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AN ACCOUNT

OF THE

CRUSTACEA

OF

NORWAY

AN ACCOUNT

Ql

0. 3

2-ob I .

CRUSTACEA

OF

NORWAY

WITH SHORT DESCRIPTIONS AND FIGURES OF ALL THE SPECIES

BY

G. O. SARS,

PROFESSOR AT THE UNIVERSITY OF CHRISTIANIA

VOL. III.

CUMACEA

BERGEN

PUBLISHED BY THE BERGEN MUSEUM

SOLD BY

ALB. CAMMERMEYERS FORLAG, CHRISTIANIA
1900

BERGEN. JOHN GRIEG

PREFACE.

This is the 3rd in succession of the long series of Volumes which will
be needed to elucidate the rich carcinological fauna of Norway. It treats of a
group of Crustacea, which until recently has continued to be very imperfectly
known, and of which, therefore, as yet, scarcely any text-book exists. Indeed, I
have myself been fortunate enough to contribute my quota to a closer know¬
ledge of these interesting Crustacea, having been enabled to institute rather
extensive studies both of indigenous and foreign forms.

In the preparation of this Volume, I have had at hand abundance of
material, which has been collected almost entirely by myself at various times
during my numerous voyages along our coasts. Indeed, I think that there are
now very few additions to be made to the Cumacean fauna of Norway, which'
at present comprises in all no less than 48 species, belonging to 17 different
genera, a number not as yet nearly attained by that of any other country. Of
these species more than half the number (28) have been first established by the
present author from Norwegian specimens, and have long been regarded as
exclusively peculiar to the Norwegian fauna. Of late years, however, some of
them have also been found in other places, in some cases far from Norway —
for instance in the Mediterranean — and I think that on a closer investigation all
of them will prove to have a much wider distribution than was at first expected.
The present Volume will therefore, I hope, be useful not only for the determi¬
nation of Norwegian species, but also for the future investigation of the Cuma¬
cean fauna of other countries.

The plan upon which the present Volume has been carried out, is
essentially the same as that followed in the 2 preceding Volumes, with one excep¬
tion, namely, that besides the strictly systematic part, a more detailed account
of the internal anatomy and development has also been given at the close of the
Volume, an addition which may not be out of place, considering the comparatively
recent date of our knowledge regarding this peculiar group of Crustacea.

VI

The plates, as in the preceding Volumes, have been prepared by the aid
of the autographic process, and great care has been applied to make them
as instructive as possible. I especially have been anxious to give good and
easily recognizable habitus-figures, not only of selected female specimens of each
species, but also of the respective adult males, which, as is well known, in most
cases are very rarely met with, and, owing to their very conspicuous difference
from the females, have given occasion to much confusion in the systematization.

As the literature referring to the Cumacea is far less extensive than
that of other Crustacean groups, it lias been possible for me to give a rather
complete list of publications arranged alphabetically according to the names of
the authors. In the greater number of these publications, however, only slight
notes on Cumacea are found. The more essential works are marked with
an asterisk.

Finally, I beg once more to offer my best thanks to the direction of the
Bergen Museum, by whose assistance I have been enabled thus far to prosecute
this great work, and which will, I hope, still assist me in continuing the work
with several successive Volumes.

G. 0. Sews.

BIBLIOGRAPHY.

Agassiz, L.
*Bate, Spence.

Bell, Th,

Beneden, P. v.
Boas, J. E.

Bonnier, J.

*

Czerniavsky, V.
*Dohrn, A.

Ehrenbaum, E.

Fischer, P.

*Goodsir, H.
Hansen, H. J.

Proceed. Acad. Nat. Sciences Philadelphia. 1852.

On the British Diastylidse. Ann. & Mag Nat. Hist. Yol. NYII.
Ann. & Mag. Nat. Hist. Yol. XVIII, XIX.

Last of the Arctic Voyages. Yol. II. Crustacea. 1855.
History of British stalk-eyed Crustacea. Appendix.

Recherches sur la faune littorale de Belgique. Crustaces. 1861.
Studien tiber die Verwandtschaftsbeziehungen der Malacostraken.
1882.

Recherches fauniques. Bull sci. France et Belgique. T. XIX.
1888.

Residtates scientifiques de la campagne du “Caudan” dans la
golfe de Gascogne. Edriophthalmes. 1S96.

Materialia ad zoographiam Ponticam comparatam. 1868.
Untersuchungen iiber Bau und Entwickelung der Arthropoden.
Heft 1. 1870.

Beitrage zur Meeresfauna von Helgoland VIII. Wissenschaft.
Meeresuntersuch. Bd. II.

Catalogue des Crustaces Podophthalmaires et Cirripedes du departe-
ment de la Gironde. 1872.

The Edinb. New Phil. Journal. 1843.

Oversigt over de paa Dijmphna Toget indsamlede Krehsdyr.
1886.

Malacostraca marina Grcenlandise occidentalis. Vid. Medd. nat.
Foren. Kjobenhavn. 1887.

Crustacea, Pycnogonida & Tunicata der Iv. Iv. 0sterr.-Ung.
Nordpol-Exped. 1875,

Heller, C.

YITI

Hoek P. r.

*Er0yer, H.

Lepechin.
*Lilljeborg, TJ

Meinert, F.

Metzger, A.
Miers, E.
Milne-Edwar
Moebius, K.
Montagu. G.
Norman, A.

Ohlin, A.
*Sars, G. 0.

C. Die Crustaceen gesammelt wahrend der Fahrten der “Willem
Barents”. Nied. Arch. f. Zool. 1882.

Crustacea Neerlandica II.

Fire nye Arter af Skegten Cuma. Naturh. Tidsskr. 1 R. Bd.
III. 1841.

Carcinologiske Bidrag. Nat. Tidsskr. Ny R. Bd. II. 184G.
Crustacea in Gaimard’s Voyage en Scandinavie.

Acta Petropol. Vol. I. 1778.

7. Hafs-Crustaceer vid Kullaherg. Ofvers. Vet. Acad. Forhandl.
1856.

Crustacea Isopoda, Amphipoda et Decapoda Daniae. Nat. Tidsskr.
3 B. Bd. II. 1877.

Do. Supplement 1880.

Crustacea malacostraca. (“Haucli” Exped.).

Nordseefahrt der Pommerania. Crustacea. 1875.

Proceed. Zool. Soc. London 1879.

Is, H. Annales d. Sci. nat. 1828. 1852, 1858.

Die wirbellosen Thieve der Ostsee. 1873.

Transact. Linn. Society. Vol. IX. 1804.

M. Transact, of the Tyneside Nat. Club. Vol. 5. 1862.

Beport of the Dredging Expedition to the Dogger Bank and the
Coast of Northumberland. Crustacea. 1862.

Beport of the Committee for exploring the coasts of the Hebrides,
Part II. Bep. Brit. Ass. Adv. of Sci. 1866.

Last Beport on dredging among the Shetland Isles. Rep. Brit.
Ass. Adv. of Sci. 1868.

Crustacea Cumacea of the Lightning, Porcupine and Valorous
Expeditions. Ann. Mag. Nat. Hist. 1879.

Ann. Bep. of the Fishery Board for Scotland. Appendix.

A Month on the Trondhjem Fjord. Ann. Mag. Nat. Hist. 1894.
Bidrag til kannedomen om Malacostrakfaunan i Baffins Bay och
Smith Sound. 1895.

Om den aberrante Krebsdyrgruppe Cumacea og dens nordiske
Arter. Christiania Vid. Selsk. Forh. 1864.

Zool. Reise ved Ivysterne af Christianias og Christiansands
Stifter. Nyt Mag. f. Naturvid. 1866.

Undersogelser over Christianiafjordens Dybvandsfauna. Nyt Mag.
1'. Naturvid. 1869.

IX

Bars, G. 0. Nye Dybvandscrustaceer fra Lofoten. Chr. V i <1 . Selsk. Forh. 1869.
— Unders0gelser over Hardangerfjordens Fauna 1. Chr. Vid. Selsk.

Forh. 1871.

* — Beskrivelse af de paa Fregatten Josephine’s Expedition fundne

Cumaceer. Svenska Vet. Acad. Hand]. Bd. 9. 1S73.

Beskrivelse af syv nye Cumaceer fra Vestindien og det sydat-
lantiske Ocean. Vet. Acad. Handl. Bd. 11. 1874.

Om Cumaceer fra de store Dybder i Nordishavet. Vet. Acad.
Handl. 1875.

Middelhavets Cumaceer. Arch. f. Mathem. & Naturvid. 1879.
Oversigt af Norges Crustaceer I. Chr. Vid. Selsk. Forh. 1882.
Den Norske Nordhavs-Expedition 1876 — 78. XIV. Zoologi.
Crustacea.

Report on the Cumacea collected by H. M. S. Challenger during
the years 1873 — 76. 1887.

Crustacea caspia. Part II. Cumacea. Bulletin de l’Acad.
Imp. des Sciences de St. Petersbourg. 1894.

On some additional Crustacea from the Caspian Sea. Annuaire
du Mus. Zool. de l’Acad. Imp. des Sciences de St. Peters¬
bourg. 1897.

Sars, M. Oversigt af de i den norsk arktiske Region forekommende

Krebsdyr. Chr. Vid. Selsk. Forh. 1858.

Say Th. Transact, of the Philadelphia Philos. Society. 1818.

Schneider, J. Sp. Undersegelser af Dyrelivet i de arktiske Fjorde. Tromso Mus.

Aarsh. 14. 1893.

Scott, Th. Report on the marine and fresh water Crustacea from Franz

Josef Land. Linn. Soc. Journ. Zoology. Vol. XXVII.

— Notes on recent gatherings of Micro-Crustacea from the Clyde

and the Moray Firth. Rep. of the Fishery Board of Scotland.

Smith, Sidney, I. Proceed. United States National Museum. 1879.

Soivinslcy, B. Les Crustaces de la Mer d’Azow (in Russian). 1893.

*Stebbing, T. B. R. A History of Crustacea (International scientific series). 1893.

Stuxberg, A. Evertebratfaunan i Sibiriens Ishaf. Vega Expeditionens Iagt-
tagelser. Bd. 1. 1882.

Thomson, Geo. M. On the occurrence of 2 species of Cumacea in New Zealand.
Linn. Soc. Journ. Zool. Vol. XXIV.

Verrill, A. E. Preliminary Check-List of the Marine Invertebrata of the Atlantic
Coast of North America. 1879.

X

Waller, A.

0. On some new species of Edriophthalma from the Irish Sea.
Linn. Soc. Journ. XXVI.

Podoplithalmia and Cumacea of Liverpool Bay. Trans. Biol.
Soc. Liverpool. Vol. VI.

Report on the Crustacea of Liverpool Bay. Proceed. Biol.
Soc. Liverpool. Vol. 11. 1888.

Third Report on the Higher Crustacea of the L. M. B. C.
District. 1889.

Report on the Schizopoda, Cumacea, Isopoda and Amphipoda
of the Channel Islands. Journ. Mar. Zool. Vol. 11. 1896.

Malacostraca from the West coast of Ireland. Transact. Liver¬
pool Biol. Soc. Vol. XII. 1S98.

INTRODUCTION.

1 he Cumacea form a sharply-defined and very peculiar group of Crustacea,
the systematic position of which has been much debated among zoologists, most
of the earlier authors referring them to the lower Decapods, whereas in recent
time they have generally been placed close to the Isopoda. The fact is that they
differ materially from both of these groups, and should thus more properly be consi¬
dered as constituting a distinct order, occupying its place between the great divisions
Podophthalmia and Edriophtha Imia . It is true, inded, as first shown by Dr. Dohrn,
that the embryonal development of the Cumacea agrees very nearly with that of the
Isopoda; but in all other respects these Crustacea exhibit, in my opinion, a much
closer relationship to the Podophthalmia than to the Isopoda. Among the former,
it is chiefly the Schizopoda with which the Cumacea have many features in com¬
mon, though the external appearance is certainly very different; and even
those anatomical characters which have been specially adduced as proofs of
the near relationship of the Cumacea with the cheliferous Isopoda, viz., the pre¬
sence of a reflexed palp on the anterior maxillse, and the peculiar development
of the epipodite on the 1st pair of maxillipeds, may be found quite as distinct
in some of the Schizopoda, e. g. Gnathophausici. In my opinion, therefore,
the recent arrangement of the Cumacea as a sub-order of the Edriophthalmia can
scarcely he supported. On the other hand, I consider that the differences from the
Schizopoda are still great enough to forbid of the Cumacea being included in the
great division Podophthalmia.

Our knowledge of these singular Crustacea does not date from very
long ago. The first form recorded is probably that described by Lepechin in the
year 1780, as Oniscus scorpioides, which has turned out to he a species of the
genus Diastijlis. Another Cumacean form was observed in the year 1804 by
Colonel Montagu, and designated by the very same specific name ; but this
author erroneously believed that the solitary specimen found was a defective

l — Crustacea.

2

Decapod (Astacus) that had lost its head. In the year 1828, H. Milne-Edwards
observed apparently the same form, and established for its reception the genus
Cuma ; and it is from this genus that the name of the whole order is derived.
Another genus, however, viz. that of Diastylis, is, in fact, of a still earlier date,
having been established by the American zoologist Say, in the year 1818. It is
rather strange that the founder of the typical genus Cuma, H. Milne-Edwards,
subsequently altogether abandoned this genus, believing the form upon which it
was founded to be only a larval form of some higher Crustacean ; and this er¬
roneous assumption was entertained by many other authors, according to whom
the Cumacea should be wholly discarded from the zoological system, as only re¬
presenting immature animals. Certainly both Kroyer and Goodsir. in the year
1841, clearly showed the Cumacea to be perfect animals, and added several new
species; but there was still for many years doubt among zoologists as to the
true nature of these Crustacea. Thus Dana, in his great work on Crustacea, did
not include the Cumacea at all in his carcinological system, urging in support of this
action a statement given in 1852 by the celebrated Prof. L. Agassiz, who claimed to
have witnessed the escape of true Cumacea from the ova of Hippolyte and other Carids.
Meanwhile the investigation of these problematical Crustacea was continued by
several distinguished zoologists, Kroyer, Sp. Bate, and Prof. Lilljeborg, and all of
them agreed in absolutely denying the larval nature of the Cumacea, giving most
convincing reasons for their opinion. Notwithstanding this, even in the year 1858,
the Cumacea were declared by a high authority, Prof. H. Milne-Edwards, to be
immature animals, and were placed in the same rank as Phyllosoma, Erichtus,
Zoea and other larval forms.

As will appear from the above short historical account, the general ack¬
nowledgement of the Cumacea as perfect animals worthy of being ranked in the
carcinological system, is of comparatively recent date. The number of species at
first detected was a very limited one, and they were generally all referred to a
single genus, Cuma. Subsequently, a few additional genera were established, but
some of these have turned out to be spurious, being founded only on the male sex.
Sp. Bate comprised all the genera at that time established, within a single family,
that of the Diastylidce, which he believed to be nearly allied to the Stomatopoda.
In recent times, by the investigation of several zoologists, the number of both
species and genera has considerably increased, and it accordingly appeared very
desirable to group together the several genera in a suitable manner, by a sub¬
division of the original family. The first attempt to effect such a classification
was made in the year 1879 by the present author, who, in his account of the
Mediterranean Cumacea, arranged the 18 genera at that time known, in 8 distinct

3

families, viz., Cumidce, Vaimthompsoniidai, Lampropidce, Leuconidce, Diastylidce,
Pseudocumidw, Cumellidce and Canypylaspidce. This classification, the only one as
yet proposed, is followed in the present account, except that one new family,
Platyctspidce, has been established, to include the anomalous genus Platyaspis,
formerly referred to the Lampropidce.

General characters of the Cumaeea.

The external appearance of the Cumaeea is quite particular and unlike that
of any other Crustacea. The slenderness and extreme flexibility of the posterior
division or tail is especially very characteristic, and has given rise to the first

specific names given, viz., scorpioides (with a tail like a scorpion). The anterior

division is much broader, in some cases exceedingly tumid, and sharply marked
off from the slender tail, whereas in other cases it gradually tapers behind.
In all the known forms, this division is covered anteriorly by a well-defined car¬
apace, behind which, never more than 5 segments of the mesosome are exposed.
By this character, the Cumaeea undoubtedly approach nearer to the Podophthal-
mia than to the Edriophthalmia, among which, only the cheliferous Isopoda ex¬
hibit any sign of the formation of a carapace by the fusion of the cephalon
with the 1st pedigerous segment. The structure of the carapace is very peculiar,
especially as regards its anterior part. In the greater number of forms, it pro¬
jects in front to a more or less distinct rostriform prominence, covering the
bases of the antenna?. On a closer inspection, however, this rostrum-like promi¬
nence is found to be very different from the so-called rostrum in other Crustacea.
In all cases, it is found to be composed of 2 juxtaposed lappets, which are generally
closely applied to each other along the dorsal line, without, however, in any

case coalescing, a narrow fissure being always present between them. This

fissure at the base of the prominence, divides into 2 diverging rami, encompas¬
sing a bell-shaped dorsal area of the carapace, the frontal lobe. Of course the
lappets forming the pseudorostral prominence, originate at the points where the
lateral fissures terminate, and more properly represent the antero-lateral corners
of the carapace, which are developed in a very peculiar manner, to encompass
its frontal part. Below them, the anterior edges of the carapace often project in
the form of a triangular lobe ; and from the sinus between these lobes and the
pseudorostral prominence, the antennae are seen to project. The lateral parts of
the carapace form a narrow duplicature below, turning abruptly inwards and limit¬
ing the oral area, which is rather narrow. They do not loosely cover the sides
of the body, as in the greater number of the Podophthalmia, but are firmly con¬
nected with it along their edges, only leaving & small slit on each side of the

4

3rd pair of maxillipeds, for the entrance of the water into the branchial cavities.
On the carapace, 4 regions may be more or less distinctly distinguished, 2 suc¬
cessive median, and 2 lateral. Of these regions the lateral ones occupy by far the
greater part of the carapace, and represent the branchial regions. They extend
throughout the whole length and depth of the carapace, and draw closer together
dorsally, so as to leave only a narrow space in the middle, by which the 2 median
regions are connected. Of these the anterior may be termed the gastric region,
as beneath it the stomachal part of the intestine is located. Anteriorly, this re¬
gion is very sharply defined by the above-mentioned diverging fissures encompas¬
sing the frontal lobe; posteriorly, it gradually contracts, passing without any
distinct limit, at about the middle of the carapace, into the posterior region.
This region occupies the posterior part of the dorsal face of the carapace, and
gradually widens somewhat behind. It may be termed the cardiac region, be¬
cause at any rate the anterior part of the heart, with the great artery-stems, lies be¬
neath its posterior part.

The exposed part of the trunk, as stated above, is generally composed of 5
segments, the 1st of which, however, is sometimes (Cuma) almost wholly concealed,
in which case, only 4 such segments appear behind the carapace. Of the segments,
the 2nd and 3rd are the largest, and are, as a rule, firmly connected, whereas
the 2 posterior segments are generally separated by thin-skinned interspaces, al¬
lowing them comparative freedom of movement. The epimeral plates are easily
observable in most of the forms, and in the adult males generally appear more
extant than in the females. In the last segment they sometimes project posteriorly
to spine-like processes.

The tail is narrow cylindric in form, very flexible, and always composed of
6 sharply defined segments, of which the penultimate is the longest. The epime¬
ral plates are wanting in the female, whereas in the adult male they are more
or less distinct in those segments which carry pleopoda. The last segment is
slightly dilated distally, and carries at the tip 2 diverging biramous appendages,
the uropoda, and in some cases a median piece between them, the telson.

The integuments, in the greater number of the forms, are rather hard and
brittle, being strongly incrusted, and they exhibit a closely reticulated, or squamous
structure. In some cases they project in spine-like processes (especially on the
carapace), or are thickly covered with strong hairs; but in other cases, they ap¬
pear perfectly smooth.

The eyes, when present, are, as a rule, united in a single organ, which
occupies the end of the bell-shaped frontal lobe, appearing generally as a small
nodule, just above the base of the pseudorostral prominence Only in the genus

5

Nannastacus are the eyes separated by a distinct interspace. The structure of
the eyes is rather simple, and they contain only a very limited number of visual
elements, corresponding to an equal number of more or less refracting corneal
lenses of the integument. In the adult male, they are generally more fully devel¬
oped than in the females.

The superior antennae are rather small, each consisting of a 3-articulate
peduncle, and 2 diminutive flagella, the inner of which is sometimes quite obso¬
lete. The outer flagellum is tipped with one or 2 slender sensory filaments, and
in the adult male, an additional bundle of such filaments is generally attached to
the base of this flagellum.

The inferior antennae are in the female, as a rule, very small and rudi¬
mentary, whereas in the adult male they are greatly developed, generally at¬
taining the length of the whole body. In structure, they resemble those in the
male Phyllocarida and Ampliipoda, each consisting of an angularly bent peduncle,
the outer part of which is densely clothed with sensory fiaments, and, together
with the slender, multiarticulate flagellum, extends straight backwards. They are
generally borne closely applied to the sides of the body, and thus easily escape
observation ; but they admit of being moved from this position, and are probably
subservient to copulation. This could be directly proved in the species of the genus
Lam/props, where they are used as true prehensile organs, to obtain a hold of the
female during copulation.

The oral aperture is bounded in front by a generally small and simple,
rounded anterior lip (which is more strongly developed only in the genus Cam-
pylaspis ), and behind by a lamellar, bilobed posterior lip.

The mandibles are strongly incrusted, and are in no case provided with
palps. They are articulated to the inner side of the carapace just at the points
where the diverging fissures encompassing the frontal lobe, terminate, and they are
extended obliquely in front. The masticatory part is divided into 2 diverging
rami, the anterior representing the cutting part, the posterior the molar expans¬
ion. The latter, in the greater number of forms, is rather thick, cylindric, and
exhibits at the end a finely fluted triturating surface. The former has generally
a dense series of curved spines immediately behind the cutting edge.

The anterior maxillae exhibit the 2 usual incurved lobes, the masticatory
and basal, the former being much the stronger, and armed at the obliquely
truncated tip with short spines. The palp is peculiarly modified, and turned
straight backwards, terminating in one or 2 band-like bristles, which project
into the branchial cavity. It is wanting in 2 of the known genera, viz., Para-
lamprops and Platyaspis.

6

The posterior maxilla; are rather small and simple in structure, somewhat
resembling those in the Isopoda. As in the latter, they carry at the end out¬
side, 2 small movable lamella;, which partly overlap each other, and are clothed
with incurved spines. These lamellae, which have often been described as the
palp, may more properly represent the modified masticatory lobe, as suggested
by Dr. Boas. In the genus Campylaspis, however, these lamellae are wholly
wanting.

Behind these true oral parts there are 3 pairs of limbs, which, judging
both from arrangement and function, appear to be subservient to mastication,
and which accordingly ought to be termed maxillipeds. In this respect the
Cumacea differ very materially from the Edriophthalmia, in which never more
than one pair of maxillipeds are found. In the higher Crustacea (Decapoda),
on the other hand, the number of maxillipeds is normally the same as in the
Cumacea.

The 1st pair of these maxillipeds is rather short and stout, exhibiting
inside the end of the basal joint a short conical lobe, clothed with peculiarly
modified spines and bristles. To the base of these limbs the remarkable branchial
apparatus is movable appended, so as to admit of being swung freely within the
roomy branchial cavities. As shown elsewhere by the present author, this ap¬
paratus is composed of the modified epipodite and exopodite, the former occupy¬
ing the greater part of the apparatus, and carrying inside it the true gill-elements
in the form of densely crowded lamellae, or more scattered digitiform sacs. The
exopodal portions of the apparatus extend straight forwards, and together form
a funnel-shaped tube, through which the water introduced into the branchial cavities
is at certain intervals expelled by the oscillatory movements of the epipodal
portions. They are to some extent connected with the latter at the base, and their
extremities are closely applied to each other, admitting of being exserted from the tip
of the pseudorostral projection. In some cases, they terminate in 2 incrusted
lamellae, which work as a valve by alternately opening and closing the anterior
aperture leading to the branchial cavities. In other cases, they form together a
long delicate tube, which admits of being protruded and again withdrawn, and
which is opened and closed at the tip by its own elasticity. The explanation
here given has been contested by some recent authors : but after renewed
careful examination. I must still insist on its correctness. Anything analogous
to this singular apparatus is only found in the Schizopoda (Lophogastrid* and
Mysidae) and in the cheliferous Isopoda; but in these it is only the epipodite
which is peculiarly modified for branchial purposes, and in no case does this
part carry true gill-elements, as in the Cumacea.

/

The 2nd pair of maxillipeds is much more slender than the 1st pair,
and also more simple in structure. At their base. 2 small rounded lamella? are
appended, which, in the ovigerous females, are fringed with long set® forming
together a broad fan. which projects within the incubatory cavity. It is some¬
what doubtful whether these lamellae should he regarded as the epipodites or as
a pair of modified incubatory plates.

The 3rd pair of maxillipeds are considerably larger than any of the
preceding pairs, and. as a rule, more or less completely cover all the other oral parts
below. The basal joint is very large ard curved, being sometimes produced at the end
outside to a linguiform setiferous lobe. In all the known forms, these limbs are pro¬
vided at the base with well developed natatory exopodites; and this is also
the case with the next succeeding pair of limbs (the 1st pair of legs). In the
greater number of forms, also the 2nd pair of legs, sometimes, too. the 3rd pair,
carry similar appendages; and in the adult males the entire number of legs, with
exception of the last pair, are, as a rule, provided with well-developed natatory exopo-
dites. only the family Cumidce forming an exception in this respect. The presence of
these appendages is another character by which the Cumacea differ very materially
from the Edriophthalmia, and in which they evidently approach much nearer to
the lower Podophthalmia (Schizopoda).

As regards structure, the legs (the number of which, accordingly, as in the
higher Crustacea, is only 5 pairs) are rather simple, none of them being cheliform or
even suhcheliform. The 1st pair is generally the largest, and somewhat resem¬
bles in structure the 3rd pair of maxillipeds ; but they are much more slender. They
extend forwards below the carapace, with their outer, doubly genieulated part
generally projecting far beyond its extremity. These legs seem to act chiefly as
a sort of imperfectly developed preying organs, and for conveying food to the mouth.
The 4 remaining pairs of legs are the ti-ue pereiopoda, or more properly, fossorial
legs. Of these the anterior pair differs slightly from the other 3. being some¬
what intermediate in structure between them and the 1st pair. In all the legs,
as also in the maxillipeds, the normal number of 7 joints may generally he found.
Only in the 2nd pair does a fusion of 2 of the joints (the basal and ischial)
sometimes take place, whereby this pair, in such cases, appears to he only 6-ar-
ticulate. Of the joints, the coxal one is so firmly connected with the body, that,
on dissection, it is generally separated from its connection with the other part of the
leg. It is, however, always present, though often of very inconsiderable size.
The basal joint, on the other hand, is by far the largest of all the joints, and in
those legs which are provided with natatory exopodites, is considerably dilated

8

to receive the strong muscles moving these appendages. For this reason the legs
in the adult males often appear very unlike those in the females.

The pleopoda are always wanting in the female, and sometimes in the
male also ; but more generally the adult male possesses them either on all the
caudal segments except the last, or at least on some of the anterior segments.
These limbs are rather small, with the rami very short, and never composed of
more than 2 joints, and carrying at the tip long ciliated setae. In some|cases
the rami are coalesced or quite rudimentary.

The uropoda generally have the basal part very slender and elongated,
often much longer than the rami. The latter are narrow, styliform, and the in¬
ner one often densely spinulous inside.

The telson is only fully developed in 3 of the 8 families, viz., the
Lampropidce, Platyaspidce and Diastijlidm. In the Pseudocumidce it is certainly
present, but only as a rudiment.

The sexual dimorphism of the Cumacea is very pronounced, the adult
males looking, as a rule, very different from the females, both as regards their
outward appearance and the structure of the several appendages, whereas the
young, not yet sexually developed males on the whole closely resemble the females.
This circumstance has caused much confusion, and has given rise to the estab¬
lishment of several spurious genera, even in quite recent times.

Of the inner organisation and development of the Cumacea, a detailed
account will be given at the close of this work. I will here only remark
that the structure of the various internal organs, which is said to resemble closely
that in the Isopoda, agrees fully as well with that found in the lower Schi-
zopoda (Mysidae). The embryonal development also exhibits many points of
agreement with that in the Mysidw and Lophogastridas, though the resemblance
with that of the Isopoda is perhaps still more obvious. The embryos undergo
their metamorphosis within a roomy marsupial pouch formed by 4 pairs of thin
plates issuing from the bases of the 3rd pair of maxillipeds and the 3 anterior
pairs of legs. On escaping from the marsupium, the young, like those of the
Isopoda, still want the last pair of legs.

In occurrence, the Cumacea are exclusively marine, and, on the whole, true
bottom-forms, though the more agile adult males of some species may be found at
times swarming near the surface, especially at night. Some of the forms are
littoral or sub-littoral in their occurrence; but by far the greater number of species
are pronounced deep-water forms, descending to the greatest depths explored.
Cumacea are found in every part of the ocean, and as far north as deep¬
water exploration has been instituted, these peculiar Crustacea have been met

9

with rather plentifully. Indeed, in the Arctic Ocean they seem to reach their maximum
of development, the huge Diastylis Goodsiri being more than an inch in length.
The occurrence of Cumacea in the Caspian Sea, as stated hy the present author,
is of considerable interest. The fauna of this large basin also exhibits in other respects
a pronounced marine character, and undoubtedly has originally been derived from
the Ocean, when long ago an open communication existed.

Of the 9 families into which the Cumacea are divided, all, except one,
the Vaunthompsoniidee , are represented in the fauna of Norway, and will be
treated of below.

Fam. 1. Cumidae.

Characters. — Body in some cases rather short, in others very slender,
with no sharp demarcation between the anterior and posterior divisions. Carapace
comparatively large, with a distinct notch on each side below the pseudo-rostral
projection; the latter more or less distinct, in some cases wanting. 1st pedigerous
segment more or less concealed. Eye distinct or wanting. Superior antennae
with the flagella very short, the inner one, as a rule, rudimentary. Inferior an¬
tennae in female very small, scale-like, Inarticulate ; in male well developed, with
the flagellum filiform and composed of numerous, short articulations. Oral parts
normal. Branchial apparatus well developed, with the gill-elements leaf-like and
densely crowded together in a straight series. 3rd pair of maxillipeds generally
very large, with the joints more or less expanded. The 4 posterior pairs of legs in
both sexes simple, without natatory exopodites. Pleopoda in male present on all
the caudal segments except the last. Uropoda with the outer ramus biartieulate,
the inner uniarticulate or biartieulate. Telson wanting.

Remarks. — This family is prominently distinguished by the absence in
both sexes of natatory exopodites on the 4 posterior pairs of legs. The male, on
the other hand, is provided with 5 well-developed pleopoda, a number which is only
found in one of the other families, viz., the Vaunthompsoniidce. The family
as yet comprises 6 genera, viz., Cuma, Ipliinoe, Cyclaspis, Cyclaspoides, Cumopsis
and Stephanomma. Of these the first 3 are represented in the fauna of Norway,
and will be characterised below.

2 — Crustacea.

10

Glen. 1. Cuma, M.-Edw., 1828.

Syn: Bodotria, Goodsir (male).

Generic Characters. — Body of female less slender than in male. Inte¬
guments strongly incrusted, squamous. Carapace not at all vaulted above, slightly
carinated along the middle, sides sculptured with one or 2 carime, pseudo-rostral
projection short, but distinct. 1st pedigerous segment ^conspicuous, being al¬
most wholly concealed; 2nd segment very large. Eye distinct, much larger in
male than in female. Superior antennae with the outer flagellum biarticulate and
carrying 2 sensory filaments, inner flagellum quite rudimentary, knob-like. Infe¬
rior antennae in female with 3 plumose setae of the basal joint; those in male
equalling the body in length. Posterior lip with the lateral lobes narrowly rounded
at the tip and finely ciliated. Palp of anterior maxillae very slender, with 2 un¬
equal apical setae. 3rd pair of maxillipeds with the basal joint expanded at the
end outside to a large Iinguiform lobe. 1st pair of legs not much prolonged;
2nd pair with the basal and ischial joints coalesced; the 3 posterior pairs rather
small, and but sparingly setiferous. Uropoda with the rami much shorter than
the basal part, the inner one uniarticulate or biarticulate.

Remarks. — This genus may be regarded as the type of the family Cumidse
and indeed of the whole order, as from it the name generally' used has been
derived. It is easily recognised from the other genera comprised in this
family, by the greatly incrusted, squamous integuments, the form and sculpture
of the carapace, and the almost wholly concealed 1st pedigerous segment. We
know as yet of only 4 species, 2 of which belong to the fauna of Norway, and
will be described below.

l. Cuma seorpioides, (Mont,).

(pi. i, ir, iii.)

Cancer (Astacus) seorpioides, Montagu, Transactions of the Linnean Society, Vol. IX, p. 70, PI. VI, fig. 5.

Syn: Cuma Audouini, M.-Edw.

„ Bodotria arenosa, Goodsir (male).

„ Cuma pusilla , G. 0. Sars.

Specific Characters. — Body of female moderately slender, with the anterior
division oblong oval in form, and, like the tail, slightly keeled along the
back. Carapace about the length of the exposed part of the trunk, and exhibiting
on each side, somewhat above the middle, a very conspicuous, horizontal carina
extending from the lower side of the pseudo-rostral projection to the hind edge;

11

upper margin straight, lower strongly arcuate, pseudo-rostral projection short but
distinct. 1st pedigerous segment only visible in its epimeral parts; 2nd segment
rather large, but scarcely elevated above the level of the carapace, and exhibit¬
ing on each side a well marked carina meeting that of the carapace; the last 2
segments much smaller than the preceding ones, and rather widely separated.
Eye in both sexes with 8 distinct corneal lenses. 1st pair of legs scarcely longer
than the carapace, basal joint rather broad in its proximal part, and much longer
than the succeeding joints combined; 2nd pair moderately curved, with 3 apical
spines on the terminal joint. Uropoda exceeding in length the last 2 segments
combined, rami scarcely half the length of the basal part, the inner one uniarti-
culate, with the inner edge serrate and carrying 3 ciliated spinules, tip narrowly
truncate and armed with 2 unequal spinules. Adult male much more slender
than female, with the carapace comparatively larger, and the pedigerous segments
less tumid ; caudal segments with distinct epimeral plates ; uropoda clothed inside
the basal part with ciliated set®. Colour yellowish brown, with a whitish trans¬
versal band across the carapace in front of the middle. Length of female rea¬
ching to 7 mm., that of male about the same.

Remarks. — This is probably the form at first recorded by Montagu as
Cancer scorpioides, though his description and figure would equally well apply to
the succeeding, very nearly allied species. The form subsequently described by
Milne-Edwards as Cuma Andouini seems to be identical with Montagu’s species,
and Bodotria arenosa of Goodsir is unquestionably the male. The form at first
recorded by the present author as Cuma pusilla, I now consider to be only
a young specimen of this species. It is quite distinct from the 3 other
known species, from the fact that the inner ramus of the uropoda is uniarticu-
late, instead of biarticulate.

Occurrence. — I have met with this form in several places, both on the
south and west coasts of Norway, up to Appelvser in Namdal. It generally oc¬
curs at a few fathoms’ depth on a sandy bottom, in which it is able to bury
itself with great dexterity, so as wholly to escape attention. As usual, the adult
males (Bodotria) are much more agile than the females, swimming about with
great rapidity, especially with the aid of the well-developed pleopoda. In spite of
the indurated integuments, the flexibility of the body in both sexes is very great,
the tail admitting of being twisted in various directions.

Distribution. — British Isles (Montagu), coast of France (M.-Edwards);
Kattegat (Meinert).

12

2. Cuma Edwardsii, Goodsir.

(pi. in).

Cuma Edwardsii , Goodsir, Edinburgh New Phil. Journal 1843, Vol. XXXIV, PI. 2, p. 123, figs. 1 — 13.

Syn: Cuma Audouini , Bell.

Specific Characters. — Body of female very like that of the type species,
but somewhat shorter and thicker, with the 2nd pedigerous segment more sharply
carinated dorsally, and somewhat elevated above the level of the carapace. Uro-
poda scarcely longer than the last 2 caudal segments combined, rami slightly ex¬
ceeding half the length of the basal part, the inner one distinctly Inarticulate,
distal joint rather shirt, coarsely serrate inside and carrying 2 rather strong
apical spines, proximal joint with 4 spinules inside. Adult male much more slen¬
der than female, and very like that of C. scorpioides, though, like the female, hav¬
ing the inner ramus of the uropoda distinctly biarticulate. Colour light yellow,
with scattered patches of a darker brownish hue. Length of adult female scarcely
exceeding 5 mm., that of male reaching to 6 mm.

Remarks. — Of this species established by Goodsir, a detailled description
with figures has been given by the present author in his account of the Mediter¬
ranean Cumacea. It is very nearly allied to the type species, with which it may
easily be confounded. On a closer comparison, however, some well marked
specific differences may be found to exist. Of these, the different structure of the
uropoda is especially very obvious.

Occurrence — This species seems to be very rare off the Norwegian coast.
I have only found a few specimens, some in Rsekefjord, south coast of Norway,
some at Skudesnses, north of Stavanger. They occurred in similar localities to
those in which the type species is found.

Distribution. — British Isles (Goodsir), coast of France (Bonnier), Medi¬
terranean at Syracuse, Naples and Spezia (the present author).

Gen. 2. Iphinoe, Sp. Bate, 185(1.

Syn: Halia, Sp. Bate.

„ Yenilia , Sp. Bate (male).

„ Cyrianassa , Sp. Bate (male).

„ Iphithoe, Norman.

Generic Characters. — Body slender, subcompressed, carinated dorsally.
Integuments rather thin. Carapace in female generally cristated dorsally, but

13

without lateral keels; antero-lateral corners in female acutely produced, in male
obtuse; pseudo-rostral projection rather prominent. 1st pedigerous segment di¬
stinctly exposed dorsally. Eye distinct in both sexes, but much more fully de¬
veloped in male. Superior antennae of exactly same structure in the 2 sexes, peduncle
rather slender, flagella extremely small, the outer one tipped with a single large,
annulated sensory filament. Inferior antennae in female with 4 plumose setae on
the proximal joint; those in male about as in Cuma. Posterior lip with the la¬
teral lobes coarsely dentate at the anterior corners. 3rd pair of maxillipeds, as
in Cuma, having the basal joint produced at the end outside to a rather prominent
linguiform lobe; meral joint likewise forming outside a broad lamellar expansion,
fringed with strong plumose setae. 1st pair of legs rather slender and nearly
naked; the remaining pairs comparatively short, and more densely setiferous
than in Cuma; 2nd pair with the basal and ischial joints coalesced. Uropoda
rather strongly built, with the basal part spinulose inside, inner ramus distinctly
biarticulate, proximal joint short and thick, distal one slender linear, both densely
spinulose inside.

Remarks. — This genus was established by Sp. Bate, to include the Cuma
tnspinosa of Goodsir. The generic name first proposed, Halia, being already appro¬
priated, it was subsequently changed by the same author to Iphiuoe (sometimes
erroneously spelt Iphithoe). Two other generic names proposed by that author,
viz., Venilia and Cyrianassa, ought to be wholly withdrawn, being only founded
on the adult male of this species. The genus, though evidently belonging to
the same family as Cuma, is quite distinct from the latter by the very slender
form of the body, the thin integuments, and the clearly exposed 1st pedigerous
segment. Moreover the structure of the antennae is rather peculiar, and some
of the other appendages also exhibit well marked differences. Of this genus,
the present author has described 3 species from the Mediterranean, and Dr.
Hansen has recently added 3 other species from the German Plankton-Expedition,
making,' together with the type species, 7 in all. To the fauna of Norway be¬
longs only the type species, to be described below.

14

3. Iphinoe trispinosa, (Goodsir).

(PI. v & VI.)

Cuma trispinosa. Goodsir, Edinburgh New Phil. Journal 1843, Vol. XXXIV, p. 120, PI. Ill, figs. 1 — 7.

Syn: Ualia trispinosa , Sp. Bate.

„ Venilia gracilis , Sp. Bate (male).

„ Cyrianassa gracilis, Sp. Bate (male).

„ Iphithoe trispinosa, Norman.

„ Iphinoe gracilis, Meinert.

Specific Characters. — Body in both sexes extremely slender and elongated.
Carapace in female scarcely longer than the exposed part of the trunk, its upper
edge somewhat elevated in the middle, and at this place armed with 3 or 4
closely-set denticles; pseudo-rostral projection rather prominent, horizontal and
acutely produced at the tip, antero-lateral corners triangular. Carapace of
male quite smooth above and having the antero-lateral corners blunted. 1st pe-
digerous segment partly covered at the sides by the succeeding segment, its
dorsal part, however, quite conspicuous. Tail, not including the uropoda, longer
than the anterior division. Eye in male much more fully developed than in
female, with the corneal lenses exceedingly prominent. Superior antennse with the
last joint of the peduncle almost twice as long as the preceding one, outer fla¬
gellum very short, uniarticulate, inner much smaller, but distinctly biarticulate.
Inferior antennse of male equalling the body in length. 3rd pair of maxillipeds
with the basal joint about twice the length of the succeeding joints combined,
outer expansion of meral joint with about 10 plumose setae. 1st pair of legs
scarcely longer than the carapace, basal joint about the length of the succeeding
joints combined; 2nd pair of legs shorter than the 3rd, its last joint about the
length of the 2 preceding joints combined ; this pair, as also the 3 posterior ones,
rather abundantly supplied with bristles. Uropoda with the basal part in female
armed with about 10 spinules, in male with numerous short ciliated bristles; inner
ramus a little shorter than the outer, its proximal joint scarcely half the length
of the distal one, and armed inside with 5 spines, the outermost of which is
rather strong. Body straw-coloured, without any distinct pigmentary ornament.
Length of adult female reaching to 10 mm., that of male somewhat less.

Remarks. — The female of this species was first described by Goodsir as
Cuma trispinosa, and subsequently included by Sp. Bate in his genus Halia, after¬
wards changed to Iphinoe. Sp. Bate also observed the adult male, but did
not recognise it as such, describing it as the type of a new genus under the
name of Venilia (Cyrianassa) gracilis. A very closely-allied species was estab¬
lished by Norman as I. serrata. Of this form, a detailed description with

Id

figures has been given by the present author in bis account of the Mediterranean
Cumacea, but it was at that time regarded as only a variety of the type species.
Now, however, I am inclined to regard this form as specifically distinct from Good-
sir’s species, as it slightly differs, not only in the armature of the carapace, but
also in some other structural details.

Occurrence Of this form, a single adult male was found by the present
author in the year 1875 at Flekkere, near Christiansand. This specimen, which
is figured in PI. V, is the only proof of the occurrence of the present form off
the Norwegian coast. The figures of the female here given are from British speci¬
mens kindly sent to me by the late David Robertson.

Distribution. — British Isles (Goodsir), coast of France (Bonnier), Kattegat
(Meinert).

Gen. 3. CyelaspiS, G. 0. Sars, 18(14.

Generic Characters. — Body slender and elongated, with , the anterior divi¬
sion rather tumid in front, but abruptly tapered behind. Integuments hard, cal¬
careous. Carapace very large and deep, being strongly vaulted dorsally, pseu¬
do-rostral projection small or obsolete. 1st pedigerous segment wholly concealed
both dorsally and laterally. Tail exceeding in length the anterior division, last
segment rather elongated and obtusely produced behind. Eye present or want¬
ing. Superior antenna; with the flagella very small, the outer one Inarticulate
and tipped with 2 very slender sensory filaments, the inner rudimentary, knob-like
Inferior antennae in female with only 2 plumose set® of the proximal joint; those
in male shorter than the body. Posterior lip with the lateral lobes incurved at
the tip, and armed with lamellar teeth. 3rd pair of maxillipeds with the basal
joint very large, and produced at the end outside to a broad setiferous lobe.
1st pair of legs slender, but having the proximal part of the basal joint lamel-
larly expanded. The remaining pairs very small and but sparingly setous; 2nd
pair with the full number of joints. Uropoda comparatively short, with both rami
lanceolate, the outer biarticulate, the inner uniarticulate.

Remarks. — This genus was established by the present author in the. year
1864, to include a peculiar deep-water Cumac.ean found off the Norwegian coast.
3 other species, undoubtedly belonging to the same genus, were added by him

16

from the Challenger Expedition, and recently Mr. G. Thomson has made known
a New Zealand species, C. Icevis. On the other hand, the anomalous form de¬
scribed by the present author from the Mediterranean as Cyclaspis cornigera
is scarcely congeneric, and, indeed, this form has recently been included by the
French zoologist Jules Bonnier, in a new genus, Cyclaspoides. The species be¬
longing to the present genus are easily recognized by the peculiar form of the
carapace, the long and slender tail, and the structure of the uropoda. Only a
single Norwegian species is as yet known.

4. Cyclaspis longicaudata, G. O. Sars.

(PI. VII & VIII.)

Cyclaspis longicaudata, G. 0. Sars. Om den aberrante Krebsdyrgruppe Cumaeea og dens nordiske
Arter. Chr. Vid. Selsk. Fork. 1864, p. 82.

Specific Characters. — Carapace of female very large and tumid, almost
globose in form, and perfectly smooth, with the upper margin boldly vaulted,
pseudo-rostral projection distinct, though rather short, sub-rostral incisions well
marked; that in adult male much less deep and more evenly vaidted above,
pseudo-rostral projection less prominent, antero-lateral corners blunted. 1st pedi-
gerous segment not visible at all; 2nd segment well developed; the 3 succeeding
ones narrowing abruptly. Tail exceedingly slender and elongate, much longer
than the anterior division, all the segments contracted in their anterior part;
last segment nearly as long as the preceding one, gradually widening distally,
and considerably produced behind. Eye wholly absent. Superior antennm with
the sensory filaments of the outer flagellum extremely elongate; those in male
with an additional bundle of such filaments at the base ol the flagellum. Palp
of anterior maxillae with a single apical seta. 2nd pair of maxillipeds with the
basal joint unusually large, lamellar, and coarsely denticulated in the distal part
of the outer edge. 3rd pair of maxillipeds with the basal joint strongly developed,
being more than twice as long as the succeeding joints combined, and angularly
bent in the middle; terminal expansion very large, reaching beyond the meral
joint. 1st pair of legs exceeding the carapace in length, basal joint large and la-
mellarly expanded in the middle, terminal part very slender, with the propodal
joint the longest; 2nd pair longer than the succeeding pairs, and terminating in
4 diverging spines. Uropoda in female scarcely longer than the last segment,
basal part very short and perfectly smooth, rami twice the length of the former
and sub-equal, both terminating in a sharp point, the inner one without spines or
setae; those in adult male considerably more slender, basal part much longer

17

than in female, and carrying inside 7 ciliated bristles, inner ramus armed inside
with a dense row of small, ciliated spinules. Colour pure white. Length of female
reaching to 8 mm., of male 7 mm.

Remarks. — This is an easily recognizable form, highly remarkable for the
exceedingly tumid, almost globose carapace, and the slender and elongated tail.
From the other known species it is at once distinguished by the perfectly smooth
and boldly vaulted carapace, the distinctly projecting pseudorostral prominence,
and the total absence of eye. Moreover, in the structure of the several appen¬
dages several well-marked differences are to be found.

Occurrence. — I first detected this interesting form off the Lofoten Islands,
and have subsequently met with it occasionally in several other places on the
Norwegian coast, for instance in the Trondhjem and Hardanger Fjords, at Aale-
sund and Christiansund. It is a true deep-water form, being only found in
depths of more than 100 fathoms. Of the adult male, only a solitary specimen,
that here figured, has come under my notice. Young males are, however, almost
as frequent as females.

Distribution. — Off the Spanish coast (Porcupine Exp.) and in the North
Atlantic (Valorous Exp.), in both places, according to the Rev. A. M. Norman,
in very considerable depths, down to 1450 fathoms; Gulf of Gascogne (Bonnier)
in 960 metres.

Fam. 2. Lampropidae.

Characters. — Body more or less slender, somewhat resembling in form
that of the Cumidie. Integuments, as a rule, thin, distinctly squamous. Cara¬
pace, as a rule, rather small, with no sinus below the pseudorostral projection;
the latter generally very small. 1st pedigerous segment well defined. Last
caudal segment truncated behind, and carrying a well-developed telson. Eye
present or wanting. Superior antennae with both flagella distinctly devel¬
oped and not very unequal in length. Inferior antennae in female less rudi¬
mentary than usual, being nearly as large as the superior, and divided into
4 or 5 successive joints. Oral parts on the whole normal. Palp of anterior
maxillae short, bisetose, in some cases wholly wanting. Branchial apparatus

3 — Crustacea.

18

less fully developed than in the Cumidce, branchial elements scattered, digiti-
form. 3rd pair of maxillipeds with the outer corner of the basal joint not
produced. 1st pair of legs generally very slender; 2nd pair likewise slender,
with the full number of joints, and in both sexes provided with well developed
natatory exopodites; 3rd and 4th pairs in female with a small Inarticulate ap¬
pendage near the base (rudimentary exopodite). All the legs in male, except the last,
provided with natatory exopodites. Pleopoda in male generally present on the
3 anterior caudal segments, more rarely wholly wanting as in the female. Uro-
poda very slender, with the inner ramus always longer than the outer, and di¬
stinctly 3-articulate. Telson with more than 2 apical spines.

Remarks. — The forms belonging to this family are at once distinguished
from the Cumidce —to which they bear considerable resemblance in the general
form of the body — by the presence of a well-developed telson, a character only
found in 2 of the other families, viz., the Platyaspidce and the Diastylidce.
Moreover the structure of the antennse and uropoda is essentially different, and
in no case are there more than 3 pairs of pleopoda in the male. On the other
hand, unlike what is the case in the Cumidce, in this sex all the legs, except
the last pair, are provided with well-developed natatory exopodites. The family
comprises, as yet, 3 genera, viz., Lamprops, Hemilamprops and Paralamprops. Of
these genera, the first 2 are represented in the fauna of Norway, and will be
treated of below.

Gen. 1. Lamprops, G. 0. Sars, 1862.

Generic Characters. — Body less slender than in the other genera, with
the anterior and posterior divisions more sharply marked of from each other.
Carapace of moderate size, upper margin straight, pseudorostral projection more
or less prominent, antero-lateral corners obtuse. 2nd and 3rd pedigerous seg¬
ments rather large, with broad epimeral plates. Tail, exclusive of the caudal
appendages, scarcely longer than the anterior division. Eye well developed, with
distinct corneal lenses. Superior antennse with the flagella not much elongated,
the outer one in female 3-articulate, the inner biarticulate. Inferior antennse in
male much shorter than the body, and in some cases pronouncedly prehensile.
1st pair of legs of moderate length; 2nd pair not much smaller. Pleopoda in

19

male altogether wanting. Uropoda with the basal part and inner ramus spinulose
inside. Telson sublaminar, tapering distally, tip obtusely truncate and spiniferous.

Remarks. — This genus was established by the present author as early as
in the year 1862, and may accordingly be regarded as the type of the present
family, though the characters of the adult male have turned out to be rather
anomalous. It contains, as yet, only 2 species, to be described below.

l. Lamprops fasciata, G. 0. Sars.

(PI. rx & X.)

Lamprops fasciata, G. 0. Sars, Zoolog. Reise i Sommeren 1862, p. 44.

Specific Character.- Body moderately slender, with the anterior division
oblong oval in form. Carapace much shorter than the exposed part of trunk,
blunt in front, and exhibiting on each side 3 obliquely cm-ved folds crossing
the branchial regions; pseudorostral projection very short and obtuse, scarcely
projecting beyond the blunt antero-lateral corners. Tail, inclusive of the telson,
nearly as long as the anterior division. Eye rather conspicuous, with dark red
pigment. Inferior antennae of male about half the length of the body, and less
distinctly prehensile than in the next species. 1st pair of legs with the basal
joint about the length of the succeeding joints combined, and but slightly curved;
2nd pair with the last joint scarcely as long as the preceding one, both together
equalling in length the antepenultimate one ; the 3 posterior pairs densely setifer-
ous. Uropoda somewhat exceeding in length the last 2 segments combined, inner
ramus but little longer than the outer. Telson nearly twice as long as the last
segment, and rather broad at the base, but rapidly tapering distally, being pro¬
vided with a single pair of slender lateral spines, apical spines 5 in number, the
middle one and the 2 outermost much larger than the remaining 2, and strongly di¬
vergent. Body ornamented with a very conspicuous dark brownish violet pigment,
forming more or less distinct transversal bands across the segments, and in the cara¬
pace occupying the greater part of the branchial regions behind the anterior fold.
Length of adult female reaching to 9 mm., that of male considerably less.

Remarks. — This form is easily recognizable by its very conspicuous co-
ouring, which is retained for a long time even in preserved spsecimens. The
adult male, unlike what is generally the case in Cumacea, does not differ much
in its external appearance from the young female, with which it may easily be
confounded. On a closer examination, however, it may be recognized by the presence
of natatory exopodites on all the legs except the last pair, and by the structure
of the inferior antennae. The latter organs, which are generally concealed are

20

exserted during copulation, and are used as a pair of claspers, by which the
female is embraced at the boundary between the last 2 pedigerous segments.
The hold is so firm, that I have succeeded in preserving the 2 sexes still locked
together (see the figure given on PI. IX).

Occurrence. — I have met with this beautiful form along the whole coast
of Norway, from the Christiania Fjord to Vadso, in a few fathoms’ depth, on a
sandy bottom. In some places, for instance off the Jsederen coast and at Sorvser
and Vardo in Finmark, I have taken it in great abundance and of very large
size. It moves rather quickly, and is able to bury itself with great ease
in the sand, so as to be quite hidden.

Distribution. — British Isles (Norman), Kattegat (Meinert), Heligoland
(Ehrenbaum).

2. Lamprops fuseata, G. 0. Sars.

(PI. XI.)

Lamprops fuseata, G. O. Sars. Om den abevrante Krebsdyrgruppe Cumacea
og dens nordiske Arter, p. 67.

Specific Character. — Body comparatively short and robust, with the anterior
division in female rather tumid, ovoid, and considerably vaulted above. Carapace
about the length of the exposed part of the trunk, conically tapering in front and
slightly keeled dorsally in its anterior part, sides perfectly smooth, pseudorostral
projection rather produced, acute, antero-lateral corners sub-obsolete. Tail, in¬
cluding the telson, scarcely as long as the anterior division. Eye distinct, though
rather small. Inferior antennae in male unusually short, and pronouncedly prehen¬
sile, the flagellum being divided into two sharply-defined parts, of which the proximal
one is thickened and armed inside with small hook-like projections 1st pair
of legs comparatively more slender than in the. type species, with the basal joint
more strongly curved ; 2nd pair nearly as long as the 1st, terminal joint much
longer than the penultimate one; the remaining pairs comparatively more slender
and less richly setous than in L. fasciata. Uropoda with the inner ramus much longer
than the outer. Telson in female tapering considerably distally. and provided
with 2 pairs of short lateral spinules, apical spines 5 in number, the middle one
the shortest, the 2 outermost longer than the others. Telson in male less tapered
distally, with the 2 pairs of lateral spinules more widely apart, and the middle
apical spine much shorter than the other 4, which are about equal-sized and less
divergent than in female. Colour more or less fuscous, carapace mottled in front
with opaque white. Length of adult female 6 mm., that of male scarcely
reaching 5 mm.

21

Remarks. — This species is easily distinguishable from the preceding one
by the much shorter and more robust form of the body, the acutely produced
pseudorostral projection, and the absence of the oblique lateral folds on the cara¬
pace. Moreover, the 2nd pair of legs and the caudal appendages exhibit well
marked differences, and the colour is also different. Finally, the adult male
is well characterised by the peculiar structure of the inferior antennae, the prehen¬
sile nature of which is more pronounced than in any other known Cumacean.
Of this species also I have succeeded in preserving specimens of the 2 sexes still
locked together in copulation. The mode in which the female is grasped by the
male is exactly as in the preceding species.

Occurrence. — This species seems to be a true arctic form, as I have
never met with it off the south and west coasts of Norway, whereas in the arctic
region it is very common, from the Lofoten Islands to Vadso. It is generally
found in places similar to those in which the preceding species occurs.

Distribution. — Greenland (Hansen), Franz Joseph Land (Th. Scott).

Gen. 2. HemilamprOpS, G. O. Sag, 1882.

Generic Characters. — Body, as a rule, very slender, with the anterior and
posterior divisions generally less sharply marked off from each other. Carapace
not very large, without any subrostral sinus, the antero-lateral corners being quite
obsolete, pseudorostral projection more or less distinct. Eye well developed or
wanting. Superior antennae with the flagella comparatively longer than in Lam-
props; inferior antennae in male normally developed. 1st pair of legs slender and
elongated, with the terminal part much longer than the basal joint; 2nd pair
likewise slender. 3rd pair in male more or less transformed. 3 pairs of well
developed pleopoda present in the male. Telson and uropoda of a similar struc¬
ture to that in Lamprops.

Remarks. — This genus was proposed by the present author in the year
1882, to include some species formerly referred by him to the genus Lamprops,
but materially differing in the sexual characters of the adult male. Otherwise
the 2 genera are closely related, exhibiting the very same structure of the ter¬
minal caudal appendages. The genus comprises, as yet, 5 species, one of which,
H. Normani, has recently been recorded by M. Bonnier from the Gulf of Gas¬
cogne, the 4 others belonging to the Norwegian fauna.

22

3. Hemilamprops rosea (Normau).

(PI. XII, XIII, XIV.)

Vavmthompsonia rosea, Norman, Transact, of the Tyneside Nat. Club; Vol. 5, p. 271, IT 13,

figs. 1 — B.

Syn: Cyrianassa elegans , Normau (male).

„ Lamprops rosea , G. O. Sars.

Specific Characters. — Body rather slender, especially in the male, with
the tail exceeding the anterior division in length. Integuments thin, semipellucid.
Carapace in female rather small, much shorter than the exposed part of the
trunk, upper margin straight, horizontal, lower evenly arcuate, sides perfectly
smooth, pseudorostral projection very small, almost obsolete. Carapace of male
comparatively larger with the lower edges less regularly arcuate. Eye very large
and conspicuous, with beautiful red pigment and 8 corneal lenses. 1st pair of
legs exceedingly slender and elongated, when extended, fully twice the length of
the carapace, penultimate joint longer than the 3 preceding ones combined.
2nd pair with the last joint longer than the penultimate one. 3rd pair in female
slender, with the basal joint narrow linear and more than twice as long as the
remaining part of the leg; those in male, as usual, with the basal joint greatly
expanded, and moreover marked by the presence of 2 peculiar, smooth, falciform
spines appended to the inside of the ischial joint. Uropoda very slender, equalling
in length the last 3 caudal segments combined, inner ramus much longer
than the outer, with the 1st joint much the largest and armed inside with
about 15 spinules. Telson rather broad, lamellar, fully twice as long as the
last segment, and but slightly narrowed distally, with generally 2 pairs of slender
setiform spines laterally, and 8 spines issuing close together from the rounded
apex, the 2 outermost of which are longer than the others. Body ornamented
with a beautiful crimson pigment arranged in ramified, stellate patches both on
the carapace and the several segments. Length of female 6 mm., of male 7 mm.

Remarks. — This form was first described by the Rev. A. M. Norman, but erro¬
neously referred by him to the genus Vaunthnmpsonia of Sp. Bate, which is very
different. The adult male was described by the same author, but was not recog¬
nized as such. It was recorded in the same paper under the name of Cyrianassa
elegans. Some years afterwards the present author found this species off the
Norwegian coast, and referred it to his genus Lamprops , not being at that time
aware of the sexual differences in that genus. It is a very beautiful form,
easily recognizable in fresh condition by the bright crimson pigment ornamenting
the body and especially the carapace. In the adult male the natatory exopodites
of the legs are very fully developed, and in order to receive the strong muscles

23

moving them, the basal joint is much dilated, not only in the 2 anterior pairs,
but also in the 2 succeeding pairs. The 3rd pair of legs, as in several other
male Cumacea, are moreover characterised by the presence of 2 peculiar, smooth,
falciform spines appended to the inside of the ischial joint, and much resembling
those found in the adult male of Leucon nasicus (= Leuconopsis ensifer Walker).

Occurrence. — I have found this beautiful form rather frequently along the
whole south and west coasts of Norway, and occasionally also off the Finmark
coast as far as Varda. It generally occurs in moderate depths, from 20 to 50 fathoms,
on a muddy bottom. Owing to the abundant supply of natatory organs, the adult
male moves with great agility through the water, whereas the female leads a
much more sedentary life on the bottom.

Distribution. — British isles (Norman).

4. Hemilamprops assimilis, G. 0. Sars.

(PI. XV.)

Hemilamprops assimilis, G. 0. Sars, Oversigt af Norges Crustaceer 1 p. 55, PI. 1, figs. 23, 24.

Specific Characters. — Very like the preceding species as to external ap¬
pearance, but with the eye imperfectly developed, without corneal lenses, and
having the pigment whitish. Inferior antennae of male extending about to the
end of the penultimate caudal segment. 1st pair of legs somewhat less slender
than in H. rosea, with the penultimate joint scarcely as long as the 3 preceding
joints combined; 3rd pair in male with the 2 peculiar spines of the ischial joint
more slender, not falciform, their distal part closely annulated and denticulate
on one side. Uropoda nearly as in H. rosea. Telson, however, more narrowed
distally, with only a single pair of slender lateral spines, apical spines only 6 in
number, the 2 outermost much longer than the others, which are about equal¬
sized. Body in both sexes semipellucid, without any pigmentary ornament.
Length of adult female 5 mm., of male 6 mm.

Remarks. — This species is very nearly allied to H. rosea, though easily
distinguishable by the rudimentary condition of the visual organ, as also by the
absence of the beautiful pigmentary ornament constantly found in that species. On
a closer comparison, some other slight differences are also to be found in the
structure of the several appendages, proving the validity of the species.

Occurrence. — I have only met with this form off the Finmark coast, at
Vardo, Hammerfest and Hasvig, in depths varying from 60 to 200 fathoms.
It is accordingly a much more pronounced deep-water form than the preceding
species. Out of Norway, this form has not yet been recorded.

24

5. Hemilamprops uniplieata, G. 0. Sars.

(Pl. XVI, XVII.)

Lamp-ops uniplieata, G. 0. Sars, Undevsogelser over Hardangerfjordens Fauna I, Chr. Vid. Selsk.

Forh. 1871, p. 27.

Specific Characters. — Body in both sexes exceedingly slender and elongated,
with the anterior division somewhat vaulted dorsally and rather sharply marked
off from the posterior, though its last segment is not much broader than the 1st
caudal one. Tail considerably exceeding the anterior division in length and
gradually attenuated distally. Carapace about the length of the exposed part ot
the trunk, and exhibiting on each side, somewhat in front of the middle, a single
very conspicuous, obliquely curved fold or carina, upper margin straight, lower
evenly arcuate, anterior extremity, viewed laterally, conically tapered, viewed
dorsally, bluntly rounded; pseudorostral projection somewhat produced, though
rather short; frontal lobe slightly keeled dorsally. Eye very small, though
distinct, with red pigment. Inferior antennae of male not attaining the length
of the body. 1st pair of legs slender and elongated, almost equalling in
length the anterior division of the body, last joint very narrow and fully as
long as the penultimate one; 2nd pair with the antepenultimate joint longer
than the last 2 combined, and coarsely spinous inside; 3rd pair in male
with the outer 2 joints peculiarly transformed. Uropoda very slender, exceeding
in length the last 2 caudal segments combined, inner ramus much longer than
the outer, and armed inside with numerous short spinules, outside with about
16 setse. Telson about the length of the basal part of the uropoda, narrow
linguiform in shape, and armed with from 12 to 16 marginal spines, 3 of which
issue from the rounded tip and are somewhat longer than the others. Colour
bright orange. Length of female 7 mm., of male about the same.

j Remarks. — The present species is easily distinguishable from the 2 pre¬
ceding ones by the form and sculpture of the carapace, as also by the structure
of the terminal caudal appendages. The colour also is rather characteristic.

Occurrence. — I first detected this species at Mosterhavn in the outer part
of the Hardanger Fjord, and have subsequently also met with it in 3 other lo¬
calities of the west coast, viz., at Aalesund and Christiansund, in the Trondhjem
Fjord, and finally off the Lofoten Islands. It is a true deep-water form, only
occurring in depths of from 60 to 150 fathoms, sandy bottom.

Distribution. — Stat. 31 & 124 of the Norwegian North Atlantic Expedition,
both belonging to the cold area, outside the Norwegian coast.

25

6. Hemilamprops eristata, G. 0. Sars.

(pi, xvm.)

Lamprops eristata. G-. 0. Sars, Nye Dybvandscrastaceer fra Lofoten.

Chr. Vid. Selsk. Fork. 1869, p. 13.

Specific Characters. — Body slender and elongated, somewhat resembling
that of H. uniplicata. Carapace, however, rather different, conically tapered in
front, and without any lateral folds, gastric region surmounted by a distinctly
elevated longitudinal crest, which in female is finely denticulated throughout, the
denticles being also continued on the ocular lobe; branchial regions very pro¬
minent; pseudorostral projection short, but distinct, acute. Tail much longer
than the anterior division, and very slender, attenuated distally. Eye small, but
distinct, with bright red pigment. 1st pair of legs very slender, equalling in
length the anterior division of the body, terminal joint exceedingly narrow, linear,
and longer than the penultimate one; the remaining pairs about as in H. uni¬
plicata; 3rd pair in male but slightly transformed. Uropoda slender and elon¬
gated, exceeding in length the last 2 segments combined, inner ramus but
slightly longer than the outer, the latter densely setiferous along both edges.
Telson comparatively short, being scarcely longer than the last segment, and not
nearly attaining the length of the basal part of the uropoda, sub-lageniform in
shape, with the outer part abruptly contracted, and exhibiting 2 or 3 pairs of
lateral spinules; apical spines 3 in number, much larger than the spinules and
subequal in length. Colour light orange, or golden yellow. Length of female 7
mm., of male about the same.

Remarks. — This form is easily distinguishable from any of the preceding
species by the finely denticulated crest surmounting the gastric region of the
carapace, in which respect it agrees with the species recently described by M.
Jules Bonnier from the Gulf of Gascogne as H. Normani; but in other respects,
this form is rather different. It is moreover easily distinguished from H. unipli¬
cata, to which it bears some resemblance in the slender and elongated form, by the
absence of lateral folds on the carapace, and by the form and armature of the telson.

Occurrence. — I first detected this species off the Lofoten Islands, and have
subsequently also taken it in several other localities, for instance at Mosterhavn
in the outer part of the Hardanger Fjord, at Christiansund and in the Trondhjem
Fjord. It is a pronounced deep-water form, only occurring in depths of more
than 100 fathoms.

Distribution. — British Isles (Robertson), Stat. 23 of the Porcupine Ex¬
pedition (Norman).

4 — Crustacea.

26

Fam. 3. Platyaspidae.

Characters. Body considerably dilated in front, with the carapace very
large and applanated, pseudorostral projection distinct, antero-lateral corners obso¬
lete. All 5 pedigerous segments distinctly exposed, the 1st being of unusual
size. Tail slender and narrow. Antennae and oral parts of a similar structure
to that in the Lampropidce. Legs, however, very different, the 4 posterior pairs
being quite simple in female, without any traces of exopodites; all pairs in male,
except, the last, provided with well-developed natatory exopodites. 3 pairs of pleopoda
present i male. Uropoda slender, resembling somewhat in structure those in the
Lampropidce. Telson distinctly defined, conically tapered, terminating with 3 spines.

Remarks.— 1 have felt justified in establishing this new family, to include
the anomalous genus Plat y asp is, formerly referred to the Lampropidce. It is true that
in certain points this genus seems to approach that family, namely, as regards
the structure of the antennas, oral parts and terminal caudal appendages, as also
in the number of pleopoda in the male; but there are several other characters,
in which it differs so very essentially, as scarcely to allow of its being included
in the said family. The carapace, for instance, is of quite a peculiar structure, unlike
that in any other known Cumacea, and the 1st pedigerous segment exhibits a
development likewise unique in this order. Finally, the structure of the legs is
very unlike that in the Lampropidce , and more resembles that in the Cumidce, at
least as regards the female, in which only the 1st pair is provided with exopo¬
dites. Besides the typical genus Platyaspis, I am of opinion that the genus
Chalarostylis of Norman ought to be referred to this family. The latter genus,
however, is still but imperfectly known, having only been founded upon a solitary
specimen of the male sex.

Gen. Platyaspis, G. O. Sars, 18fi9.

Generic Characters. — Carapace large and broad, slightly vaulted above,
sides greatly expanded, fornicate; pseudorostral projection triangular. 1st pedi¬
gerous segment much larger than any of the others. Integuments rather thin,
squamous. Eye wholly absent. Superior antennae with both flagella well deve¬
loped and nearly equal, the outer one in male provided at the base with numerous,

27

closely set sensory filaments. Inferior antennae in female 4-articulate, in
male much shorter than the body. Anterior maxillae without any traces of palps
3rd pair of maxillipeds rather unlike those in other Cumacea, the basal joint
being quite straight, and not expanded distally. 1st pair of legs comparatively
short, resembling in structure the 3rd pair of maxillipeds, the outer joints partly
lamellar. 2nd pair of legs slender and elongated, with the full number of joints,
outer part spinous; the 3 posterior pairs exceedingly narrow, and almost
naked. Uropoda with the inner ramus longer than the outer and 3-articulate.
Telson without lateral spinules.

Remarks. — This genus was established by the present author in the year
1869, to comprise the peculiar Cumacean described below, the name being de¬
rived from the pronouncedly depressed form of the carapace. The genus is as
yet only represented by the type species.

Platyaspis typiea, G. 0. Sars.

(PI. SIX, XX.)

Flatyaspis typiea, G. 0. Sars, Nye Dybvandscrustaceer fra Lofoten. Chr. Vid. Selsk. Forh. 1869, p. 14.

Specific Characters. — Body moderately slender, with the anterior division
considerably dilated, though rapidly tapering behind. Carapace more than twice
as long as the exposed part of the trunk, and, viewed dorsally, of oval quadran¬
gular form, the greatest width occurring behind in female, in male quite in front,
dorsal face gently vaulted, with an obtuse keel along the middle, sides lamellarly
expanded, forming a horizontally projecting smooth carina, which extends on each
side throughout the whole length of the carapace; pseudorostral projection short,
almost rectangular. 1st pedigerous segment nearly as long as the 3 succeeding seg¬
ments combined, and rather broad in front, exhibiting dorsally a saddle-like
depression. Tail, including the telson, about the length of the anterior division,
and extremely slender. Superior antennae with the outer flagellum in female
3-articulate, in male 5-articulate, inner flagellum in female biarticulate, in male
triarticulate. Inferior antennae in female with 3 plumose setae, in male scarcely
longer than the anterior division of the body. 3rd pair of maxillipeds with the
carpal joint rather large, and dilated in its proximal part. 1st pair of legs with
the terminal part scarcely longer than the basal joint, ischial joint extremely
small, the 3 succeeding joints of about equal size and sublamellar, terminal joint
much smaller. 2nd pair of legs scarcely shorter than the 1st, but much nar¬
rower, antepenultimate joint about the length of the last 2 joints combined, and
strongly spinous inside. The 3 posterior pairs extremely slender, and gradually

28

diminishing in length, propodal joint in all of them unusually produced and
carrying at the tip, outside the dactylus, a single spiniform seta. Uropoda fully
as long as the last 3 segments combined, inner ramus somewhat shorter than
the basal part, but projecting considerably beyond the outer, its 1st joint with 2
spinules, each of the other 2 joints with one ; outer ramus with the proximal
joint quite short. Telson about twice the length of the last segment, and much
shorter than the basal part of the uropoda, gradually tapering distally to an
obtuse point carrying 3 subequal spines. Colour light yellow, with a whitish band
across the carapace. Length of adult female about 6 mm., of male 5 */2 mm.

Remarks. — This is an easily recognizable form, being at once distinguished
from all our other Cumaeea by the peculiar development of the carapace, the
fornicate character of which, indeed, makes it rather difficult to obtain an exact
lateral view of the animal.

Occurrence. — I first found this remarkable form off the Lofoten Islands,
and have subsequently met with it occasionally also in some other localities of
the Norwegian coast, for instance, in the outer part of the Hardanger Fjord, at
Aalesund, and in the Trondhjem Fjord. It is a pronounced deep-water species,
only occurring in greater depths ranging from 120 to 400 fathoms. Out of Nor¬
way, this form has not as yet been recorded.

Fam. 4. Leuconidae.

Characters. — Body more or less slender, with no sharp demarcation be¬
tween the anterior and posterior divisions. Integuments rather thin Carapace
generally small, with the antero-lateral corners more or less produced, pseudoro-
stral projection in some cases distinctly prominent, in other cases obsolete. 1st
pedigerous segment well defined. Tail with the last segment obtusely produced
behind. Eye, in all the known forms, absent. Superior antennae with the outer
flagellum 3-articulate, the inner uniarticulate. Inferior antennae in female very
small, in male well developed, attaining the length of the body. Mandibles com¬
paratively short, with the body triangular in form, or forming outside an angular
expansion, masticatory part strongly incurved, with only 2 small setae behind the
cutting edge, molar expansion short and massive. Anterior maxillae with the

massive.

29

palp unisetose ; posterior maxillse very small, without any setse inside. Branchial
apparatus with a limited number of digitiform gill-elements. 3rd pair of maxilli-
peds comparatively short, with the basal joint dilated distally, and carrying on
the projecting outer corner a number of very strong setse. The 3 anterior pairs
of legs in female provided with well-developed natatory exopodites ; 2nd pair
strongly built, conspicuously fossorial in character, and having the ischial and
literal joints coalesced. Adult male with very fully developed natatory exopodites
on all the legs except the last pair, but with only 2 pairs of pleopoda. Uropoda
with both rami Inarticulate, the inner spinulose, the outer setiferous. Telson
absent.

Remarks. — This family comprises forms of rather different external ap¬
pearance, but very closely agreeing in some of the anatomical details. The struc¬
ture of the oral parts in particular, is very characteristic, and rather unlike that
found in most other Cumacea. The presence in the female of well-developed
natatory exopodites not only on the 2 anterior pairs of legs, but also on the
3rd pair, is another character by which the present family is distinguished, only
the family Vaunthompsoniidce agreeing with it in this respect. But, whereas in that
family, the male has 5 well-developed pairs of pleopoda, the number of these ap¬
pendages in the present family is limited to 2 pairs only, as in the family
Diastylidce. By the total absence of the telson, the family Leuconidce is, how¬
ever, at once distinguished both from the last-named family and from the 2 im¬
mediately preceding it.

We only know at present of 3 genera belonging to this family, and all
of these are represented in the fauna of Norway, and will be treated of below.

Gen. 1. LeilCOn, Kr0yer, 1846.

Generic Characters. — Body, as a rule, slender, with the anterior division
more or less compressed. Carapace in female with a serrated crest along the
middle, pseudorostral projection prominent, and defined from the antero-lateral
corners by an angular cleft, lower edges of carapace bent in the middle, with
the anterior half serrate. Carapace of male generally without any dorsal crest,
and having both the pseudorostral projection and the antero-lateral corners blunted.
Tail slender and very|mobile. Superior antennre of moderate size, with the pe¬
duncle not geniculate, inner flagellum quite rudimentary, knob-like. Inferior

30

antennae in female with the distal joint well defined. 1st pair of legs slender,
with the terminal part much longer than the basal joint, last joint compressed
and densely clothed with slender curved spines; 2nd pair rather robust, last joint
armed with diverging spines; the succeeding pairs comparatively short, and densely
setiferous; 3rd pair in male with 2 or 3 peculiar appendages attached to the
ischial joint inside. Uropoda with the rami scarcely differing in size.

Remarks. — This genus was established by Kroyer as early as in the year
1846; but he also comprised within it species of the other 2 genera belonging
to this family. In the restriction here adopted, the genus is easily recognized,
at any rate in the female sex, by the crested carapace, the distinctly prominent
pseudorostral projection, and the angular incision below the latter. The genus
comprises, as yet, no less than 1 1 species, 5 of which belong to the fauna of
Norway, and will be described below.

l. Leueon nasieus, Kroyer.

(PI. XXI, XXII.)

Ouma nasica, Kroyer, Nat. Tidsskr. Vol. Ill, p. 524, PI. VI, figs. 31 — 33.

Syn: Leuconopsis ensifer, Walker (male).

Specific Characters. — Body exceedingly slender and elongated, with the
tail very fully developed, and longer than the anterior division. Carapace in
female shorter than the exposed part of the trunk, dorsal crest extending beyond
the middle, and reappearing for some distance also in the hindmost part, pseudo¬
rostral projection exceedingly prominent and somewhat upturned, obliquely truncate
at the tip, with the ^terminal edges very minutely denticulate and setiferous, in-
fero-lateral corners triangularly produced, and defined above by a deep angular
cleft. Carapace in male comparatively larger and less compressed, without any
trace of a dorsal crest, pseudorostral projection shorter and almost transversely
truncated at the tip, infero-lateral corners blunted, subrostral sinus obsolete.
Superior antennae with the last joint of the peduncle fully as long as the 2nd,
and conically tapered. 1st pair of legs rather elongated, and but slightly attenu¬
ated, with numerous plumose setae both on the basal and terminal parts, penulti¬
mate joint almost as long as the antepenultimate, and twice the length of the terminal
joint; 2nd pair with the last joint shorter than the antepenultimate one, and car¬
rying about 9 diverging ciliated spines. 3rd pair in male with 2 very conspicuous,
ensiform appendages of somewhat unequal size, originating from inside the ischial
joint. Uropoda about the length of the last 2 segments combined, and rather
robust, rami of about equal length, the inner one with numerous unequal spinules

31

inside, and a row of ciliated setse outside, its distal joint scarcely half as long
as the proximal one, and carrying on the tip a remarkably strong spine accom¬
panied by a long seta; outer ramus densely clothed with ciliated setse. Body
without any pigmentary ornament, of whitish colour, changing in female to pale
yellow. Length of adult female reaching to 12 mm., of male to 10 mm.

Remarks. — This form was first described by Kroyer as a species of
Cuma, but was subsequently separated as the type of his genus Leucon. It is
the largest of the Norwegian species, and moreover easily recognizable by its
very slender form and the nose-like, upturned pseudorostral projection. In the
young, not yet sexually mature state, the male does not exhibit any pronounced
difference in its general appearance from the female, the form and armature of
the carapace being the very same in both. It is quite otherwise when the male
has reached full sexual maturity. In this state, on account of the peculiar
transformation of the carapace, it looks so very different from the female that
even in quite recent times, its true relation has been wholly misapprehended. In¬
deed, there cannot be any doubt that the form recently recorded by Mr. Walker
as Leuconopsis ensifer is nothing else than the adult male of the present species.
As will be shown farther on, an altogether analogous transformation of the male
is proved to take place in all our other species of this genus.

Occurrence. — This is one of the commonest Cumacea of the Norwegian
coast, occurring very frequently throughout its whole length, from the Christiania
Fjord to Yadso, in depths from 30 to 100 fathoms, soft muddy bottom. The
adult males seem, only at certain seasons, to appear in some numbers. They are
extremely agile, swimming about with great rapidity by the aid of the very fully
developed exopodites, and the likewise well-developed 2 pairs of pleopoda. The
females, on the other hand, lead a much more stationary life, mostly dwelling on
the bottom, in which they are able to bury themselves with great dexterity.

Distribution. — British Isles (Norman), Kattegat (Meinert), Heligoland
(Ebrenbaum), Greenland (Hansen), the Kara Sea (Hansen), Atlantic coast of
North America (Verrill).

2. Leueon nasieoides, Lilljeborg.

(pi. xxm.)

Leucon nasicoicles, Lilljeborg, Ofvevs. af Vet. Akad. Fork. 1855, p. 122.

Specific Characters. — Body of female considerably shorter and more robust
than in the type species, with the tail scarcely exceeding in length the anterior
division. Carapace rather deep, and about the length of the exposed part of

32

the trunk, dorsal crest extending to the hind edge, frontal lobe moreover armed
on each side with 3 small denticles, 2 successive subdorsal, and one lateral,
pseudorostral projection much shorter than in L. nasicus, horizontal and obtusely
truncated at the tip, its terminal edges being cut off into 4 denticles, infero-lateral
corners but slightly produced. Adult male much more slender than the female,
and having the carapace smooth, with only 2 small successive denticles close to
the end of the frontal lobe; pseudorostral projection transversely truncated, with
only 2 denticles on the terminal edges below, infero-lateral corners obtusangular.
Superior antennse smaller than in the type species, with the last joint of the
peduncle shorter than the 2nd. 1st pair of legs comparatively feebler in structure,
with the penultimate joint much shorter than the antepenultimate one. 2nd pair
of legs with the last joint about the length of the antepenultimate one, and
armed with several rather unequal spines, which are not ciliated. 3rd pair ot legs
in male with 2 subequal, narrow lanceolate appendages of the ischial joint. Uro-
poda with the rami subequal in length, and somewhat longer than the basal part,
the inner one without any ciliated setae outside, its distal joint not nearly at¬
taining half the length of the proximal one. and carrying about 6 ciliated spines
gradually increasing in length distally; outer ramus with only a very limited
number of setae. Colour whitish, with a faint yellowish tinge. Length of adult
female 6 mm., of male about the same.

Remarks. — This form, first described by Prof. Lilljeborg, is easily distin¬
guishable from the type species by its much shorter and more robust body, the
fuller development of the dorsal crest of the carapace, and the shorter pseudo¬
rostral projection. In the structure of the several appendages also, well-marked
differences are found to exist.

Occurrence. — I have met with this form, though nowhere in any abun¬
dance, in several localities of the Norwegian coast, from the Christiania Fjord to
the Lofoten Islands, in depths varying from 10 to 50 fathoms.

Distribution. — Kattegat (Lilljeborg), Greenland (Hansen).

3. Leueon fulvus, G. 0. Sars.

(Pi. xxrv.)

Leueon fulvus, G. O. Sars, Om den aberrante Krebsdyrgruppe Cumacea og dens nordiske Arter

Chr. Yid. Selsk. Fork. 1864, p. 55.

Specific Characters. — Body rather slender, especially in the male, with the
tail unusually narrow and scarcely as long as the anterior division. Carapace
in female about the length of the exposed part of the trunk, dorsal crest well

33

developed, extending beyond the middle, and reappearing for a short distance in
the hindmost part; pseudorostral projection not much produced, almost horizontal,
and obtuse at the tip, terminal edges cut off into 5 denticles ; antero-lateral
corners somewhat produced. Carapace of male quite smooth, with only a single
small denticle at the end of the frontal lobe; pseudorostral projection obtusely
rounded at the tip, with the terminal edges smooth; antero-lateral corners! blunted.
1st pair of legs rather feeble, with several plumose setse outside the terminal
part, penultimate joint nearly as long as the antepenultimate; 2nd pair with the
last joint about the length of the 2 preceding joints combined, and linear in
form, with about 8 unequal spines. 3rd pair in male with 2 comparatively short,
falciformly curved appendages of the ischial joint. Uropoda rather slender, with
the rami much narrower than in the 2 preceding species, the inner one
with the distal joint scarcely shorter than the proximal one, and armed with
5 or 6 spines, the outermost very much elongated; outer ramus witli scattered setse.
Colour bright fulvous, somewhat lighter in male. Length of adult female scarcely
5 mm., of male 5V2 mm.

Remarks. — This form, in the fresh state, is at once recognized by its
beautiful bright orange or fulvous colour, a character which has indeed given
rise to the specific name. The species is also otherwise easily distinguishable
from the 2 preceding ones, both as regards the general form and the structure
of some of its appendages, especially that of the uropoda.

Occurrence. — I found this form many years ago rather plentifully at the
Lofoten Islands, in a depth of from 6 to 12 fathoms sandy bottom covered with
a thin layer of mud, and have subsequently also met with it in several places of
the Finmark coast, as far east as Vardo; but south of the Lofoten Islands, I have
never come across it, and we must conclude from this, that it is a true Arctic form.

Distribution. — Iceland, at Rejkjavik. Spitsbergen (Norw. North Atlantic
Expedition).

4. Leueon pallidus, G. 0. Sars.

(PI. XXV.)

Leueon pallidus , G-. 0. Sars, Om den aberrante Krebsdyrgruppe Cumacea og dens nordiske

Arter, p. 57.

Specific Characters. — Body slender and highly compressed, with the tail about
the length of the anterior division. Carapace in female somewhat exceeding the
length of the exposed part of the trunk, dorsal crest very fully developed, extending
to the hind edge; pseudorostral projection considerably produced, horizontal, at-

5 — Crustacea.

34

tenuated distally, tip obtusely acuminate, and exhibiting on each side a small
semilunar notch; antero-lateral corners triangular, defined above by a deep sinus.
Carapace of male less compressed, exhibiting, however, a complete series of den¬
ticles along the middle of the dorsal face ; pseudorostral projection much shorter
than in female, with the lower edges serrate; antero-lateral corners blunted. 1st
pair of legs about as in L. fulvus\ 2nd pair likewise rather similar, though hav¬
ing the last joint shorter than the 2 preceding ones combined. 3rd pair of legs
in male with 3 very largely developed lanceolate appendages of the ischial joint.
Uropoda scarcely attaining the length of the last 2 segments combined, rami
exceeding in length the basal part, outer ramus much the longer, and carrying
9 or 10 ciliated setae, inner ramus with the distal joint gradually tapered to a
mucroniform point. Colour pure white. Length of adult female 4 mm., of
male 4'/2 mm.

Remarks. — This form is easily distinguishable from the 3 preceding species,
not only by its small size and pale colour, but, in the female sex at least, by the
comparatively long and attenuated, horizontally extended pseudorostral projection,
as also by the different structure of the uropoda. The adult male, too, differs
conspicuously from the males of the other species in the presence of a distinct
series of denticles along the middle of the dorsal face of the carapace ; moreover,
in the 3rd pair of legs there are 3, instead of 2 appendages of the ischial joint.

Occurrence. — I first found this form in the Christiania Fjord, at Drobak,
and have subsequently met with it also in a few other places of the Norwegian
coast, for instance in the Trondhjem Fjord and off the Lofoten Islands. It is a
true deep-water form, only occurring in greater depths, from 60 to 400 fathoms.

Distribution. — South of Spitsbergen (Norw. North Atl. Exped.).

5. Leueon acutirostris, G. 0. Sars.

(PI. XXVI.)

Lexicon acutirostris , G. O. Sars, Om den aberrante Krebsdyrgruppe Oumacea og dens nordiske

Arter, p. 56.

Specific Characters. — Body in female rather short and thick, with the
tail scarcely as long as the anterior division. Carapace about the length of the
exposed part of the trunk, dorsal crest only confined to the anterior half; pseudo¬
rostral projection rather small, horizontal, and terminating in a sharp point, below
which the edges for some distance are finely denticulate and setiferous; antero¬
lateral corners distinctly produced, and defined above by an angular cleft. Adult
male much more slender than the female, with the carapace quite smooth above,

35

pseudorostral projection considerably shorter, antero-lateral corners blunted. 1st
pair of legs with the penultimate and antepenultimate joints of about equal size,
the latter with only a few very short setse outside ; 2nd pair with the last joint
scarcely longer than the antepenultimate one, and carrying about 8 unequal
spines. 3rd pair of legs in male with 3 lanceolate appendages of the ischial joint,
similar to those in the male of L. pallidus, but comparatively smaller. Uro-
poda with the inner ramus about the length of the basal part, but shorter than
the outer, its distal joint much smaller than the proximal, and linear in form,
with from 6 to 8 spines, the apical one rather elongated ; outer ramus with about
8 ciliated setae. Colour whitish, with a faint olivaceous tinge. Length of adult
female scarcely exceeding 3 mm., of male 3V2 mm.

Remarks. — This is the smallest of the Norwegian species, and is, moreover,
easily recognized, in the female sex at least, by the comparatively small, acutely
produced pseudorostral projection, and the limited extent of the dorsal crest of
the carapace.

Occurrence.- — I have found this form rather frequently in the inner part
of the Christiania Fjord, in depths varying from 30 to 60 fathoms, and have
also occasionally met with it in many other places of the Norwegian coast as far
as Vadso. Out of Norway, however, this form has not as yet been recorded.

Gen. 2. EudOrella, Sp. Bate, 1867.

Syn: Leucon , Kroyer (part.).

„ Eudora, Sp. Bate.

Generic Characters. — Body in all the known species slender and elongated,
with the anterior division club-shaped and shorter than the posterior. Carapace
comparatively small, but rather deep, quite smooth above, and subtruncate in
front, without any distinct pseudorostral projection, the antero-lateral lappets as¬
cending perpendicularly, to meet with their tips in close approximation to the
frontal lobe, the usual opening for the expulsion of the water from the branchial
cavities being, of course, placed quite dorsally. Anterior edges of carapace
more or less distinctly insinuated and dentated below, lower edges serrate in their
anterior half. Not the slightest trace of any eye or even of an ocular lobe present.
Superior antennae rather strongly built and coarsely setiferous, exhibiting in the
middle, or between the 2 outer peduncular joints, a very conspicuous elbow¬
shaped bend, inner flagellum well developed, though consisting of only a single

36

joint. Inferior antennae in female with 3 plumose setae in front, distal joint im¬
perfectly defined. Oral parts exactly as in Leucon. Legs likewise rather similar,
though comparatively more strongly huilt, especially the 2nd pair. 3rd pair in
male scarcely transformed. Uropoda with the inner ramus longer than the outer,
otherwise of a very similar structure to that in Leucon.

Remarks. — This genus was established by Sp. Bate in the year 1856;
but as the name, Eudora , at that time proposed, had already been appropriated
in zoology, it was changed in 1867 by the same author to Eudorella. The genus
is closely related to Leucon, exhibiting a very similar structure both of the oral
parts and of the legs and uropoda; but still this genus is very easily recogniz¬
able by the apparently very different structure of the carapace, and the superior
antennae also exhibit a rather characteristic appearance. We know as yet of 8
species belonging to this genus, 3 of which belong to the fauna of Norway, and
will be described below.

6. Eudorella emarginata, (Ivroyer).

(PI. XXVII, XXVIII.)

Leucon emaryinatus , Kroyer, Nat. Tidsskr. Vol. 2 (new series), p. 181, PI. 1, fig. 7.

PI. 2, figs 3 a — li.

Syn: Cyrianassa ciliata, Norman (male).

i Specific Characters. — Body slender and elongated, though rather strongly
built, and finely hairy all over, with 2 unusually long, juxtaposed bristles at the
end [of the penultimate caudal segment dorsally. Carapace about the length of
the 4 anterior exposed segments combined, and almost transversely truncated in
front; anterior edges in female with a broad similunar emargination below, de¬
fined above by a rounded dentated prominence, below by a very prominent,
somewhat upturned spinifonn process, upper part of the edges smooth and fringed
with short uniform hairs. Carapace of male with the antero-lateral parts more
expanded, and the emargination much smaller than in female. Superior antennae
very strongly built, 1st joint of the peduncle broad and massive, the other 2 of
about equal length, all 3 joints clothed on both edges with strong ciliated set®,
outer flagellum about the length of the last peduncular joint, and likewise clothed
outside with strong setae, inner flagellum about half the length of the outer, and
tipped with 3 subequal setae; those of male with a dense fascicle of sensory fila¬
ments at the base of the outer flagellum, which is distinctly 4-articulate. Inferior
antennae in female with 2 plumose setae inside the base, in addition to the 3
usual setae of the anterior edge. 1st pair of legs projecting far beyond the

37

limits of the carapace, penultimate joint much longer than the antepenultimate
one; 2nd pair exceedingly robust, with the terminal joint broad and spatulate in
form, carrying numerous radiating spines. Uropoda with the inner ramus con¬
siderably produced, exceeding the basal part in length, its proximal joint armed
inside with numerous somewhat unequal spinules, outside with a row of short ci¬
liated setae, the distal joint rather small, and exserted at the tip to a mucronate
point, outside which a long seta is attached. Uropoda of male with a number of
slender setae inside the basal part and the proximal half of the inner ramus.
Colour whitish, with a more or less distinct grayish or yellowish tinge. Length
of adult female reaching to 12 mm., of male about the same.

Remarks. — This is by far the largest of the known species, and is, more¬
over, easily recognizable, at least in the female sex, by the large semilunar
emargination in the lower part of the anterior edges of the carapace, and the
strongly prominent process defining this emargination below. The Cyrianassa
ciliata of Norman is unquestionably the adult male of this species.

Occurrence. — It is one of our commonest Cumacea, occurring rather plenti¬
fully along the whole Norwegian coast, from the Christiania Fjord to Vadso, in
depths varying from 30 to 150 fathoms, soft muddy bottom. In habits it agrees
very closely with Leucon nasicus, together with which it is generally found, pos¬
sessing, like the latter, great dexterity in burying itself in the loose bot¬
tom material.

Distribution. — British Isles (Norman), Kattegat (Meinert), Heligoland
(Ehrenbaum). Greenland (Hansen), Atlantic coast of North America (Yerrill).

7. Eudorella truneatula, Sp. Bate.

(PI. XXIX.)

Eudora truneatula, Sp. Bate, On the British Diastylidse. Ann. Mag. Nat. Hist. Vol. 17, p. 457,

PI. 14, fig. III.

Syn : Eudorella inermis, Meinert (male).

Specific Characters. — General form of body about as in the preceding
species, though perhaps somewhat less elongated, and with the tail narrower.
Carapace in female with the anterior edges smooth in their upper part, and
moderately setiferous, lower part cut off into 2 successive dentated prominences,
having between them a narrow sinus, antero-lateral corners not at all produced.
Carapace of male with the anterior edges quite entire, antero-lateral corners
rounded off, and armed with 3 or 4 denticles. Superior antennae resembling those
in E. emarginatci , but less abundantly setiferous, and having the last joint of the

38

peduncle shorter than the 2nd. 1st pair of* legs less robust, with the penultimate
joint fully as long as the 2 preceding joints combined; 2nd pair with the termi¬
nal joint narrower, and carrying a smaller number of spines. Uropoda with the
rami less unequal, the inner one with only a limited number of spinules, the
outer one but scantily setiferous. Colour whitish. Length of adult female scarcely
exceeding 5 mm., that of male about the same.

Remarks. — This species, first described by Sp. Bate, is very closely allied
to the preceding one, though on a closer examination, it is easily distinguishable by
the rather different armature of the anterior edges of the carapace. It is also
much inferior in size. The Eudorella inermis of Meinert is undoubtedly the adult
male of this species.

Occurrence. — Along the south and west coasts of Norway this form is far
from being rare, occurring not infrequently in moderate depths, from 6 to 30
fathoms. The most northern locality in which I have observed it, is the Lofoten
Islands; farther north, off the Finmark coast, I have never met with it, and its
foreign distribution also shows it to be evidently a more southern form than the
preceding species.

Distribution. — British Isles (Sp. Bate), Kattegat (Meinert), Heligoland
(Ehrenbaum), Mediterranean at Naples and Spezia (the present author).

8. Eudorella hirsuta, G. 0. Sars.

(PI. XXX.)

Eurlora hirsuta, G. O. Sars, Undersogelser over Christianiafjordens Dvbvandsfauna, p. 43.

Specific Characters. — Body extremely slender and elongated, with the in¬
teguments rather densely hairy. Carapace with the anterior edges coarsely den¬
ticulate throughout their whole length, and in the upper part clothed with nume¬
rous stiff, anteriorly curving bristles, exhibiting, moreover, below the middle a
well-marked, though rather small sinus; antero-lateral corners not produced.
Carapace of (young) male with the anterior edges unarmed, and without any di¬
stinct sinus. Superior antennse about as in E. truncatula. 1st pair of legs com¬

paratively more robust, with the penultimate joint scarcely longer than the ante¬
penultimate one; 2nd pair with the antepenultimate joint unusually elongated
and narrowed, last joint comparatively short. Uropoda resembling in structure
those in E. truncatula, but having the apical spine of the inner ramus well de¬
fined at the base. Colour whitish. Length of adult female 5 mm.

Remarks. — This form is about same size as E. truncatula, and may
easily be confounded with that species. On a closer examination, however, it is

found to differ in the still more slender and elongated form of body, and

39

still more in the rather different ■ armature of the anterior edges of the
carapace. In the structure of the 2 anterior pairs of legs also, well-marked dif¬
ferences are found to exist. I have not yet met with fully adult males of this
species; but even in young specimens the carapace has become somewhat
transformed, both the marginal denticles and the sinus of the anterior edges
having been lost.

Occurrence. — I have found this form in 2 widely-distant localities of the
Norwegian coast, viz., in the Christiania Fjord and off the Lofoten Islands. In
both places it only occurred in considerable depths, from 150 to 200 fathoms,
muddy bottom. Out of Norway, this form has not yet been recorded.

Gen. 3. Eudorellopsis, G. O. Sara, 1882.

Generic Characters. — Body short and compact, club-shaped. Carapace of
a structure similar to that in Eudorella , the pseudorostral projection being obso¬
lete, and the efferent branchial orifice placed dorsally in close approximation to
the frontal lobe. Tail comparatively short. Superior antennae strongly built, and
conspicuously geniculate, the geniculation, however, occurring between the 1st and
2nd peduncular joints, not, as in Eudorella, between the 2nd and 3rd, inferior
antennae in female very small, uniarticulate, with 2 very strong and densely hir¬
sute setae. Oral parts as in the 2 preceding genera. Legs comparatively robust,
and densely setiferous. Uropoda likewise robust, with the outer ramus much
larger than the inner, and partly spinous.

BemarTcs. — This genus was proposed by the present author in the year
1882, to comprise the anomalous form recorded by Ivroyer as Leticon deformis,
which I at first had referred to the genus Eudorella. Indeed, this form agrees
more nearly with the latter genus than with Leucon, yet exhibits several well-
marked differences from any of these genera, both as regards the general form
of the body, and the structure of some of its appendages, especially the antennae
and uropoda. Besides the type species described below, another species has
been recorded by Prof. Sidn. Smith from the east coast of North America, as
E. Integra.

40

9. Eudorellopsis deformis, (Kroyer).

(PI. XXXI, XXXII.)

Leucon deformis, Kreyer, Nat. Tidsskr. Vol. 2 (2nd series) p. 194, pi. 4.

Syn: Eudorella deformis , G. O. Sars.

Specific Characters — Body of female exceedingly short and stout, with the
anterior division rather dilated, and considerably longer than the posterior. Cara¬
pace comparatively large and deep, exceeding in length the exposed part of the
trunk, and transversely truncated in front, tips of the lateral lappets appearing
above as 2 juxtaposed horn-like projections, in front of which the rather wide
efferent branchial orifice occurs; anterior edges of carapace perfectly straight,
without any sinus, but fringed throughout their whole length with broad lamellar
teeth; antero-lateral corners triangularly produced. Adult male somewhat more
slender than the female, and exhibiting the usual sexual characters, carapace dif¬
fering in the circumstance that the anterior edges are dentate only in the middle, and
the antero-lateral corners not produced. Superior antennse with the last peduncular
joint longer than the 2nd, both armed at the end with a circlet of strong spines,
outer flagellum about the length of the last peduncular joint, inner much smaller,
scale-like, with 3 short apical spines. Palp of anterior maxillae with a small cili¬
ated projection at the base outside. Branchial apparatus with only 2 digitiform
gill-elements on each side. 1st pair of legs moderately slender, with a row of
long plumose setae outside the meral and carpal joints, propodal joint about the
length of the carpal one, terminal joint somewhat shorter and very narrow, subli-
near, carrying on the tip 3 slender spines and 2 unequal bristles ; 2nd pair with
the last joint fully as long as the antepenultimate one, and provided with 5 api¬
cal, and 2 lateral spines. Uropoda in female very strongly built, with the basal
part short and thick, and the rami very unequal, the outer one being much the
larger, with the distal joint rather expanded and obliquely truncated at the tip,
which carries about 7 ciliated setae, the dorsal face of the joint being, moreover,
armed with several rows of strong spines; inner ramus conically tapered, with
scattered spinules inside, and carrying oil the tip of the comparatively small dis¬
tal joint, a short spine and a slender seta. Uropoda in male less robust, with
the inner ramus more produced and, like the basal part, provided with ciliated
sette in addition to the spinules; outer ramus with the distal joint narrower
and less spinous. Colour whitish. Length of adult female 5 mm., of male
4 '/a mm.

41

Remarlcs. — This form is very easily recognizable from our other Cumacea
by its short, club-shaped body, and, indeed, its form appeared to Kroyer so
unusual that he applied to it the specific name deformis (misshapen). A de¬
tailed description of the female of this species, accompanied by figures, has been
given by the present author in his account of the Cumacea from the ‘Josephine’
Expedition.

Occurrence. — Off the Norwegian coast this form seems to be rather rare.
It was first found here by the late I)r. A. Boeck, who collected a few specimens
at Haugesund, west coast of Norway; and I have myself subsequently taken it
occasionally in 2 other places, viz., at Skudesnses and ofi the Jaederen coast. In
both these places it occurred in comparatively shallow water, on a sandy bottom.

Distribution. — Greenland (Kroyer), Kattegat (Meinert), Heligoland (Ehren-
baum), Atlantic coast of North America (Verrill).

Fam. 5. Diastylidae.

Characters. — Body, as a rule, not very slender, with the anterior division
more or less tumefied, and sharply marked oft’ from the slender, cylindrical tail.
Carapace large, more or less vaulted above, pseudorostral projection distinct,
lower edges serrate at least in their anterior half. First pedigerous segment
well defined, though rather narrow, band-shaped. Segments of tail generally
strongly emarginated above on the hind edge, and exhibiting a more or less
pronounced nodular appearance. Eye present or wanting. Superior antennae
slender, with both flagella distinctly developed. Inferior antennae in female form¬
ing a cylindrical stem divided into several successive joints. Mandibles well de¬
veloped, with numerous curved spines behind the cutting edge, its body of
different shape in the different genera. Anterior maxillae with the palp bisetose;
posterior maxillae normal. Branchial apparatus with the gill-elements much more
fully developed in male than in female, and generally arranged along a spiral
line; ends of the exopodal portions forming together a thin-skinned, protractile
tube. 3rd pair of maxillipeds with the basal joint very much elongated and
slightly dilated at the end, its outer corner carrying several long plumose set®,
terminal part comparatively short. 1st pair of legs very slender, with the 3 outer

6 — Crustacea.

42

joints narrow and elongated, forming angular bends with each other; 2nd pair
likewise slender, though shorter, and exhibiting the full number of joints. Both
these pairs in female with well-developed natatory exopodites, the 3 posterior pairs
simple. All the legs in male, except the last pair, provided with very fully de¬
veloped exopodites. Pleopoda in male only 2 pairs. Uropoda slender, with the
hasal part very narrow and spinulose inside, inner ramus triarticulate, outer In¬
articulate. Telson well defined, with the outer part generally narrowly produced
and spinulous, tip with only two spinules. Sexual dimorphism generally very
pronounced.

Remarks. — This family is well distinguished from the other Cumacean
families by a number of easily recognizable characters. As to the external ap¬
pearance, the sharp demarcation between the anterior and posterior divisions of
the body is rather characteristic, the former being generally very tumid, whereas
the latter is always extremely narrow, with the segments connected in a parti¬
cular manner, so as to admit of very great mobility, not only in a ventral, but
also in a dorsal direction. In all the known forms, the anterior extremity of the
body is produced in a nose-slmped prominence, the pseudorostral projection, and
the posterior in a more or less elongated, narrowly lageniform piece, the telson,
which projects between the slender, diverging uropoda. The structure of the an-
tenme is rather unlike that in other Cumacea, and in the structure of the other
appendages also, several peculiarities are to be found. As to the number of
pleopoda in the male, this family agrees with the Leuconidce, but is otherwise
very different. The family comprises as yet 5 genera, 4 of which are represented
in the Norwegian fauna and will be treated of below, the 5th, Pachystylis, having
recently been established by Dr. Hansen, to include an exotic form from the
German Plankton-Expedition.

Gen. 1. Diastylis, -Say, 1818.

Syn: Condylura , Latreille (not Illiger).

„ Alaunay Goodsir.

„ Cuma , Kroyer (not Edwards).

Generic Characters. — Body in female rather robust, in male much more
slender. Integuments generally hard and brittle, exhibiting an irregular reticulated
structure, and more or less densely hairy. Carapace large and tumid, not infre¬
quently armed with spiniform projections, sometimes also with lateral folds, but never

43

with any dorsal crest; pseudorostral projection always distinct, triangular, and
horizontally extended; antero-lateral corners only slightly produced. Epimeral
plates of the pedigerous segments generally narrow and incrassated, those of
last segment sometimes produced to posteriorly-pointing spines. Caudal segments
constricted at the base and also immediately in front of the posterior end, with
the lateral corners more or less projecting; last segment flattened, sub-pentagonal.
Eye generally present, and much larger in male than in female. Sivperior an¬
tennae in female with the peduncle very slender, outer flagellum 4-articulate, inner
3-articulate and much the smaller; those in male not very different, though
having the peduncle somewhat thicker, and the outer flagellum 5-articulate with
the usual additional fascile of sensory filaments at the base. Inferior antennae
in female 4-articulate, with 4 plumose setae, one apical; those in male, as a
rule, exceeding the body in length, last joint of the peduncle large and com¬
pressed, being clothed below with comparatively short sensory appendages, fla¬
gellum very slender, filiform, with rather elongate articulations. Mandibles large,
oblong, with the body regularly navicular in form. 3rd and 4th pairs of legs in
female with no rudiments of exopodites. Both pairs of pleopoda in male nor¬
mally developed, with the rami well defined, the outer one Inarticulate, the inner
uniarticulate. 3rd and 4th caudal segments in male with 4 plumose setse in place
of the pleopoda. Uropoda with the rami much shorter than the basal part, the
inner one mucroniform and, as a rule, shorter than the outer, which is very nar¬
row, linear, and sparingly setiferous. Telson narrow lageniform, with the outer
part conically tapered and densely spinulous on each side; that in male geni¬
culate in the middle, or exhibiting a projecting angle dorsally.

j Remarks. — Of all the Cumacean genera this is the oldest as regards date,
having been established by the North American zoologist, Th. Say, as early as in
the year 1818. According to the general rule, the order should therefore more
properly have been named from this genus, and not from the genus Cuma, which
was established 10 years afterwards; but the term Oumacea is now so universally
accepted, that a change would be rather inconvenient. At any rate, the term
Diastylidce proposed by Sp. Bate cannot, in consequence of its composition, be
used to designate the whole order, but must be restricted to one of the families
into which the order -is divided. The present genus is the type of this family, and
even in the restriction here adopted, it is, of all the Cumacean genera, that which
comprises the greatest number of species, amounting at present to about 30 in
all. 10 of these species belong to the fauna of Norway, and will be described
below; among them are some of the largest known Cumacea.

44

l. Diastylis Rathkei (Kreyer).

(pi. sxxni, xxxxv).

Cuma Rathkei, Kreyer, Nat. Tidsskr. Vol. 3, p. ol3, pi. 5, 6, figs 17 — 30.

Syn : Cuma angulata , Kroyer (adult male).

Specific Characters. — Female: Body more slender than in most other
species of this genus, with the anterior division scarcely at all tumefied, and
oblong in form. Carapace exceeding the exposed part of the trunk by about 1/z
of its length, and but slightly vaulted above; frontal lobe armed along the
middle with a double row of strong, anteriorly-curving denticles, sometimes
crossed by one or 2 imperfect transverse rows, lateral faces below the frontal
lobe exhibiting a somewhat varying number of scattered small denticles; pseu-
dorostral projection conically produced, horizontal; subrostral corners more or less
distinct. Last pedigerous segment with the anterior edge coarsely serrate, lateral
parts produced behind to rather large acute processes, extending almost to the
end of the 1st caudal segment. Tail somewhat exceeding the length of the an¬
terior division, segments simple, without any spiniform projections. Eye rather
small, though distinct. Superior antenna; not very slender, the peduncle scarcely
reaching beyond the tip of the pseudorostral projection, 1st joint about the length
of the other 2 combined, and armed at the end inside with a small denticle.
First pair of legs scarcely longer than the carapace, basal joint equalling in
length the remaining part of the leg, and denticulate in its distal part, the last
3 joints of about equal length; 2nd pair with the terminal joint not much longer
than the preceding one, both together scarcely exceeding half the length of the
antepenultimate one; 3rd and 4th pair very strongly built and densely setiferous.
Uropoda about half the length of the tail, outer ramus rather robust, being con¬
siderably larger than the inner, though scarcely exceeding half the length of the
stem, and densely setiferous along the outer edge and the tip; inner ramus with
the 1st joint fully as long as the other 2 combined, spinules of the inner edge
about 11 in number (6 of the 1st, 3 of the 2nd, and 2 of the last joint), apical
spine strong, mucronate. Telson rather produced, extending fully as far as the
stem of the uropoda, its proximal thickened part comparatively short, scarcely
occupying more than l/± of the length of the telson, distal part gradually attenuated,
and armed on each side with numerous (about 15) spinules, apical spinules of
exactly the same appearance as the lateral. Colour whitish, with a more or less
distinct carneous tinge. Length amounting to 16 mm.

Fern arks. — This form was first described by Ivroyer in the year 1841 as
a species of the genus Cuma. The form subsequently recorded by the same

45

author as Cuma angulata, is, according to my opinion, in which I am supported by
Dr. Hansen, the adult male of this species. It is one of our largest and finest
species, and in the polar sea it attains a still larger size. I have examined
some specimens kindly sent to me by Dr. Stuxherg from the Siberian polar sea, and
which had a length of no less than 26 mm. It is, moreover, easily recognized
from our other species by its comparatively slender form and by the large spini-
form processes formed by the lateral parts of the last pedigerous segment. The
species which most closely resembles it is D. Bradyi Norman (not yet found off
the Norwegian coast), and indeed some forms of D. BathJcei exhibit by their more
spiny carapace, as it were, a transition to this species.

Occurrence.- I have met with this form along the whole coast of Norway,
from the Christiania Fjord to Yadso, and in some places in great abundance.
It is generally found in moderate depths varying from 10 to 30 fathoms, especi¬
ally where the bottom consists of very loose mud, in which it buries itself with
great dexterity. Sometimes I have found it rather abundantly on a bottom covered
with a thick layer of putrid dark mire avoided by most other Crustacea. Although
young males are nearly as frequent as females, I have not yet met with any
sexually mature male specimen (= Cuma angulata Kr.), probably owing to the
circumstance that the existence of such specimens is limited to certain short
periods of the year.

Distribution. — Kattegat (Meinert), Bay of Kiel (Moebius), Pommerian
coast (Zaddach), the Baltic (Lindstrom), Heligoland (Ehrenbaum), Dutch coast
(Hoek), British Isles (Sp. Bate), Atlantic coast of North America (Verrill), Green¬
land (Hansen), Spitsbergen (Norw. North Atl. Exp.), Franz Joseph Land (Heller),
the Barents Sea (Hoek), the Kara Sea (Hansen), the Siberian Polar Sea (Stuxberg).

2. Diastylis cornuta (Boeck).

(PI. xxxv & XXXVI).

Cuma cornuta, Boeck, Christiania Vid. Seisk. Forh. 1863, p. 190.

Syn: Diastylis bispinosa, G. O. Sars (not Stimpson).

„ „ bicornis, Sp. Bate.

Specific Characters. — Female: Body less slender than in the preceding
species, with the anterior division rather tumid and oval in form. Carapace
comparatively large, about twice as long as the exposed part of the trunk, and
somewhat vaulted above, surface rather uneven, owing to numerous unequal spiniform
projections, some of which are very conspicuous, 2 of them especially, issuing one
on each side of the frontal lobe, being distinguished by their size, looking like a

46

pair of anteriorly-curving horns, frontal lobe itself unarmed and somewhat de¬
pressed; pseudorostral projection of moderate size, conically produced, horizontal;
subrostral corners distinct, obtusangular. Exposed part of trunk with small
scattered spinules forming dorsally a double row ; last segment with a median
.spinule behind, lateral parts produced to comparatively short acute projections.
Tail (exclusive of the terminal appendages) somewhat shorter than the anterior
division, and clothed with numerous small spinules. Eye very small and imper¬
fectly developed. Superior antennae rather slender, with the peduncle projecting
far beyond the tip of the pseudorostral prominence, its 1st joint somewhat shorter
than the other 2 combined, and coarsely denticulate along the outer edge and
at the end, last joint very slender, linear. First pair of legs considerably longer
than the carapace, basal joint not nearly attaining the length of the remaining
part, and rather spiny in its distal part, penultimate joint much longer than the
antepenultimate one, last joint comparatively short, not even attaining half the
length of the penultimate one; 2nd pair with the ischial joint produced below to
a strong spiniform projection, antepenultimate joint somewhat longer than the last
2 combined; 3rd and 4th pairs comparatively less robust than in D. Eathkei,
and having the basal joint coarsely denticulate behind. Uropoda exceeding half
the length of the tail, stem very narrow, rami more slender than in D. Eathkei,
and scarcely differing in length, being about half as long as the stem, outer
ramus with scattered short bristles outside, inner with the 1st joint shorter than
the other 2 combined, spinules of the inner edge about 10 in number (6 on the
1st, and 2 on each of the last 2 joints) apical spine very strong and forming the
immediate continuation of the joint. Telson not reaching quite as far as the
stem of the uropoda, its proximal third part of uniform width, cylindric, distal
part gradually tapering, with about 8 — 9 spinules on each side, apical spinules
somewhat longer than the lateral, and pointing straight behind. Colour greyish
white, with a yellowish tinge. Length amounting to 12 mm.

Adult male. Body much more slender than in female, with the anterior
division considerably narrowed behind. Carapace very large and tumid, more
than twice as long as the exposed part of the trunk, and nearly smooth, having,
however, along each side a low, minutely serrated carina, joining, at about the
anterior 3rd part of the length of the carapace, an obliquely transverse plica
extending downwards ; the horn-like spines found in the female replaced by 2 very
slight tubercles; pseudorostral projection minutely denticulated on each side, and
ha ving at the base 2 juxtaposed rounded protuberances, between which the eye
is, as it were, sunk; subrostral corners produced in the form of rounded, coarsely
dentated lobes. Exposed part of trunk perfectly smooth above, lateral projections

47

of last segment much larger than in female. Caudal segments coarsely spinulose
both dorsally and ventrally. Antennae and legs exhibiting the usual transforma¬
tion. Pleopoda of the structure characteristic of the genus. Uropoda much more
elongated than in female, inner ramus with numerous small ciliated spinules inside.
Telson exhibiting the usual abrupt bend at about the middle, distal part very
narrow. Colour uniformly greyish white. Length amounting to 14 mm.

Remarks. — This form was briefly noticed in the year 1863 by the late
A. Boeck as a new species of the genus Curna. The same species was subsequently
recorded by Dr. Danielssen as Diastylis bispinosa Stimpson, and I myself likewise
at first believed it to be identical with the North American form. Having,
however, subsequently had an opportunity of examining the latter, I found that
both forms, though nearly allied, were evidently specifically distinct. It is an
easily recognizable species, at least in the female sex, being highly distinguished
by the strong horn-like processes projecting on each side of the frontal lobe of
the carapace. The adult male, as usual, looks so very different from the female,
that it is not easy at once to recognize its true relation, whereas in the young,
not yet sexually mature state the males closely resemble the females, both as to
the general form of the body and the armature of the carapace.

Occurrence. — This is one of our most common species, being found rather
abundantly along the whole south and west coasts of Norway, and northwards at
least to the Lofoten Islands. It is, however, a true deep-water form, only occur¬
ring in greater depths, from 50 to 300 fathoms, especially where the bottom con¬
sists of loose mud and clay. Owing to its spiny armature, the body is often so
thickly covered with muddy particles, that it is rather difficult at once to recog¬
nize its form exactly. Adult male specimens are, as usual, only found quite
occasionally. They are much more agile than the females, swimming about with
great speed by the aid of their powerfully developed exopodites and pleopoda.
The females, on the other hand, generally dwell on the bottom, burying them¬
selves more or less deeply in the loose mud, and only seldom making a short
swimming trip through the water.

Distribution. — Kattegat (Meinert), British Isles (Sp. Bate), coast of France
(Fischer), Stat. 21 of the Porcupine Expedition (Norman).

48

3. Diastylis rugosa, G. 0. Sars.

(PI. XXXVII).

Diastylis rugosa, G. 0. Sars. Om den aberrante Krebsdyrgruppe Cumacea og dens

nordiske Arter, p. 41.

Syn: Diastylis strigata, Norman (adult, male).

Specific Characters. — Female. General form of body rather robust, some¬
what resembling that of I), cornuta, the anterior division being sharply marked
off from the posterior, and oval in form, with the dorsal face highly arched.
Carapace comparatively large and deep, with the surface rather uneven, exhibiting
laterally several transverse plicae, some of which, however, are rather indistinct
and partly interrupted, dorsal face moreover armed with 2 pairs of well-marked
spiniform projections, the anterior pair occupying the very same place as the
horn-like processes found in D. cornuta, but not nearly so lai’ge, the posterior
pair being more approximate and occurring behind the frontal lobe on the most
prominent part of the branchial regions; pseudorostral projection of moderate
size, conically produced, horizontal; subrostral corners very slight. Exposed part
of trunk without any spinules, but, like the carapace, clothed with scattered hairs ;
last segment with the anterior edge minutely crenulate, lateral parts scarcely at
all produced behind. Tail a little shorter than the anterior division and without
spinules. Eye well developed and rather conspicuous. Superior antennae mode¬
rately slender, with the peduncle projecting somewhat beyond the tip of the
pseudorostral prominence, its 1st joint shorter than the other 2 combined and
unarmed. First pair of legs of a similar structure to those in I), cornuta, but
having the basal joint scarcely at all spinous, and the last joint about half the
length of the penultimate one; 2nd pair with the antepenultimate joint about the
length of the last 2 combined; 3rd and 4th pairs without any spinules on the
basal joint. Uropoda moderately slender, outer ramus very narrow and somewhat
longer than the inner, the latter with about 12 spinules inside (6 on the 1st, 3
on each of the last 2 joints), apical spine of moderate size. Telson not reaching
as far as the stem of the uropoda, proximal part rather thick, distal part coni¬
cally tapering, and armed on each side with about 9 spinules, apical spinules of
same appearance as the lateral ones. Colour greyish white. Length 8 mm.

Adult male very similar, as to general appearance, to that of D.
cornuta, but of smaller size, and having 2 distinct transverse plicae on each side
of the carapace anteriorly, the longitudinal carinse being less prominent and quite

49

smooth; eye much larger and more prominent. The several appendages very
nearly as in the male of D. cornuta. Length 9 mm.

Remarks. — This species is nearly related to D. cornuta, but is easily distin¬
guishable in botli sexes, the female especially being at once recognized by the
peculiar sculpture of the carapace, which has given rise to the specific name
rugosa. The Diastylis strigata of Norman seems to be the adult male of this
species, judging from the diagnosis given by that author.

Occurrence. — I have met with this form in several places, both on the
south and west coasts of Norway, from the Christiania to the Trondhjem Fjord.
It is generally found at less considerable depths than most other species, from 10 to
20 fathoms, occurring not infrequently at the roots of Laminarise and between the
red algae, where no other Diastylis is met with.

Distribution. — Kattegat (Meinert), Heligoland (Ehrenbaum), British Isles
(Norman), coast of France (de Folin), Mediterranean at Spezia, Messina and
Syracusa (the present author).

4. Diastylis lueifera (Kroyer).

(PI. XXXVIII).

Oiima lueifera, Kroyer, Nat. Tidsskr. Bel. 3, p. 527.

Syn : Diastylis borealis, Sp. Bate.

Specific Characters. — Female. Body comparatively short and thick, with
the anterior division ovoid in form and but slightly arcuate dorsally. Carapace
not very large, but slightly exceeding in length the exposed part of the trunk,
and somewhat sloping in front; dorsal face rather densely clothed with small
denticles arranged on the frontale lobe in transverse rows, one of them originating
from the ocular lobule itself; pseudorostral projection conically produced, hori¬
zontal; subrostral corners almost obsolete. Exposed part of trunk smooth above,
last segment with the lateral parts not produced behind. Tail shorter than the
anterior division, segments simple, unarmed. Eye distinct, though rather small.
Superior antennae slender, with the peduncle projecting far beyond the tip of the
pseudorostral prominence, its 1st joint somewhat shorter than the other 2 com¬
bined and unarmed. First pair of legs not much elongated, and having the 3
distal joints of about equal length; 2nd pair with the antepenultimate joint much
shorter than the last 2 combined, and scarcely longer than the terminal joint;
3rd and 4th pairs without any denticles on the basal joint. Uropoda with the
outer ramus somewhat longer than the inner, and considerably exceeding half the

7 — Crusatcea.

50

length of the stem, inner ramus with the 1st joint scarcely longer than the 2nd,
spinules of the inner edge about 7 in number (3 on each of the 2 first joints,
and one on the last), apical spine rather strong, mucronate, forming the imme¬
diate continuation of the joint. Telson not extending as far as the stem of the
uropoda, and of the usual narrow lagenifonn shape, distal part sublinear, and
having on each side only 3 or 4 spinules, apical spinules somewhat larger than
the lateral. Colour greyish 'white, with a faint olivaceous tinge. Length scarcely
exceeding 6 mm.

Adult male much more slender than the female, with the anterior division
considerably narrowed behind. Carapace rather large and somewhat vaulted above,
being only armed in front with 3 small denticles, one originating from the ocular
lobule, the other 2 occurring on each side of the anterior part of the frontal
lobe, lateral carinse sub-obsolete. Last pedigerous segment with the lateral parts
acutely produced behind. Tail unarmed. Uropoda and telson much more elon¬
gated than in female, exhibiting, like the other appendages, the usual transfor¬
mation. Body whitish, semipellucid. Length amounting to 8 mm.

Remarks. — This form was first described by Kroyer in the year 1841 as
Cuma lueifera, the specific name apparently referring to the fact that by the
discovery of ovigerous females of this form, the hitherto much disputed question
about the true nature of the Cumacea as perfect animals, could be finally settled.
This form is easily distinguishable from the other Norwegian species in both
sexes by the form and armature of the carapace. The Diastylis borealis of Sp.
Bate is unquestionably identical with Kroyer’s species.

Occurrence. — This species occurs rather plentifully along the whole Nor¬
wegian coast, from the Christiania Fjord to Yadso, in moderate depths, varying
from 20 to 50 fathoms, muddy bottom. In the Christiania Fjord it is one of
the commonest Cumacea, occurring rather abundantly even in the innermost part
of the Fjord, in the immediate vicinity of the town. Adult males are sometimes
found in considerable numbers, but only at certain limited periods of the season.
They are extremely agile, being in almost constant motion, whereas the females
lead a much more sedentary existence on the bottom, burying themselves more
or less deeply in the loose mud.

Distribution. — Kattegat (Meinert), Heligoland (Ehrenbaum), British Isles
(Sp. Bate), Atlantic coast of North America (Verrill).

5. Diastylis rostrata, (Goodsir).

(PI. XXXIX.)

Alauna rostrata , Goodsir, Edinburgh New Phil. Journal 1843, Yol. XXXIV.

Syn: Diastylis Icevis, Norman.

Specific Characters. — Female. Body moderately robust, with the anterior
division ovoid in form and hut slightly arcuate above. Carapace comparatively
larger than in I). lucifera and more evenly vaulted above, surface perfectly
smooth, hut clothed with scattered hairs; pseudorostral projection rather pro¬
duced, acuminate, horizontally extended, subrostral corners very slight. Exposed
part of trunk, like the carapace, smooth, with scattered hairs, last segment with
the anterior edge minutely serrate and setiferous, lateral parts slightly produced
behind. Tail about the length of the anterior division, exclusive of the pseudo¬
rostral projection, and perfectly smooth. Eye well developed and somewhat
convex. Superior antennaj very slender, with the peduncle extending far beyond
the tip of the pseudorostral projection, its 1st joint much shorter than the other
2 combined and unarmed, last joint very narrow, linear. First pair of legs much
longer than the carapace, basal joint densely fringed with plumose setse, pen¬
ultimate joint considerably longer than the antepenultimate one, last joint some¬
what exceeding half the length of the penultimate one; 2nd pair rather densely
setiferous, antepenultimate joint about the length of the last 2 joints combined;
3rd and 4th pairs, like the 2 preceding pairs, without any denticles on the basal
joint. Uropoda with the outer ramus about half the length of the stem, inner
ramus somewhat shorter, and having the 1st joint as long as the other 2 com¬
bined. spinules of the inner edge about 12 in number (7 on the 1st, 3 on the
2nd, and 2 on the last joint), apical spine strong, forming the immediate con¬
tinuation of the joint. Telson rather produced, reaching as far as the stem of
the uropoda, proximal thickened part occupying about Vs °f the length of the
telson, distal part very narrow, with about 12 spinules on each side, apical
spinules scarcely different from the lateral. Colour greyish white. Length
amounting to 10 mm.

Adult male resembling in external appearance that of D. cornuta, the
carapace having on each side a distinct longitudinal carina crossed in front by
an obliquely transverse plica; but this carina is quite smooth, not, as in the
male of D. cornuta. serrate. Last pedigerous segment with the lateral parts
considerably produced behind. Caudal segments spinulous. Eye larger than in
the female, though, in the lateral view of the animal, partly concealed by a

52

slight swelling of the carapace on each side at the base of the pseudorostral
projection. Appendages of the usual structure. Length 11 mm.

Remarks. — I cannot doubt that this is the form originally recorded by
Goodsir as Alauna rostrata. There is no other species of Diastylis, which agrees
better with the figure and description given by that author, and its occurrence
in comparatively shallow water would also seem to point to the identity of these
2 forms. The Diastylis Icevis of Norman is unquestionably the same species. By
the perfectly smooth carapace, this form is easily distinguished from any of the
preceding species, somewhat resembling in this respect the next species, D. tumida
Lilljeborg, which, however, is a true deep-water form, and differs, among other
things, in the larger size of the carapace, and in the different shape of the telson.

Occurrence. — I have met with this form only in a few places on the south
coast of Norway, viz, in the outer part of the Christiania Fjord, at Farsund, and
at Egersund. In all 3 places it occurred in only a few fathom’s depth, on a
sandy bottom covered by a thin layer of mud.

Distribution. — Kattegat (Meinert), Heligoland (Ehrenbaum), British Isles
(Goodsir), Stats. 6, 11, 18 of the Porcupine Expedition (Norman).

6. Diastylis tumida, (Lilljeborg).

(PI. XL.)

Cuma tumida , Lilljeborg, 0fvers. af Vetensk. Akad. Forliandl. 1855, p. 119.

Specific Characters. — Female. Body rather robust, with the anterior di¬
vision greatly tumefied, and of rounded ovoid form, with the dorsal face boldly
arched. Carapace very large and deep, more than twice as long as the exposed
part of the trunk, and considerably vaulted in its posterior part; surface perfectly
smooth, only clothed with scattered short hairs; pseudorostral projection not much
produced, with the tip very slightly upturned ; subrostral corners well marked,
almost rectangular. Last pedigerous segment with the lateral parts rounded oh
behind. Tail about the length of the anterior division, segments simple, unarmed.
Eye well developed and rather conspicuous, appearing as a distinctly projecting
tubercle at the end of the frontal lobe. Superior antennae slender, with the
peduncle reaching far beyond the tip of the pseudorostral projection, its 1st
joint shorter than the other 2 combined and unarmed. First pair of legs about
the length of the carapace, basal joint much shorter than the remaining part of
the leg, the last 3 joints of rather unequal length, the penultimate one being
much the longest, last joint comparatively short, not even attaining half the
length of the penultimate one; 2nd pair with the ischial joint produced below to

53

2 short successive dentiform projections, antepenultimate joint about the length
of the last 2 joints combined; 3rd and 4th pairs, like the 2 preceding pairs,
with the basal joint unarmed. Uropoda with the rami subequal in length and
about half as long as the stem, inner ramus rather narrow, with the 1st joint
shorter than the other 2 combined, spinules of the inner edge about 12 in
number (7 on the 1st, 3 on the 2nd, and 2 on the last joint), apical spine rather
produced, mucronate. Telson scarcely reaching as far as the stem of the uro¬
poda, proximal half thick, cylindrical, distal half gradually narrowed, and armed
on each side with about 9 spinules, apical spinules a little larger than the lateral.
Colour whitish, joints of the superior antennae and 1st pair of legs tinged at the
end with reddish brown. Length amounting to 9 mm.

Adult male of the usual slender form. Carapace much shallower than
in the female and almost 3 times as long as the exposed part of the trunk,
exhibiting on each side a slight longitudinal keel, pseudorostral projection com¬
paratively shorter than in female, ocular tubercle rather large and prominent.
Last pedigerous segment considerably produced at the lateral corners. Caudal
segments armed dorsally with scattered denticles. The several appendages trans¬
formed in the usual manner. Length amounting to 10 mm.

Remarks. — This form was first described by Prof. Lilljeborg from Kulla-
berg in Skane as Cuma tumida, and was subsequently observed by Dr. Daniels-
sen on the west coast of Norway. At first I believed it to be the Alauna rostrata
of Goodsir, and that it was the same species as Diastylis Icevis of Norman ; but,
as stated above, this supposition has turned out to be wrong. It is unques¬
tionably specifically different from that form, and easily distinguished both by its
more robust form of body, and by several structural details, mentioned in the
above diagnosis.

Occurrence. — I have found this form in several pdaces on the Norwegian
coast, from the Christiania Fjord to the Lofoten Islands, though nowhere in any
considerable number. It is a true deep-water form, scarcely occurring in shal¬
lower water than 30 fathoms, whereas it descends to depths of more than 300
fathoms. Only a few specimens of the adult male have come under my notice.

Distribution. — Kullaberg (Lilljeborg), Kattegat (Meinert).

54

7. Diastylis Goodsiri (Bell)

(PI. XLI.)

Alauna Goodsiri, Bell, in Belcher’s Last of the Arctic Voyages, Yol. II, p. 403,

PI. XXXIV, fig. 3.

Syn: Diastylis plumosa, M. Sars.

Specific Characters. — Female. Body of very robust form, and thickly
covered all over with short plumose hairs, anterior division considerably tumefied
and broadly oval in form, with the dorsal face boldly arched. Carapace large
and deep, fully twice as long as the exposed part of the trunk, and greatly
vaulted above, surface without any spines or denticles; pseudorostral projection
rather produced, conical, horizontal, subrostral corners obsolete. Last pedigerous
segment with the lateral parts scarcely produced behind. Tail (exclusive of the
terminal appendages) somewhat shorter than the anterior division, lateral corners
of the 5 anterior segments much produced, spiniform. Eye inconspicuous. Sup¬
erior antennae with the 1st joint of the peduncle very large, much longer than
the other 2 combined, and clothed at the tip with numerous long plumose sets,
last joint shorter than the 2nd. Inferior antennae with the terminal joint un¬
usually large, conically produced, apical seta very much elongated. First pair of
legs scarcely longer than the carapace, basal joint almost attaining the length of
the remaining part of the leg, and spinulose in its distal part, being moreover
fringed with numerous long plumose setm, the last 3 joints not very different
in length ; 2nd pair with the basal joint rather large and curved, being minutely
denticulate outside, and fringed along the lower edge with a dense row of long
plumose setse, antepenultimate joint longer than the last 2 combined; 3rd and
4th pairs comparatively strongly built and densely setiferous, basal joint partly
denticulate. Uropoda with the rami subequal in length, and about half as long
as the stem, inner ramus mucronate, with the joints imperfectly defined, spinules
of the inner edge about 12 in number and, like those of the stem, unusually
slender, setiform. Telson rather produced, reaching as far as the stem of the
uropoda, proximal thickened part comparatively short, distal part armed on each
side with numerous slender, setiform spinules, amounting to 20 in all, apical
spinules very small. Colour whitish. Length about 25 mm.

Remarks. — This form was first recorded by Bell from the polar islands
of America as Alauna Goodsiri, and was some years afterwards found off the
Finmark coast by my late father, who regarded it as new, and described it
briefly under the name of Diastylis plumosa. It is by far the largest of all

55

known Cumacea, growing in the polar sea to a still larger size than off the
Norwegian coast. Dr. Hansen gives the length of a specimen from the Kara
Sea to no less than 35 mm., a truly gigantic size for a Cumacean. Like the 2
preceding species, this form is distinguished by the total absence of any spines
or denticles on the carapace, being however well distinguished not only by its
much larger size, but also by several other characters mentioned in the above
diagnosis. Dr. Hansen has given a most elaborate description of both sexes
in his paper on the Crustacea procured during the Danish “Djimpha” Expedition.

Occurrence. — I have not infrequently taken this huge form in the Varanger
Fjord at Vadso, where it was also found hy my late father. It occurred here
at a depth of about 60 fathoms, on a bottom consisting of very soft clay, with
which the specimens were generally thickly covered. This form has also been
found more recently in the fjords near Tromso, for instance the Malangen Fjord;
but farther south it has not been observed. No fully adult male specimen has yet
come under my observation; but Dr. Hansen describes such specimens from the
Kara Sea, and from his figure and description, it appears that the transformation
is perfectly analogous to that observed in other species of the genus.

Distribution. Polar Islands of North America (Bell), Greenland (Hansen),
Jan Mayen (Norw. North Atl. Exped.), Spitsbergen (do.), the Barents Sea (Hoek),
the Kara Sea (Hansen), the Siberian Polar Sea (Stuxberg).

8. Diastylis spinulosa, Heller.

(PL XL II.)

Diastylis spinulosa, Heller, Crust., Pycn. uud Tunic. Oestr. Ungar., Nordpol Expd. p. 28,

PI. 1, fig. 5.

Specific Characters.— Female. Body somewhat resembling in its general
form that of D. Goodsiri, but at once differing in its coarse spiny armature;
anterior division rather tumid, and boldly arched dorsally. Carapace very large,
more than twice as long as the exposed part of the trunk, and somewhat depressed
in its anterior part, the dorsal face sloping rather steeply towards the base of
the pseudorostral projection, surface without hairs, but exhibiting a number of
very strong anteriorly-curving spiniform projections, especially densely crowded
together on the upper part of the branchial regions, about 15 being counted on
each side; a row of 4 strong spines also extends forwards to each side of
the frontal lobe, occupying, in the dorsal view of the animal, the lateral edges,
the frontal lobe itself having, somewhat in front of the middle, 2 somewhat smal¬
ler and more erect, juxtaposed spines; pseudorostral prominence horizontally

56

projecting and somewhat depressed, minutely spinulose laterally, and terminating
in a conical point ; subrostral corners obsolete. Exposed part of trunk with
scattered spiniform projections, two of which on each of the 4 anterior segments
are very conspicuous, forming together dorsally a double longitudinal row, last
segment with a median spine above, its lateral parts but slightly produced be¬
hind, terminating in an acute corner. Caudal segments with the lateral corners
produced in a similar manner to that in D. Goodsiri, and moreover coarsely
denticulate. Eye inconspicuous. Superior antennae with the peduncle scarcely
extending beyond the tip of the pseudorostral projection, its 1st joint longer
than the other 2 combined. First pair of legs of moderate length, basal joint
spinulous in its distal part, penultimate joint somewhat longer than both the
preceding and succeeding joints; 2nd pair with the basal, ischial and meral joints
spinulous, antepenultimate joint scarcely longer than the last 2 combined; 3rd
and 4th pairs rather strong, with the basal joint partly denticulate. Uropoda
with the rami somewhat exceeding half the length of the stem, the inner one
having the joints well defined, the 1st being somewhat shorter than the other 2
combined; spinules of the inner edge of usual appearance and about 8 in number
(4 on the 1st, and 2 on each of the last 2 joints), apical spine rather slender.
Telson very much produced, extending far beyond the stem of the uropoda, prox¬
imal thickened part occupying somewhat more than 1/3 of the length, distal part
armed on each side with about 8 spinules, apical spinules somewhat thicker, but
scarcely longer than the lateral. Colour pale carneous. Length 18 mm.

Memories. — This form was first described under the above name by Heller
from specimens procured at Franz Joseph Land during the Austrio-Hungarian
Expedition. It is one of the largest known Cumacea, and clearly distinguished
by the coarse spiny armature of the body. The form described by the present
author from a single young male specimen procured during the Norwegian North
Atlantic Expedition as D. nodosa, is very nearly allied to the present species, and
is even regarded by Dr. Hansen as merely a variety of D. spinulosa.

Occurrence. — A few specimens of this beautiful form were taken by the
present author, many years ago, in the Varanger Fjord at Vadso, from a depth
of about 100 fathoms. During the Norwegian North Atlantic Expedition 2 other
specimens were found at about the same depth in the Porsanger Fjord. These
are the only localities of the Norwegian coast where this species has hitherto
been found. Among the specimens procured are also 2 young males, and both
af these agreed exactly with the females as regards the armature of the carapace.

Distribution. — Franz Joseph’ Land (Heller), the Barents Sea (Hoek), the
Kara Sea (Stuxberg), Greenland (Hansen).

57

9. Diastylis eehinata, Sp. Bate.

(pi. xxni.)

Diastylis eehinata , Sp. Bate, Ann. & Mag. Nat. Hist. ser. 3, Vol. XV, p. 81, PI. I, fig. 1.

Specific Characters. — Female. Body less robust than in the 2 preceding
species, and minutely spiny all over, anterior division evenly vaulted above, and
having its greatest width in front of the middle. Carapace very large and tumid,
the width considerably exceeding the height, surface finely spinulous, with scattered
somewhat larger spines, lateral faces partly mapped out by rows of small spin-
ules into polygonal areas having, as a rule, at each corner an anteriorly-pointing
spine, 3 or 4 somewhat larger spines forming on each side a lateral series
extending forwards to the base of the pseudorostral projection, the latter of
moderate size, conically produced, horizontal and finely spinulose laterally ; subro-
stral corners obsolete. Exposed segments of trunk each with 2 very conspicuous
juxtaposed spines dorsally forming together a double longitudinal row, epimeral
parts of the 3 posterior segments dentiformly produced. Caudal segments coarsely
denticulate both dorsally and laterally. Eye inconspicuous. Superior antennae
not much elongated, the peduncle scarcely extending beyond the tip of the pseudo¬
rostral projection, its 1st joint about the length of the other 2 combined. First
pair of legs rather slender, through scarcely exceeding the length of the carapace,
basal joint fully as long as the remaining part of the leg, and coarsely spinulous
at the edges, ihe last 2 joints of about equal length and shorter than the an¬
tepenultimate one; 2nd pair with the basal, ischial and meral joints coarsely
spinulous, antepenultimate joint rather slender, exceeding the length of the last
2 combined ; 3rd and 4th pairs slender, with the basal joint partly spinulous.
Uropoda not much elongated, rami exceeding half the length of the stem, the
inner one a little shorter than the outer, and having only 6 spinules inside (3
on the 1st, 2 on the 2nd,, and 1 on the last joint), apical spine strong, mucroni-
form. Telson extending beyond the stem of the uropoda, and less narrowed
than usual, its proximal half being of nearly uniform width throughout, distal half
slightly tapered, and armed on each side with only 3 spinules, apical spinules
a little larger than the lateral. Colour whitish. Length amounting to 10 mm.

Adult male, as usual, much more slender than the female, with the
carapace less deep and more evenly vaulted above, having on each side behind,
a coarsely denticulated lateral keel, which however scarcely extends beyond the
middle; anterior part of carapace fringed on each side with a row of densely

8 — _ Crustacea.

58

crowded spinules continued along the side of the pseudorostral projection, lateral
faces otherwise nearly smooth, with only very slight traces of the polygonal
areas found in the female. Exposed part of trunk with the dorsal spines less
distinct than in female. Caudal segments partly denticulate also on the ventral
face. The several appendages transformed in the usual manner. Length 1 1 mm.

Remarks. — This form was first described by Sp. Bate in the year 1865
from Shetland specimens, and was subsequently found by the present author also
off the Norwegian coast. It is an easily recognizable species, being markedly dis¬
tinguished by the elegant manner in which the spiny armature of the carapace
is arranged.

Occurrence. — Though occurring nowhere in any considerable number, this
form seems to be distributed along the whole south and west coasts of Norway,
from the Christiania Fjord to Hasvig in West Finmark. It is, however, a very
pronounced deep-water form, being only found in greater depths ranging from
100 to 400 fathoms. Of the adult male, I have as yet seen only 2 specimens,
one of which is figured on the accompanying plate.

Distribution. — Shetland Isles (Sp. Bate), off the Skagen Lighthouse (Meinert),
Stat. 9 of the Lightning Expedition (Norman), Stats 31 & 124 of the Norwegian
North Atlantic Expedition (the present author).

10. Diastylis scorpioides (Lepechin).

(PI. XLIV.)

Oniscus scorpioides , Lepechin, Acta Petropol. 1778. Yol. I.

Syn: Cuma Edwardsii, Kroyer.

„ Cuma brevirostris , Kroyer (adult male).

„ Diastylis Edwardsii (auctorum).

Specific Characters. — Female. Body comparatively robust, with the
anterior division of ovoid form and boldly arched dorsally. Carapace of moderate
size, with the dorsal margin considerably sloping in front, surface without any
spines, but sculptured on each side with 5 rather conspicuous, obliquely trans¬
verse plicae minutely crenulated at the edge, the 2 anterior rather short and
curved anteriorly, the 3 succeeding ones extending throughout the whole depth
of the carapace from the most prominent part of the branchial region to the
anterior part of the lower edge, where they unite; hind edge of carapace like¬
wise elevated in the form of a crenulated plica; pseudorostral projection rather
short, conical, horizontal; subrostral corners very slight. Exposed segments of
trunk with the anterior edge more or less distinctly elevated and finely crenulated,

59

epimeral parts of last segment scarcely produced behind. Tail (exclusive of the
terminal appendages) about the length of the anterior division, segments simple,
unarmed. Eye fairly well observable and somewhat convex. Superior antennae
of moderate length, the peduncle reaching somewhat beyond the tip of the pseu-
dorostral projection, its 1st joint about the length of the other 2 combined.
First pair of legs a little longer than the carapace, basal joint densely fringed
with setae and slightly spinulous in its distal part, the last 3 joints scarcely
differing in length; 2nd pair with the antepenultimate joint nearly twice the
length of the last 2 combined; 3rd and 4th pairs of moderate size and scarcely
spinulous. Uropoda with the outer ramus about half the length of the stem,
inner ramus somewhat shorter, and armed inside with about 8 spinules (4 on
the 1st, 2 on each of the last 2 joints), apical spine, as usual, strong, mucro-
nate, not defined at the base. Telson extending as far as the stem of the uropoda,
proximal thickened part occupying about y3 of the length, distal part rather
narrow, and armed on each side with about 8 spinules, apical spinules of about
the same appearance as the lateral. Colour reddish brown. Length 10 mm.

Adult male much more slender than the female, with the anterior division
of the body less strongly arcuate above. Carapace, as usual, less deep and more
tumid in its anterior part, exhibiting, however, the very same sculpture as in
the female; pseudorostral projection shorter and more obtuse. Last pedigerous
segment with the lateral corners very little produced, though clothed with the
usual plumose setae. Tail unarmed. Inferior antennae remarkably short, scarcely
exceeding in length the anterior division of the body; the other appendages
transformed in the usual manner. Length 11 mm.

Remarks. — According to Dr. Stuxberg, the species generally known as
Diastylis (Cuma) Edwardsii Ivroyer is without any doubt identical with the form
recorded by Lepechin as early as in the year 1778 as Oniscus scorpioides, and
the specific name proposed by that author ought accordingly to be retained for
this species. The Cuma brevirostris of Ivroyer is unquestionably the adult male
of this species. It is an easily recognizable form, being at once distinguished
from the other northern species by the peculiar sculpture of the carapace, which
is equally distinct in both sexes. The shortness of the inferior antennae in the adult
male is a unique character as regards the species of the present genus.

Occurrence. — I have found this form rather abundantly in several places
on the Finmark coast, as also off the Lofoten Islands. During the Norwegian
North Atlantic Expedition it was also taken in the inner part of the Saltenfjord;
but it has not yet been observed outside the polar circle.

60

Distribution. — Greenland (Kr0yer), Jan Mayen (Norw. North Atl. Exp.),
the Kara Sea (Stuxberg), the Siberian Polar Sea (Stuxberg).

Gen. 2. Diastyloides, G. 0. Bars, n.

Generic Characters. — General appearance that of the genus Diastylis, the
anterior division being sharply marked off from the posterior and rather tumid,
at least in the female. Carapace large, with the pseudorostral projection strongly
prominent. Tail slender. Eye wanting. Superior antennae about as in Diastylis.
Inferior antennae in female with the last joint very small, tuberculiform, and
without the apical plumose seta, which is replaced by a few very small auditory
bristles; those in male fully attaining the length of the body. Mandibles rather
unlike those in Diastylis, the body forming, as in Leucon, a broad lateral ex¬
pansion, and having at the base of the thick molar process a conical projection;
masticatory part comparatively short and stout, cutting teeth indistinct, spines of
the inner edge few in number. The other oral parts, as also the legs, about
as in Diastylis. Pleopoda of male less perfectly developed than in that genus,
1st pair with both rami uniarticulate, 2nd pair with the rami confluent to a
single piece. Uropoda with the rami very slender, the inner one generally longer
than the outer, and scarcely mucroniform, apical spine well defined at the base.
Telson less produced than in Diastylis, with the apical spinules much larger
than the lateral ones; in male very much bent, forming above at the flexure
a projecting angle.

Remarks.— 1 have felt justified in establishing this new genus to comprise
2 Norwegian species iormerly referred by me to the genus Diastylis, but differing
from it very pronouncedly in some characters of apparently generic value. The
structure of the mandibles especially is very unlike that in Diastylis, and much
more resembling that found in the family Leuconidce. Moreover, the inferior
antennae of the female are rather different, and the pleopoda of the male are
less fully developed. It is as yet scarcely possible to state with certainty, if
there are any species among the exotic Diastylidae referable to this genus, though
it may probably be the case.

61

11. Diastyloides serrata, G. 0. Sars.

(PI. XLV.)

Diastylis serrata , G. 0. Sars. Om den aberrante Iirebsdyrgruppe Cumacea, p. 44.

Specific Characters. — Female. Body moderately slender, with the anterior
division oval in form, and considerably vaulted dorsally. Carapace very large
more than twice as long as the exposed part of the trunk, and evenly arcuate
above, frontal lobe short and broad, ocular lobule almost obsolete, surface nearly
smooth throughout, though, on a closer examination, the upper part of the
branchial regions appears clothed with very small, anteriorly-curving denticles;
pseudorostral projection greatly produced, horizontal, tip acuminate and slightly
deflexed, subrostral corners obsolete, lower edges of carapace coarsely serrate
throughout their whole length. Last pedigerous segment with the lateral parts
scarcely produced behind, though terminating in an acute corner. Tail slender,
with the segments quite simple. Superior antennte with the peduncle not reaching
to the tip of the pseudorostral projection, its 1st joint somewhat shorter than
the other 2 combined. First pair of legs scarcely longer than the carapace,
basal joint not nearly attaining the length of the remaining part of the leg, and
strongly spinous on the lower edge, penultimate joint longer than the antepenulti¬
mate, last joint comparatively short, not even attaining half the length of the
penultimate one; 2nd pair with the basal joint produced at the end below to a
strong spiniform projection, antepenultimate joint about the length of the last 2
combined; 3rd and 4th pairs rather slender and having the basal joint coarsely
denticulate behind. Uropoda with the rami nearly equal in length, and not much
shorter than the stem, the inner one slender and attenuated, with the 1st joint
almost twice as long as the other 2 combined, spinules of the inner edge about
12 in number (9 on the 1st, 2 on the 2nd, and 1 on the last joint), apical
spine slender and well defined at the base. Telson comparatively short, scarcely
exceeding in length 1/3 of the uropoda, its proximal part rather thick, distal part
but slightly tapered, and armed on each side with about 5 small spinules, apical
spines rather large and pointing straight behind. Colour whitish with a faint
yellowish tinge. Length 6 mm.

Aclult male very slender, with the anterior division far less tumid than
in the female, and but slightly vaulted above. Carapace perfectly smooth and
less deep than in female, pseudorostral projection somewhat shorter and more
horizontal. Last pedigerous segment with the lateral parts narrowly produced
behind. Tail very slender and having the segments unarmed. Antennse and

62

legs exhibiting the usual transformation. Pleopoda of the structure characteristic
of the genus. Uropoda very slender, with the inner ramus somewhat longer
than the outer, and armed inside with about 20 ciliated spinules. Telson consi¬
derably more produced than in the female, and exhibiting above at the flexure
a very distinct angular projection, distal part narrow, linear. Length amounting
to 7 mm.

Remarks. — The present species, first described in the year 1864 by the
present author, may be easily recognized in both sexes by tbe evenly vaulted
carapace, the very prominent pseudorostral projection, and the coarse serration
of the lower edges of the carapace, which latter character has given rise to the
specific name serrata.

Occurrence. — Of the south and west coasts of Norway, this form is by
no means unfrequent, occurring in some places, for instance in the Christiania
Fjord, rather abundantly in depths ranging from 30 to 100 fathoms, muddy
bottom. Its northern distribution extends to Hasvig in west Finmark, and I
have found it there, as also in some other places, down to a depth of 300
fathoms. Male specimens (in the adult state) are found at some periods of the
year not infrequently. They are extremely agile and in almost constant motion.

Distribution. — Off the Skagen Lighthouse (Meinert).

12. Diastyloides biplieata, G. O. Sars.

(PI. XLVI).

Diastylis biplieata, 6. 0. Sars, Om den aberrante Kvebsdyrgruppe Cuniacea, p. 46.

Syn : Diastylis lamellate, Norman.

„ Diastylis Calveri, Norman (adult male).

Sjtecific Characters. — Female. General form of body resembling that of
the preceding species, anterior division, however, still more tumefied, approaching
the globular shape. Carapace large and broad, the width considerably exceeding
the height, dorsal face somewhat gibbously vaulted behind, lateral faces sculptured
with 2 very distinct oblique plicae extending from the most prominent part of the
branchial region, and joining at the anterior part of the lower edge, hind edge
of carapace elevated to a similar plica; pseudorostral projection rather large and
slightly upturned, being somewhat hollowed at the base, subrostral corners in¬
conspicuous, anterior half only of the lower edges coarsely serrate. Exposed seg¬
ments of trunk with the anterior edge more or less distinctly elevated, lateral
parts of last segment scarcely produced behind, though terminating in an acute
corner. Caudal segments simple, unarmed. Superior antennae with the peduncle

63

extending about to the tip of the pseudorostral projection, its 1st joint shorter
than the other 2 combined. First pair of legs very much elongated, about
equalling in length, when fully extended, the whole anterior division, basal joint
scarcely half as long as the remaining part of the leg, and coarsely spinous on
the lower edge, penultimate joint fully as long as the 3 preceding joints combined,
last joint not attaining half the length of the former; 2nd pair of legs with both
the basal and ischial joints produced at the end below to a strong spiniform
projection, antepenultimate joint rather slender, exceeding the last 2 combined;
3rd and 4th pairs with the basal joint coarsely denticulate. Uropoda rather
slender, with the inner ramus considerably longer than the outer, and almost
attaining the length of the stem, its 1st joint more than twice as long as the
other 2 combined, spinules of the inner edge about 12 in number (9 on the 1st,
2 on the 2nd and one on the last joint), apical spine very slender. Telson more
produced than in I). serrata, though scarcely reaching as far as the stem of the
uropoda, being abruptly constricted near the base, distal part very narrow, linear,
with about 6 small spinules on each side, apical spines rather large, slightly
diverging. Colour more or less tinged with reddish brown. Length 7 mm.

Adult male exhibiting the usual slender form, with the anterior division
of the body considerably narrowed behind. Carapace more evenly vaulted above
than in female and very tumid in its anterior part, lateral faces exhibiting a low
longitudinal keel in addition to the 2 oblique plicre, which are fully as distinct
as in the female. Last pedigerous segment with the lateral corners acutely pro¬
duced. Tail nearly smooth. Antennae and legs transformed in the usual manner.
Pleopoda about as in the male of D. serrata. Uropoda exceedingly slender, inner
ramus exceeding the outer by its last joint, and armed inside with about 28 spi¬
nules. Telson abruptly geniculate at about the first third of its length. Length
about 8 mm.

Remarks. — Though nearly allied to the preceding species, as regards
the chief structural details, this form is at once distinguished by the still more
tumid anterior division of the body, and especially by the form and sculpture
of the carapace. The D. lamellata of Norman is unquestionably the same species,
and the D. Calveri of the same author must also be withdrawn as only founded
on the adult male of this species.

Occurrence. — I have found this form not unfrequently in several places,
both on the south and west coasts of Norway, from the Christiania Fjord to the
Lofoten Islands. It is generally found together with the preceding species, and,
like it, has a very great range in depth.

«

64

Distribution. — Skagerak and Kattegat (Meinert), British Isles (Norman),
Several Stations of the Porcupine Expedition, down to 1630 fathoms (Norman).

Gen. 3. DiaSty lopsis, Sidn. Smith, 1880.

Generic Characters. — General appearance resembling that of Diastylis.
Carapace, however, less tumid, and having the antero-lateral corners well marked ;
pseudorostral projection more or less produced. Third and 4th exposed segments
of trunk more or less completely consolidated, at least in the female. Tail
slender and very flexible. Eye wanting. Superior antennae comparatively strongly
built, with the 1st joint of the peduncle unusually short, 3rd rather large and
clothed with plumose setae. Inferior antennae in female very small, in male
almost attaining the length of the body. Oral parts about as in Diastylis.
First pair ot legs with the outer 3 joints very slender; 2nd pair comparatively
short; the 3 posterior pairs very robust and adapted for digging. Pleopoda of
male of a similar structure to that in Diastylis. Uropoda and telson likewise
of essentially the same structure as in that genus.

Remarks. — This genus was established in the year 1880 by Prof. Sidn.
Smith, to comprise a North American species, D. Dawsoni, and the Rev. T. R.
Stebbing has recently pointed out, that Kr oyer’s Cuma resima ought to be re¬
ferred to the same genus. It was chiefly founded upon the supposed unique
character, that the 3rd and 4th exposed segments of the trunk appeared wholly
consolidated. It is true that these segments are very firmly connected; but in
the Norwegian species at least, a well-marked suture may in reality be proved to
exist between them. There are, however, otherwise sufficient differences from
Diastylis to warrant the maintenance of this genus. The species recorded by
Dr. Bonnier from the Gulf of Gascogne as Diastylopsis (?) tumida scarcely belongs
to this genus, as, like Leptostylis, it has rudimentary exopodites to the 3rd and
4th pairs of legs.

65

13. Diastylopsis resima (Kroyer).

(PI. XLVII.)

Cuma resima, Krayer, Nat. Tidsskr. new series, Vol. II, pp. 165 & 206, PI. II, figs. 2a, 2b.

Syn: Diastylis resima (auctorum)

Specific Characters. — Female. Body comparatively short and clumsy,
with the anterior division, seen dorsally, oblong oval in form. Carapace rather
large, though scarcely twice as long as the exposed part of the trunk, dorsal
face evenly vaulted, frontal lobe rather broad, with a double row of small den¬
ticles along the middle (3 in each row), lateral parts with a row of 3 similar
denticles on each side of the frontal lobe, surface otherwise perfectly smooth;
pseudorostral projection rather large and abruptly upturned, nose-like, with a
number of long plumose setae issuing from the tip and diverging in a radiating
manner; lower edges of carapace coarsely denticulate in their anterior halves,
the 2 distal denticles placed somewhat more widely apart, the foremost one
rather strong and occupying the antero-lateral corner, being defined from the
pseudorostral projection by a slight sinus. The 3 posterior pedigerous segments
remarkably flattened above, with the epimeral parts abruptly recurved and very
large, rounded behind; dorsal part of 3rd segment very narrow, band-shaped.
Tail (exclusive of the terminal appendages) scarcely as long as the anterior
division, segments simple, unarmed. Superior antennae with the peduncle more
or less bent upwards, 1st joint armed at the end on each side with a strong
spine, accompanied above by a plumose seta, last joint about the length of
the other 2 combined, and carrying along the outer edge 9 strong plumose setae.
First pair of legs about the length of the carapace, basal joint scarcely more
than half as long as the remaining part of the leg, and armed in its distal
part below with 3 strong spiniform projections, the middle one especially being

very prominent, penultimate and antepenultimate joints of about equal length,

last joint considerably shorter; 2nd pair not attaining even half the length of
the 1st, basal joint about the length of the remaining part of the leg and fringed
with a limited number of long plumose setae, antepenultimate joint scarcely at¬
taining the length of the last 2 combined ; 3rd and 4th pairs very strongly built,
and considerably larger than the 2nd, carpal joint unusually short, lamelliform,
and fringed along the inner edge with 6 strong, unciliated setae. Uropoda with

the outer ramus almost the length of the stem, and clothed along the outer edge

and at the tip with numerous setae increasing in length distally, inner ramus con¬
siderably shorter than the outer, and narrowly attenuated, with only 3 spinules
inside (1 on each of the 3 joints), apical spine long and slender. Telson scarcely

9 — Crustacea.

66

extending to the end of the stem of the uropoda, proximal half thick and cylindrical,
distal half abruptly attenuated, and armed on each side with about 4 slender,
almost setiform spinules, apical spinules likewise slender and about the length of
the lateral. Colour greyish, with a more or less distinct yellowish brown tinge.
Length about 5 mm.

Adult male much more slender than the female, with the carapace less
deep and quite unarmed, pseudorostral projection of a rather different appearance
from that of the female, being nearly horizontal, with the apical setae very small,
subrostra] corners rectangular, unarmed. Exposed segments of trunk of altogether
normal appearance, epimeral parts of last segment acutely produced behind.
Each of the 3 anterior caudal segments with a median denticle ventrally. The
several appendages transformed in a manner similar to that in Diastylis.
Length 6 mm.

Remarks. — This peculiar form was first described in the year 1846 by
Kroyer from Greenland specimens, and was subsequently found by the present
author also off the Norwegian coast. From the upturned, nose-like pseudorostral
projection with its long, radiating, apical set®, the peculiar form of the exposed
segments of the trunk, and the generally much bent, narrow tail, the female
acquires a rather extraordinary appearance, well represented by Kroyer in PI. 3
of the great work, Gaimard’s “Voyage en Scandinavie5', Zoology. The hitherto
unknown adult male, on the other hand, exhibits a much more normal aspect,
resembling on the whole the males of other Diastylidse.

Occurrence. — I have found this form in great abundance in the Varanger
Fjord at Vadso, as also in another place on the Finmark coast, viz, Hammerfest.
More recently I have also met with it in certain localities on both the west and
south coasts of Norway, for instance in the Trondhjem Fjord, at Christiansund,
and at Mterdo, off Arendal. From this occurrence it would seem, that the
present species is distributed along the whole coast of Norway, though it must
evidently be regarded as originally a true arctic form. It is generally found in
moderate depths, ranging from 6 to 20 fathoms, on a bottom consisting of muddy
clay, with which the body is generally thickly covered. As indicated by the very
strongly built posterior pairs of legs, it possesses very great dexterity in rapidly
burying itself deeply in the mud, so that often only the tip of the upturned
pseudorostral projection with its circle of apical set® is visible above the surface.
When taken up, it generally curves its tail abruptly upon the dorsal face of the
anterior division. The adult males, as is generally the case, are much more
agile than the females, and are often found swimming about with great speed,
whereas it is rather unusual to see the females ever leave the bottom.

67

Distribution. — Greenland (Kro'yer), Atlantic coast of North America
(Verrill), Spitsbergen (Norw. North Atl. Exped.), the Kara Sea (Stuxberg), Skage¬
rak and Kattegat (Meinert).

Gen. 4. Leptostylis, G. 0. Sars, 1869.

Generic Characters. — General form of body that of Diastylis, being some¬
times very slender, sometimes rather robust, anterior division (at least in female)
considerably tumefied and sharply marked off from the tail. Eye wanting. Superior
antennae in female about as in Diastylis, in male conspicuously transformed, the
peduncle being greatly dilated, claviforin, and clothed at the end with numerous
diverging sensory filaments forming a dense brush, which almost conceals the
flagella. Inferior antennae in male much more feebly developed than in Dia¬
stylis, and scarcely exceeding the anterior division of the body in length. Oral
parts and anterior pairs of legs about as in Diastylis. Third and 4th pairs of
legs in female with a very small, though distinct biarticulate appendage (rudi¬
mentary exopodite) outside the basal joint. Pleopoda in male less fully developed
than in Diastylis. Uropoda with the rami very slender, the inner one being much
the longer, and distinctly 3-articulate. Telson remarkably short, with only a
single pair of lateral spinules.

Remarlcs. — This genus was established in the year 1869 by the present
author, to comprise some species formerly referred by him to the genus Diastylis,
but, on a closer examination, found to differ in certain characters rather con¬
spicuously, especially as regards the structure of the antennae and pleopoda of the
male. Another distinguishing character of the female, at first overlooked, is the
presence of rudimentary exopodites on the 3rd and 4th pairs of legs, like those
found in the genera Lamprops and Hemilamprops. The generic name Leptostylis
is derived from the unusually slender rami of the uropoda ; and the very short
telson, with its single pair of lateral spinules, also forms an easily recognizable
character of the present genus. We know as yet of 6 species, 4 of which belong
to the Norwegian fauna, and will be described below. Moreover, Dr. J. Bonnier
has recorded a form from the Gulf of Gascogne as Leptostylis longicaudata, which
however, in my opinion, cannot properly be referred to the present genus,
in spite of its being provided with rudimentary exopodites on the 3rd and 4th
pairs of legs.

68

14. Leptostylis longimana, G. 0. Sars.

(pi. xLvra).

Diastylis longimana, G. 0. Savs. Om den aberrante Krebsdyrgruppe Cumacea, p. 48.

Specific Characters. — Female. Body comparatively slender, though having
the anterior division considerably tumefied and rounded oval in form. Carapace
large and deep, more than twice as long as the exposed part of the trunk, and
slightly vaulted above, surface perfectly smooth throughout, and only clothed
with scattered small hairs; pseudorostral projection of moderate size, triangular,
subrostral corners obsolete, lower edges of carapace abruptly curved in the
middle, with the anterior half minutely denticidate. Epimeral parts of the 3
posterior pedigerous segments comparatively small and rounded off behind. Tail
(exclusive of the terminal appendages) exceeding the length of the anterior division
and very slender. Superior antennae rather elongated, the peduncle extending far
beyond the tip of the pseudorostral projection, its last joint scarcely shorter than
the 1st, but much narrower, and, like the 2nd, clothed on both edges with slender
bristles. First pair of legs exceedingly slender and elongated, and, when fully
extended, exceeding half the length of the body, basal joint occupying scarcely more
than V3 of the length of the leg, and without any spinules, penultimate joint of
extraordinary length, fully equalling that of the 3 preceding joints combined, last
joint comparatively short, not attaining even 1/3 of the length of the penultimate
one; 2nd pair likewise rather slender and much curved, basal joint comparatively
short, last joint very slender, exceeding the length of the antepenultimate one; 3rd
and 4th pairs rather narrow, with the rudimentary exopodite easily observable and
carrying a single apical bristle. Uropoda much elongated, with the inner ramus
very narrow, and exceeding the outer by its last joint, 1st joint longer than the
other 2 combined, spinules of the inner edge only 5 in number (3 on the 1st,
and 1 on each of the last 2 joints), apical spine very slender, almost setiform.
Telson not attaining even the length of the last caudal segment, and rather thick
at the base, distal part abruptly narrowed and, as in the other species, provided
with only a single pair of lateral spinules near the tip, apical spines somewhat
larger, and extended straight behind. Colour whitish. Length 0V2 mm.

Adult male scarcely more slender than the female, but having the
carapace less deep, and the pseudorostral projection more prominent. Tail scarcely
exceeding in length the anterior division, and very narrow, unarmed, terminal
appendages scarcely different from those in the female. Length about 5 mm.

Remarks. — This form was first described by the present author as a
species of the genus Diastylis, the specific name proposed being derived from the

69

unusually prolonged 1st pair of legs. It may be regarded as the type of the
present genus, and also in other respects is easily recognizable from the 3 other
Norwegian species.

Occurrence. — I first found this form in the Christiania Fjord, both in the
immediate vicinity of Christiania, and at Drobak. Subsequently I have also met
with it, though rather sparingly, in some other places on the south and west
coasts of Norway, as far north as the Lofoten Islands. It generally occurs in
depths ranging from 30 to 100 fathoms, muddy bottom.

Distribution. — Off the Skagen Lighthouse (Meinert), Atlantic coast of
North America (Verrill).

15. Leptostylis maerura, G. 0. Sars.

(PI. XLIX).

Leptostylis maerura, (i. O. Sars. Nye Dybvandscrustaceer fra Lofoten. Chr. Yid. Selsk.

Forhandl. 18o9, pag. 156.

Specific Characters.— Female. General form of body resembling that of
the preceding species, the anterior division being very tumid, almost globose in
form, and sharply marked off from the slender tail. Carapace large, more than
twice as long as the exposed part of the trunk, and but slightly vaulted above,
surface smooth, though rather densely clothed with hairs, pseudorostral projection
comparatively shorter than in the type species. Tail (exclusive of the terminal
appendages) much longer than the anterior division, and very narrow. Superior
antennse less elongated than in L. longimana, last joint of the peduncle much
shorter than the 1st, and setiferous only at the end. First pair of legs slender,
though not nearly so elongate as in the type species, basal joint exceeding half
the length of the remaining part of the leg, penultimate joint about the length
of the 3 preceding joints combined, last joint rather short; 2nd pair with the
terminal joint shorter than the antepenultimate one; 3rd and 4th pairs very
narrow, rudimentary exopodite with 3 apical setae. Uropoda less elongated than
in L. longimana, inner ramus with the last joint longer than the 1st, spinules
of inner edge 5 in number (2 on the 1st joint, 1 on the 2nd, and 2 on the last),
apical spine very slender, setiform. Telson very small and but slightly narrowed
distally, exhibiting a similar armature to that in L. longimana. Colour greyish
white. Length about 5 mm.

Adult male comparatively more slender than that of the type species.
Carapace somewhat more depressed than in female, and provided on each side
with a very conspicuous, coarsely serated carina extending throughout its entire

10 — Crustacea.

70

length. Appendages transformed in a similar manner to that in the male of
L. lonyimana.

Remarks. — This form is nearly allied to the type species, though easily
distinguishable in both sexes, being especially recognizable by the extremely slender
and narrow tail, and by the coarsely serrated lateral keels of the carapace in
the male.

Occurrence. — I first found this form off the Lofoten Islands, and have
subsequently met with it also in several other places on the Norwegian coast,
for instance, in the outer part of the Hardanger Fjord, at Aalesund, in the Trond-
hjem Fjord, and at Vadso. It is generally found in depths ranging from 50 to
150 fathoms, muddy clay.

Distribution. — Stat. 33 of the Norwegian North Atlantic Expedition (the
present author).

16. Leptostylis ampullaeea (Lilljeborg).

(PL L, fig. 1).

Duma ampullaeea, Lilljeborg, 0fvvrs. Vet. Akad. Forh. 1855, p. 120.

Syn: Diastylis ampullaeea, G. 0. Sars.

Specific Characters. — Female. Body comparatively short and clumsy, with
the anterior division much tumefied and considerably vaulted above. Carapace
large and somewhat sloping in front, surface smooth and clothed with scattered
slender hairs, pseudorostral projection comparatively short and bluntly triangular
in form, subrostral corners rounded off, inferior edges coarsely serrate in their
anterior halves. The first 2 pedigerous segments each having the anterior edge
emarginated in the middle, and forming on each side of the emargination a slight
appressed lappet. Tail (exclusive of the terminal appendages) scarcely longer
than the anterior division, and comparatively less slender than in the 2 preceding
species. Superior antenna with the 1st joint of the peduncle almost as long as the
other 2 combined. First pair of legs not much elongated, scarcely exceeding in
length the carapace, basal joint about the length of the last 3 joints combined,
penultimate joint somewhat longer than the antepenultimate one, last joint com¬
paratively short; 2nd pair with the terminal joint nearly as long as the ante¬
penultimate one; the 3 posterior pairs less slender than in the 2 preceding species.
Uropoda comparatively short, inner ramus almost as long as the stem, and exceeding
the outer by about V* of its length, 1st joint about the length of the other 2
combined, spinules of the inner edge 5 in number (3 on the 1st, and 1 on each
of the last 2 joints), apical spine slender, setiform. Telson about half the length

71

of the stem of the uropoda, and exhibiting the form and armature characteristic
of the genus. Colour dark yellowish grey or fuscous. Length 6 mm.

RemarTcs. — This form was briefly described in the year 1855 by Prof.
Lilljeborg as Cuma ampullacea, and was subsequently referred by the present
author to the genus Diastylis. It is, however, unquestionably referable to the
genus Leptostylis, exhibiting, as it does, all the leading features of that genus,
though differing remarkably from the 2 preceding species in its unusually clumsy
form of body.

Occurrence. — Though nowhere in any abundance, I have found this form
along the whole Norwegian coast, from the Christiania Fjord to Vadso, in mode¬
rate depths ranging from 30 to 100 fathoms. Fully adult male specimens have not
yet come under my notice; but even in the immature state, the strong development
of the superior antennse, so characteristic of the present genus, is very obvious.

Distribution. — Kullaberg (Lilljeborg), Kattegat (Meinert), Atlantic coast
of North America (Verrill).

17. Leptostylis villosa, G. 0. Sars.

(PI. L, fig. 2).

Leptostylis villosa, G. 0. Sars. Undevsegelser over Christiamafjordens Dybvandsfauna, p. 40.

Specific Characters. — Female. Anterior division of body greatly tumefied,
almost globose in form, and very sharply marked of from the extremely slender
tail. Carapace large and deep, more than twice as long as the exposed part of
the trunk, and thickly covered with stiff hairs in a fur-like manner ; pseudorostral
projection very short and blunt, lower edges throughout divided into peculiar
lamellar serrations. The first 2 pedigerous segments exhibiting a structure of the
anterior edge similar to that in L. ampullacea. Tail (exclusive of the terminal
appendages) exceeding the length of the anterior division, and exceedingly nar¬
row. Superior antennse with the last joint about the length of the 1st, but much
narrower. First pair of legs very slender, exceeding the length of the anterior
division of the body, basal joint scarcely attaining more than half the length of
the leg, penultimate joint much longer than the antepenultimate, last joint com¬
paratively short; 2nd pair with the terminal joint very slender, exceeding the
length of the antepenultimate; rudimentary exopodite of 3rd and 4th pairs
extremely small though distinct. Uropoda of moderate length, inner ramus much
longer than the outer, and nearly attaining the length of the stem, its 1st joint
not nearly as long as the other 2 combined; spinules of the inner edge only 4
in number (2 on the 1st, and 1 on each of the last 2 joints), apical spine slender,

72

setiform. Telson not attaining half the length of the stem of the uropoda, and
exhibiting the usual shape and armature. Colour light fuscous. Length 4 mm.

Remarks. — This form is nearly allied to L. ampullacea, though easily
distinguishable by its less strongly built body, the almost globose and densely hairy
anterior division, and the extremely slender tail. It is also much inferior in size.

Occurrence. — I first found this form in the Christiania Fjord, at Holme-
strand, where it occurred rather abundantly, and have subsequently met with it
also in several other places on the Norwegian coast, as far north as Vadso. It
is a pronounced deep-water form, only occurring in depths below 60 fathoms, on
a muddy bottom. I have not hitherto succeeded in finding adult male specimens
of this species either. Out of Norway, this form has not yet been recorded.

Fam. 6. Pseudocumidae.

Characters. — Body of various forms, sometimes very slender, sometimes
comparatively short and clumsy. Anterior division generally well marked off from
the posterior, and having 5 segments exposed behind the carapace; the latter of
moderate size and without any spiniform protuberances, pseudorostral projection
of varying form, subrostral corners generally well marked, lower edges unarmed.
Tail slender, smooth. Eye generally well developed. Superior antennse only
slightly different in the two sexes, inner flagellum rudimentary. Inferior antennae
in female very small, in male well developed, resembling those in the male
Diastylidce. Oral parts on the whole normal. The 2 anterior pairs of legs in
female, and all but the last pair in male, provided with well-developed exopodites;
3rd and 4th pairs in female with a small appendage (rudimentary exopodite)
outside the basal joint. Two pairs of pleopoda present in the male, the posterior
pair, however, very small and rudimentary. Uropoda with the inner ramus uni-
articulate, the outer Inarticulate. Telson well defined from the last caudal seg¬
ment, but very small, flap-shaped.

Remarks. — This family in some characters apparently approaches the
Diastylidce, in others the Lampropidce, but evidently ought to be kept apart from
all of them. With the Diastylidce it agrees among other things in the structure
ot the inferior antennse in the male, as also in the presence of only 2 pairs of

73

pleopoda; with the Lampropidce in the presence of rudimentary exopodites to the
3rd and 4th pairs of legs in the female. From both these families it differs
conspicuously in the structure of the telson, and the uniarticulate inner ramus of
the uropoda. The marine forms of this family are very few in number, and
belong to two nearly-allied genera, to he described below. On the other hand,
as recently stated by the present author, this family is very abundantly repre¬
sented in the Caspian Sea, exhibiting in this isolated basin quite a wonderful
variety of form. No less than 13 different species have hitherto been detected,
and some of these differ so widely in their external appearance from the marine
forms, that at first sight they might easily he supposed to belong to quite diffe¬
rent families. A closer examination has proved, however, that they all agree in
the more essential anatomical features first pointed out in the genus Pseudocuma,
and for this reason they have all been described as members of this genus. If,
however, the establishment of the family Pseudocumidce be sanctioned, of course
a more general value must be ascribed to several of these characters ; and indeed
I am now of opinion that the Caspian species ought to be referred to several
distinct genera comprised within the present family, only one of them, P. cerca-
roides belonging to the type genus. The other species I propose to arrange
as follows:

Gen. 1, Pterocuma, G. 0. Sars, with the species pectinata. Sowinskyi and
rostrata; gen. 2, Stenocuma, G. 0. Sars, with the species gracilis, graciloides,
tmuicauda and diastyloides ; gen. 3, Schizorhynchus with the species bilamellatus,
eudorelloides, scabriusculus and dbbreviatus ; gen. 4, Caspiocuma with the species
campylaspoides.

Gen. 1. Pseudocuma, G. 0. Sars, 1864.

Syn: Lexicon, v. Beneden (not Kroyer).

Generic Characters. — Body not very slender, with the anterior division well
marked off from the posterior. Integuments thin, exhibiting a densely squamous
structure. Carapace of moderate size, dorsal face flattened and sloping in front,
lateral faces generally sculptured with oblique plicse, pseudorostral projection
more or less prominent, with the lateral parts contiguous along the dorsal line,
subrostral corners obtusangular. Exposed segments of trunk unarmed. Tail

74

rather slender. Superior antennae of normal appearance. Inferior antennae in
female extremely small, uniarticulate, with a single apical seta; those in male
generally shorter than the body. Branchial apparatus with the gill-elements rudi¬
mentary. Third pair of maxillipeds pediferm, with the outer corner of the basal
joint not produced, and carrying a single strong plumous seta. First pair of
legs of normal structure, and not much produced; 2nd pair with the terminal
joint in male more or less distinctly hooked at the tip. Anterior pair of pleopoda
rather large, with the basal part lamellar and carrying strong setse inside, rami
confluent; posterior pair very small, claviform, without setae. Uropoda moderately
slender, rami narrow lanceolate, the inner one the longer.

Remarks. — This genus was established by the present author in the year
1864, to include a small Cumacean found off the Lofoten Islands, and at that
time regarded as new, but subsequently identified with a form very imperfectly
described and figured by P. van Beneden as Lexicon cercaria. In the restriction
of the genus here adopted, it comprises only 3 other species, viz., the Mediter¬
ranean form, P. ciliata G-. 0. Sars, the Caspian form, P. cercaroides G-. 0. Sars,
and a new Norwegian species, to be described farther on.

l. Pseudoeuma eerearia (v. Beneden).

(PI. LI & LII).

Lexicon cercaria l’. v. Beneden, Recherches sur la Paune littorale de Belgique.’

Crustaces, p. 85, PI. IV.

Syn: Pseudoeuma histriata, G. 0. Sars.

„ ? Cyrianassa longicornis, Sp. Bate (male).

„ Ouma bella, Meinert.

Specific Characters. — Female. Body more slender than in the other species,
with the anterior division considerably vaulted dorsally and ovate in form. Cara¬
pace somewhat exceeding in length the exposed part of the trunk, and sloping
considerably in front, lateral faces sculptured with 2 distinct oblique plicae
extending from the hindmost part of the branchial regions to the subrostral
corners, the latter unarmed; pseudorostral projection rather prominent, termi¬
nating in an acute point. Tail very slender, slightly exceeding in length the
anterior division. First pair of legs scarcely longer than the carapace, basal
joint occupying about half the length of the leg, the 3 distal joints rapidly dimi¬
nishing both in length and width, terminal joint very narrow, linear; 2nd pair
with the terminal joint conically tapered and about the length of the antepenulti¬
mate one; 3rd and 4th pairs not very slender, rudimentary exopodite distinctly

75

biarticulate, and carrying 2 seta? at the tip. Uropoda moderately slender, outer
ramus about the length of the stem, inner ramus considerably longer, with about
10 spinules inside, apical spine rather strong. Telson semicircular, with 3 slight
serrations on each side. Body more or less richly ornamented with a dark brown
pigment. Length scarcely exceeding 4 mm.

Adult male considerably more slender than the female, and having the
anterior division less vaulted above. Carapace more flattened, and with the
pseudorostral projection less prominent. Eye larger, with the visual elements
more distinct. Basal joint of the 4 anterior pairs of legs greatly dilated; termi¬
nal joint of 2nd pair with a single apical hook. Anterior pleopoda with 4 strong
set® inside the basal part; posterior pair with 2 slender spines outside the tip.
Uropoda more slender than in female, stem with 4 slender setae inside, inner
ramus rather produced, and armed inside with about 14 spinules. Telson fully as
long as it is broad at the base, edges unarmed.

Jiemarlcs. — As mentioned above, this form was first recorded by P. v.
Beneden as a species of the genus Leucon ; but both the description and the
figures given are rather unsatisfactory, and on this account I did not at first
recognize its identity with the Norwegian form, but described the latter as a new
species under the name of P. bistriata. The Cyrianassa longicornis of Sp. Bate
may perhaps be the male of this species, and if so, the specific name longicornis
has really priority in date to that proposed by P. v. Beneden. This name, however,
would, be rather inappropriate, as it only refers to the one sex, and even there
is far from being significant. The Cuma bella of Meinert is unquestionably the
female of this species. The form described by the present author from the Medi¬
terranean as P. cercaria, differs slightly from the Norwegian form; but the diffe¬
rences do not seem to me to be great enough to warrant a specific distinction.

Occurrence. — I first found this form off the Lofoten Islands, where it is
very common in the shallow sounds and bays around the fishing stations. Sub¬
sequently I have also met with it in several other places on the Norwegian coast,
from the Christiania Fjord to Vadso, though nowhere in such abundance as off
the Lofoten Islands. It generally occurs in comparatively shallow water, on a
bottom composed of fine sand covered with a thin layer of blackish mud. Some¬
times it is even found on the beach in pools left by the tide. It is a very active
little animal, being almost constantly in motion, now swimming about through the
water, now burrowing in the sand, and twisting its slender tail in all directions.
Adult males are not infrequently found together with the females and, as usual,
are still more agile and less confined to the bottom.

76

Distribution. — Kattegat (Meinert), British Isles (Robertson), Heligoland
(Ehrenbaum), Dutch coast (v. Beneden), coast of France (de Folin), Mediterranean
at Messina, Syracusa and Goletta (the present author).

2. Pseudoeuma similis, G. 0. Sars, n. sp.

(Pi. LIII).

Specific Characters. — Very like the type species, but of larger size and
less slender in form. Carapace sculptured on each side with 2 well-marked
oblique plicae similar to those occurring in P. cercaria, pseudorostral projection
less prominent, subrostral corners armed in front with 3 distinct denticles. Tail
(excluding the terminal appendages) about the length of the anterior division,
and less narrow than in the type species. Eye very conspicuous, especially in
the male. Antennae, oral parts and legs about as in P. cercaria, terminal joint
of 2nd pair of legs in male, however, with 3 denticles at the tip, the distal one
hamiform. Anterior pair of pleopoda with only 2 setae inside the basal part,
posterior pair with a single spine outside. Uropoda somewhat more slender than
in the type species, rami shorter than the stem, and differing very little in length,
the inner one in female with about 6, in male with 12 spines inside. Telson in
female rounded quadrangular in form, being transversely truncated behind, edges
smooth. Colour yellowish, anterior division of body more or less variegated with
a light brownish pigment. Length of female about 5 mm., of male 5 ‘/a mm.

Remarks. — This form' is closely allied to the type species, and, indeed,
it is only quite recently that I have become aware of its specific distinctness. It
is of somewhat larger size than P. cercaria, and less slender in form, and also
lighter in colour. On a closer examination, it may also be easily distinguished
by the less prominent pseudorostral projection, the quadridentate subrostral cor¬
ners, and the structure of the uropoda and telson.

Occurrence. — The only place where I have hitherto met with this form,
is at Skudesnses, west coast of Norway. It occurred here together with the type
species in a depth of 6 — 12 fathoms, on a bottom consisting of coarse sand
and gravel.

Gen. 2.

Petalosarsia, stebbing, 1893.

Sj'n : JPetalopws, G. 0. Sars.

„ Petalomera , G. 0. Sars.

Generic Characters. — General form of body about as in Pseudocuma, though
comparatively shorter and more compact, at least in female. Integuments greatly
indurated. Carapace large, with the upper face flattened and declining obliquely
to the prominent pseudorostral projection. Exposed segments of trunk smooth.
Eye less perfectly developed than in Pseudocuma. Superior antennje with the 2nd
joint of the peduncle lamelliformly dilated, last ioint very small. Inferior antennse
in female distinctly biarticulate, with an apical and a lateral seta, those in male
attaining the length of the body. Oral parts about as in Pseudocuma. First pair
of legs of a rather peculiar appearance, the ischical and meral joints being firmly
connected with each other, and the carpal joint enormously developed, folia-
ceous, last 2 joints small and admitting of being bent in against the inner face
of the carpal one. Second pair of legs comparatively short; 3rd and 4th pair
in female with a very small rudimentary exopodite. Pleopoda of male resembling
in structure those in Pseudocuma. Uropoda with the stem much shorter than the
rami, the inner of which is densely hairy inside. Telson semicircular, unarmed.

Remarks. — This genus was established by the present author in the year
1864; but as the name at that time proposed, Petalopus, and also that substituted
later, Petalomera, had been previously appropriated in Zoology, the Rev. Mr.
Stebbing has recently proposed to name the genus as above, a compound indeed,
which is quite sure not to have been previously employed. The genus is closely
allied to Pseudocuma, more so, indeed, than at first supposed. The peculiar
structure of the 1st pair of legs still seems, however, to warrant the validity of
the genus. We know at present of only a single species, to be described below'.

3. Petalosarsia deelivis, G. 0. Sars.

(PI. LIV).

Petalopus deelivis, G. 0. Sars. Om den aberrante Krebsdyrgruppe Cumacea, p. 72.

Syn : Petalomera deelivis , G. 0. Sars.

Specific Characters. — Female. Body comparatively short and compact,
writh the anterior division rather tumid and sharply marked off from the posterior,
dorsal face boldly vaulted behind the middle. Carapace nearly twice as long as

li — Crustacea.

78

the exposed part of the trunk and rather deep, with a strongly marked carina
running on each side, nearer the dorsal side, from the hindmost part of the
branchial regions to the base of the pseudorostral projection, the latter rather
prominent, acute, subrostral corners very small, terminating in a minute denticle.
Tail (excluding the terminal appendages) shorter than the anterior division. Su¬
perior antennae with the peduncle scarcely projecting beyond the tip of the pseu¬
dorostral projection, its 2nd joint rounded oval, with 3 blunt serrations of the
inner edge, last joint extremely small. First pair of legs about the length of the
carapace, ischial and meral joints forming together a rather short and broad
triangular piece intercalated between the basal and carpal joints, the latter joint
very large and broad, forming an oblong quadrangular plate, to the outer corner
of which the 2 small distal joints are very movably attached. Second pair of
legs scarcely more than half as long as the 1st, antepenultimate joint rather
broad, and of same appearance as the preceding one, terminal joint conically
tapered, with several long bristles at the tip. Uropoda about the length of the
last 2 caudal segments combined, inner ramus somewhat larger than the outer,
and almost twice the length of the stem, with only 3 spinules, 2 apical and one
lateral, inner edge minutely serrate and densely hairy throughout. Colour uni¬
formly yellow, without any pigmentary ornament. Length about 4 mm.

Adult male much more slender than the female, with the anterior divi¬
sion less vaidted above. Carapace with an additional carina on each side,
running parallel to the other and nearer the ventral side; pseudorostral projection
shorter and blunter than in female. Appendages exhibiting the usual transfor¬
mation. Length nearly 5 mm.

Remarks. — This form was originally described from only 2 specimens,
both of the female sex, the one not fully developed; and owing to this scantiness
of material, some errors had been introduced in the original diagnosis. Thus
the 1st pair of legs are described as only 5-articulate, whereas in reality, they
are composed of the normal number of joints, 2 of them, however, the ischial
and meral ones, being so firmly connected as to exhibit the appearance of a
single joint. The eye, which was stated to be wholly wanting, is in reality
present in its usual place, though in a rather imperfect condition. Moreover,
the extremely small and rudimentai’y exopodites on the 3rd and 4th pairs of
legs were at that time overlooked. The characters of the male, too, could of
course not be given.

Occurrence. — The 2 specimens from which the original description was
made, were taken off the Lofoten Islands in a depth of 50 — 60 fathoms, on a

79

sandy bottom. Subsequently I have met with this form not unfrequently in 2
places on the Finmark coast, viz., Hasvig and Yadso in about the same depth.

Distribution. — Spitsbergen (Norw. North Atl. Expedition), Franz Joseph
Land (T. Scott), Heligoland (Ehrenbaum).

Fam. 7. Nannastacidae.

Syn : Cumellidce, G. 0. Sars.

Characters. — Body, as a rule, not very slender, sometimes even unusually
short and compact, with the anterior division well defined from the posterior.
Carapace large, with the pseudorostral projection more or less produced, subrostral
corners well defined and sometimes very prominent, lower edges generally serrate
in their anterior part. Five pedigerous segments freely exposed behind the cara¬
pace, the first very narrow, band-like. Tail slender and narrow. Eyes two in
number, separated by a distinct interspace, or confluent to a single median organ,
as in most other Cumacea. Superior antennse of exactly the same appearance
in the two sexes, inner flagellum rudimentary. Inferior antennse in female very
small and indistinctly articulated, in male well developed, though as a rule shorter
than the body. Oral parts on the whole normal. The 2 anterior pairs of legs
in female with well developed exopodites, the 3 posterior pairs simple and very
narrow, terminating in a hooked claw. All legs in male, except the last pair,
with exopodites, and having the basal joint greatly dilated. Pleopoda absent.
Uropoda resembling in structure those in the Pseudocumidce. No telson.

Remarks. — The present family comprises as yet 2 very distinct genera,
viz., Nannastacus Sp. Bate and Cumella G. 0. Sars, especially distinguished by
the very different structure of the visual organ, the species of the first-named
genus having 2 well-defined eyes, whereas those of the 2nd have hut a single
median eye, as in most other Cumacea. The genus Nannastacus being the first to be
established, the family, according to the rule in Zoology, ought to be named from
it, and not from the genus Cumella, as previously done by the present author.
The family in some respects forms a transition to the last very anomalous family,
Campylaspidce, agreeing with it, among other things, in the total absence of a
telson and of pleopoda in the male. The structure of the oral parts, however, is

80

very dissimilar in these two families, only the anterior lip exhibiting some approach
to the structure characteristic of the Campylaspidoe. The genus Spenccbatea of
Norman may perhaps be referable to the present family ; but this genus is as
yet very imperfectly known, only a solitary male specimen having been procured.
The genus Diops of Paulson, I regard as identical with Sp. Bate's genus Nanna-
stacus. In the Norwegian Fauna, only one of the two genera is represented.

Gen. Cumella, G. O. Sars, 1864.

Generic Characters. — Body of rather different appearance in the two sexes.
Carapace in female somewhat compressed, and provided with a dentated crest
along the middle, in male quite smooth throughout; pseudorostral projection more
or less produced. Tail in both sexes very slender and mobile, with the last
segment angularly produced behind. Integuments rather thin, and exhibiting a
distinctly squamous structure. Eyes confluent to a single organ occupying its
usual place at the end of the frontal lobe, and much more fully developed in male
than in female. Superior antennae rather slender, with the inner flagellum biarticulate
or uniarticulate. Inferior antennae in female biarticulate, with 2 plumose set® inside,
terminal joint extremely small and tipped with a simple bristle; those in male with
the penultimate joint of the peduncle well defined, and clothed with unusually long
sensory filaments. Anterior lip produced in front to a conical prominence. Man¬
dibles rather slender, with the cutting part narrowly exserted, and provided with
only a limited number of spines inside, molar expansion short and thick. Maxillae
of quite normal structure. First pair of maxillipeds with the terminal joint
lamelliform, epipodal part of branchial apparatus in female quite simple, in male
provided with a limited number of digitiform gill-elements. Second pair of maxilli¬
peds with the basal joint much shorter than the remaining part, and carrying
inside 2 unusually strong plumous setae; 3rd pair with the basal and meral joints
produced at the outer corner, the former carrying 2, the latter 1 strong ciliated
seta. First pair of legs with the basal joint comparatively short and thick, ter¬
minal part slender; 2nd pair normal; the 3 posterior pairs successively diminishing
in length. Uropoda moderately slender, with the rami shorter than the stem, the
inner one the larger and spinulous inside.

Remarks. — This genus, established by the present author in the year 1864,
is at once distinguished from Nannastacus of Sp. Bate by the eyes being confluent

81

to a single organ, as in most other Cumacea, and also by the dentated crest of
the carapace in the female. Besides the type species described below, another
very distinct species, C. limicola, has been recorded by the present author from
the Mediterranean.

Cumella pygmaea, G. 0. Sars.

(PI. LV).

Cumella pygmcea, G. 0. Sars. Om den aberrante Krebsdyrgruppe Cumacea, p. 74.

Syn: Cumella agilis, Norman (male).

Specific Characters. — Female. Body comparatively short, with the anterior
division very sharply marked off from the slender tail. Carapace exceedingly
large and deep, being more than 3 times as long as the exposed part of the
trunk, its anterior part rather compressed, dorsal face evenly arched, and crested
throughout its entire length, the crest being armed with from 8 to 12 minute
anteriorly-curving denticles; pseudorostral projection comparatively short, sub-
rostral corners distinctly prominent, and defined above by an even emargination.
Tail (excluding the terminal appendages) somewhat shorter than the anterior divi¬
sion, and very narrow. Eye fairly conspicuous and circular in form. Superior
antennse with the inner flagellum distinctly biarticulate. First pair of legs scarcely
attaining the length of the carapace, basal joint about the length of the 3 suc¬
ceeding joints combined, and strongly serrate at the end on both edges, ante¬
penultimate joint fully as long as the last 2 joints combined; 2nd pair with the
terminal joint about the length of the antepenultimate one. Uropoda with the
stem coarsely serrate inside, inner ramus rather large, though shorter than the
stem, and armed with about 7 spinules increasing in length distally, outer ramus
very narrow, with a slender spine at the tip. Body more or less dark-coloured
owing to a brown pigment, especially conspicuous on the carapace. Length
about 2V2 mm.

Adult male somewhat more slender than the female, with the anterior
division far less vaulted above, and scarcely at all compressed in front. Cara¬
pace shallower and quite unarmed, with the upper margin nearly straight ; pseu¬
dorostral projection shorter, subrostral corners less prominent. Eye very large,
and subquadrangular in form, with 7 distinct cornern, one median and 3 lateral
on each side, the former very prominent. Inferior antennse slightly exceeding
the anterior division of the body in length. Basal joint of the 4 anterior pairs
of legs greatly dilated. Uropoda differing but slightly in structure from those
in female.

82

Remarks. — This is one of the smallest known Cumacea, and may thus
easily escape attention in an examination of the contents of the dredge. It is,
however, an easily recognizable form, being clearly distinguished in both sexes
from our other Cumacea. As is generally the case in this order, the sexual
dimorphism is very pronounced, and indeed the adult male looks so different from
the female, that it was at first regarded by the Rev. Mr. Norman as belonging
to a distinct species, C agilis.

Occurrence. — Though nowhere in any abundance, this form seems to occur
along the whole south and west coast of Norway, from the Christiania Fjord to
the Lofoten Islands. It is generally found in comparatively shallow water, on a
sandy bottom covered with a thin layer of blackish mud, sometimes also at the
roots of Laminarias. The adult males are very agile, and have been taken by
English naturalists (Robertson) rather abundantly in the tow-net at night.

Distribution. — British Isles (Norman), Heligoland (Ehrenbaum), Mediter¬
ranean at Messina and Spezia (the present author).

Fam. 8. Campylaspidse.

Characters — Body comparatively short and robust, with the anterior
division much dilated and boldly arched above. Carapace of unusual size, more
or less depressed in front and strongly vaulted behind. Five pedigerous segments
exposed behind the carapace, the 2 anterior ones, however, very short, band-like.
Caudal segments more or less depressed, the last one short, pentagonal. Integu¬
ments greatly indurated. Eye present, thougl rather imperfectly developed.
Superior antennae of exactly the same structure in the two sexes; inner flagellum
rudimentary. Inferior antennae in female imperfectly developed and without any
setae, in male attaining the length of the body. Oral parts of a structure rather
different from that in other Cumacea, some of them being very fully developed,
others rather imperfect. The 2 anterior pairs of legs in female, and all but the
last pair in male provided with exopod ites. Pleopoda wanting in male. Uropoda
with the rami comparatively short, the inner uniarticulate, the outer Inarticulate.
No telson.

83

Remarks. — This family is founded upon a single genus, Campylaspis G. 0.
Sars, which, however, in several respects, and especially in the structure of the oral
parts, differs so materially from the other known Cumacea, that it should not pro¬
perly be referred to any of the above-recorded lamilies. Dr. Bonnier has recently
established another genus, Procampylaspis, to include a very remarkable Cumacean
taken in the Bay of Gascogne ; but I regard it as very questionable, if this genus
in reality is referable to the present family. In some respects it seems to me
to approach nearer to the Nannastacidce.

Gen. Campylaspis, G. 0. Sars, 1864.

Generic Characters. — Body in female short and compact, in male conside¬
rably more slender. Carapace of enormous size, and more or less bulging behind
over the exposed segments of trunk, its anterior part more or less exserted, and
terminating in a comparatively short pseudorostral projection, subrostral corners
very slight or wanting, lower edges af carapace smooth throughout. The first 2
pedigerous segments very narrow, and generally elevated dorsally to thin pro-
curved lamellae, epimeral plates of the 3 succeeding ones rounded and extended
laterally. Caudal segments, except the last, exhibiting laterally, in female, a pro¬
jecting nm, in male a deep groove, to receive the flagellum of the inferior
antennae. Superior antennae with the inner flagellum uniarticulate, knob-like.
Inferior antennae in female tuberculiform, in male well developed, with the penulti¬
mate joint of the peduncle distinctly defined, and clothed with very long sensory
filaments, flagellum . extremely slender, with elongated articulations. Anterior lip
unusually large, helmet-shaped, conically produced in front; posterior lip very
delicate, with the lateral lobes quite membranous. Mandibles with the body
slightly expanded inside, masticatory part distinctly incurved, and having the
cutting edge strongly dentated and somewhat oblique, with an appendicular plate
on the left mandible, and in both mandibles a restricted number of spiniform
set.se; molar expansion very narrow, styliform. Anterior maxillae very strong, with
both the masticatory and basal lobes abruptly incurved, and armed with strong,
partly denticulated spines, palp long and narrow, with one or two apical setae.
Posterior maxillae imperfectly developed, each forming a simple triangular plate
with a limited number of simple bristles at the tip. First pair of maxillipeds
with the meral joint lamellarly expanded, terminal part quite rudimentary, being

84

reduced to a single very small joint attached near the inner corner of the meral
joint; branchial apparatus well developed, gill-elements arranged in a semicircle,
digitiform in female, leaf-like in male. Second pair of maxillipeds of rather
anomalous appearance, basal joint very massive and confluent with the ischial
one, carpal and propodal joints connected at nearly a right angle, the former
triangularly expanded inside, the latter oblong oval in form, and terminating in
a setiform lappet, terminal joint very small and armed with strong diverging
spines. Third pair of maxillipeds of more normal structure, with the meral joint
more or less dilated. First pair of legs unusually small, and resembling in structure
the 3rd pair of maxillipeds; 2nd pair much bent, with the terminal joint styli-
form. The 3 posterior pairs of legs in female successively diminishing in length
and rather narrow, basal joint of 3rd and 4th pairs in male greatly dilated.
Uropoda with the rami shorter than the stem, the inner one the larger and
spinulous inside, stem in male clothed with slender setae inside.

Remarks. — This genus was established by the present author in the year
1864, to include the anomalous form described by Prof. Lilljeborg as Cuma
rubicunda, and at the same time 2 new Norwegian species were added. Subse¬
quently the number of species has been considerably augmented, amounting at
present to no less than 14. One of these species, however, the Greenland form,
C. earinata of Hansen, is, I think, scarcely referable to the present genus, and
may indeed even belong to a different family, the Nannastacidce. As, however,
neither the legs nor the oral parts of this form have been examined, it is impos¬
sible at present to settle this question. To the fauna of Norway belong 8 different
species, to be described below.

l. Campylaspis rubicunda (Lilljeborg).

(P). LVI, LVII).

Cuma rubicunda , Lilljeborg. 0fvers. af Vet. Akad. Fbrhandl. 1855, p. 121.

Specific Characters. — Female. Body very short and robust, with the an¬
terior division greatly tumefied. Carapace of quite an extraordinary size, occupying
half the length of the body, and boldly arched behind, surface perfectly smooth
throughout, frontal part but slightly exserted, pseudorostral projection short,
though acute at the tip, subrosti’al corners obsolete. The first 2 pedigerous seg¬
ments elevated dorsally to well-marked procurved lamellae. Caudal segments
distinctly depressed and comparatively short. Eye distinct, semicircular and
somewhat prominent. Anterior maxillae with the palp very slender and carrying
a single apical seta; posterior maxillae with only 3 apical bristles and one lateral.

85

Terminal joint of 1st pair of maxillipeds rather small, conical, with a single small
apical bristle; that of 2nd pair with 4 strong spines increasing in length from
before backwards. Third pair of maxillipeds rather robust, with the joints partly
serrate on the edges, meral joint considerably expanded, equalling in length the
2 succeeding ones combined. Second pair of legs with the last joint considerably
produced and very narrow, exceeding in length the 2 preceding joints taken
together. Uropoda not much elongated, stem coarsely serrate inside, inner ramus
about half its length, and armed with about 8 spinules increasing in length distally.
Colour bright red, frontal lobe and adjacent part of the dorsal face opaque white.
Length 5 mm.

Adult male considerably more slender than the female, with the anterior
division of the body less tumefied. Carapace comparatively shallower, with the
pseudorostral projection shorter and more obtuse. Uropoda more elongated, stem
clothed inside with about 12 minutely ciliated setae, of which the 5 outer ones are
rather elongated, inner ramus comparatively longer than in female and having a
greater number of spinules inside. Colour as in the female. Length about 6 mm.

Remarks. — As above stated, this form was originally described by Prof.
Lilljeborg as a species of the genus Cuma, and was subsequently subjected to a
closer examination by the present author. It is the first species noticed, and
may therefore be regarded as the type of the genus. From the other known
species it is easily recognizable by its bright red colour and the perfectly smooth
and strongly vaulted carapace. In the latter respect it only agrees with one of
the other Norwegian species, viz., C. glabra, whereas in the remaining species
the carapace exhibits a more or less pronounced sculpture, either in the form of
tuberculiform protuberances, or oblique plicae.

Occurrence. — I have found this form in several places on the Norwegian
coast, from the Christiania Fjord to Yadso, though nowhere in any abundance.
It generally occurs in depths ranging from 30 to 100 fathoms, on a muddy bottom,
in which it conceals itself with great dexterity. It moves rather rapidly through
the water, but only for a short while, very soon again sinking to the bottom by
its own weight. Adult males are found occasionally together with the females.
They are, as usual, much more agile, swimming about with great speed by the
aid of their numerous well-developed exopodites.

Distribution. — Kullaberg (Lilljeborg), Kattegat (Meinert), Arctic Ocean in
Lat. 75° 45' (the present author), Greenland, off Hosteinsborg (Norman), Atlantic
coast of North America (Verrill).

12 — Crustacea.

86

2. Campylaspis glabra, G. 0. Scars.

(PI. LVIII).

Campylaspis glabra, G. 0. Sai-s. Middelhavets Cumaceer, p. 129, PI. 44 — 47.

Specific Characters. —Female. Very like the type species, but of conside¬
rably smaller size, and comparatively less robust in form. Carapace very large
and boldly vaulted above, surface perfectly smooth throughout, frontal part as in
C. rubicunda. The first 2 pedigerous segments less strongly produced dorsally.
Tail more slender, with the segments nearly cylindric in form. Maxillae exactly
as in C. rubicunda. Terminal joint of 1st pair of maxillipeds still more rudi¬
mentary than in that species. Third pair of maxillipeds with the meral joint
large and expanded. Second pair of legs with the terminal joint shorter than
the 2 preceding ones combined. Uropoda rather slender, with the stem com¬
paratively narrow, and scarcely at all serrate inside, inner ramus somewhat
exceeding half the length of the stem, and armed with about 8 unusually slender
spinules. Colour whitish. Length scarcely exceeding 3 mm.

Adult male more slender than the female, with the carapace far less
vaulted above. Limbs transformed in the usual manner. Length nearly 4 mm.

Remarks. — On going through my material of C. rubicunda from the Nor¬
wegian coast, I have recently found some specimens of a form, which had previ¬
ously escaped my attention, and which I am unable to distinguish from the
Mediterranean species described in the above-mentioned paper. It is very closely
allied to C. rubicunda, but on a closer examination is easily distinguished by
its much smaller size and less robust form of body, as also by the different colour.

Occurrence. — As the specimens were found mingled together with C.
rubicunda from different localities, it is impossible for me at present to state
with certainty from which locality they were derived. I believe, however, that
at least some of the specimens were collected in the Trondhjem Fjord.

Distribution. — Mediterranean at Messina and Spezia (the present author).

3. Campylaspis sulcata, G. 0. Sars.

(PI. LIX).

Campylaspis sulcata , G. O. Sars, Nye Dybvandscrustaceer fra Lofoten.

Chr. Yid. Selsk. Forh. 1869, p. 161.

Specific Characters. — Female. Form of body resembling that in the type
species, though somewhat less robust. Carapace very large and boldly arched
above, dorsal face somewhat uneven in front, lateral faces with a very conspi-

87

cuous band-like depressed area, bounded by 2 projecting plicae, and extending
obliquely from the most prominent part of the branchial region to the base of
the pseudorostral projection, the latter rather short, subrostral corners very slight.
The first 2 pedigerous segments elevated dorsally to very distinct procurved
lamellae. Tail somewhat more slender than in the type species. Eye easily
observable, semicircular in form. Anterior maxillae with the palp bisetose; posterior
ones as in the 2 preceding species. Terminal joint of 1st pair of maxillipeds
extremely small; that of 2nd pair with 4 diverging spines. Third pair of maxilli¬
peds less robust than in the 2 preceding species, with the meral joint much
smaller, and not nearly attaining the length of the 2 succeeding joints combined.
Second pair of legs with the terminal joint rather produced, exceeding in length
the 2 preceding joints combined. The 3 posterior pairs of legs with the ante¬
penultimate joint serrate along the anterior edge. Uropoda comparatively slender,
stem coarsely serrate inside, inner ramus scarcely more than half as long as the
stem, and only armed with 3 spinules, inner edge minutely serrate. Colour whitish,
with a faint reddish tinge on the median part of the carapace. Length 47a mm.

Adult male, as usual, more slender than the female, with the carapace
less vaulted, but exhibiting the very same sculpturing. Uropoda considerably
more elongated, stem clothed with slender setse, inner ramus narrower and armed
with about 10 ciliated spinules. Length 5 mm.

Remarks. — This form is easily distinguishable by the very conspicuous
depressed area extending obliquely along each side of the carapace, a character
which has given rise to the specific name sulcata. It is otherwise very nearly
related to the 2 preceding species, both as regards the general appearance and
the structure of the several appendages.

Occurrence. — I first found this form off the Lofoten Islands, where it is
not unfrequent in depths ranging from 120 to 250 fathoms, on a bottom consisting
of sandy clay. Subsequently I have also met with it occasionally in 2 other
localities of the Norwegian coast, viz., in the outer part of the Hardanger Fjord
at Mosterhavn, and in the Trondhjem Fjord, at about the same depth. Out of
Norway this form has not yet been recorded.

4. Campylaspis eostata, G. 0. Sars.

(PI. LX).

Oampylaspis eostata, G. 0. Sars. Om den aberrante Krebsdyrgruppe Cumacea, p. 79.

Specific Characters. — Female. Body of the usual short and robust form,
with the anterior division greatly dilated. Carapace somewhat smaller than in

88

the 3 preceding species, not nearly attaining half the length of the body, dorsal
face evenly vaulted behind, anterior part somewhat exserted, lateral faces sculp¬
tured with 3 distinct oblique plicae, the hindmost being bifurcate in its upper
half; pseudorostral projection slightly prominent, subrostral corners distinct, though
obtuse. The first 2 pedigerous segments slightly produced dorsally, last segment,
like the 4 anterior caudal segments, with 2 small juxtaposed tubercles dorsally.
Eye rather narrow, of oval form. Anterior maxillae with the palp bisetose;
posterior ones with 5 apical bristles Terminal joint of 1st pair of maxillipeds
less rudimentary than in the 3 preceding species, and carrying on the tip a short
spine and a bristle; that of 2nd pair with 2 diverging spines having between them
a third much smaller one. Third pair of maxillipeds rather slender, with the
meral joint but very little expanded. Second pair of legs with the last joint
scarcely longer than the 2 preceding ones combined. Uropoda moderately slen¬
der, stem smooth, inner ramus somewhat exceeding half the stem in length, and
armed with about 8 spinules. Colour (in the living state of the animal) pale
reddish. Length 5 mm.

Adult male much more slender than the female, with the carapace conside¬
rably more flattened, though exhibiting the very same sculpturing. Limbs trans¬
formed in the usual manner. Length 6V2 mm.

Remarks. — By the peculiar sculpturing of the carapace, this species is
at once recognizable from any of the preceding ones. Moreover the carapace is
of somewhat smaller size and less vaulted above, and in the structure of the
appendages also some minor differences are found to exist.

Occurrence. — I have found this form not infrequently along the whole
Norwegian coast, from the Christiania Fjord to Yadso. It generally occurs in
depths ranging from 30 to 100 fathoms, on a muddy bottom.

Distribution. — British Isles (Th. Scott), Heligoland (Ehrenbaum).

5. Campylaspis undata, G. 0. Sars.

(PI. LXI),

Caynpylaspis undata , G. 0. Sars. Om den aberrant^ Krebsdyrgruppe Cumacea, p. 80.

Specific Characters. — Female. General form of body resembling that in
( ’. costata. Carapace, however, less strongly arched above, with the dorsal face
very uneven owing to irregular protuberances and ridges, which give the upper
contour an undulated appearance; lateral faces sculptured with 2 very prominent
plicse, originating from the hind part and extending in front, the upper one being
continued on the side of the pseudorostral projection, the lower terminating at

89

the subrostral corner, both plicae having a somewhat flexuous course. The first
2 pedigerous segments elevated dorsally to well-marked procurved lamellae, the 3
posterior ones each with 2 juxtaposed dorsal tubercles. Caudal segments rather
short, and somewhat elevated dorsally. Eye, as in C. costata, oval in form.
Antennae and oral parts almost exactly as in C. costata. Second pair of legs
rather robust, with the terminal joint less narrowed than in the other species,
and scarcely longer than the antepenultimate joint, its edges clothed with strong
curved bristles; the 3 posterior pairs with the antepenultimate joint serrate along
the anterior edge. Uropoda with the stem slightly serrate inside, rami very short,
the inner one not nearly attaining half the length of the stem, and armed with
only 4 spinules. Colour pale carneous. Length 6 mm.

Adult male exhibiting the usual differences from the female, the body
being more slender, and the carapace shallower, with a short transverse fold
connecting the 2 lateral plicae in front. Length reaching 7 mm.

Remarks. — In its general appearance, this form very much resembles
C. costata. It is, however, of considerably larger size, and, on a closer examina¬
tion, is moreover easily distinguishable by the less vaulted carapace and its
coarse sculpture. Some minor differences may also be proved to exist in the
structure of the legs and uropoda.

Occurrence. — I have hitherto only met with this form off the Lofoten
Islands, where it occurred rather sparingly in a depth of 100 — 200 fathoms.
Out of Norway it has not yet been recorded.

6. Campylaspis horrida, G. 0. Sars.

(PI. LXII).

Campylaspis horrida, G. 0. Sars. Nye Dybvandscrustacper fra Lofoten.

Chr. Yid. Selsk. Forh. 1869, p. 162.

Specific Characters. — Female. General form of body about as in the 2
preceding species. Carapace large and tumid, with the anterior part rather
exserted, surface very uneven owing to numerous conically produced protuberances,
especially densely crowded together on the dorsal face, whereas laterally they are
arranged in 2 longitudinal rows, the lower of which forms an almost continuous
carina, both series being connected in front by a somewhat irregular transverse
prominence continued on the side of the pseudorostral projection, which is rather
prominent, subrostral corners small but well defined. The first 2 pedigerous
segments, as usual, elevated dorsally to thin lamellae, the 3 succeeding ones, like
the 4 anterior caudal segments, provided with 2 juxtaposed dorsal tubercles,

90

lateral parts in all these segments acutely produced. Ocular lobule unusually
produced, linguiform ; visual elements imperfectly developed. Antennae and oral
parts as in the 2 preceding species. Second pair of legs resembling in structure
those in C. undata, though somewhat more slender. Uropoda with the stem
coarsely serrate on both edges, rami unusually small, the inner one scarcely
exceeding 1/3 of the length of the stem, and armed with only 4 spinules. Colour
dark red. Length about 6 mm.

Adult male exhibiting the usual sexual differences from the female, being
much more slender, and having the carapace shallower, with the dorsal protu¬
berances less produced. Length nearly 7 mm.

Remarks. — Though nearly related to the 2 preceding species, as regards
the structure of the several appendages, this form is at once recognizable by the
densely crowded conical protuberances occurring on the carapace and giving it
a very rough appearance, a character which has given rise to the specific name
horrida. Moreover the anterior part of the carapace is unusually exserted, and
the ocular lobule of a peculiar form.

Occurrence. — This form, too, was at first found off the Lofoten Islands,
and subsequently I have also met with it in several other places on the Nor¬
wegian coast, for instance in the outer part of the Hardanger Fjord, at Christian-
sund, and in the Trondhjem Fjord. It is generally found in depths ranging from
100 to 300 fathoms, on a soft muddy bottom. This species also has not as yet
been recorded out of Norway.

7. Campylaspis verrucosa, G. O. Sars.

(PI. LXI1I).

Campylaspis verrucosa, G. O. Sars. Zool. Reise veil Kysterne af Christianias og Christiansands

Stifter 1865, p. 24.

Specific Characters. — Female. Body rather short and stout, with the
anterior division greatly tumefied. Carapace large and swollen, evenly vaulted
above, and having the anterior part but slightly exserted, surface uneven owing to
scattered nodiform protuberances, which laterally have a tendency to arrange them¬
selves in longitudinal rows; pseudorostral projection short and obtuse, subrostral
corners well marked. The first 2 pedigerous segments elevated dorsally to pro-
curved lamellae, the 3 succeeding ones, like the 4 anterior caudal segments, with
a pair of slight dorsal tubercles. Ocular lobule oblong oval in form, visual
elements imperfectly developed. Antennae and oral parts as in the 3 preceeding
species. Second pair of legs with the terminal joint about the length of the

91

antepenultimate one and comparatively narrower than in the 2 preceding species.
Uropoda with the stem slightly serrate on both edges, inner ramus exceeding
half the length of the stem, and armed with 5 spinules. Colour whitish with a
faint greenish tinge. Length 5 Vs mm.

Adult male much more slender than the female, with the carapace shal¬
lower, and scarcely at all vaulted above. Appendages exhibiting the usual trans¬
formation. Length 6V2 mm.

Remarks. — This form is allied to C. horrida, but may be readily distin¬
guished by the somewhat different form of the carapace and the less numerous
and more obtuse protuberances clothing its surface. Moreover the stem of the
uropoda is considerably shorter, and the colour of the body very different. The
species described by the present author from the Challenger Expedition as C.
nodulosa strongly resembles the Norwegian form in its external appearance; but
the remoteness of the locality (Kerguelen Islands) must put its specific distinctness
beyond all doubt.

Occurrence. — I have found this species along the whole south and west
coast of Norway, as far north as the Lofoten Islands, and in some places, for
instance in the Trondhjem Fjord, very abundantly. It occurs in depths ranging
from 60 to 100 fathoms, muddy clay. The species is hitherto only known from
the Norwegian coast.

8. Campylaspis afflnis, CL 0. Sars.

(PI. LXIV).

Campylaspis affinis, G. 0. Sars. Nye Dybvandscrustaceer fra Lofoten.

Chr. Vid. Selsk. Forh. 1869, p. 160.

Specific Characters. — Female. Body comparatively more slender in form
than usual, with the anterior division less tumefied. Carapace of moderate size
and evenly vaulted above, with the anterior part but slightly produced, surface
nearly smooth, with only slight traces of a few obtuse protuberances in the anterior
part of the dorsal face; pseudorostral projection comparatively short, subrostral
corners small, though distinct. The first 2 pedigerous segments less narrow than
usual, and having the posterior edge but slightly elevated dorsally ; the succeeding
segments, as also the caudal ones, perfectly smooth. Terminal joint of 1st pair
of maxillipeds less rudimentary than usual, oval fusiform in shape, and finely
ciliated on the edges, tip carrying 2 unequal spines. Second pair of maxillipeds
with the seta issuing from the inner corner of the basal joint peculiarly trans¬
formed, penultimate joint not nearly so large as in the other species. Structure

92

of the ox-a] parts in other respects resembling that in the 4 preceding species.
Second pair of legs with the terminal joint considerably produced, exceeding in
length the 2 preceding joints combined. Uropoda rather slender, stem elongated
and perfectly smooth, inner ramus about half the length of the stem, and armed
with 8 spinules. Colour pale reddish. Length 5V2 mm.

Adult male comparatively more slender than the female, with the carapace
shallower. Uropoda still more elongated, and having the stem, as usual, clothed
inside with slender setae, inner ramus more produced and armed with about 15
spinules. Length 6 mm.

Remarks.— In the nearly smooth and evenly vaulted carapace this form
somewhat resembles the 2 species described at the head of this account. It is
however in reality more nearly allied to some of the other species, for instance
C. verrucosa, as regards the structural details. From any of the species it may
be easily distinguished by the less tumid carapace and by the structure of
the uropoda.

Occurrence. — Only 2 or 3 specimens of this form have hitherto come
under my notice. They were taken many years ago off the Lofoten Islands in
a depth of 200 — 250 fathoms. This species has not been recorded more recently
by any author.

On the Internal Organisation of Cumaeea.

(PI. LXV— LXVIII).

To show more clearly the relation of the Cumaeea to other Crustacea,
I propose in the following pages to give a short account of the internal organs
in this peculiar group. These investigations were made many years ago, chiefly
by the examination of fresh specimens, and only a few additions and corrections
have recently been supplied. In order to get a general view of the internal organs
in their natural situation, it is necessary to select some more pellucid forms, and
to examine them, while still alive, under the microscope,' applying transmitted
light. Several of the organs may thus be at once observed, whereas other
organs are less distinctly traced, owing to the imperfect pellucidity of the
integuments. In every case a close examination of the organs cannot be accom¬
plished without dissection. This should, if possible, be performed on fresh speci¬
mens, immediately after they have been killed, as a dissection of specimens
preserved for a long time in alcohol or other preserving fluids, always gives
far less satisfactory results as regards this part of the anatomy. An attempt
to make sections of alcoholic specimens, after applying the usual staining and
imbedding method, was not successful, probably owing to the difficulty with which
the integuments are permeated by the melted paraffin.

1. Intestinal System.

The intestinal tract (see PI. LXV — LXVIII, fig. 1) commences with a
very short muscular cesophagus (PI. LXV, fig. 2, oes), which ascends almost
perpendicularly from the mouth to the stomachal part of 'the intestine (s t), and
is marked off from the latter inside by 2 projecting lips. The stomachal part forms
a considerable dilation, which extends through the part of the body covered by
the carapace, curving at the hindmost limit of this part abruptly downwards, and

13 — Crustacea.

94

at the same time contracting to the narrow cylindrical intestinal tube, which
traverses the remaining part of the body. On a closer examination (see PI. LXV,
figs. 2, 3, 4), this dilated part, or stomach, as it may be termed, is found to
consist of 2 divisions, differing in the structure of their walls. The anterior
division exhibits a rather strong chitinous coating, which inside projects in
several setiferous lappets and thickened fillets clothed with stiff hairs, which in
some places are arranged in a fairly regular comb-like manner. It answers to
the so-called triturating stomach in higher Crustacea, and forms below a rounded
expansion, to the end of which the liver-sacs are appended. Along the ventral
face of this expansion, the setiferous fillets are arranged in a peculiar manner
(see figs. 3 & 4), serving apparently as a filter, to prevent the alimentary matter
contained in the stomach from entering the liver-sacs. The walls of the posterior
division of the stomach (see figs. 2 & 3) are quite soft, and exhibit numerous closely-
set circular muscle-fibres, which behind gradually assume a more oblique course.
They are, more-over, lined inside with large oblong, secretory cells, arranged
at some distance from one another in oblique rows. The intestine proper (i)
forms a narrow tube, which, in the exposed part of the trunk, runs nearer to
the ventral face, whereas in the posterior division it occupies the axis of the body
(see PI. LXV — LXVIII, fig. 1). Its walls are rather thin, and, like the posterior
part of the stomach, exhibit closely-set circular muscles, but are without secretory
cells. In the last segment it terminates in a short muscular rectum, which opens
in a longitudinal anal aperture situated on the lower side of this segment, or, if a
telson is present, on the lower side of this part, more or less distant from its base.

The liver-sacs, unlike what is the case in Amphipoda and Isopoda, are
comparatively short, being chiefly confined to the part of the body covered by
the carapace. I hey are arranged in 2 sets, and, as above mentioned, are ap¬
pended to the end of the ventral expansion of the stomach. Ivroyer has
already observed these sacs in IHastylis: but he erroneously believed them to
originate from the dorsal face of the stomach. In the above-named genus they are
3 .in number on each side (see PL LXV, figs. 1, 2, 10 1, PI. LXVI, figs. 1, 9),
issuing from a short common trunk, and are of about equal size, cylindrical in
form, and each terminating in a short filament. They are irregularly wrinkled,
owing to the large secretory cells lining their walls (see PI. LXV, figs. 7, 9),
and in the living animal exhibit a deep yellow colour, shai'ply contrasting with
the dark-coloured stomach. In its natural position, the upper sac on each side
(l1) curves upwards at the end. beyond the dorsal face of the stomach, whereas
the other 2 (P, F) extend straight backwards along the sides of the stomach.
At first I believed that the liver-sacs in all Cumacea were of the above-described

95

appearance; but on a closer examination I have found them in reality to differ
not a little in different genera. In the genus Cuma (PI. LXVI, fig. 10) there
is apparently only a single such sac on each side; but this divides at the end
into 2 unequal rami, and has a slight protuberance above at the base, which
may answer to the upper liver-sac in Diastylis. In the genus Lamprops (fig. 11)
there are 4 liver-sacs on each side, the uppermost of which, however, is much
shorter than the other 3, which have much the same appearance as in Diastylis.
In the genus Leucon (PI. LX VII, figs. 1, 7, 8) likewise, 4 liver-sacs occur on
each side, but of very different size, the lowest but one being much the lon¬
gest. In Leucon fulvus (fig. 8) the 3 other sacs are very much shortened, but
less so in Leucon Nasica (fig. 7). In the genus Pseudocuma (PI. LXVI, fig. 12)
I have only found 2 liver-sacs on each side, of nearly equal size, and rather
regularly annulated throughout, the secretory cells being arranged in successive
circlets, and in the genus Campylaspis (fig. 13) these sacs are represented by a
single large oval pouch on each side lined inside with unusually large, and irregu¬
larly disposed, secretory cells.

2. Vascular System.

The central part of this system, the heart, is not difficult to observe in
living specimens, owing to its rapid pulsations. It is situated (see PI. LXV —
LXVIII, fig. 1, h) dorsally at about the middle of the anterior division of the
body. Its anterior extremity extends for some distance within the part of the
body-cavify covered by the carapace, and the posterior extremity reaches more
or less far into the 3rd exposed segment of the trunk. In shape it is oblong
fusiform, tapering at each extremity to a narrow neck, which is apparently conti¬
nued in an arterial vessel. It exhibits 3 pairs of lateral, fissure-like openings for
the reception of the blood, of which the middle one, occurring within the 1st
exposed segment, is especially distinct. The walls of the heart (see PI. LXVII,
fig. 9) are strengthened by band-like, circular muscles, which, especially in the
vicinity of the lateral openings, are rather strong. The heart lies imbedded within
a thin membranous capsule or pericardium, by which it is attached to the dorsal
walls of the body.

About the peripheric part of the vascular system, or the blood-vessels,
I have very little to state. Besides the 2 arterial stems forming the immediate
continuation of the heart, 2 lateral stems seem to occur in front and one ventral
behind ; but I have failed to trace any ramifications of these stems, which indeed
seem to open into lacunae between the organs. It may, however, be noted

96

that Dr. A. Dohrn has described and figured under Cuma a rather complicated
system of arterial vessels issuing on each side from a single stem originating
from the heart. Through this system, the blood is said to be carried both
backwards and forwards, the vessels, especially in the walls of the carapace,
exhibiting abundant ramifications. There can be no doubt that this statement is
based upon direct observation; but I suspect that the existence of these vessels
has merely been assumed from the course of the blood-corpuscles, which indeed
circulate through the body with great regularity, though not in my opinion,
enclosed in any distinctly defined vessels.

3. Renal System.

Under this head, I may mention a pair of problematic organs occurring
in all Cumacea, one on each side of the heart, and easily observable owing to
their opaque whitish colour (see PI. LXV — LX VIII. fig. 1, n). These organs
have the form of rather short, somewhat curved tubes, exhibiting several rounded
lobules and slightly diminishing in thickness behind (see PL LXVI, fig. 6). They
contain a uniform, finely granular mass without any cellular elements (see fig. 7),
the granules, under a high magnifying power, exhibiting a somewhat irregularly
angular form, and thus resembling calcareous concretions. I have failed to detect
any excretory duct, and indeed, I am of opinion that strictly speaking these
organs are not secretory, but that they merely serve as storing places for some
unserviceable matter secreted from the blood. I long ago1) described a pair
of undoubtedly homologous organs in Asellus aquations, where they likewise occur
on each side of the heart, and at that occasion I expressed a similar opinion
as to the significance of these organs.

4. Nervous System.

As in other Crustacea, the central parts of the nervous system consist
(see PI. LXVI, fig. 2) of the cephalic ganglion situated in front dorsally, and
the fiervous chord running along the ventral side of the body. The latter is
composed of a series of 16 ganglia connected by double commissures. Of these
ganglia the first 10 belong to the anterior division of the body, and are much
larger than the remaining 6 caudal ones, which, with the exception of the last,
are very slight, almost obsolete. All the ganglia consist of 2 symmetrical parts,

0 Crustaces d’eau douce de Norvege.

97

thereby indicating their original duplicity. The cephalic ganglion is considerably
larger than the others, and of a rounded quadrangular form. It occurs, as stated
above, quite in front dorsally, below the anterior part of the frontal lobe of the
carapace (see PI. LXV — LXVIII, fig. 1, C. gl). Its dorsal face (see PI. LXYI,
fig. 3) is rather uneven, being divided into several lobes by more or less deep
grooves, one of which, running along the middle, is especially distinct and
divides the ganglion into 2 symmetrical halves. Of the lobes, the 2 median
ones, separated by the above-mentioned longitudinal groove, are narnow linear
in form, and in front curve abruptly outwards. I he nerves for the antennae
seem to originate from the lower face of the ganglion, and this is probably also
the case with the optic nerves; but I have not been able to trace these nerves
distinctly. Behind, the comparatively short oesophageal commissures are sent off
(see fig. 2), connecting the cephalic ganglion with the ventral ganglionic chain.
From each of these commissures, a very large nerve-stem issues, ascending to
each side immediately behind the cephalic ganglion, and curving backwards
along the dorsal side (see also PI. XXXVI, middle fig.). It sends off numerous
nerves to the strong mandibular muscles, and apparently also provides the stomach
and the heart with nerves, thus representing the visceral part of. the nervous
system. Of the ganglia belonging to the ventral chain, the 3 anterior ones are
placed close together, and the commissures connecting the 2 foremost ones are
almost obsolete, though a small opening is seen between them in the middle.
The 3rd ganglion is considerably larger than the 2 anterior ones, and also
somewhat exceeds the next succeeding ones in size. It belongs to the segment
carrying the 1st pair of maxillipeds with their voluminous branchial appa¬
ratus, the 2 preceding ganglia being destined for the 2 pairs of maxillse. The
7 remaining ganglia belonging to the anterior division of the body are of
rather uniform appearance, and are connected by well-defined slender commis¬
sures, between which, moreover, a median longitudinal nerve-stem is seen (see
fig. 4). They each send off laterally several nerves, and from the anterior part
of the commissures, issues another slender nerve extending upwards and outwards.
The hindmost of these ganglia is somewhat smaller than the others, and the
commissures connecting it with the preceding ones are rather short. The caudal
ganglia, as above stated, are very small, and only indicated by a slight thickening
of the commissures, which at this place assume a cellular structure, and are
confluent in the middle (see fig. 5). The last caudal ganglion, however, (see
fig. 2) is more distinctly defined, and sends off nerves behind to the telson and
the uropoda.

98

5. Sexual System.

The ovaries, when fully developed (see PI. LXV — LXVII, fig. 1, o v).
have the form of two very large oblong oval sacs occupying the greater part of
the body-cavity behind the carapace, often even extending for some distance
within the part covered by the latter. They are generally in immediate contact
with each other above, whereas below they diverge, to allow the intestine to
run between them (see PI. LXY, fig. 11). Each ovarial sac contains a somewhat
variable number of ova, which are all of nearly the same size and development,
and by mutual pressure assume a more or less polygonal form. In Diastylis
I have found from 30 to 40 such ova in each sac; in Leucon their number is
much smaller, sometimes only 7 ova being found in each ovary (see PI. LXVII,
fig. 1, o v, fig. 2). The ova are of different colour in different genera, being
of a fine rose hue in Diastylis, whereas in Lamprops and Pseudocuma they are
dark green. They contain a more or less opaque granular yolk, in the centre
of which the germinal vesicle is faintly to be traced, and they are enveloped by a
very thin pellucid membrane (see fig. 3). The uniform development of the ova in the
ovarial sacs seems to indicate that the true germinal stratum must occur in another
place, and indeed in quite young specimens of Diastylis I have distinctly seen a small
median part connecting the 2 sacs, and exhibiting in the middle a dense stratum
of small nucleated cells (see fig. 4). I have failed to detect any oviduct leading
outwards from the ovarial sacs, and indeed, I believe that no oviduct in reality
exists, the ova, by the rupture of the thin enveloping membrane, being simply
received into the body-cavity, where they undergo their development. It is true
that a marsupial pouch is found; but its cavity is confluent with the body-cavity,
the thin incubatory plates being formed by the splitting of the ventral wall of the
body itself. In gravid females, it is easily seen that the embryos are not confined
to the marsupial pouch, but are distributed throughout the w'hole body-cavity
behind the carapace, even up to the region of the heart. The purpose of the
so-called marsupial pouch is thus merely to afford the necessary increase of
breeding-space for the successive growth of the embryos. The Cumacea are
accordingly true viviparous animals, and it is very probable that the females
become gravid only once in their life, and soon die off after the breed has been
discharged.

The testes (see PL LXVIII, fig. 1, t) are rather difficult to observe in
the living animal, as they are comparatively small, of whitish colour, and lie in
such close proximity to the intestine as easily to escape attention. By dissec¬
tion of fresh male specimens, they admit, however, of being isolated and studied

99

in detail (fig. 2). They each form a slender tube extending through the exposed
part of the trunk in close juxtaposition to the intestine. At the anterior extre¬
mity, which, unlike what is often the case with the ovaries, never penetrates the
part of the body-cavity covered by the carapace, 4 small ccecal lobes are seen
outside. These lobes, in the genus Leucon (figs. 2, 3), are very short and
somewhat unequal in size, whereas in Diastylis (figs. 12, 13) they are more
prominent, almost digitiform, and of about equal size. They contain the germinal
stratum of cells, from which the zoosperms are developed, the tube itself being
filled with densely crowded bundles of fully develojDed zoosperms, whereby it
acquires a closely striated appearance. Behind, each tube contracts to a narrow
duct, which in the last pedigerous segment curves abruptly downwards, debouching
on the ventral face of the latter at the tip of 2 small juxtaposed prominences
(see fig. 2). The zoosperms are of considerable size and arranged in dense
bundles, each bundle being developed from a single germinal cell and containing
about a dozen zoosperms. At first the bundle is enveloped by a thin membrane
(see fig. 4); but this soon becomes ruptured. The zoosperms, however, still
remain tied together in bundles (see fig. 5), and it is only after being evacuated
from the body that they separate. Each zoosperm (see figs. 7 — 11, 14 — 16,
22) consists of 2 unequal parts uniting at an acute angle. The smaller part is
of very delicate structure, and exhibits traces of a nucleus at its base. It varies
somewhat in form in different Cumacea, being sometimes lanceolate in shape
(figs. 9 — 11), sometimes more thread-like (figs. 7 — 8, 14 — 16), and in some cases
distinctly twisted (fig. 22). When not fully developed, this part is curled up in
a close coil, as found in young male specimens of Diastylis (figs. 17 — 20). It
seems to represent the essential part of the zoosperm, answering to the so-called
head in zoosperms of the usual form. The larger part of the zoosperm, answering
to the tail, has the form of a slender elastic seta, several times as long as the
above-mentioned part, and terminating in a very fine point.

On the Development of Cumaeea.

(PI. LX1X.)

Ivroyer was the first to state that the young of Cumaeea do not undergo
any metamorphosis, hut on leaving the mother have essentially the same appearance
as the adults. A closer investigation of the embryonal development was subse¬
quently instituted by Dr. A. Dohrn, who figured several stages of Cum opsin
Goodsiri, and pointed out the great resemblance, at least in the earlier stages,
to the development of Isopoda (Asellus). I have myself studied the development
in the following genera: Lcimprops, Leucon, Diastylis and Pseudocuma. In all
these genera it is essentially alike, and it is sufficient therefore to describe
it in one of them, viz., Diastylis.

The ova, immediately after they have left the ovarial sacs, are globular in
form (see fig. 1), and surrounded by a very thin filmy membrane, which in some
places is closely applied to the ovum, in others stands away from its surface.
They undergo, as in most other Crustacea, a superficial cleavage, whereby a
peripheric layer of clear nucleated cells is formed, surrounding the coarsely
granular opaque yolk. In one place these cells increase considerably in number,
forming a conspicuous thickening of the peripheric cell-layer. This part repre¬
sents the ventral face of the embryo, and extends like a broad band around the
greater part of the ovum. At the same time the central yolk-mass seems to
arrange itself with tolerable regularity in relation to this thickened part of the
surface, forming 2 conspicuous rounded lateral expansions (see figs. 2 & 3). In
the middle, opposite the thickened part of the peripheric layer, appears a slight
insinuation of the surface (see fig. 4, f) ; this becomes gradually deeper in the
course of the development, and represents the dorsal cleft separating the two
extremities of the embryo. The latter of course originally exhibits, like the
embryos of Isopoda, a strong dorsal curvature. The first indications of all the
limbs belonging to the anterior division of the body, with the exception of the
last pair, are very soon to be traced along the thickened ventral face of the

101

embryo in the form of a double series of bud-like prominences. Of these, however,
the 3 anterior pairs are somewhat in advance of the others in development, being
rather distinctly defined, while the other 9 pairs can be but faintly traced (see
fig. 4). These 3 anterior pairs of limbs represent the 2 pairs of antennae and
the mandibles, which, as is well known, are also those first appearing in other
Crustacea, characterising the so-called Nauplian stage. The 1st pair (a1), repre¬
senting the superior antennae, are much larger than the other 2, and have the
form of 2 spatulate plates, slightly bilobular at the tip, and extending backwards
on the sides of the embryo. The 2 succeeding pairs (inferior antennce and
mandibles, a3, M) also extend somewhat laterally, and are simple conic in form.
Between them in the middle, the ventral face projects as a rounded prominence
(L), representing the anterior lip or labrum. The remaining 9 pairs of limbs, as
stated above, are at first but very faintly defined and of rather uniform appear¬
ance, causing a slight crenulation of the ventral face.

In a succeeding stage (fig. 5) the egg-membrane or chorion is cast off,
and the 3 anterior pairs of limbs thereby become freely projecting, whereas the
others are still enveloped by the thin larval skin. The dorsal cleft has deepened
considerably, and extends somewhat obliquely behind, whereby the anterior
broadly rounded e'xtremity is defined clearly from the somewhat narrower
posterior extremity. The latter has given origin on each side to a knoblike
prominence (urp), indicating the developing uropoda. The 3 antex-ior pah's of
limbs have not greatly changed their appearance. The remaining pairs, on the
other hand, now appear vei’y distinctly, and the 2 anterior of these (m1, m2),
representing the 2 pairs of maxillae, distinguish themselves from the succeeding
7 pairs both by their form and more lateral position. They are also placed
somewhat more apart, though the anterior pair partly cover the postei'ior. The
former has developed a small lateral ramus (the reflexed palp), and the latter
appears slightly trilobate at the end. The 7 succeeding pairs of limbs have
a vei'y similar appearance, each terminating in a conical, posteriorly-curving
process (the endopodite), and having outside a knob-like protuberance (the
exopodite), which, however, in the 2nd and 2 last pairs is almost obsolete. In
the 3 middle pairs, representing the 3rd pair of maxillipeds (mp3) and the 2
first pairs of legs (pl, p2) this protuberance is easily obsei’vable; and in the
1st pair (mp1), representing the 1st pair of maxillipeds, an evidently homologous
outer appendage is also seen ; but it here issues somewhat higher up than in the
other pairs, and subsequently also becomes different in form and direction. It
represents the exopodal part of the branchial apparatus, the epipodal part being
apparently not yet formed. Just above the maxillae, there is seen on each side of

14 — Crustacea.

102

the embryo a slight arched ridge (C), indicating the lower edges of the developing
carapace, and above this ridge, imbedded in the yolk-mass, appears a sharply
defined circular area (1), representing the first indication of the liver.

Figs. 6 and 7 represent a much later stage, in which, however, the dorsal
curvature is still well marked. The larval skin has now been cast off, whereby
all the appendages appear freely projecting. The caudal part of the body is
still very 'short, as compared with the anterior division, and is abruptly curved
upon the latter. It is distinctly segmented, whereas the segmentation of the
adjoining part of the trunk is still imperfect. At the broadly rounded anterior
extremity, just above the insertion of the superior antennae, 2 small pigmentary
masses (0), well defined from each other, are seen, representing the first intimation
of the visual organ, which in this stage is double accordingly (see fig. 7). The
superior antennae (a1) have considerably increased in size, and now exhibit a
distinct boundary between the peduncle and the 2 flagella. They tire, however,
still extended behind along the sides of the embryo. The inferior antennae (a2)
and mandibles (M) have retained their appearance almost unaltered. Below them
in the middle, the oral aperture has appeared, being limited in front by the
very prominent anterior lip (L), and behind by the 2 lappets of the posterior
lip (1). The maxillae (m1, ms) are more deflexed, otherwise not very different
from those in the preceding stage. The 7 succeeding pairs of limbs, on the other
hand, have considerably increased in size, the endopodites having now assumed
a digitiform appearance, with slight instrictions indicating the incipient segmen¬
tation. In all these pairs, however, they are still curved backwards, as in the
preceding stage. The exopodites in the 3 middle pairs have likewise increased
in size, though they are scarcely more than half as long as the endopodites. Like
the latter, they are, curved backwards, and already exhibit a distinct boundary
between the basal and terminal parts, the latter being closely afmulated. In the
1st of these pairs (the 1st pair of maxillipeds mp1), the exopodite (hr. exp.) has
assumed the form of a thin lamella projecting downwards in front of the endo-
podite, and terminates in a narrow linguiform lappet. In the 2 posterior pairs,
the exopodite has retained its knob-like character, and in the 2nd pair (2nd pair
of maxillipeds) scarcely any trace of it is left. The uropoda (urp) now exhibit
a distinctly defined, but still rather short stem and 2 lanceolate rami. They
are curved downwards, embracing the hind part of the anterior division. Beyond
them, the extremity of the tail projects as an obtuse prominence, the developing
telson (t). The lower part of the carapace (C), only faintly indicated in the
preceding stage, now appears with great distinctness, and projects in front on
each side to a lanceolate lappet extending to the oral region. These lappets

103

(R) are the rostral plates, which in this stage lie widely apart, but will subsequently
meet in front, to form the pseudo-rostral projection. In the interior of the
body, the coarsely granular, opaque yolk-mass is still visible; but it has consider¬
ably diminished in volume, having been chiefly consumed to form the liver (1),
which now appears as 2 rather large sac-like organs extending backwards below
the yolk-mass.

The stage represented in fig. 8 at first sight looks very different from
the preceding one; but in reality it immediately succeeds it. The chief difference
consists in the disappearance of the dorsal curvature of the body, this having been
changed to a pronounced ventral one, and in the consequent projection of the
limbs forwards instead of backwards. The embryo in this stage has very little
resemblance to an Isopod-emhryo, whereas it agrees much more with that of a
decapodous Crustacean. The anterior division of the body is still broadly
rounded, or almost truncated in front; but its posterior (exposed) part has now
become distinctly segmented, the number of segments agreeing with that in the
adult animal. The last segment, however, is very small and still without any
trace of limbs. The posterior division, or tail, is about the length of the
anterior, and is bent in against the ventral face of the latter. It exhibits the
normal number of segments, which are very distinctly defined and of nearly
equal size, the last carrying a well-defined telson between the uropoda. At the
anterior extremity the eyes (0) are distinctly seen. They are still well defined
from each other, though in somewhat closer proximity than in the preceding stage,
each forming a rounded capsule, in which 3 visual elements have already devel¬
oped (see fig. 9). The superior antennae (a1) are rather large, and are extended
obliquely forwards, sometimes with their outer part curved more or less upwards.
The 3 joints of the peduncle are indicated by distinct instrictions, and the flagella
also exhibit traces of segmentation. The inferior antennae (a2) have stopped
in their development, being scarcely larger than in the preceding stages. The
mandibles (M), on the other hand, are much more fully developed and have
assumed their definite form and position, their upper pointed extremity being
articulated to the carapace at the place where the rostral plates originate. The
post-oral appendages are closely crowded together, and in form and mutual
size approach those in the adult animal, though not yet functionally developed.
The exopodites have wholly disappeared in the last 2 pairs, as also in the pair
representing the 2nd pair of maxillipeds. In the preceding pair, representing
the 1st pair of maxillipeds, it has considerably increased in length and extends
straight forwards, its outer part (br. exp.) having the form of a narrow lingui-
form plate. Besides this exopodal part, the epipodal part may also be traced

104

inside the lower part of the carapace. The latter is now distinctly defined not
only inferiorly, but also posteriorly, and projects on each side in front to the
rostral plates (R), which reach somewhat beyond the anterior extremity, though
still far apart. In the interior of the body the liver (1) is now very distinct,
being about to divide. Of the yolk-mass only a small, but sharply-defined
rounded portion is left, enclosed in the developing stomach. Dorsally, the heart
(h) is in process of development.

Fig. 10 represents one of the last stages of the embryo, its size being
almost twice that of the preceding stage. The Cumacean character of the
animal is now very obvious, both as to its general form and the structure of
the several appendages. The carapace is very large, and has assumed its
characteristic shape, partly also exhibiting traces of the spiny armature of the
dorsal face and the inferior edges. The rostral plates (R) are greatly prolonged,
and are about to meet in front to form the pseudorostral projection. Their
upper edges, however, are not yet in immediate contact with each other, nor do
the plates exactly fit to the frontal part. At the end of the latter the ocular
tubercle (0) is very distinct, the eyes being now confluent to a single median
organ, tipped, as in the adult animal of this species (D. lucifera), with a pro-
curved spine. Of the exposed segments of the trunk, the 4 anterior are nor¬
mally developed with distinct epimeral parts, whereas the last segment is very
small, without any epimerae, and still having no traces of limbs. The tail is
stretched out, so as now to extend more or less in the axis of the body, and
its segments have assumed the peculiar nodular appearance characteristic of the
adult animal, being defined by very deep instrictions. They are also somewhat-
unequal in size, increasing in length to the penultimate one, which is the lar¬
gest. From both their dorsal and ventral faces scattered slender hairs have
risen. Of the limbs, the mandibles and maxillae are now wholly admitted
between the lateral parts of the carapace, whereas the succeeding limbs project
more or less below. They are now all distinctly segmented, but in the superior
antennae (a1), as also in the 1st pair of legs (p1), probably also in the maxilli-
peds, the articulations are still enveloped by a thin membranous sheath. In the
3 succeeding pairs of legs"_(p- — p4), however, this sheath has been cast off, so as
to allow the spines and setae to project freely. The branchial apparatus is not
yet functionally developed, the exopodal parts (hr. exp.) being still discontinuous,
whereas they will subsequently meet at the ends to form the ejecting tube pro¬
jecting from the pseudo-rostral prominence. The distal portions of these parts in
the present stage are seen projecting downwards from about the oral region as
thin linguiform lappets. The telson (t) is conically tapered, and tipped with 2

105

slender spines; but no traces of the lateral spinules have as yet appeared, nor
do the uropoda furp) as yet exhibit any armature whatever. No trace of cal¬
careous matter has as yet been deposited in the integuments, which of course
are very thin and pellucid, admitting the inner organs to he traced with great
distinctness through their walls. The stomach (st) has assumed its characteristic
form and curvature, and all 3 liver-sacs (1) on each side have been formed ; but
the upper and lower sac are still very short, scarcely attaining half the lenght of
the middle one. Behind the carapace dorsally, the heart (h) is easily observable,
as also the renal organs (n) occurring to each side of it. The intestinal tube
is still without any contents, and on this account is less conspicuous than in the
post-embryonal stages.

When the young is ready to escape from the mother, it has assumed
much the appearance of the adult animal, and the integuments have been partly
indurated with calcareous deposits, so as to make them rather hard and intrans¬
parent. The only essential difference consists in the absence of the last pair of
legs. On a closer examination, however, these limbs are found in process of
development, but enclosed within a conspicuous ventral prominence of the last
trunk segment. They will accordingly be set free by a subsequent exuviation.

Supplementary Notes.

Pages 10 & 12. Cuma seorpioides and C. Edwardsii.

Remarks. — There seems to be some diversity of opinion about the
naming of these 2 Norwegian species of Cuma. Thus in his “History of Cru¬
stacea” (International Scientific Series) the Rev. Mr. Stebbing records Cuma
Edwardsii Goodsir as a synonym of Cuma seorpioides (Montagu) If this is
really correct — a question which only can be settled by a re-examination of
the original specimen described by Montagu — the species recorded in the present
account as Cuma seorpioides must have another specific name, and as Bodotria
arenosa Goodsir is unquestionably the male of this species, it ought to be named
Cuma arenosa, while the specific name proposed by Montagu must be trans¬
ferred to the 2nd Norwegian s{>ecies, the one here recorded as Cuma Edwardsii
Goodsir.

Occurrence. — I found both these species last summer off the Jsederen
coast, the one, Cuma arenosa, rather abundantly off Egersund in a depth of from
15 to 20 fathoms, coarse sandy bottom; of the other, Cuma seorpioides, only 2
specimens, male and female, were found at Sirevaag, somewhat farther north.
These 2 specimens, unlike those previously observed, were of a dark reddish brown
colour.1)

Page 30. Leueon Naeica.

Remarks. — I have been informed by the Rev. Mr. Stebbing, that the
name of this species ought to be spelt as above, since no adjective „nasicus“
exists in the Latin language. (Cf. Scipio Nasica).

Page 40. Eudorellopsis deformis.

Distribution. — Firth of Forth, Aberdeen Bay, Firth of Clyde (Th. Scott).

0 The latter species has also been observed by Dr. Hoek off the Dutch coast.

107

Page 44. Diastylis Rathkei, var.

(PI. LXX— LXX1I.)

Remarks. — On page 45 I have mentioned that some forms of Diastylis
Rathkei differ conspicuously from the type described by Kroyer, in their more
spiny carapace, and apparently form a transition to the British species D. Bradyi
Norman. These forms I propose to combine as a distinct variety, of which
figures, both habitus and detail, are given in the last 3 plates. It will he seen,
on comparing these figures with those given on PL XXXIII and XXXIV, which
are from a typical specimen, that this variety exhibits several differences, not
only in the form and armature of the carapace, but also in the structure of the
several appendages. In my opinion, however, these differences are not great
enough to warrant a specific distinction, and I therefore do not find it neces¬
sary to give any exhaustive diagnosis of this form. Meanwhile it may be of
interest to call attention to some of the more conspicuous differences from the
typical form. Whereas in the latter (see PI. XXXIII) only 3 small spinules
are found on each side below the frontal lobe, there is in the present variety a
considerable number of such spinules, giving the anterior part of the carapace a
rather scabrous appearance (see PI. LXX). These spinules are even partly
continued beyond the middle of the carapace along the most prominent part of
the branchial regions. The spinules of the frontal lobe have a somewhat vari¬
able arrangement, being disposed in some specimens (see the 2 habitus-figures)
in 2 or 3 transverse rows, whereas in other specimens (see the 2 figures of the
carapace) they form 2 longitudinal rows, as in the tyjrical form. As to the
shape of the carapace, a rather conspicuous difference is observed in the devel¬
opment of the subrostral corners, which in the typical form are distinctly pro¬
minent, whereas in the present variety they are almost obsolete, causing the
anterior part of the carapace, when viewed laterally, to appear more conically
tapered. The mucroniform processes of the last pedigerous segment in this
variety always point straight behind, whereas in the typical form they are
slightly divergent. In the structure of the appendages the following differences
may be noted. On the superior antennm I have failed to detect any trace of
the strong denticle found in the typical form at the end of the 1st peduncular
joint. The 1st pair of legs appear somewhat more slender, with the outer joints
more elongated, and this is also the case with the 2nd pair, the last joint of
which in particular is conspicuously longer than in the typical form. The telson
considerably exceeds in length the stem of the uropoda, and its lateral spinules
are more slender and fewer in number than in the typical form. The outer

108

ramus of the uropoda is less robust and scarcely longer than the inner, the
terminal joint of which has 3 lateral spinules, whereas only 2 are found in
the typical form.

The figures given on the last plate of the adult male are from' specimens
kindly sent to me by Mr. Th. Scott, who collected them in the Firth of Forth.

There cannot be any doubt that this is in reality, as suggested by the above-

named distinguished zoologist, the male of D. Rathlcei : and I think I am right in
considering it to belong to the present variety, which seems to be that exclusively
found off the British Isles. As seen from the figures, it is of a very slender
form, and on the whole resembles the males of other species of the genus,
having a well-marked serrated keel along the sides of the carapace, and the caudal
segments partly spinulous. It is, however, easily proved to belong to the present
species by the structure of the several appendages.

Occurrence. — This variety seems to he much more generally distributed

off the Norwegian coast than the typical form, as it occur from the Christiania

Fjord to Vadso, and in some places in great profusion.

Page 71. Leptostylis villosa.

Distribution. — Three well-marked female specimens of this form were
sent to me from Mr. Th. Scott, who collected them in the Firth of Clyde.

Page 74. Pseudoeuma eerearia.

Occurrence. — I found this form last summer in great abundance
off the Jsederen coast, outside Sirevaag, in a depth of 6 — 10 fathoms, fine
sandy bottom.

Page 76. Pseudoeuma similis.

Occurrence. — This form, which had previously only been observed at
Skudesnses, occurred not unfrequently, together with the preceding species, outside
Sirevaag.

Distribution. — According to a communication from Mr. Th. Scott, some
specimens of this species were taken by him at the “seaweed limit” of the
estuary of the Clyde.

Page 77. Petalosarsia deelivis.

Distribution. — Firth of Forth, Moray Firth (Th. Scott).

Page 84. Campylaspis rubicunda.

Distribution ■ — Firth of Forth, Firth of Clyde, Moray Firth, Loch
Fyne (Th. Scott).

INDEX

Page.

Alauna . 42

Goodsiri . 54

rostrata . 51

Bodotria . 10

arenosa . i 10

Campylaspidce . 82

Campylaspis . 83

affinis . 91

earir.ata . . 14

costata . 87

glabra . 86

horrida . 89

nodulosa . 91

rubicunda . 84, 108

sulcata . 86

undata . 88

verrucosa . 90

Campylaspoides . 73

Cancer

scorpioides . 10

Caspiocuma . 73

campylaspoides ..... 73

Clialarost.ylis . 26

Condylura . 42

Cuma . 10

ampullacea . 70

angulata . 44

arenosa . 106

Audouini . 10, 12

bella . ... 74

brevirostris . 58

cornuta . 45

Edwardsii . 12, 106

lucifera . 41

nasica . 30

pusilla . 10

Kathkei . 44

Page.

scorpioides . 10, 106

tvispinosa . 14

tumida . 52

CumeUa . 80

agnis . 81

linri colit . 81

pygmcea . 81

Cumellidse . 79

Cumidw .... 9

Cnmopsis . 9

Cyclaspis . 15

cornigera . 16

longicaudata . 16

Isevis . 16

Cyclaspoides . 9, 16

Cyrianassa . 12

ciliata . . 36

elegans . 22

gracilis . 14

Diastylidce . . 41

Diastylis . 42

ampullacea . 70

bicomis . 45

biplicata . 62

bispinosa . 45

borealis . . 49

Bradyi . 45

Calveri . 62

cornuta . 45

echinata . 57

Edwardsii . 58

Goodsiri . 54

lamellata . 62

longimana . 68

lucifera . 49

lievis . 51

nodosa . 56

Page.

plumosa . 54

Eathkei . 44

n. var . 107

resima . 65

rostrdta . 51

rugosa . 48

scorpioides . . 58

serrata . 61

spimdosa . 55

strigata . 48

tumida . 52

Diastyloides . 60

biplicata . 62

serrata . 61

Diastylopsis . 64

Dawsoni . 64

resima . 65

tumida . 64

Diops . 80

Eudora . 35

deformis . 38

hirsuta . 38

truncate la . . 37

Eudarella . 35

emarginata . 36

hirsuta . 38

inermis . 37

ti uv.catula . 37

Eudorellopsis . 39

deformis . 40, 106

integra . 34

Halia . 12

trispinosa . 14

Hemilamprops . 18

assimilis . 23

cristata . 25

Normani . 21

15 — Crustacea.

110

Page.

rosed . 22

uniplicata . ... 21

Iphinoe . 12

gracilis . 14

serrata . 14

trispinosa . 14

Ipliithoe . 12

trispinosa . 14

Lampropidc e . 17

Lamprops . 18

eristata . 25

fasciata . 19

fuscata . 20

rosea . 22

uniplicata . 24

Leptostylis . 67

ampullacea . 70

longicaudata . 67

longimana . 68

rnacrura . 69

villosa . 71, 108

Leucon . 29

acutirostris . 34

cercaria . 74

ileformis . . . 40

emarginatus . 36

Page.

fulvus . 32

Nasica . 106

nasicoides . 31

nasicus . 30

pallidus . 33

Leuconidre . 28

Leuconopsis

ensifer . 30

Nannastacidce . 79

Nannastacus . 79

Oniscus

scorpioides . 58

Pacbystylis . 42

Paralamprops . 18

Petalomera . 77

declivis . 77

Petalopus . 77

declivis . 77

Petalosarsia . 77

declivis . 77, 108

Platyasjndce . 26

Platyaspis . 26

typica . 27

Procampylaspis . 83

Pseudocwna . 73

bistriata . 74

Page.

cercaria . 74, 108

cercaroides . 73

ciliata . 74

similis . 76, 108

Pterocuma . 73

pectinata . 73

rostrata . 73

Sowinskyi . 73

Schizorhynchus . 73

abbreviatus . 73

bilamellatus . 73

eudorelloides . 73

scabriusculus . 73

Spencebatea . 80

Stenocuma . 73

diastvloides . 73

gracilis . 73

graeiloides . 73

tenuicaudis . 73

Stephanomma . 9

Vauntbompsonia . 22

rosea . 22

Vauntbompsoniidse .... 9, 29

Venilia . 12

gracilis . 14

LIST OF PLATES.

The Plates, as far as possible, have been marked in accordance with those belonging
to the first 2 Volumes (Amphipoda and Isopoda).

The following are the chief signs, with their significance :

$ female; cT male; C. carapace; 0. ocular tubercle; a1, superior antenn?e; a-, inferior
antenme; L. anterior lip; l. posterior lip; M. mandibles; tn\ anterior maxillae; m.- posterior
maxillae; mp1. 1st pair of maxillipeds; hr. branchial apparatus; exp. exopodal part of same; ep.
epipodal part of same; mp2. 2nd pair of maxillipeds; mp3. 3rd pair of maxillipeds; p1. — ps. legs
of 1st to 5th pair; pip. pleopoda of male; Urs. Urosome; t. telson; urp. uropoda.

A detailed explanation of PI. LXV
development of Cumacea, is given below.

PI. I.

Cuma arenosa, (Goodsir); female. (See sup¬
plementary notes).

pi. ir.

Cuma arenosa; female (continued).

pi. in.

Cuma arenosa; adult male.

PI. IV.

Cuma SCOl’pioides (Mont.); female and male.
(See supplementary notes).

PI. V.

Iphinoe trispinosa (Goodsir); female and male.
PI. VI.

Iphinoe trispinosa; female (continued).

PI. VII.

Cyelaspis Jongieaudata, G. 0. Sars, emaie.
PI. VIII.

Cyelaspis longieaudata; female and male
(continued).

LXIX, illustrating the internal anatomy and

PI. IX.

Lamprops faseiata, G. O. Sars; female and
male.

PI. X.

Lamprops faseiata; female and male (con¬
tinued).

PI. XI.

Lamprops fuseata, G. 0. Sars; female and
male.

PI. XII.

Hemilamprops rosea (Norman); female and
male.

PI. XIII.

Hemilamprops rosea; female (continued).

PI. XIV.

Hemilamprops rosea; female and male (con¬
tinued).

PI. XV.

Hemilamprops assimilis, G. 0. Sars; female
and male.

PI. XVI.

Hemilamprops uniplieata, G. 0. Sars; female
and male.

112

PI. XVII.

Hemilamprons uniplieata; female and male
(continued).

PI. XVIII.

Hemilamprops cristata, G. O. Sars; female
and male.

PI. XIX.

Platyaspis typica, G. 0. Saw; female and male.

PI. XX.

Platyaspis typica; female and male (continued).

PI. XXI.

Leucon Nasiea (Kroyer); female and male.
(See supplementary notes').

PI. XXII.

Leucon Nasiea; female and male (continued).

PI. XXIII.

Leucon nasicoides, Lilljeborg: female and male.

PI. XXIV.

Leucon fulvus, G. O. Sars; female and male.

PI. XXV.

Leucon pallidns, G. 0. Sars ; female and male.

PI. XXVI.

Leucon acutirostris, G. O. Sars; female and
male.

pi. xx vn.

Eudorella emarginata (Krdyer); female and
male.

PI. XXVIII.

Eudorella emarginata; female and male (con¬
tinued).

PI. XXIX.

Eudorella truneatula (Sp. Bate); female arid
male.

PI. XXX.

Eudorella hirsuta, G. 0. Sars; female and
young male.

PI. XXXI.

Eudorellopsis deformis (Krdyer); female and
male.

PI. XXXII.

Eudorellopsis deformis; female and male
(continued).

PI. XXXIII.

Diastylis Rathkei (Krdyer), typica; female
and young male.

PI. XXXIV.

Diastylis Rathkei; female (continued).

PI. XXXV.

Diastylis cornuta (Boeck); female.

PI. XXXVI.

Diastylis cornuta (continued); adult male.

Pi. XXXVII.

Diastylis rug'osa, G. 0. Sars; female and male.
PI. XXXVIII.

Diastylis lucifera (Kidyer); female and male.
PL XXXIX.

Diastylis rostrata (Goodsk); female and male.
PI. XI,.

Diastylis turnida (Lilljeborg); female and male.
PL XU.

Diastylis Goodsiri (Bell): female.

PL XLir.

Diastylis spinulosa, Heller; female and young
male.

Pl. XLIII.

Diastylis eehinata, Sp. Bate; female and male.
PL XLIV.

Diastylis scorpioides (Lepeehin); female and
male.

PL XLV.

DTastyloides sorrata, G. 0. Sars; female and
male.

PL XLVI.

Diastyloides biplicata, G. 0. Sars; female

and male.

PL XLVII.

Diastylopsis resima (Krdyer) ; female and male.
PL XL VIII.

Leptostylis longimana, G. 0. Sars; female
and male.

PL XLIX.

Leptostylis macrura, G. 0. Sars; female and
male.

PL L.

1. Leptostylis ampullaeea (Lilljeborg); fe¬
male.

2. Leotostylis villosa, G. 0. Sars; female.

PL LI.

Pseudoeuma cerearia (v. Beneden); female.

113

PI. LII.

Pseudoeuma cerearia (continued) ; adult male.
pi. Lni.

Pseudoeuma similis, G. O. Savs; female and
mate.

PL LIV.

Petalosarsia deelivis, G. 0. Savs; female and
male.

PI. LV.

Cumella pygrnaea, G. 0. Savs ; female and male.
PI. LYI.

Campylaspis rubieunda (Lilijeborg); female
and male.

PI. LVII.

Campylaspis rubieunda (continued); female
and male.

pi. Lvm.

Campylaspis glabra, G. 0. Sars; female and
male.

PI. LIX.

Campylaspis sulcata, G. 0. Sars ; female and
male.

PI. LX.

Campylaspis eostata, G. 0. Sars; female and
male.

PI. LXI.

Campylaspis undata, G. 0. Sars; female and
male.

PI. LXII.

Campylaspis horrida, G. 0. Sars ; female and
male.

pi. Lxni.

Campylaspis verrucosa, G. 0. Sars; female
and male.

PI. LXIV.

Campylaspis afflnis, G. 0. Sars; female and
male.

PI. LXV.

Internal Anatomy of Cumaeea (Diastylis
lucifera).

Fig. 1. Anterior part of body together with
the first 3 caudal segments of a young,
not, yet gravid, female, viewed from
left side. Inner organs delineated
within the body in their natural posi¬
tion. — 0 ocular tubercle; M. man¬
dible ; hr. exp. exopodal part of bran¬

chial apparatus; sc. scale-like terminal
piece of same; br. ep. epipodal part
of branchial apparatus; st. stomach;
l1.— I3, the 3 liver-sacs- on left side; i
intestinal tube; h. heart-; n. nepliridium
(renal organ); C.gl. cephalic ganglion;
gl. ventral ganglionic chain; ov. left
ovarial sac; inc. pi. incubatory plates
in process of formation.

Fig. 2. Ant erior part of intestinal tract, viewed
from left side. — oes. oesophagus; st.
stomach ; pr. v. anterior triturating
part, of same; ll—l3 the 3 liver-sacs
on left side; i. intestinal tube.

„ 3. Anterior part of stomach, more highly

magnified, exhibiting the triturating
apparatus; lateral view.

,, 4. Same part viewed from the ventral

face.

„ 5, 6, 7. Seta and pectiniform fillets of

the triturating apparatus, highly
magnified.

„ 8. Extremity of a liver-sac.

„ 9. Some of the secretory cells from same,

highly magnified.

„ 10. Schematic transverse section of body
behind the middle of the carapace,
exhibiting the internal organs in sec¬
tion. Lettering as in fig. 1.

„ 11. Another transverse section of body
through about the 2nd exposed seg¬
ment. Lettering as above.

PL LXVI.

Inner Anatomy of Cumaeea (continued).

Fig. 1. Anterior part of body together with
the first 2 caudal segments of a female
Diastylis lucifera, viewed from the
dorsal face. Inner organs delineated
within the body in their natural po¬
sition. Lettering as in fig. 1 on the
preceding plate.

„ 2. Central nervous system of same spe¬

cies, viewed from the dorsal face.

„ 3. Cephalic ganglion together with the

cesophageal commissures, viewed from
the dorsal face.

„ 4. Two of the ventral ganglia with their

connecting commissures ; dorsal view.

„ 5. Two ganglia, with their commissures,

from the caudal part of the nervous
chord.

„ 6. Left renal organ.

„ 7. One of the lobules of same, more

highly magnified, and showing the
finely granular contents.

„ 8. Ocular tubercle of same species, ex¬

hibiting trace of its original duplicity;
dorsal view.

„ 9. Anterior part of the intestine, with

the liver-sacs (Diastylis) ; ventral view.

114

Fig-. 10. Same part from Cuma arenosa.

„ 11. Same part from Lamprops fasciata
(dorsal view).

„ 12. Same part from Psciulocumci cercaria
(ventral view).

13. Same part from Campy! aspis rubicunda
(ventral view).

PI. LXVII.

Internal Anatomy of Cumacea (continued).

Fig. 1. Anterior part of body together with
the first 3 caudal segments of a young
female specimen of Lcucon Nasica,
viewed from left side. Internal organs
delineated within the body in their
natural position. Lettering as in fig.
1 on the two preceding plates.

„ 2. Left ovarial sac of the same indi¬

vidual, isolated and more highly
magnified.

„ 3. One of the ova contained in the sac

isolated.

„ 4. Ovarial sacs of a very young specimen

of Diastylis lucifera , showing the small
median connecting part.

„ 5. Egg-cell from same, highly magnified.

„ 6. Epithelial cell.

„ 7. Anterior part of intestine with the

liver-sacs from Lexicon JS'asiea ; ventral
view.

„ 8. Same part from a male specimen of

Lexicon fulviis.

„ 9. Heart with pericardium from a male

Diastyloides biplicata, as found by
dissection of an alcoholic specimen ;
left side-view.

PI. LXV1II.

Internal Anatomy of Cumacea (continued).

Fig. 1. Anterior part of body together with
the first 3 caudal segments of an
adult male specimen of Lcucon Nasica ,
viewed from left side. — t. testes;
remaining letters as in fig. 1 on the
3 preceding plates.

„ 2. Testes of same species isolted, together

with last pedigerous segment; ventral
view.

„ 3. Anterior part of one of the testes

more highly magnified, exhibiting the
ccecal lateral lobes. From the lower
ruptured end, the zoosperms are seen
protruding.

„ 4. A bundle of zoosperms still enveloped

by a thin membranous sheath.

„ 5. Another bundle, in which the envelope

has been cast off.

(i. A fully-developed zoosperm isolated.
7, 8. Front part of 2 other zoosperms
from same species, highly magnified.

Fig. 9, 10, 1 1 . Zoosperms from Lcucon fxdxms.

„ 12. One of the testes from an adult male
of Diastylis lucifera.

„ 13. Anterior part of same, more highly
magnified.

„ 14, 15, lfi. Zoosperms from the same
species.

„ 17 — 20. Not yet fully developed zoosperms
from a young male of Diastylis luci -
fera.

„ 21. Germinal cells of same specimen.

„ 22. Zoosperm from Hemilamprops rosea.

PI. LXIX.

Development of Cumacea. Diastylis lucifera.

Fig. 1. Ovum still enveloped by a thin filmy
membrane, and exhibiting the coarsely
granular central yolk-mass and the
peripheric layer of clear cleavage-cells.
The latter has considerably7 increased
on one side, to form the ventral face
of the developing embryo.

„ 2, 3. Another ovum in a somewhat later

stage, represented in 2 different po¬
sitions, to show the cruciate arrange¬
ment of the central yolk- mass.

„ 4. Early stage of the embryo, exhibiting

the first intimations of the limbs,' and
still enveloped by the chorion; left
side-view. — a1, superior antennae;
or. inferior a. .tenure: M. mandibles;
L. anterior lip; m}. anterior maxillae;
m2. posterior maxillae; mp1. 1st pair
of maxillipeds ; . mp2. 2nd pair of
maxillipeds; mps. 3rd pair of max¬
illipeds; pl.-—p*. legs of 1st to 4th
pair; f. dorsal cleft.

„ 5. Embryo in a later stage, viewed from

left side. The chorion has been cast
off, whereby’ the 3 anterior pairs of
limbs have been set free, the others
being still enclosed in the larval skin. —
C. inferior edge of the developing cara¬
pace; urp. uropoda ; /. capsule imbed¬
ded in the yolk-mass and forming the
first indication of the liver; remaining
letters as in fig. 4.

„ (5. A still more developed embryo, in

which the larval skin has been cast
off, thus causing all the limbs to
be freely exposed; lateral view. —
O. developing eyes ; It. rostral plates
of carapace ; hr. exp. exopodal part
of the branchial apparatus; t. telson;
remaining letters as in fig. 5.

, 7. Same embryo viewed from the dorsal

face.

„ 8. Embryo in the immediately succeeding

stage, viewed from left side. The
dorsal curvature of the body- has
changed to a pronounced ventral one,

1 15

Tig

ami the several limbs are extended in
front instead of being reflexed. — V.
remnant of the yolk-mass ; h. develop¬
ing heart; remaining letters as in
fig- 6.

9. Anterior extremity of same embryo,
viewed dorsally, and exhibiting the
2 still separated eyes.

10. Embryo in one of the last stages, and
considerably less magnified than those
mentioned above; lateral view. n.

renal organ ; remaining letters as in
fig. 8.

PI. LXX.

Diastylis Rathkei (Kroyer), var; female.

PI. LXXI.

Diastylis Rathkei, var. (continued); female.

PI. IiXXXI.

Diastylis Rathkei, var. (continued) : adult male.

Cumidae

Cumae e a

pi. i.

tryktiden pnv.Opmaa.ling Chra.

Cuma scorpioides,( Mont)

Cumidse.

Cumace a.

Pl.H.

tiyktiden priv.Opmaaling Chra.

Cuma scorpioides,(Mont).

(continued ).

Cumidae. CU-IYIS-C G 3-- PI. HI.

byktiden priv. Opmaaling Chra Clima SC0 p p j Q jdeS,( MOIl t).$

Cumidae.

Cumae e a.

PI. K

byktiden priv.Opmaaling Chra.

Cuma Edwardsii,Goodsir.

Cumidae.

Cumae e a

Pl.V.

Uyktiden priv.Opmaaling Chra.

Iphirtoe trispinosa/Goodsir)

cumid*. Cumacea.

Pirn.

tiyktlden priv. Op mailing Chra.

Iphinoe trispinosa,(Goodsir).

(continued ).

Cumidae.

Cumae e a.

Pl.W

Tn p /

//

txyktiden priv.Opmaaling Chra.

Cyclaspis longicaudata,G.O.Sars.

Cumidae.

Cumae e a.

pi. ■am.

Uyktiden pnv.Dpmaaling Chra. Cyders I OFl g l CaU d SLU, G.O.SaPS .

(continued).

Stiff, f)'.

Lampropidae.

Cumae e a.

PI. JX.

tryktiden priv.Opmaaling Chra-

Lamprops Fasciata,G.O.Sars

Lampropidae.

Cumae e a

P1.X.

tiykliden priv. Opm soling Chra.

Lamprops Pasciata,G.O.Sars.

(continued).

Lampropidae. CuiTl8.C 0 3--

PLXL

tiyktiden priv.Opmaaling Chra. . _

Lamprops ruscata.,G.O.Sars.

Lampropidae.

Cumae e a.

pi. xn.

trvktiden priv.Opmaalinq Chra. ■■ /ki \

Hemilamprops rosea, (Norman.)

Pirn

Lampropidae.

Cumae e a.

tryktiden priv.Opmaa.ling Chra.

Hemilamprops rosea, ( Norman.)

(continued).

Lampropidae.

Cumae e a.

pi.xcf.

Myktiden priv.Opmaaling Chra. „ / ik| \

Hemilamprops rosea, ( Norman.)

(continued).

Lampropidse

PI. JOT.

Cumace a.

Hemi lam props assimilis. G.O.Sars.

t/yktiden priv.Opmaaling Chra.

Lampropidae.

Cumae e a.

pi.m

trykt i den pr'rv.Opmaaling Chra .

Hemilamprops uniplicata.G.O.Sars.

Lampropidae.

Cumae e a.

PL2M.

Trykt i den priv. 0 pmaaJing Chr.

Hemi lam props u ni p I icata. G.O.Sars.

(continued).

Lampropidae,

Cumae e a

pi.smr.

Tryktiden priv.Opmaaling Chr.

Hems lam props crista±a,G.O.Sars.

Platyaspidae.

Cumae e a.

PL5GL

Trykt i den priv,Opmaa.ling Chr.

Platyaspis typica, G.O.Sars.

Platy&spidae.

Cumae e a.

P1.3£.

Tr^kL i den priv.Opmaa.linq Chr. . . . . r\ c*

Platyaspis typica, G.O.Sars.

(continued).

Leuconidae.

Cumae e a

P1.3XL

Tryktiden priv.Opmaa.linq Chr. , ,, „

Leucon nasicus, Kroyer.

J Cumae e a.

Leucomdae. PI. TXTT

Tryktiden priv.Opmaa.ling Chr. Leucon nSLSiCUS , KrOyer.

(continued).

Leuconidae.

Cumae e a.

PI. ML

Trykt i den priv.Opmaa.ling Chr.

Leucon nasicoides, Lil[jeb,

.

Cumae e a.

Leuconidae. PLTXTCT

Tryktiden priv.Opmaa.ling Chr.

Leucon Pulvus ,G.0.S&rs.

Leuconidse.

Cumae e a.

71. W

Tryktiden priv.Opmaa.l\ng Ch

Leucon paJlidus ^G.O.Saxs.

Cumae e a.

Leuconidae. PI.XWT

Trykt i den priv.Opmaaling Chr.

Leucon acutirostris,G.O.Sars.

Cumae e a.

Leuconidse. PLJXXML

Trykt i den priv.Opmaa.lmg Chr

Eudorella, ema.rginatcL,(Kroyer) .

Leuconidse.

Cumae e a.

Pl.Travnr

Trykt i den priv.O pmaaling Chr.

Eudoreila emarcjinata/Krdyer)

(continued).

Leuconidae.

Cumae e a.

P1.2XK.

Tryktiden priv.Opmaa.lmg Chr.

Eudorella. truncaLtula(Sp.Ba.be).

Cumae e a.

Leuconidse. PL XXX .

Tryktiden priv.Opmaaling Chr

Eudorella hirsuta, G.O.Sars.

Leuconidae

Cumae e a.

H.2XH.

Tr^kt i den priv.Opmaaling Chr.

Eudorellopsis deformis,(Krdyer)

Leuconidae.

Cumae e a.

Tryktiden priv-Opmaaling Chr.

Eudoreilopsis deformis(Kroyer) .
(continued).

Cumae e a

Pl.XXXIII.

Diastylidas.

G O Sars autogr.

Diastylis Rathkei, ( Kroyer.)

Trykt i den private Opmaaling.Chra .

Diastylidse.

Cumae e a.

PI. XXXIV.

G.O. Sars autogr Trykt i den private Opmaaling.Chra.

Diastylis Rathkei, ( Kroyer.)

( continued ).

PI. XXXV.

Diastylidae

Trykt i den private Opmaaling.Chra

Diastylis cornuta, Boeck

Diastylidse.

Cumae e a

PI. XXXVI.

G. 0, Sars autogr.

Diastylis cornuta. Boeck.

(adult male).

Trykt i den private Opmaalmg.Chra.

Diastylidae

PL XXXVII

Trj'kt i den private Opmaalmg,Chra

auto ox

Diastylis rugosa, G. 0. Sa rs

D iastylidae.

Cumae e a

PI. XXXVIII.

G- 0. Sars autogr.

D ia sty I is i u c i f e ra , ( K roy er.)

Trykt i den private 0pmaaling,Chp3 .

Diastylidae.

Cumae e a.

PI.XXXIX

G. 0. Sars autogr

Diastylis rostrata, (Goods i r).

Tr^kt i den private Opmaaling,Chra .

_

Diastylidae.

Cumae e a.

PI. XL.

G O Sars autogr

Diastylis tumida, (Lilljeborg)

Trykt i den private Opmaaling.Chra

Diastylidae.

Cumae e a,

PI.XLI

G. O.Sars autogr Trykt i den private Opmaaling,Chra .

Diastylis Goodsiri, Bell.

Diastylidaa

Cumae e a

Pl.XLIl

G. 0. Sars autogr.

Diastyiis spinulosa, Heller.

Trykt i den private Opmaaling.Chra.

D i a sty I i d se

Pl.XLIII.

Cumae e a.

U.O.Sars autogr Trykt i den private Opmaalmg.Chra

Diastylis echinata, Sp. Bate.

Diastylidss,

Cumae e a.

Pl.XLIV.

Diastylis scorpioides (Lepechin).

Diastylidae.

Cumae e a

Pl.XLY

Trykt i den private Opmaaling.Chra

Diastyloides_serrata, G. 0. Sa rs

D iasty I i d se .

Pl.XLV!

Cumae e a.

G.O.Sars autogr

D iasty loides^biplicata, G. 0. Sa rs.

Trykt i den private Opmaaling,Chra

pi.xlvii

Diastylidae. Cumae e a.

G. 0. Sars autogr

Diastylopsis resima, ( Kroyer.)

_ Trykt i den private Opmaaling,Chra.

Pl.XLVIII.

Diastylidss. Cumae e a.

G.O. Sars autogr

Leptostylis longimana, G.O. Sars.

Trykt i den private Opmaalmg.Chra

Diastylidas .

Cumae e a

Pl.XLIX.

G.O. Sars autogr.

Leptostylis macrura,G.O.Sars.

Trykt i den private Opmaaling,Chra

Diastylidae.

Cumae e a.

PI. L.

G. 0. Sars autocjr. Trykt iden private Opmaa!ing,Ct"'a.

1. Leptostyiis ampullacea (Lilijeb.)

2. „ villosa, G.O.Sars.

Pseudocumidse

Cumae e a

PILL

G.O. Sars autogr

Pseudocuma cercaria (v. Bened.)?

Trykt i den private Opmaaling.Chra

Pseudocumidae.

Pl.LII.

G.O. Sars autogr

Trykt i den private Opmaaling,Chra

Pseudocuma cercaria (v. Bened.)

Pseudocu midas.

Cumae e a

pi. Lin.

G.O. Sars autogr.

Pseudocu ma similis, G. 0. Sars.

Trykt i den private Opmaaling,Chra .

Pseudocu midae.

Cumae e a

Pi. LIY.

G. 0. Sars autogr

Petalosarsia declivis, G. 0. Sars.

Trykt i den private 0pmaaling,Chf'3

' •

Nannastacidae.

Cumae e a.

PL LV.

G. 0. Sars autogr

Cumella pygmsea, G. 0. Sars.

Trykt i den private Opmaaling.Chra

Campylaspidae. Cumae e a

PI. LVI.

G. 0. Sars autoqr. . | I • 11. i v Trykt I den private Opmaalinq,Chra

Campylaspis rubicunda (Lilljeb.)

Campylaspidae.

Cumae e a

PI. LVII.

G.O.Sars autogr. Trjfkt i den private Opmaaling.Chra

Campylaspis rubicunda (Lilijeb.)

(continued).

Campylaspidae.

Cumae e a

pi. ran.

G. 0. Sars autogr

Campylaspis giabra, G. 0. Sars.

Trjpkt i den private Opmaaling.Chra.

Cam pylasp Idas

Cumaoe a

PI. LIX.

G. O. Sars autogr. , _ _ „ Trykt i den private Opmaaling.Chra

Campylaspis sulcata, u. U. oars.

Campylaspidse. Cumae e a.

PI. LX.

G. 0. Sars autogr.

Campylaspis costata, G. 0. Sars.

Tr^kt i den private Qpmaalmg.Chra ,

Campy (asp id®

Cumae e a

Pl.LXI

G.O. Sars autogr

Campylaspis undata, G.O. Sars.

Trykt i den private Opmaaling.Chra

W..J

G. 0. Sars autogr

Trykt i den private Opmaalmg.Chra

Campylaspis horrida, G. 0. Sars

Campylaspidae.

Cumae e

a

PI. LXII.

Campylaspidae. Cumae e a

PI. LX III.

G.O. Sars autogr

Campylaspis verrucosa, G.O. Sars.

Trykt i den private Opmaaling,Chra .

Campylaspidce.

Cumae e a

PI. LX IV.

G. 0. Sars autogr

Campylaspis affi n is. G. 0. Sars

Trykt i der. private Opmaaling.Chra.

Anatomy.

Cumae e a

PI. LXV.

>r-£ix.v

//■

G. 0. SaTs autogr

D iasty I is

Trjrkt i den private Opmaaling.Chra

Anatomy.

Cumae e a

PI. LXVI.

G.O. Sars autogr

Diastyiis-Cuma-Lamprops-

Pseudocuma-Campylaspis.

frykt i den private Opmaalirig,Gt>ra

Anatomy.

Cumae e a

PL LXVII.

G.O. Sars autogr

Leu con - D iastylis.

Trykt i den private Opmaalmg.Chra

Anatomy.

Cumae e a

PlJSWfn

Trykt i den private 0pfnaalinp,,Chr3

G.O. Sars autogr

Leucon-i) i a sty I is - Hemiiamprops.

Development. 0 U ITl 3. G 0 ct

PI.LXIX

G. O. Sars autogr.

Diastylis

Trjrkt i den private Opmaalmg,Chra

D iasty lidae

Cumae e a

Pl.LXX

w i

f\ ..

s% \ ; A

ft

\ ?k|§ i 1

% Yrn i

V }jg|| v

G. 0. Sai’s autogr.

D iasty I is Rathkei, ( Kroyer).

Trykt i den private Opmaaling,Chra

var.

Diastylidse.

Pl.LXXI.

Cumae e a.

6. 0. Sars autogr-

Diastylis Rath ke i, ( Kroyer). van.

(continued ).

Trykt i den private Opmaaiing.Chra.

Diastylidse

Cumae e a

Pl.LXXIL

Dlastylis Rafhkei, ( Kroyer). var. Tyktide"PrivateOpmaa,in9'Chra
(adult male).

AN ACCOUNT

OF THE

CRUSTACEA

OF

NORWAY

WITH SHORT DESCRIPTIONS AND FIGURES OF ALL THE SPECIES

G. O. SARS

* » ,v

VOL. Ill

CUMACEA

PART I & II

CUMIDiE, LAMPROPIDiE (part)

WITH 16 AUTOGRAPHIC PLATES

BERGEN

PUBLISHED BY THE BERGEN MUSEUM

SOLD BY

ALB. CAMMERMEYER’S FOIi LAG. CHRISTIANIA
1899

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11 MAY !

N^/onai

1 900j

AN ACCOUNT

OF THE

CRUSTACEA

OP

NORWAY

WITH SHORT DESCRIPTIONS AND FIGURES OF ALL THE SPECIES

G. O. SARS

1 * t

VOL. III.

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PART III & IV

LAMPROPIDvE (concluded), PLATYOSPID^, LEUCONIDvE

WITH 16 AUTOGRAPHIC PLATES

t,

BERGEN

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WITH SHORT DESCRIPTIONS AND FIGURES OF ALL THE SPECIES

BY

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PART V & VI

DI ASTYLID At

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BERGEN

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1900

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G. O SARS

• 4 »

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PART VII & VIII

PSEUDOCUMIDJE, NANNASTACIDAs, CAMPYLASPID^E

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BERGEN

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WITH SHORT DESCRIPTIONS AND FIGURES OF ALL THE SPECIES

G. O. SARS

VOL. Ill

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PART IX & X

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