N. van Kampen et H. Boschma.
Isopoda, H. F. Nierstrasz et G. A. Brender a
Amphipoda, Ch. Pérez. [Brandis').

C^prellidae, P. May er.
Stömatopoda, H. J. Hansen.
Cumacea, W. T. L'alman.
Schizopoda, H. J. Pansen.
Serzestidae, H. J. Hansen.

Decapoda, J. G. de Man, J. E. W. Ihle et J.J. Tesch").
Pantopoda, J. C. C. Loman.
Halobatidae, D. Mac Gillavry.
Crinoidea, L. Döderlein et Austin H. Clark.
Echinoidea, J. C. H. de Me ij e re.
HolothurioiSea, C. Ph. Sluiter.
Opbiuroidea, R. Kohier.
Asteroidea, L. Döderlein1).
Solenoga9tres, H. F. Nierstrasz.
Chitonidae, H. F. Nierstrasz.
Prosobranchia, M. M. Schepman.

P.osobranchia parasitica, H. F. Nierstrasz et M.M.
Opisthobranchia, R. Bergh. [Schepman.

Heteropoda, J. J. Tesch.
Pteropoda, J. J Tesch.

Lamellibranchiata, P. Pelseneer et Ph. Dautzenberg ').
Scaphopoda, M'l« M. Boissevain.
Cephalopoda, L J o u b i n.
Tunicata, C. Ph. Sluiter et J. E. W. Ihle.
Pisces, Mal Weber.
Cetacea, Max Weber.
Liste des alïues, Mme A. Weber').
Halimeda, MUe E. S. Barton. (Mme E. S. Gepp).
Corallinaceae, Mme A. Weber et M. Foslie.
Codiaceae, A. et Mme E. S. Gepp.
Dinollagellata. Cocco9phaeridae, J. P. Lotsy.
Diatomaceae, J. P. Lotsy.
Deposita raarina, O. B. Böggild.
Résultats ge'ologiques, A. Wichmann.

Siboga-Expeditie

BY

ANDREW SCOTT

Associate of the Linnean Society Londen,
Honorary Lecturer on Economie Ichthyology, University of Liverpool

PART I

FREE-SWIMMING, LITTORAL and SEMI-PARASITIC

COPEPODA

With 69 plates

Monographe XXIXa of:

UITKOMSTEN OP ZOOLOGISCH,
BOTANISCH, OCEANOGRAPHISCH EN GEOLOGISCH GEBIED

verzameld in Nederlandsch Oost-Indië 1899 — 1900

aan boord H. M. Siboga onder commando van
Luitenant ter zee ie kl. G. F. TYDEMAN

UITGEGEVEN DOOR

Dr. MAX WEBER

Prof. in Amsterdam, Leider der Expeditie

(met medewerking van de Maatschappij ter bevordering van het Natuurkundig
Onderzoek der Nederlandsche Koloniën)

BOEKHANDEL EN DRUKKERIJ

VOORHEEN

E. J. BRILL

LEIDEN

iW.MHiiW.ilMllii! i".:i. .: ■■ ,..,:ii u ;iilu,il;,H.!i: ...

11. I,...'. ... i.iii .

Publié Septembre 1909

* Les numéros avec un astérique out déja paru ; ceux raarqués 1) seulement en partie

Prix:

Souscription Monographies
a I'ouvrage complet séparées

77e Livr. (Monogr. XIV) Sydney J. Hickson. The Pennatulacea of the Siboga Expedition,

with a general survey of the order. With 10 plates, 45 text figures and 1 chart . . . . ƒ10.75 ƒ16.20
78e Livr. (Monogr. XXXIX<$') J. E. W. Ihle. Die Decapoda brachyura der Siboga-Expedition.

II. Oxyslomata, Dorippidae. Mit 39 Figuren im Text „ 1.90 „ 2.90

79e Livr. (Monogr. LXV) O. B. BÖggild. Meeresgrundproben der Siboga-Expedition. Mit

1 Tafel und 1 Karte „ 2.25 „ 3.40

80e Livr. (Monogr. XXIV b) R. Horst. Polychaeta errantia of the Siboga Expedition.

Part II. Aphroditidae and Chrysopetalidae. With 19 plates and 5 textfigures . . . „ 7.75 „ 11.70

8 ie Livr. (Monogr. XLVIrt) L. DÖderlein. Die Asteriden der Siboga-Expedition

I. Die Gattung Astropecten und ihre Stammesgeschichte. Mit 17 Tafeln und 20 Figuren

im Text „ 8.75 „ 13.20

82e Livr. (Monogr. XXXIX c) J. J. Tesch. The Decapoda brachyura of the Siboga Expedition.

I. Hymenosomidae, Retropïumidae,Ocypodidae,Grapsidae and Gecarcinidae. With 6 plates. „ 5. — „ 7.50
83e (Monogr. XLII^) Austin H. Clark. The unstalked Crinoids of the Siboga Expedition.

With 28 plates and 17 textfigures. „ 16. — „ 24. —

84e Livr. (Monogr. XXXIXc1) J. J. Tesch. The Decapoda brachyura of the Siboga Expedition.

II. Goneplacidae and Pinnotheridae. With 12 plates „ 6.75 „ 10.20

85e Livr. (Monogr. XXXIX^2) J. E. W. Ihle. Die Decapoda brachyura der Siboga-Expedition.

III. Oxystomata: Calappidae, Leucosiidae, Raninidae. Mit 71 Figuren im Text. . . . „ 5.60 „ 8.40
86« Livr. (Monogr. XXXVIII) H. J. Hansen. The Sergestidae of the Siboga Expedition. With

5 plates and 14 text figures . . . „ 4.50 „ 6.80

87e Livr. (Monogr. XXXIXa3) J. G. de Man. The Decapoda of the Siboga Expedition.

Part IV. Families Pasiphseidae, Stylodactylidae, Koplophoridae, Nematocarcinidae,
Thalassocaridae, Pandalidae, Psalidopodidae, Gnathophyllidae, Proces-
sidae, Glyphocrangonidae and Crangonidae. With 25 plates . . . . „ 18. — „ 27. —
88e Livr. (Monogr. XLVlb) L. DÖderlein. Die Asteriden der Siboga-Expedition.

II. Die Gattung Luidia und ihre Stammesgeschichte. Mit 3 Tafeln und 5 Figuren im Text. „ 5. — , 7.50
89e Livr. (Monogr. LIX£) A.Weber-van Bosse. Liste des Algues du Siboga.

II. Rhodophyceae. Première Partie. Protoflorideae, Nemalionales, Cryptonemiales.

Avec 3 planches et 57 figures dans Ie texte . „ 6.75 , 8.50

90e Livr. (Monogr. XVIb) C. J. van der Horst. The Madreporaria of the Siboga-Expedition.

Part II. Madreporaria Fungida. With 6 plates „ 4. — „ 5. —

9lt Livr. (Monogr. XLVI') L. DÖderlein. Die Asteriden der Siboga-Expedition.

I. Porcellanasteridae , Astropectinidae , Benthopectinidae. Mit 13 Tafeln und

7 Figuren im Text . . n 10.80 n 13-50

92e Livr. (Monogr. XVIc) C. J. van der Horst. The Madreporaria of the Siboga Expedition.

Part III. Eupsammidae. With 2 plates and 9 textfigures n 2.50 „ 3.75

93e Livr. (Monogr. XXXIX a*) J. G. de Man. The Decapoda of the Siboga Expedition.

Part. V. On a collection of Macrurous Decapod Crustacea of the Siboga Expedition,

chiefly Penaeidae and Alphaeidae. With 4 plates „ 7. — „ 8.75

94e Livr. (Monogr. LlXc) A. Weber-van Bosse. Liste des Algues du Siboga.

III. Rhodophyceae. Seconde Partie. Ceramiales. Avec 2 planches et 33 figures

dans Ie texte „ 10. — „ 12.50

95e Livr. (Monogr. XXXII/) H. F. Nierstrasz und G. A. Brender a Brandis. Die Iso-
poden der Siboga-Expedition.

II. Isopoda genuina. I. Epicaridea. Mit 6 Tafeln „ 9. — „ 11.25

96e Livr. (Monogr. XVId) H. Boschma. The Madreporaria of the Siboga Expedition.

Part IV. Fungia patella. With 2 plates „ 3.50 „ 4.50

97e Livr. (Monogr. LVIII) Max Weber. Die Cetaceen der Siboga-Expedition. Mit 3 Tafeln

und 5 Figuren im Text * „ 7.75 „ 9.75

98e Livr. (Monogr. XLVI1) L. DÖderlein. Die Asteriden der Siboga-Expedition.

II. Pentagonasteridae. Mit 6 Tafeln „ 6.40 „ 8. —

99e Livr. (Monogr. XXIV1 f) R. Horst. Polychaeta errantia of the Siboga Expedition

Part III. Nereidae and Hesionidae. With 7 plates . .'..", 9.60 „ 12. —

100e Livr. (Monogr. LXVI) A. Wichmann. Geologische Ergebnisse der Siboga-Expedition.

Mit 33 Figuren im Text „ 14.50 n 18. —

101e Livr. (Monogr. XXXlbis) F. N. van Kampen und H. Boschma. Die Rhizocephalen

der Siboga-Expedition. Mit 3 Tafeln und 45 Figuren im Text „ 8.40 „ 10.50

102e Livr. (Monogr. XXXIX a5) J. G. de Man. The Decapoda of the Siboga Expedition.

Part VI. The Axiidae collected by the Siboga Expedition „ 16. — „ 20. —

103e Livr. (Monogr. Vllb) A. Billard. Les Hydroïdes de 1'Expédition du Siboga.

II. Synthecidae et Sertularidae. Avec 3 planches et 58 figures dans Ie texte . . „ 12. — „ 15. —
104e Livr. (Monogr. XXXV) H. J. Hansen. The Stomatopoda of the Siboga Expedition.

With 2 plates „ 4.20 , 5.25

105e Livr. (Monogr. XXVIII3) Sir Sidney F. Harmer. The Polyzoa of the Siboga Expedition.

Part IL Cheilostomata Anasca. With 22 plates and 23 textfigures B 26. — „ 32.50

Voor de uitgave van de resultaten der Siboga-Expeditie hebben bijdragen beschikbaar gesteld ■

De Maatschappij ter bevordering- van het Natuurkundig Onderzoek der Nederlandsche Koloniën.

Het Ministerie van Koloniën. — Het Ministerie van Binnenlandsche Zaken.

Het Koninklijk Zoologisch Genootschap „Natura Artis Magistra" te Amsterdam.

De „Oostersche Handel en Reederij" te Amsterdam.

De Heer B. H. de Waal, Oud-Consul-Generaal der Nederlanden te Kaapstad.

M. B. te Amsterdam. — The Elizabeth Thompson Science Fund. — Dr. J. G. de M. te Ierseke.

1

i

J

I

I

1 lil