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AN ACCOUNT

OF THE

CRUSTACEA

OF

NORWAY

AN ACCOUNT

OF THE

CRUSTACEA

OF

NORWAY

WITH SHORT DESCRIPTIONS AND FIGURES OF ALL THE SPECIES

BY

G. 0. SARS

PROFESSOR OF ZOOLOGY AT THE UNIVERSITY OF CHRISTIANIA

VOL. VIII

COPEPODA

MONSTRILLOIDA & NOTODELPHYOIDA

WITH 37 AUTOTYPIC PLATES

BERGEN
PUBLISHED BY THE BERGEN MUSEUM

SOLD BY

ALB. CAMMERMEYERS FORLAG, CHRISTIANIA
1921

LIBRARY

UNIVERSITY OF CALIFORNIA
DAVIS

BERGEN, A.S. JOHN GRIEGS BOKTRYKKERI OG N. NILSSEN & S0N

PREFACE.

By this Volume I definitely conclude my Account of the Norwegian
Copepoda, it being my purpose in the next Volume to enter upon an entirely
different group of Crustacea, viz., the Ostracoda. Although my Account of
the former group has required no less than 5 Volumes, and more than 500
species have been described, I do not by any means imagine, that it gives a
fully exhaustive record of the existing forms, and I am indeed convinced that
many interesting species still remain to be detected, especially of the smaller
deep-water Harpacticoida and of the semiparasitic forms. Yet, I hope that my
Account may have thrown some light on this formerly much neglected part
of our Fauna, and that it may serve as the basis for further investigations.

As to the two anomalous groups treated of in the present Volume, no
record whatever has as yet been given on the Norwegian forms belonging to them.

I will not omit, also on this occasion, to tender my most sincere thanks
to the Direction of the Bergen Museum for the interest, it still shows for the
progress of my work.

6. 0. Sars

87^3

INTRODUCTION.

In the present volume I propose to give an account of 2 anomalous
groups of Copepoda, viz., the Monstrllloida and the Notodelphyoida, the
systematic position of which has not been fully recognised by earlier authors.
In the more recent classification of the Copepoda proposed by Giesbrecht, and
now generally adopted by carcinologists, only the systematic rank of families
is alloted to these groups, and they are both, together with several other
heterogeneous families, comprised within the 2nd tribe of this suborder Podoplea,
to which the name Ampharthrandria is given. I have otherwise shown, that
the principles upon which Giesbrechts classification is founded do not at all
hold good in every case, and this is also proved in regard to the Copepoda
here in question. It may be that the name Ampharthrandria is appli-
cable to the MonstrUloida; but this is by no means the case with the
Notodelphyoida, this group comprising many forms with the anterior antennae
quite alike in the 2 sexes. Moreover, the genus Thaumatopsyllus among the
Monstrilloida differs conspicuously even in the principal character by which
the 2 suborders Gymnoplea and Podoplea are distinguished by Giesbrecht,
viz., the mutual relation between the anterior and posterior divisions of the
body. The many essential characters distinguishing the 2 groups here treated
of, both from each other and from the other known Copepoda, have led me
to the conclusion, that they ought to be raised to the rank of distinct divisions,
to be again subdivided into real families. The relation of these divisions to
other known groups of Copepoda is somewhat obscure, though in some instances
a tendency towards the Cyclopoid type is unmistakable. On the other hand,
by an extreme degradation of the whole body and its appendages, some forms
belonging to the Notodelphyoida acquire an appearance, strongly recalling that
of the Lernceoida. All the forms here in question are in some measure
parasitic in habits. But the parasitisme is of a very different kind in the

1 — Crustacea.

2 divisions. The Monstrilloida are, according to the interesting observations
of Malaquin, in their juvenile state true endoparasites, living as simple, sac-like
bodies in the blood-vessels of some invertebrate animals (Annelids), whereas
in the adult state they are freely living pelagic animals provided with power-
fully developed natatory appendages. The Notodelphyoida, on the other hand,
are for whole their life confined to their hosts (simple and compound Accidians),
all stages of growth being mostly found together in the branchial cavity of these
Tunicata. Yet they do not seem, as a rule, to feed on the juices of their
hosts, but more properly on the nourishing particles and small organisms
introduced, together with the constantly renewed water, in the branchial cavity
by the breathing process. Of course they cannot at all be regarded as true
parasites, but more properly as commensals or messmates. Both divisions
here treated of are well represented in the Fauna of Norway, and as there is
some confusion in regard to the exact definition of the genera and species,
and moreover the descriptions and figures given by earlier authors in many
cases are very incomplete and partly erroneous, I think that a thorough revision of
these 2 interesting groups, accompanied by good figures, cannot fail to be
of interest.

MONSTRILLOIDA.

Remarks.— The most prominent morpliological character distinguishing
this group of Copepoda, is the total absence, in the adnit state, of both
the posterior antennae and of any traces of oral appendages, as also of a
functional alimentary canal. Of course the fully developed animal is quite
incapable to feed in the ordinary manner, but may only subsist on the
nourishing matter accumulated within the body-cavity during its juvenile
parasitic existence, the adult stage being exclusively devoted to the propagation.
The division Monstrilloida comprises as yet only a rather restricted number of
forrns, which all formerly were referred to a single genus, viz., MonstrUla of
Dana, with which the genus Thaiimaleus of Kreyer was considered to be
identical. In recent times, it is true, a subdivision of the genus MonstrUla
into 2 or 3 genera has been attempted, but these genera are so closely allied,
that they at all events must be comprised within the same family. Yet an
interesting new genus (Thaumatopsyllus), apparently referable to the Monstril-
loida, has recently been added by the present author, and this genus is so
very different from the other Monstrilloid genera, that it cannot by any means
be included in the same family with them, but must be regarded as the type
not only of a separate family, but even of a distinct section, for which I have
proposed the name Monstrilloida cyclopimorpha. Of course the division
Monstrilloida appears at present cleft into 2 well defined sections, the M.
cyclopimorpha and the M. geniiina; but each of these sections is as yet only
represented by a single family.

Section 1.

Monstrilloida cyclopimorpha

Remarks.— Iht type of this section is the remarkable form described by
the present author in another place under the name of Thaumatopsylliis
paradoxus. The reception of this form within the division Monstrilloida
appears to be warranted by the above-mentioned general morphological character:
the total absence of both the posterior antennae and of any oral appendages.
Otherwise this form differs considerably from the Monstrilloid type.

Fam. Thaumatopsyllidae.

Remarks. — As this family at present only comprises a single genus, it
may be sufficient to give the characters of that genus.

Gen. Thaumatopsyilus, G. O. Sars, 1913.

Generic Characters. — Body of adult female cyclopoid in shape, the anterior
division being conspicuously dilated, the posterior slender and attenuated. Head
consolidated with the 1st trunkal segment, and having the front produced
below to a short and blunt rostral prominence. The 2 succeeding trunk-
segments normally developed, the 2 posterior ones, however, abruptly much
narrower and firmly connected with the tail, to form with it the posterior
movable portion of the body. Tail proper composed in female of only 3
segments, the last extremely slender and narrow, rod-like. Caudal rami well

developed, with the normal number of setae, Anterior antennae composed of a
limited number of well defined joints, and extended laterally. No traces
of posterior antennae and oral appendages observable, nor of any distinct oral
tubule. Three pairs only of natatory legs present, the 2 posterior pairs of legs
being quite rudimentary and of similar structure. Two ovisacs present in female.
Remarks. — In the above diagnosis i have attempted to give the most
essential characters, by which the present genus distinguishes itself from the
other known Monstrilloida. The mutual relation of the 2 chief divisions of
the body is very peculiar, and does not agree either with that mentioned by
Giesbrecht as characteristic to his suborder Gymnoplea or with that characterising
the Podoplea, the movable articulation between the 2 divisions occuring in
quite a different place, viz., at the junction between the penultimate and anti-
penultimate trunk-segments. This is indeed a quite unique character distinguishing
this genus from any other form known to me. As anomalous characters may also
here be named the presence of only 3 pairs of natatory legs, and the narrow
rod-like shape of the last caudal segment. The genus comprises as yet only
a single species, to be described below.

1. Thaumatopsyllus paradoxus, G. O. Sars.
(PI. I.)

Thaumatopsyllus paradoxus, G. O. Sars, Arcli. f. Mathem. og Naturvidenskab. Bd. XXXllI,

No. 6, p. 5, w. plate.

Specific Characters. — Female. Body comparatively slender, with the
anterior division somewhat depressed and oblong oval in outline. Cephalic seg-
ment very large and slightly contracted anteriorly, frontal part narrowly rounded.
The 2 succeding segments well developed, with the lateral parts closely conti-
guous and rounded behind. Penultimate trunk-segment scarcely more than
half as broad as the preceding one; last segment still smaller. Tail exceedingly
slender, almost attaining half the length of the body; genital segment slightly
constricted in the middle; 2nd segment quite short and having the posterior
edge somewhat produced dorsally; 3rd segment more than twice as long as
the other 2 combined, and extremely narrow, rod-like, with the slightly dilated
extremity transversely truncated. Caudal rami but slightly diverging and oblong
quadrangular in form, being about 4 times as long as they are broad, and
a little widening distally; seta of outer edge occuring about in the middle;
apical setae of moderate size and densely ciliated, the outermost one shorter
than the other 3. Antennae not nearly attaining the length of the cephalic

segment, and each composed of 9 joints clothed with scattered simple setae;
3rd joint much the largest, the 6 outermost joints comparatively short and
equal-sized. The 3 pairs of natatory legs normally developed and of essential
same structure, with both rami 3-articulate and nearly of equal size. The
last 2 pairs of legs very unlike the former, and reduced to simple small
3-articulate stems, with the middle joint very small, last rounded in shape and
provided with 2 unequal apical spines. Ovisacs very large, rounded oval in form.

Body in the living animal highly transparent and nearly colourless, its
anterior part being filled up with a number of clear oil-bubbles of unequal
size and partly of a light orange colour. Eye replaced by a comparatively
large transverse patch of a light red pigment, in which, however, no trace
of refracting elements could be detected.

Length of adult female 1.65 mm.

Male unknown.

Remarks. — The above-described form is easily recognisable from any of
the other known Copepoda, both as regards its outward appearance and the
structure of the several appendages. I am much inclined to believe, that its life-
history will turn out to be a similar one to that stated by Malaquin for the
Monsirlllidce, and that in the juvenile state this form leads a true parasitic
existence within the body of some invertebrate animals.

Occurrence. — Three specimens only of this remarkable form, all of the
female sex, have as yet come under my notice. One of them was taken,
many years ago, in the Christiania Fjord, at Drobak, the other 2 in the
Trondhjem Fjord, at Selven. All 3 specimens were captured, together with
other pelagic animals, by the aid of a plankton-net lowered to a depth of
about 60 fathoms. The living animal was seen moving through the water in
a similar jumping manner to that observed in most Cyclopoida. It was,
however, by no means particularly agile in its movements.

Section 2.

Monstrilloida genuina.

Remarks. — In this section are comprised the typical Monstrilloida, the
general characters of which coincide with those given below for the sole
family as yet representing the section.

Fam. Monstrillidae.

General Characters. — Body more or less slender and elongated, with the
anterior division only slightly dilated and not sharply marked of from the
posterior. Head and 1st trunkal segment completely coalesced, forming together
a very large segment of a more or less cylindrical shape, and as a rule occupying
rather more than half the body, its anterior extremity obtusely truncated, without
any rostral prominence; ventral face of the segment in the greater extent of
its length quite smooth, exhibiting no traces of either posterior antennae or
any oral appendages, being only provided in the median line with a small
tubular process, from which a short canal leads to the inner substance of the
body; the latter in female specimens retracted from the walls of the segment
in a most peculiar manner, so as to form a rather narrow band-like chord
passing through the axis of the segment. Exposed part of trunk composed
of 4 well defined segments gradually diminishing in size behind. Tail poorly
developed, with the number of segments more or less reduced, and exhibiting
well marked sexual differences. Caudal rami, as a rule, short, but provided
with strong plumose setae, the number of which is somewhat variable in the

8

different genera. Eye, when present, exhibiting 3 highly refracting lenses, one
ventral and 2 lateral, imbedded in a dark pigment. Anterior antennae, unlike
what is generally the case in Copepoda, extended straight forwards, and composed
of a limited number of joints clothed with rather unequal setae pointing in
different directions, some of them being much elongated and finely ciliated,
some others, attached to the terminal joint, exhibiting not seldom a peculiar
dichotomous ramification ; same antennae in male distinctly hinged. Natatory
legs present in the usual number, and very powerfully developed, with
the basal part large and muscular and both rami 3-articulate. Last pair
of legs in female represented on each side by a single more or less lamellar
joint carrying a restricted number of plumose setse; in male much reduced, or
wholly absent. Alimentary canal quite obliterated. Ovaria, when fully developed,
very massive, filling up the greater part of the body-cavity and extending
anteriorly within the frontal part of the head; the ripe ova not included in
any true ovisacs, but agglutinated to 2 slender juxtaposed spines or filaments
issuing from the ventral face of the genital segment, these spines being in
male replaced by a thickish, somewhat clavate appendage, into which the
spermatophores are received before extrusion.

Remarks. — Of this family at first only 2 species were known, derived
from 2 widely remote localities, the one recorded by Dana from the Sulu Sea
as Monstrilla viridis, the other by Kr0yer from thn Norwegian coast as
Thaumaleus iypicus. These 2 species, though bearing very different names,
are evidently nearly allied, and were also by most subsequent authors regarded
as congeneric, hi more recent times a considerable number of additional
forms of the same remarkable type have been recorded from different
parts of the oceans, and it appeared desiderable to group these species
according to some more conspicuous diversities found between them.
Thereby the first step to a subdivision of the genus Monstrilla was intimated.
Such a subdivision was indeed carried out in the year 1892 by Giesbrecht,
who referred the Monstrillidae at that time known to 2 nearly-allied genera,
chiefly characterised by the segmentation of the tail and by the number of
the caudal setae. For the one of these genera he retained the old name
Monstrilla, for the other he applied the name Thaumaleus proposed by Kr0yer,
and this arrangement has now generally been admitted by carcinologists. I am
also of opinion that these 2 genera should be supported ; but I am by no
means prepared to consent with Giesbrecht in his application of the name
Thaumaleus to the one of these genera. For it is quite certain, that the form
recorded by Krayer is not referable to Giesbrecht's genus, differing as it does,

just in one of the 2 principal characters by which that genus is distinguished
from Monstrilla, viz., in the number of caudal setae. Both according to the
description given by Kroyer in "Naturhistorisk Tidsskrift" and to the figures in the
Atlas to Gaimards voyage, the caudal rami in Kr0yers species are each provided
with 5 well-developed setse, as in most species of the genus Monstrilla, whereas
in Giesbrecht's genus the number of setae is much reduced, only 3 such setae
occuring on each ramus (at last in female), hi any case, if it should be
found advisable to support the genus Thaumaleiis of Kroyer, it must be
confined to the species recorded by that author. Fortunately we have another
generic name to replace that given by Giesbrecht to his genus, viz.,
Cymbasoma, proposed as early as the year 1888 by I. C. Thompson for
a species (rigidum), which evidently is referable to Giesbrecht's genus. The
genus Hcemocera of Malaquin I regard as synonymous with that genus. In
addition to the 2 genera Monstrilla and Cymbasoma, I have found it advisable
to establish another genus, Monstrillopsis, to include the anomalous species
described by Scott under the name of Monstrilla dubia. The family Monstrillidae
thus at present comprises 3 genera, all of which are represented in the fauna
of Norway.

Though I have not myself as yet had any opportunity to study the
peculiar life-history of the Monstrillidae, I think that a short resume of the
interesting investigations made in this respect by the French naturalist Malaquin^)
may here be given. According to that distinguished author, the young live
the eggs as small Nauplii, without mouth or alimentary canal, but provided
in front with the usual 2 pairs of limbs (anterior and posterior antennae) and
behind them on each side with a hook-like appendage (mandibles). The Nauplii
soon attach themselves to some polychaete Annelid and penetrate through the
body-wall of the same, then entering the vascular system. By this process
they lose completely all their appendages, and become converted to simple
ovoid bodies merely consisting of an assemblage of indifferent embryonic
cells surrounded by a thin cuticle. From the one end of these bodies 2 soft
horn-like processes grow out, gradually increasing in length, and at last assuming
the form of slender thread-like appendages. It is supposed that through these
appendages the absorbtion of the blood-serum of the host is performed, and
according to their position they may answer to the posterior antennae. During
the rapid growth of these endo-parasitic larvae a remarkable differentiation take
place in their interior, resulting in the formation of the characteristic and rather

- ij. See: Arch. Zool. Exp. (3), Vol. 9, 1901.
2 — Crustacea.

_10_

complicated body of a true Monstrillid. In the last larval stage the enclosed
Monstrillid is very distinctly traced through the thin outer cuticle of the larva,
filling up nearly the whole inner cavity, and exhibiting all the definitive appen-
dages, as also d stinct traces of the generative organs, at least the female
ones. At this time the larva is ready to force its way out of the body of the
host, and this is apparently accomplished by a burrowing action of the hind
acutely produced extremity, which is surrounded with several rows of small
hooklike spinules. After the escape of the larva its thin outer cuticle soon
burst, and the enclosed Monstrillid is thus allowed to emerge, unfolding its
several appendages Its movements are at first lather slow, but very soon, by
a single moult, it aquires its full development, moving quickly about, to
commence its free pelagic existence

Gen. 2. Monstrilla, Dana, 1848.

Syn: ? Thaumaleus, Kroyer (not Giesbrecht).

Generic Characters. — Body as a rule very slender and elongated, especially
in female, with the cephalic segment in most cases occupying rather more than
half its length and more or less cylindrical in shape; exposed part of trunk
gradually narrowed behind, with the lateral parts of the segments rounded off.
Tail composed in female of 3, in male of 4 well defined segments, the last
one rather small and obtusely truncated behind.' Caudal rami sublamellar,
each provided in female with 5 or 6 setae, one of which is generally shorter
than the others and attached more dorsally; those in male of same appearance
as in female, but lacking one of the setae. Eye in most of the species imper-
fectly developed. Oral tubule generally fai remote from the frontal part
of the head. Antennae more or less elongated, with the joints generally imper-
fectly defined in female. Natatory legs with the basal part very massiv, rami
comparatively short, buth clothed inside and at the end with long plumose
setae; outer ramus somewhat longer than the inner and only provided with
2 small spines outside, the one attached to the 1st joint, the other to the end
of the last joint. Last pair of legs in female sublamellar and somewhat extended
laterally, inner edge more or less expanded, extremity slightly exserted and
provided with 3 (in some cases only 2) plumose setae; those in male much
reduced in size, knob-like, and tipped with one or two slender setae.

Remarks. — The present genus was established as early as in the year
1848 by Dana, and may be legarded as the type not only of the family Mon-
strillidae, but also of the whole division here treated of. It is chiefly distin-

11

guished from the other 2 genera comprised within the present family by the
more complete segmentation of the tail and the increased number of caudal
setae. Another character by which the species of this genus may be readily
recognised, is the position of the oral tubule, wich is more or less far remote
from the frontal part of the head, whereas in the other 2 genera it generally
occurs in close approximation to that part.

Seven Norwegian species referable to this genus will be described in the
sequel, one of them being, however, somewath doubtful and only observed in
the male sex,

2. Monstrilla longicornis, Thompson.

(PI. H & III).

Monstrilla longicornis, I. C. Thompson, Trans. Biol. Soc. Liverpool, Vol IV, p. 1 19, PI. IV,

figs. 1, 2. 4 (cT).
Syn: Mcnstrilla intermedia, Aurivillius.

Specific Characters. ^Female. Body moderately slender, with rather coarse
integuments, which exhibit everywhere a finely granular or dotted surface.
Cephalic segment occupying about half the length of the body, and almost of
equal width throughout, though, seen dorsally, exhibiting somewhat behind the
middle a slight but easily observable dilatation, frontal part bluntly truncated.
Tail about equalling half the length of the exposed part of the trunk; genital
segment comparatively large, being fully as long as the remaining part of the
tail, and oblong quadrangular in shape, with a well marked transverse suture
in the middle of the dorsal face; ovigerous spines about twice the length of
the tail. Caudal rami about equalling in length the last 2 segments combined,
and only slightly divergent, each provided with 5 strong plumose set« of
nearly equal size, the outermost one attached to a well-marked ledge of the
outer edge, the others to the somewhat obliquelly rounded apex. Eye imper-
fectly developed, without any trace of refracting elements, and only replaced
by a diffuse yellowish pigment. Antennae rather slender and elongated, though
scarcely exceeding in length the cephalic segment, and each apparently com-
posed of 5 joints, of which, however, only the 1st is distinctly defined, the
others being confluent and only indicated by slight constrictions of the antenna;
most of the setae attached around the middle of the fusiform terminal joint
reachly ramified. Oral tubule well marked and occurring somewhat behind the
middle of the cephalic segment. Natatory legs all of the very same structure and
also of about equal size; 2nd basal segment not very sharply defined from the
1st, and armed inside with 2 sm;all juxtaposed denticles; terminal joint of outer

12

ramus rather produced, being fully twice as long as the middle one, and having
the outer edge divided into 4 very distinctly marked crenulations. Last pair of
legs rather broad at the base, but having the outer part abruptly narrowed
and provided at the obtusely rounded extremity with 3 ciliated set«, the inner-
most of which is much smaller than the other 2; inner expansion almost rect-
angular and carrying a single, but well developed seta.

Male considerably smaller than female and of somewhat shorter and
stouter form of the body, but exhibiting a very similar shape of the cephalic
segment. Tail comparatively more slender than in female, and composed of
4 well defined segments of nearly equal length, the 1st, as usual, produced
below to a club-like copulative appendage terminating in 2 short diverging
rami, each armed at the end with a short spine. Caudal rami of a similar shape
to that in female, but with one of the apical setae absent. Antennae more strongly
built than in female and having the joints more distinctly defined, being more-
over conspicuously hinged, the hinge occurring between the last 2 joints. Natatory
legs of exactly same structure as i female. Last pair of legs, however, much
reduced in size, forming 2 small knob-like prominences issuing from a common
base, each prominence tipped by 2 (in some cases only 1) slender setae.

Body in both sexes of a yellowish grey colour, and on the whole less

transparent than in most other species.

Length of adult female 3.50 mm., of male 2.30 mm.

Remarks.— ^This species was established in the year 1890 by J. C. Thomp-
son, and was only based on a solitary male specimen taken by him off the
Puffin Islands. Subsequently, however, Th. Scott recorded this form from many
other localities, and has given in the report of the Fishery Board for Scotland
(1904) good descriptions and figures of both sexes. He is of opinion
that Giesbrecht's species, M. longlremis, is identical with that observed by
him; but this is certainly not the case, as will be shown further on. The
present species may be easily distinguished from its nearest allies by the some-
what robust body and the rather coarse and distinctly granular integuments.
Two other characters, both derived from the structure of the natatory
legs, may also here be named, viz., the presence inside the 2nd basal seg-
ment of 2 well defined denticles, and the very conspicuous crenulation of the
outer edge on the terminal joint of the outer ramus. These characters are pretty
constant and found quite alike in both sexes. The form recorded by Aurivil-
lius under the name of M. intermedia is identical with the present species.

Occurrence. — I have met with this form occasionally in several places,
both on the south and west coast of Norway, among other pelagic animals

13

taken by the aid of the tow-net near the surface of the sea. The movements
of the animal are very rapid, and are performed in abrupt bounds, whereby
the body is kept in a more or less erect position. Male specimens seem to
occur in nearly sariie number as the females.

Distribution. British Isles (Thompson, Scott), Skagerak (Aurivillius).

3. Monsirilla longiremis, Giesbrecht.

(PI. IV & V)

Monstrilla longiremis, Giesbrecht, Pelagische Copepoden des Golfes von Neapel, p. 589, PI.

46, figs. 10, 14, 22, 37, 41.

Specific Characters.— Fernale. Body considerably more slender than in
the preceding species, with thinner and scarcely at all granular integuments.
Cephalic segment occupying rather more than half the length of the body,
and slightly narrowed in its anterior part, with no distinct dilatation in the
middle. Tail agreeing with that in M. longicornis, as regards its relativ size
and its segmentation, but having the ovigerous spines considerably more
elongate. Caudal rami comparatively narrower than in that species and
remarkably divergent; number of marginal setae, as in M. longicornis, 5 on
each ramus, the innermost but one conspicuously shorter than the others. Eye
inconspicuous. Antennae exceedingly slender and elongated, considerably ex-
ceeding in length the cephalic segment, and, as in the preceding species,
having all the joints, except the 1st, confluent. Oral tubule rather small, and
occurring about in the middle of the cephalic segment. Natatory legs resemb-
ling in structure those in M, longicornis, but differing in the presence of only
a single denticle inside the 2nd basal segment, and in the total absence of
any crenulations on the outer edge of the terminal joint of the outer ramus.
Last pair of legs comparatively narrower, with the inner expansion less pro-
minent and evenly rounded off; number of marginal setae as in M. longicornis.
Ova attached to the genital spines very nqmerous, and in some cases accu-
mulated to form an oblong oval mass extending far beyond the limits of the body.
Male of rather small size, as compared with the female, but exhibiting
a much similar slender and narrow form of the body. Cephalic segment
nearly perfectly cylindrical in ghape and exceeding somewhat in length the
remaining part of the body. Tail, as in the male of M. longicornis, dfstinctly
4-articulate, with the copulative appendage of a very similar structure. Caudal
rami agreeing in shape with those in female and spread out in the same remark-
able manner, each of them, however, only provided with 4 setae. Antennae
much more slender than in the male of M. longicornis, with the 2nd joint of

14

unusual length, otherwise built in a muclv similar manner. Natatory legs
exactly as in female. Last pair of legs, however, very small, knob-like, each
only tipped with a single slender seta.

Body in both sexes rather pellucid with only a very slight yellow tinge, and
provided in some places with a few small pigmentary patches of a darker colour.

Length of adult female generally about 3 mm., though in some instances
reaching 3.70 mm. ; that of male scarcely attaining 2 mm.

Remarks. — The above-described form is unquestionally the same as that
recorded by Giesbrecht from the Mediterranean, the identity of both being at
once seen by a comparison of the figures here given with those in Giesbrecht's
work. It is true that the present form in several respects shows a near
relationship to M. longicomis ; but I think that the above given descriptions
of these 2 forms will prove them to be in reality specifically distinct.

Occurrence. — Several specimens of this form have been taken by me at
different times and in different places on the Norwegian coast, from the
Christiania Fjord and northwards to Kvalo. Only a single male has, however,
as yet come under my notice, all the other specimens were of the female sex.

Distribution. — Mediterranean (Giesbrecht).

4. Monstrilla clavaia, G. O. Sars, n. sp.

(PI. VI)

Specific Characters. — Female. Body rather stout and clumsy, being
considerably dilated in its anterior part and viewed laterally, of a pronouncedly
clavate shape. Cephalic segment very large, occupying rather more than half
the length of the body, and having its greatest width about in the middle,
dorsal face remarkably vaulted in front. Tail about half the length of the
exposed part of the trunk, and on the whole resembling in structure that in
the 2 preceding species; ovigerous spines rather produced, being fully 3 times
as long as the tail. Caudal rami exceeding somewhat in length the last 2
segments combined, and only slightly divergent, each, as in the 2 preceding
species, provided with 5 setae, the innermost but one being, however, consider-
ably shorter than the others. Eye inconspicuous. Antennae not nearly attaining
the length of the cephalic segment, otherwise built in much the same manner
as in the 2 preceding species. Oral tubule rather prominent and occurring
somewhat behind the middle of the cephalic segment. Natatory legs, as in
M. longiremis, armed inside the 2nd basal segment with a single well-marked
denticle, terminal joint of outer ramus with a slight indication of a crenulation

15

of the outer edge. Last pair of legs very similar in shape to those in M.
longicornis, the inner expansion being rather prominent.

Body in the living animal whitish pellucid, and ornamented with irregular
patches of a light reddish brown or chestnut-coloured pigment.

Length of adult female 4.50 mm.

Male unknown.

Remarks.- This is much the largest of the species observed by me, and
I therefore at first believed it to be the M. grandis of Giesbrecht. On a closer
examination I have, however, found it to differ in some respects very essenti-
ally from that species, being in reality much more nearly related to the 2
preceding species, though easily distinguishable from them by the rather
different shape of the body.

Occurrence. — A solitary female specimen of this form was taken, many
years ago, at Hval0r, outside the Christiania Fjord.

5. Monstrilla leucopis, G. O. Sars, n. sp.
(PI. VII)

Specific Characters.— Female. Body exceedingly slender and elongated,
resembling somewhat in shape that of M. longiremls. Cephalic segment
considerably exceeding half the length of the body, and of a narrow cylindrical
form. Tail comparatively short, scarcely attaining half the length of the ex-
posed part of the trunk; genital segment rather dilated at the base, and
without any trace of a dorsal suture; ovigerous spines of moderate length.
Caudal rami rather large, exceeding in length the last 2 segments combined,
and only slightly divergent, inner edge perfectly straight, outer considerably
protuberant in front of the middle; each ramus provided with 5 setae, 3 of
which issue from the narrowly rounded apex, the other 2 from the outer edge,
the latter of very unequal size, the proximal one being normally developed,
whereas the distal one is greatly reduced, and only slightly exceeds in length
the corresponding ramus. Eye inconspicuous, and replaced by an opaque
whitish substance apparently answering to the ocular pigment. Antennae rather
slender, though not nearly attaining the length of the cephalic segment, and
having their 5 joints more distinctly defined than in the preceding species,
none of the setae attached to the terminal joint ramified. Oral tubule rather
small, and occurring somewhat in front of the middle of the cephalic segment.
Natatory legs without any denticle inside the 2nd basal segment, outer ramus
rather produced and having the outer edge of the terminal joint perfectly

16

smooth. Last pair of legs gradually narrowed distally, and only provided
with 2 apical setae, inner edge scarcely expanded.

Male much smaller than female, but exhibiting a very similar slender
form of the body. Tail, as usual, composed of 4 well defined segments, the
1st of which is the largest, and is produced below to a rather large and
prominent copulative appendage of an oblong oval form and armed on each
side with a straight rod-like spine. Caudal rami of the very same shape as
in the female, and having the outermost but one of the setse reduced in a
similar manner, differing, however, as in the males of the preceding species, in
the absence of one of the apical setae. Anterior antennae hinged in the usual
manner. Last pair of legs reduced to 2 very small knob-like prominences,
each tipped with a single slender seta.

Body (in female) highly transparent and ornamented in some places with
pigmentary patches of a light reddish colour. Length of adult female reaching
to 3.30 mm.; that of male scarcely exceeding 1.60 mm.

Remarks. — I have been in some doubt, if not the above-described form
should be the same as that recorded by Scott under the name of M. anglica
Lubbock. Indeed, in the structure of the last pair of legs and the peculiar
reduction of the outermost but one of the caudal setae, both these forms seem
to agree pretty well. On the other hand, is the general shape of the body,
to judge from the figure given by Scott, rather unlike, and another very
essential difference is found as regards the number of the caudal setae, which,
both according to the description and the figure given by Scott, is stated to
be 6 on each ramus in the form observed by him. In any case the specific
name anglica cannot be applied either to the present form, or to that observed
by Scott, as it seems evident that Lubbock's species is different from both of
them. I have retained for the species here treated of the name assigned to
it long ago in my notes.

Occurrence.— SiOm^ few specimens of this form, among them a single
male, were collected, many years ago, at Kvale on the Nordland coast.

6. Monstrilla gracilicauda, Giesbrecht.

(PI. VIII)
Monstrilla gracilicauda, Giesbrecht. Pelagische Copepodeii des Golfes von Neapel, p. 587,

PI. 46, figs. 9, 16, 18, 29, 32, 43.

Specific Characters. — Female. Body moderately slender, with the anterior
division slightly dilated in the middle. Cephalic segment about occupying half

17

the length of the body, and, viewed dorsally, exhibiting a very slight dilatation
in front of the middle, frontal edge somewhat produced between the insertion
of the antennae. Tail exceeding half the length of the exposed part of the
trunk; genital segment rather large, being considerably longer than the remaining
part of the tail, and gradually narrowed behind, dorsal face with a very slight
transverse suture in the middle; ovigerous spines unusually short. Caudal
rami comparatively small and somewhat divergent, each provided with 6 setae,
one of which, however, is very short and attached somewhat dorsally. Eye
easily observable in the living animal, though of a somewhat incomplete structure,
lateral lenses small and rather remote from each other, being connected by
a narrow stripe of dark pigment, ventral lens apparently imperfectly developed.
Antenna rather shorter than in the species described in the preceding pages,
not even attaining half the length of the cephalic segment, and only composed
of 4 joints, the last of which is about as long as the other 3 combined and
somewhat fusiform in shape, with none of the setae ramified. Oral tubule
occurring unusually far in front, at about the end of the first V3 of the cephalic
segment. Natatory legs without any denticle inside the 2nd basal segment,
outer ramus considerably longer than the inner and having the terminal
joint well developed, with the outer edge perfectly smooth. Last pair of legs
somewhat clavate in outline, the inner edge forming a rounded expansion
immediately inside the extremity, apical setae 3 in number and of nearly
equal size.

Body in the living animal rather transparent and in some places tinged
with a light yellow pigment.

Length of adult female reaching to 3.55 mm.

Male unknown.

Remarks. — The present species is easily distinguished from those described
in the preceding pages by the comparatively shorter antennae, the position of
the oral tubule, and the shape of the last pair of legs. The tail, moreover,
appears more elongate and the genital segment of larger size than in those species.

Occurrence.— ^Some few specimens of this form, all of the female sex,
were collected, many years ago, in 2 different places on the Nordland coast,
viz., Valdersund and Kvale.

D/s/'/-/^«//o/z.— Mediterranean (Giesbrecht) Scottish coast (Scott).

Crustacea.

18

7. Monstrilla helgolandica, Glaus.

(PI. IX)
Monstrilla helgolandica, Claus. Die freilebenden Copepoden, p. 165, PI. 12, fig. 9.

Specific Characters. — Female. Body comparatively short and stout, and
somewhat dilated in its anterior part. Cephalic segment about occupying half
the length of the body and, viewed dorsally, exhibiting a somewhat fusiform
shape, with the greatest width a little in front of the middle and almost
attaining half the length. Tail of a similar shape to that in M. gracllicauda,
the genital segment being rather large and gradually narrowed behind; ovigerous
spines of moderate length. Caudal rami considerably divergent, and narrow
oblong in shape, each provided with 6 setae of somewhat unequal length, one
of them, attached somewhat dorsally, being very small, that next to it on the
outer side somewhat shorter than the 4 remaining ones, all the setae issuing
from the outermost rounded part of the ramus. Eye easily observable, and
having all 3 lenses distinctly developed. Antennae scarcely attaining half the
length of the cephalic segment, and, as in M. gracllicauda, only composed of
4 joints. Oral tubule well marked, and occurring about in the middle of the
cephalic segment. Natatory legs without any denticle inside the 2nd basal
segment, outer ramus less elongate than in the other species, with the terminal
joint of smaller size. Last pair of legs rather unlike those in the other known
species, each forming a narrow cylindrical stem, angularly bent in the middle
and tipped with 2 subequal setae.

Body very transparent in its anterior part, but behind tinged with a dark
brownish pigment.

Length of adult female scarcely exceeding 1.40 mm.

Male unknown.

Remarks. — This is a very small-sized species, and may moreover be
easily recognised by the unusual short and stout form of the body, as also
by the structure of the caudal rami and that of the last pair of legs. The
form recorded by Bourne as M. helgolandica is quite certainly not that species,
but more properly referable to M. longiremis Giesbrecht.

Occurrence.— 1^0 female specimens only of this form have as yet come
under my notice. They were taken, many years ago, at Christiansund, west
coast of Norway.

Distribution. — Helgoland (Claus), Skagerak (Timm).

19

8. Monstrilla serricornis, G. O. Sars, n. sp.

(PI. X, fig. 1).

Specific Characters. — Male. Body comparatively short and stout, and,
seen laterally exhibiting a somewhat clavate shape. Cephalic segment shorter
than usual, only slightly exceeding in length the exposed part of the trunk
and, seen dorsally, nearly of equal width throughout, its ventral face forming
anteriorly a rather prominent gibbous convexity, but without any distinctly marked
oral tubule. Tail rather narrow, and composed of 4 well defined segments,
the 1st of which is produced below to a sub-clavate copulative appendage
provided at the end on each side with a short auriculiform lobe. Caudal
rami comparatively small and somewhat divergent, each having the form of
a rounded oval lamella edged with 5 subequal setae. Eye inconspicuous. An-
tennae about equalling in length 2/3 of the cephalic segment, and rather strongly
built, being composed of 5 well defined joints, the last of which is, as usual,
very movably articulated to the preceding one, and somewhat knife-shaped,
with the inner sharpened edge divived at the extremity into 5 small recurved
denticles. Natatory legs of the usual structure. 5th pair of legs wholly absent.

Colour not yet ascertained. Length of the body 1.75 mm.

Female unknown

Remarks. — It is only provisionally that I refer the above-described re-
markable form to the genus Monstrilla, from which it in some respects seems
to differ rather conspicuously. As, however, only the one sex as yet has been
observed, its true relationship cannot at present be fully made out. The pecu-
liar armature of the antennae may suffice to distinguish at once this form from
any of the hitherto known Monstrillidae.

Occurrence. — Two specimens only of the present form have as yet come
under my notice, both of the male sex and exactly agreeing with each other.
The one was taken at Bukken, outside the Stavanger Fjord, the other at Kval0,
on the Nordland coast.

Gen. 3. Cymbasoma, Thompson, 1888.

Syn : Thamaleiis, Giesbrecht (not KrOyer).
, Hcemocera, Malaquin.

Generic Characters. ^General form of the body resembling that in Mon-
strilla. Tail however having the number of segments reduced in both sexes,
only 2 segments being present in female and 3 in male. Caudal rami com-

20

paratively short and more or less pronouncedly club-shaped, each ramus pro-
vided in female with only 3 distinctly developed setae, whereas in male, con-
trary to what is the case in Monstrilla, their number is generally increased by
one additional seta. Eye as a rule well developed. Antennas rather short in
female and only composed of 4 joints, in male much more elongate, and
distinctly 5-articulate, with a well-marked hinge between the last 2 joints. Oral
tubule generally occurring far in front, in close approximation to the frontal
part of the head. Natatory legs built in the usual manner. Last pair of
legs in female comparatively short, but provided inside with a well defined
lobe; in male wholly absent.

Remarks.— lh\s genus was proposed in the year 1888 by J. C. Thomp-
son, to include a peculiar Copepod (C. tigidtim), of which at first only a
single female specimen was found. As, on a closer examination of several other
specimens taken by the same author partly in the Mediterranean, partly on the
British coast, the near relationship of this form to the species at that time
referred to the genus Monstrilla of Dana was recognised, the generic name
Cymbasoma was subsequently withdrawn in favour of that of Monsirilla. By the
subdivision of the latter genus into 2 nearly-allied genera carried out by Giesbrecht,
it was, however, of course required to decide to which of these 2 genera the species
of Thompson should be referred, and in this regard no doubt can arise. It
is quite certainly a true member of the genus to which Giesbrecht had applied the
name Thaumaleus. Since, however, as stated above, the application of this
name to the present genus is quite inadmissibel, I have felt justified to restore
the generic name proposed by Thompson.

The genus here treated of is chiefly distinguished from Monstrilla by the
reduced number of segments in the tail, and, by the likewise reduced number
of caudal setae. Moreover the position of the oral tubule and the total
absence in the male of the 5th pair of legs may be named as characters di-
stinguishing the present genus. Three well defined species with be described
in the succeeding pages.

21

9. Cymbasoma rigidum, Thompson.

(PI. X, fig. 2, PI. XI).

Cymbasoma rigida, J. C. Tliompson, Linn- Soc. Journ. Zool., Vol., XX, p. 154, PI.

XIII, figs. 1-4.

Syn : Monstrilla rigida, Bourne.
Thaumaleus rigidiis, Scott.
„ Thaumaleus Claparedi, Giesbrecht.
„ Thaumaleus germanicus, Timm.
, Hcpmocera Dance, Malaquin.

Specific Characters.— Female. Body moderately slender, and generally
extended in a manner to give it a somewhat rigid appearance. Cephalic seg-
ment fully as long as the remaining part of the body and, viewed dorsally,
somewhat dilated in the middle, ventral face evenly convex throughout. Tail
scarcely exceeding half the length of the exposed part of the trunk; genital
segment of moderate size and evenly narrowed behind, ovigerous spines nearly
3 times as long as the tail; distal segment somewhat flattened and gradually
widening behind, exhibiting in front of the middle, on each side, a slight
notch, as an attempt to a subdivision, the notch not being, however, continued
in any difining suture. Caudal rami only slightly longer than they are broad, and
not much divergent, with the inner edge somewhat concaved, the outer gib-
bously produced, each ramus provided with 3 strong subequal setae, the outer-
most of which is attached to a rather prominent ledge; a very small appendi-
cular bristle is moreover generally found attached near the inner corner to the
ventral face. Eye well developed, with all 3 lenses distinct. Antennae rather
short, scarcely attaining Vs of the length of the cephalic segment, terminal
joint somewhat shorter than the other 3 combined, with none, of the setae
ramified. Oral tubule rather small, and occurring at about the end of the
first Vi of the cephalic segment. Natatory legs with the outher ramus only
slightly longer than the inner, its terminal joint not much produced. Last
pair of legs with 3 apical setee, the innermost of which is much smaller than
the other 2, inner edge produced to a narrow linguiform lobe curving outwards
along the terminal part of the leg, and in most cases extending as far as the
latter. Ova attached to the genital filaments very numerous and in some
cases accumulated to form an elongate almost cylindrical mass extending far
beyond the limits of the body.

Male, as usual, smaller than female and of a shorter and more robust
form of the body, with the cephalic segment somewhat clavate in outline.
Tail rather narrow and composed of 3 segments, the last exhibiting on each

22

side a quite similar notch to that observed in female; copulative appendage
divided at the end into 2 comparatively large diverging lobes of a somewhat
sausage-shaped form. Caudal rami more pronouncedly clavate than in female,
each provided with 4 slender subequal set^ attached to the obtusely truncated and
distinctly thickened extremity, one of them apparently answering to the small
appendicular bristle found in the female. Antennae much more elongate than
in female and distinctly 5-articulate, last joint very movably articulated to the
preceding one, and terminating in a slender, slightly curved spine. Natatory
legs of exactly same structure as in female. Of a 5th pair of legs not the
slightest trace is to be detected.

Body of female, as usual, very transparent in its anterior part, but other-
wise exhibiting a light yellowish-grey colour, and tinged in some places with
a darker brownish pigment.

Length of adult female reaching to 2.50 mm., of male to 1.75 mm.

Remarks. — That the present form is identical with that recorded by
I. C. Thompson under the name of Cymbasoma rigidiitn and subsequently
more fully described by Scott as Thaunialeus rigidiis, appears to me to be
beyond any doubt, and I am also of opinion, that several other forms, described
under different names, should be referred to that species. Indeed, I have been
unable to find any reliable character to distinguish the several forms enumerated
above as synonymes, and I am thus led to the conclusion, that they all should
be combined into the very same species, for which of course the earliest name
ought to be retained.

Occurrence. — Several specimens of this form have been taken by me at
different times and in different places, both on the south and west coast of
Norway. Most of the specimens collected were of the female sex; but I have
also come across a few male specimens, one of which has been subjected to
a closer examination and is figured on PI. X.

Distribution. — Atlantic Ocean off Teneriffe (Thompson). Mediterranean
(Giesbrecht), coast of Normandie (Claparede), British Isles (Thompson, Scott),
Eastern part of North Sea (Timm).

23

10. Cymbasoma Thompson!, (Giesbrecht).

(PI. XII)
Thaumaleus Thompsoni, Giesbrecht, Pelagische Copepoden des Golfes von Neapel, p. 584,

PI. 46, figs. 7, 27, 31, 36, 40.
Syn. Monstrilla Danae, Moebius (non Claparfede)

Specific Characters.— Female. Body comparatively more slender than in
the preceding species, with the cephalic segment narrower and considerably
exceeding in length the remaining part. Tail very short, scarcely longer than
the last 2 trunkal segments combined; genital segment unusually tumid, seen
dorsally almost circular in outline, ventral face strongly protuberant, ovigerous
spines of moderate length; distal segment without any traces of lateral notches.
Caudal rami rather small, each provided with 3 subequal setae; no appedicular
bristle present. Eye apparently well developed. Antennae scarcely attaining
Va of the length of the cephalic segment, and of a structure very similar to
that in the preceding species. Oral tubule somewhat more approximate to the
frontal part of the head. Natatory legs with the outer ramus considerably
longer than the inner, and the terminal joint more produced than in the
preceding species. Last pair of legs resembling in structure those in C. rigidum,
though having the innermost of the apical setae rather smaller and the lobe
of the inner edge less prominent.

Male comparatively more slender than that of the preceding species,
and having the cephalic segment shorter and less pronouncedly clavate in
shape. Tail composed of 3 well defined segments, the last of which, as in
female, does not exhibit any traces of lateral notches. Caudal rami of the
very same structure as in the female, each ramus being only provided with 3
setae. Antennae very strongly built, with the joints rather expanded, the
last one very mobile and somewhat thickened at the extremity, which is
armed with 2 small denticles. No traces of a 5th pair of legs present.
Copulative appendage comparatively smaller than in the preceding species,
with the terminal lobes less produced.

Colour of the living animal not yet assertained.

Length of adult female 1.20 mm., of male 0.80 mm.

Remarks. — The precent species was described by Giesbrecht from some
specimens taken in the Baltic, east of Langeland, and sent to him from
Moebius, who had previously recorded this form under the name of Monstrilla
Dance^ Claparede. It may easily be distinguished from the preceding species
by its much inferior size, and more particularly by the rather different shape

24

of the tail. The form described by Scott as Thaiimaleus Thompsoni is quite
certainly different from Giesbrecht's species.

Occurrence. — Three specimens only of this species, 2 females and 1 male,
have as yet come under my notice. They were taken in as many different
localities, viz., Christiansund, Skutesnaes and Ris0r.

Distribution.— Western part of the Baltic (Moebius).

11. Cymbasoma longispinosum (Bourne).

(PI. XIII)
Monstrilla longispinosa, Bourne, Quart. Journ. Micr. Science, (2), Vol. 30, p. 575, Pi. 37,

figs. 1-^4, 10.
Syn: Th.iumnlcus longispinosus, Giesbreclit.

Specific Characters. — Female. Body rather slender, with the cephalic
segment only very slightly dilated in the middle, and considerably exceeding
half the length of the body. Tail very short, not even attaining the length
of the 2 preceding segments combined; genital segment about the size of the
last trunkal segment and, seen from above, of a very similar subquadrate form
its ventral face considerably protuberant; ovigerous spines of quite an extra-
ordinary length, attaining in some instances nearly the double length of the
body, and confluent at the base for some distance; distal segment much
narrower than the proximal one, being conspicuously constricted at the base,
and without any trace of a subdivision. Caudal rami very small, scarcely
longer than they are broad, and each only provided with 3 thickish setae of
equal length. Eye well developed, at least in female. Antennae comparatively
short and stout, scarcely exceeding in length V4 of the cephalic segment and,
as in the other species of the present genus, only composed of 4 joints, the
last of which is about the length of the other 3 combined and gradually
narrowed distally, some of its setae distinctly ramified. Oral tubule occurring
far in front, at only at short distance from the frontal part of the head.
Natatory legs with the terminal joint of the outer ramus unusually short,
scarcely longer than the middle one, and of a rounded form. Last pair
of legs provided at the obtusely truncated extremity with 3 plumose setae,
the innermost of which is a little shorter than the other 2; inner lobe
well defined, triangular, and extending at right angle to the axis of the leg.

Male somewhat smaller than female and less slender of form, with the
cephalic segment comparatively shorter and nearly of equal width throughout.
Tail exceeding somewhat half the length of the exposed part of the trunk,
and composed of 3 well defined segments, the middle of which is the smallest;

25

copulative appendage divided at the end into 2 comparatively short diverging
lobes. Caudal rami of a similar shape to those in Ihe female, but each
provided with 4, instead of 3, setae of nearly equal length. Antennae compara-
tively much larger than in female, and each composed of 5 well defined
joints, the 3 middle ones lamellarly expanded inside and armed with several
short spines in addition to the setae, last joint comparatively small, but very
movably articulated to the preceding one. Natatory legs agreeing exactly in
structure with those in female. 5th pair of legs wholly absent.

Body, as usual, much more transparent in female than in male, being
in the latter, according to Giesbrecht, everywhere of a dark fuscous colour.

Length of adult female 2.60—3.16 mm., of male 2.30 mm.

Remarks.— The present form is chiefly characterised by the extraordinary
length of the ovigerous spines in the female and their peculiar coalescence
at the base. In its general appearance it bears a very close resemblance to
the form recorded by Claparede under the name of Monstrilla dance, and,
were it not that no mention has been made by that author on the above-
named distinguishing character, I should indeed have been much inclined to
regard these 2 forms as identical.

Occurrence.— Ih^ present species, it is true, has not yet been observed
off the Norwegian coast; but I regard it as very probable that on further
investigations it will be found to occur in some place or other on the south
and west coast. As I have had an opportunity of examining this form, I
find it advisable to give here a detailed description of it, for comparison with
the other 2 species. The figures given on PI. XIII have been drawn from
specimens collected during one of the Monaco-Expeditions in the Mediterranean
off Sardinia.

Distribution. — British Channel (Bourne), Mediterranean at Naples (Gies-
brecht).

Gen. 4. Monstrillopsis, G. O. Sars, n.

Generic Characters. — Body of very different appearance in the 2 sexes,
being exceedingly slender in female, much shorter and stouter in male. Tail
composed in female of 3 well defined segments, the middle of which is the
smallest, in male distinctly 4-articulate. Caudal rami in both sexes of the
very same structure, being unusually produced, and each provided with 4 well

4 — Crustacea.

26

developed setae, 2 apical and 2 lateral. Eye very fully developed, especially
in male. Antennae in female 4-articulate, in male much larger and distinctly
5-articulate, with the usual hinge between the last 2 joints. Oral tubule
occurring far in front. Natatory legs built in the usual manner. Last pair of
legs, however, in female of rather a peculiar structure, being somewhat fusi-
form in shape, and each produced into 2 smooth conical lappets, the outer
of which is the more prominent; setae of these legs not, as usual, attached to
tbe terminal edge of the leg, but arranged in a line crossing the base of the
outer lappet. Male without any trace of these legs, but having the copulative
appendage normally developed.

Remarks. — This new genus is established to include the anomalous form
recorded by Scott under the name of Monstrilla dubia. Indeed, I have found
it impossible to place this species either in the genus Monstrilla or in that of
Cymbasoma, as it in some respects seems to combine characters of both these
genera, in other respects to differ conspicuously from either of them.

12. Monstrillopsis dubia, (Scott).

PI. XIV.

Monstrilla dubia, T. Scott, Twenty-second Ann. Rap. of the Fishery Board for Scotland, Part III,

p. 247, PI. XIII. fig. 14, PI. XIV, figs. 16—18

Specific Characters. — Female. Body exceedingly slender and narrow,
with the anterior division not at all dilated. Cephalic segment exceeding the
remaining part of the body by Va of its length, and narrow cylindrical in
form, being almost of equal width throughout. Tail about equalling half the
length of the exposed part of the trunk; genital segment a little longer than
the other 2 segments combined and slightly dilated at the base, with the
ventral face somewhat protuberant; ovigerous spines of moderate length; anal
segment somewhat flattened and sharply defined from the rather small middle
segment. Caudal rami rather produced, exceeding somewhat in length the 2
preceding segments combined, and slightly divergent, each ramus provided
with 4 setae, one about in the middle of the outer edge, 2 at the apex, and
one inside at some distance from the end. Eye very conspicuous in the
living animal, with dark pigment and all 3 lenses well developed. Antennae
exceeding somewhat in length Va of the cephalic segment, and composed of
4 well defined joints, the last of which is fully as long as the other 3 com-
bined; none of the setae ramified. Oral tubule well marked, and occurring
near the frontal part of the head. Natatory legs with the outer ramus con-

27

siderably longer than the inner, and having the terminal joint well developed.
Last pair of legs rather narrow at the base, but considerably widening towards
the end, which is produced to a conical lappet, across the base of which 3
slender setae are attached; inner edge of the leg produced to a similar lappet,
which, however, is quite smooth.

Male very unlike the female and of much smaller size, with the body
much shorter and stouter. Cephalic segment somewhat club-shaped, and
scarcely exceeding half the length of the body. Tail very narrow and com-
posed of 4 well defined segments, the 1st of which is produced below to a
rather large copulative appendage divided at the end into 2 diverging sub-
cylindrical rami. Caudal rami of much the same appearance as in female,
with the same number of setae. Eye still more largely developed than in
female, with the ventral lens rather prominent and highly refractive. Antennae
considerably exceeding half the length of the cephalic segment and distinctly
5-articulate, with the last very mobile joint abruptly attenuated distally.

Body in the living animal rather pellucid, with a pale yellow hue, and
in some places dotted with a chestnut-coloured pigment.

Length of adult female 3.80 mm., of male 2.10 mm.

Remarks. — This form was described in the year 1904 by Scott from
some female specimens taken in 2 different places of the Scottish coast. The
resemblance of this form to Monstrilla Dance Claparede, vindicated by Scott in
a note to his description, I find to be a very slight one. In fact the present form
is easily distinguishable both from this and from any other of the Monstrillidae.

Occurrence. — Two specimens only of this remarkable form, a female and
a male, have as yet come under my notice. They were captured, many
years ago, at Bejan, outside the Trondhjem Fjord, and coloured drawings of
both, when still alive, were immediately executed.

Distribution. — Scottish coast (Scott).

NOTODELPHYOIDA.

Remarks. — This division comprises a number of Copepoda, which partly
differ considerably from each other and according to their organisation, represent
several distinct types. Yet, all these forms agree as to habits, in so far that
they live as parasites, or more properly as commensales, within Ascidians of
different kinds. They were all by earlier authors comprised within a single
family, the AscidicolidcBj and this family was by Giesbrecht, together with the
Monstrillidce and several other heterogeneous groups, included in the 2nd tribe
of his suborder Podoplea, for which the name Ampharthrandria was proposed.
I have already mentioned, that the latter name is quite inapplikable for the
present group of Copepoda, which comprises both forms with the anterior
antennae in the male transformed to prehensile organs, and such in which
these antennae are quite alike in the 2 sexes. According to the classification
proposed by Giesbrecht, these latter forms should of course be trans-
ferred to his 1st tribe, the Isokerandria; but such a transfer appears quite
unreasonable, since there are forms, otherwise closely related and even referred
to one and the same genus, in which the above-named difference, as to the
structure of the anterior antennae, is found. Thus in the male of Doropygus
longicauda Aurivillius, as will be shown farther on, these antennae are very
distinctly hinged, whereas in the other species referred to that genus they are
quite alike in the 2 sexes. It is thereby clearly proved that the above-named
character, upon which Giesbrecht laid so much stress, is of far inferior systematic
value than opined by that author, and that it in reality must be considered
unserviseable as the basis for a more geneial classification of the Copepoda.
There are many other much more important diversities to be found on a
comparison of the several forms comprised within the present group, and
these diversities are in fact of such an essential quality as to make it inad-
missible to include all these forms within a single family. This was also
recognised by Thorell, who referred the forms observed by him to 3 different
families, viz., Notodelphyldce, Ascidlcolidce and Buprorldce. The 1st of these
families has subsequently been subdivided by Prof. Brady into 2 nearly-allied

29

families: Notodelphyidce (proper) and Doropygidce, and 2 other very distinct
families, BotryllophilidcE and Enterocolidce, are here added. The present
division thus comprises at least 6 families, and I regard it as very probable*
that their number will still be augmented, on a closer investigation of the
many peculiar forms found by Hesse within compound Accidians, but rather
imperfectly described by that author.

Fam. 1. Notodelphyidae.

General Characters. — Body in both sexes cyclopoid in shape and more
or less straight, with the anterior division somewhat depressed, the posterior
much narrower and cylindric in form. Exposed part of trunk composed in male of
the usual number of segments, whereas in female the last 2 segments are confluent,
forming together a large median piece somewhat broader in front than behind
in young specimens, but in the adult female greatly expanded behind, to form
dorsally a very voluminous, somewhat flattened bag or incubatory pouch, into
which the ripe ova are received. Tail composed in both sexes of 5 segments
not very different in size. Caudal rami well developed and provided at the
end with strong ciliated setae present in the usual number. Eye of the structure
generally met with in the Copepoda. Anterior antennae of moderate size, and
extended laterally, being composed of numerous short joints densely clothed
with setae; those in male distinctly hinged. Posterior antennae much smaller
than the anterior, but distinctly prehensile, each terminating in a strong mobile
claw. Oral parts, as a rule, well developed, and built on a somewhat similar
type to that in the family Cyclopinidce. The 4 anterior pairs of legs likewise
cyclopoid in structure, and adapted for swimming; 5th pair of legs extremely
small and rudimentary, biarticulate.

Remarks.— lh\s family is here taken in a much more restricted sense
than done by Thorell, who included into it also his 2 genera Doropygus and
Botachus. In the restriction here adopted, the family only comprises 2 genera,
viz., Notodelphys Allman and Agnathaner Canu.

30

Gen. 1. Notodelphys, Allman, 1847.

Generic Characters. — Body more or less elongated, and in female con-
spicuously dilated in the middle on account of the greatly expanded matrical
part; integuments rather soft and flexible. Cephalic segment not very large,
and produced in front to an obtuse deflexed rostral prominence. The 2
succeeding segments in both sexes well defined and separated by deep lateral
incisions. Incubatory pouch in female broad, flattened, more or less advancing
over the base of the tail. The latter perfectly cylindrical in form, with the
1st segment in female scarcely larger than the succeeding ones, in male some-
what swollen and generally containing 2 oval spermatophores. Caudal rami,
as a rule, finely ciliated on both edges, ?nd each carrying at the tip 4 well
developed and somewhat diverging plumose set«, being moreover provided
with 2 small bristles, the one attached to the outer edge, the other to the
dorsal face, near the inner corner. Eye comparatively small, but easily observ-
able in the living animal, being provided with 2 lateral lenses imbedded in a
bright red pigment. Anterior antennae in female gradually tapered distally,
and generally composed of 15 joints clothed with comparatively short, but
distinctly ciliated setae; those in male having the number of joints somewhat
reduced, and exhibiting between the penultimate and antipenultimate joints a
well marked hinge. Posterior antennae only composed of 3 distinctly defined
joints, the first 2, representing the basal part, somewhat compressed and
separated by an oblique suture, at the end of which outside 2 juxtaposed
plumose setae are attached; terminal joint very movably articulated to the basal
part, and linear in form; apical claw accompanied by a number of short
curved setae. Anterior lip projecting at the end into 2 triangular lappets.
Mandibles with the masticatory part lamellarly expanded and divided at the
end into several unequal teath; palp well developed, biramous. Maxilla with
all their constituent parts distinctly defined. Anterior maxillipeds with the 1st
basal joint very large and massive, exhibiting inside 3 or 4 short setiferous
lobes; 2nd basal joint much narrower, and armed at the end inside with a
strong claw-like spine accompanied by a slender seta; terminal part thin,
3-articulate. Posterior maxillipeds much smaller than the anterior ones, and
3-articulate, 1st joint much the largest and provided inside with several short
plumose setae arranged in 2 groups, each of the other 2 joints armed with a
slender incurved spine, that of the terminal joint accompanied by 2 small setae.
Natatory legs with the basal part broad and flattened, rami in all the pairs

31

distinctly 3-articulate and armed in the usual manner, those of 1st pair some-
what unequal, in the other pairs of about equal size. Last pair of legs extremely
small, and in female quite concealed beneath the dilated matrical part of the
body; proximal joint short and broad, and produced outside to a digitiform
process tipped with a small bristle; distal joint more or less scale-like, with a
small apical bristle and a short spine inside.

Remarks. — This genus was established as early as in the yeart 1847 by
Allman, and may be regarded as the type, not only of the present family, but
of the whole division Notodelphyoida. It comprises the most perfectly organised
forms of that division, and exhibits some unmistakable relations to certain
gnathostomous Cyclopoida, in particular the Cyclopinidce. Indeed, the forms
included in the present genus may be regarded as Cyclopoids, which by a close
adaptation to the particular conditions of life as commensales of Ascidians, have
acquired some extraneous characters apparently distinguishing them very essenti-
ally from their original ancestors. The genus was in the year 1859 subjected by
Thorell to a careful investigation, and its general characters were made out
by him in a very satisfactory manner. Thorell distinguished within the genus
no less than 7 different species, all of which I have had an opportunity of
examining from material collected off the Norwegian coast. These species are
very closely related to each others, and as the distinctive characters given by
Thorell in the short diagnoses in Latin, preceding the description of each species,
appeared to be of a rather trifling kind, the validity of most of them has
been questioned by recent authors. On a careful examination I have, however,
come to the conclusion, that they all ought to be supported, though their
distinction indeed is attended with no small difficulties, at least in the case
of preserved specimens. I hope that the descriptions given below, in connection
with the figures on the accompaying plates, may render the species more
easily recognisable than this has been possible by consulting the work of Thorell.

1. Notodelphys Allmani, Thorell.

(PI. XV & XVI)

Notodelphys Allmanni, Thorell. Bidrag til kannedomen om Krustaceer som lefva i Arter af

slagtet Ascidia, p. 31, PI. I, PI. II, 1.
Syn: Notodelphys mediterranea, Buchholtz,

Specific Characters.— Female. Body moderately slender, with the anterior
division pronouncedly depressed, and nearly twice as long as the posterior.
Cephalic segment scarcely longer than the 2 succeeding segments combined,

32

and gradually narrowed anteriorly, terminating in an obtuse point. Incubatory
pouch, when fully develoved, very broad, rounded quadrate in outline, with
the posterior edge slightly concave in the middle. Caudal rami rather slender,
sublinear in form, and more or less divergent, attaining nearly twice the length
of the anal segment, and more than 4 times as long as they are broad, both
edges distinctly ciliated; apical setae of moderate length and rather divergent;
bristle of outer edge occurring at a distance from the end equalling about Va
of the length of the ramus. Anterior antennae nearly as long as the cephalic
segment and rather thick at the base, but rapidly tapered distally, 3rd joint
the largest, the 3 succeeding joints gradually diminishing in size, remaining
joints very small; setae attached to the anterior face of these antennae rather
coarse and very distinctly ciliated. Posterior antennae moderately slender, with
the terminal joint about the length of the other 2 combined. 1st pair of legs,
as in the other species, differing from the succeeding ones by the presence,
at the inner corner of the 2nd basal segment, of a short deflexed spine;
rami moreover rather unequal, the outer one being considerably shorter than
the inner and bent outwards in a peculiar manner, its 1st joint comparatively
large and having the outer edge finely denticulate. Last pair of legs with the
proximal joint rather broad and finely denticulate at the inner rounded corner,
digitiform process considerably produced; distal joint small, scale-like and
conspicuously contracted at the base, spine of inner edge accompanied proxim-
ally with a few small denticles.

Male of much smaller size than female, with the body gradually attenu-
ated behind. Cephalic segment comparatively larger, exceeding in length the
3 succeeding segments combined. Last trunkal segment scarcely broader
than the genital segment. Anterior antennae of coarser structure than in female
and only composed of 11 joints very unlike in size, the outer 2 rather
elongate and forming together a very mobile piece, which admits to be im-
pinged against the preceding part of the antenna. Posterior antennae, oral
parts, and legs of same structure as in female. Genital lobes contiguous at
the base inside, and subtriangular in form, their extremity somewhat truncated
and provided at the outer corner with a small bristle, at the inner with 2
unequal juxtaposed spines.

Body in the living animal semipellucid, with a light yellowish gray hue;
ovarial tubes in female pale greenish, the ripe ova included within the incu-
batory pouch being of a somewhat darker green colour.

Length of adult female attaining 4.50 mm; of male 1.90 mm.

Remarks.— This is the largest and also the most common of the species,

Thamatopsyllidae

Copepoda

Monstrilloida

PI. I

6. O. Sars del.

Thaumatopsyllus paradoxus, 6. O. Sars

Monstrillidae

Copepoda

Monstrilloida

PI. II

f iiin I

G. O. Sars del.

Monstrilla longlcomis, Thomps.

Monstrillidae

Copepoda

Monstrilloida

Pi. Ill

f^'

^
VU

;l

\

y^.ihi^l

'is'^ >

^i.

G. O. Sars del.

Monstrilla longicornis, Thomps.
(continued)

Monstriliidae

Copepoda

Monstrilloida

PI. IV

G. O. Sars del.

Monsirilla longiremis, 6iesbr.

Monstrillidae

Copepoda

Monstrilloida

PI. V

e. 0. Sars del.

Monstrilla longiremis, 6iesbr.
(male)

Monstrillidae

Copepoda

Monstrilloida

PI. VI

6. O. Sars del.

Monstrilla clavata, 6. O. Sars

Monstrillidae

Copepoda

Monstrilloida

PI. VII

X" iN

if.

6. O. Sars del.

'^r^,.

?

drf

'*i

Monstrilla leucopis, 6. 0. Sars

MonstrillidaB

Copepoda

Monstrilloida

PI. VIII

k w

If V

ur I

i

I.

^k 4

ii

i^ 7

w

fs.,m ^

H'P\T

^v

U;-.

^'

f*

/ / r'is J -I 'iVi *

tV'

7

6. O. Sars del.

Monstrilla gracilicauda, Giesbr.

Monstrillidae

Copepoda

Monstrilloida

PI. IX

6. O. Sars del.

Monslrilla helgolandica, Ciaus

Monstrillids

Copepoda

Monstrilloida

PI. X

/-' :C

AC

^.^'/

H

/

/.TO

\

u

i?

^■n'

r

6. O. Sars del.

1. Monstrllla serricornis, 6, 0. Sars. d"

2. Cymbasoma rigidum, Thomps. </

Monstrillidae

Copepoda

Monstrilloida

PI. XI

6. O. Sars del.

Cymbasoma rigidum, Thomps,

Monstrillidae

Copepoda

Monstrilloida

PI. XII

G. O. Sars del.

Cymbasoma Thompsoni, (6iesbrecht)

MonstrillidaB

Copepoda

Monstrilloida

PI. XIII

*■ -n

s

>/^-^

H

^'J.i

f

/;!

\ -■■■.•vl

i..i> t

.;.-f' i

^
M

rt#i ^

• ^ I

6, O. Sars del.

Cymbasoma longispinosum, (Bourne)

Monstrillidae

Copepoda

MonstriNoida

PI. XIV

'A

-:% /0t^

Z,/a.

i h/:J

i

V

■ J

II

'%

.^

y?r*'l

^\\m\

rrf.

m

/ex

»i.:

^^-o

":./

fe^-j^.

I \ I

\ a^^tijH

^

3
In

optl,

G. O. Sars del.

Monstrillopsis dubia, (Scott)

Notodelphyidas

Copepoda

Notodelphyoida

PI. XV

^^¥%^^-

unidfiSS.-'

-^

i>y

->■'

-<j

6. O. Sars del.

Notodelphys Allmani, Thorell

33

and may moreover be recognised by the relative length of the caudal rami,
by the shape of the incubatory pouch in the female, and, when examined in
the living state, also by the colour of the ripe ova. It may be, that Allman
has had before him specimens of this form, but as he has evidently combined
in his species N. ascidicola several other very different forms, I agree with
Thorell in the discarding of the specific name proposed by that author. The
form recorded by Buchholtz from the Mediterranean under the name of N.
niediterranea I am unable to distinguish from the present species.

Occurrence. — I have met with this species in many different places on
the Norwegian coast, from the Christiania Fjord to Finmark (Hammerfest).
It occurs, often in considerable number, within the branchial cavity of several
kinds of simple Ascidians, being generally found attached by the aid of the
posterior antennae to the inner wall of that cavity. When losened from its
hold, the animal moves quickly about in the usual jerking manner observed
in most Cyclopoida; but very soon it again get hold of some other place.
Male specimens are much more scarce than female ones, and indeed among
the numerous specimens of this species collected, I have only succeeded in
finding 3 or 4 males.

Distribution.— CodiSi of Bohuslan (Thorell), British Isles (Brady), coast of
France (Canu), Mediterranean (Buchholz).

2. Notodelphys rufescens, Thorell.

(PI. XVII, 1).

Notodelphys rufescens, Thorell, 1. c. p. 35, PI. II, 2.

Specific Characters. — Female. Body comparatively a little more slender
than in N. Allmani, otherwise of a very similar appearance. Incubatory pouch
oval in outline, with the posterior extremity evenly rounded. Caudal rami
scarcely twice as long as the anal segment, and rather narrow, sublinear in
form, with the apical setae comparatively shorter and less divergent than in
N. Allmani; bristle of outer edge more remote from the apex. Anterior
antennae almost exactly as in that species. Posterior antennae however com-
paratively less slender, with the terminal joint not nearly attaining the length
of the other 2 combined. Oral parts and natatory legs very like those parts
in N. Allmani. Last pair of legs likewise very similar, though having the
proximal joint comparatively less broad, and the distal joint of a more irregular
shape.

5 — Crustacea.

34

Body, according to Thorell, in the living animal pellucid, of a whitish
grey colour, with the ovarial tubes and the ripe ova pale reddish.

Length of adult female attaining 4.20 mm.

Remarks. — The present form is so closely allied to N. Allmani, that I
have had much trouble in finding any more reliable character to distinguish
it from that species. It is however of somewhat smaller size, and, on a closer
comparison, the caudal rami are found to differ somewhat in their relativ
length, and more particularly in the position of the outer-edge bristle, which
is conspicuously more remote from the apex than in N. Allmani. Moreover
the shape of the incubatory pouch is rather different, and, according to Thorell,
also the colour of the ovarial tubes and the ripe ova in the living animal.

Occurrence.— k few female specimens of this form were selected from
some material collected many years ago off the south coast of Norway. From
what species of Ascidia they were derived, I am unable to ascertain. Thorell
found it in A. scabra Miill. and Aurivillius in Phallasia obliqwa Alder.

Distribution. — Coast of Bohuslan (Thorell, Aurivillius).

3. Notodelphys caerulea, Thorell.

(PI. XVII, 2).

Notodelphys ccemlea. Thorell, 1. c. p. 37, PI. Ill & IV, 4.

Specific Characters.— Female. Body conspicuously more slender than in
the 2 preceding species, with the anterior division narrower and the posterior
more produced. Incubatory pouch oval in outline, with the greatest width
somewhat in front of the middle, posterior extremity evenly rounded. Caudal
rami rather shorter and broader than in the 2 preceding species, only very
slightly exceeding in length the anal segment, and scarcely more than 3 times
as long as they are broad; apical setae comparatively short, bristle of outer
edge considerably remote from the apex, being attached nearly in the middle
of the edge. Antennae, oral parts, and natatory legs not exhibiting any marked
difference from those appendages in the preceding species. Last pair of legs,
however, rather different in shape, the proximal joint being not nearly so
broad, with the inner corner less prominent; distal joint rounded in shape and
less conspicuously constricted at the base.

Body in the living animal whitish pellucid, with the ovarial tubes and
the ripe ova of a bright bluish colour.

Length of adult female attaining 4.30 mm.

35

Remarks. — The above-described form may be easily distinguished from
the 2 preceding ones by the comparatively much shorter and broader caudal
rami, and by the position of the outer-edge bristle on these rami. In the
living state the female of this species may moreover at once be recognised
by the bright bluish colour of the ova included within the incubatory pouch.

Occurrence. —StvtmX specimens of this form have been selected from
material collected in different places on the south coast of Norway. Thorell
found it rather frequently in Ascldla venosa, and Aurivillius records it from
Phallus ea vlrginea.

Distribution.— Coast of Bohuslan (Thorell), British Isles (Brady).

4. Notodelphys agilis, Thorell.

(PI. XVII, 3).
Notodelphys agilis, Thorell, 1. c. p. 40, PI. IV & V, 6.

Specific Characters. — Female. Body moderately slender, resembling in
shape that of N. rufescens. but of much smaller size. Incubatory pouch sub-
oval in outline, slightly widening distally, with the hind extremity broadly
rounded. Caudal rami rather slender, nearly twice as long as the anal seg-
ment, and somewhat narrowed in their outer part, with the outer edge finely
ciliated, the inner smooth; apical setae of moderate length; bristle of outer
edge attached to a distinct ledge in the middle of the edge. Both pairs of
antennae somewhat more slender than in the 3 preceding species. Last pair
of legs with the proximal joint rather broad and quite smooth, digitiform
process comparatively short; distal joint not at all constricted at the base, and
of a somewhat irregular form, with the outer edge angularly bent in the middle
and the spine of the inner edge very thin.

Body in the living animal whitish pellucid, with the ripe ova dark fus-
cous in colour.

Length of adult female scarcely exceeding 3.60 mm.

Remarks. — This form also is most readily distinguished by the shape of
the caudal rami, and more particularly by the exactly median position of the
outer-edge bristle on these rami. Otherwise it agrees closely with the 3 pre-
ceding species.

Occurrence. — I have met with this form in many different places on the
Norwegian coast, from the Christiania Fjord to Finmark (Hammerfest). It is
found in different kinds of Ascidians, most frequently perhaps in A. paralello-

36

gramma. In its movements it is more active than most other species, and
thus deserves the specific name given to it by Thorell.

Distribution. — Coast of Bohuslan (Thorell), British Isles (Brady), coast
of France (Canu).

5. Notodelphys tenera, Thorell.

(PI. XVIII, 1).
Notodelphys tenera, Thorell, 1. c. p. 36, PI. Ill, 3.

Specific Characters. — Female. Body comparatively slender, with the
anterior division somewhat dilated in its anterior part. Cephalic segment
exceeding in length the 2 succeeding segments combined, and conically pro-
duced in front. Incubatory pouch, when fully developed, of rather a charac-
teristic shape, being almost gibbously dilated in the middle and fully as broad
as it is long. Caudal rami rather narrow, and exceeding the anal segment
by about V4 of their length; apical setae unusually slender and elongated;
bristle of outer edge occurring close to the apex. Both pairs of antennae
conspicuously more slender and elongated than in the other known species.
Last pair of legs with the proximal joint short, but rather broad, and having
the digitiform process large and extended obliquely outwards; distal joint
very narrow at the base, but gradually widening distally, so as to assume a
somewhat claviform shape, spine and seta issuing close together from the
inner distal corner.

Body in the living animal whitish hyaline, with the ripe ova yellowish
red in colour.

Length of adult female 3.20 mm.

Remarks.— Ih^ present species may be recognised by the unusual slend-
erness of both pairs of antennae and the rather elongated caudal setae. The
shape of the caudal rami and the position of the outer-edge bristle is also
peculiar. Another easily observable distinguishing character, not mentioned by
Thorell, is derived from the shape of the incubatory pouch, which differs
conspicuously from that in any of the other known species.

Occurrence. — I have taken this form occasionally in 3 widely remote
localities on the Norwegian coast, viz., Ris0r, Trondhjem Fjord, and Valder-
sund on the Nordland coast. The specimens were found in the branchial
cavity of A. canlna.

Distribution. — Coast of Bohuslan (Thorell).

37

6. Notodelphys elegans, Thorell.

(PI. XVIII, 2).
Notodelphys elegans, Thorell, 1. c. p. 39, PI. IV, 5.

Specific Characters. — Female. Body less slender than in any of the
preceding species, with the cephalic segment comparatively large, considerably
exceeding the length of the 2 succeeding segments combined. Incubatory pouch
nearly of equal width throughout and obtusely truncated behind. Caudal rami
shorter and broader than in N. tenera, only slightly exceeding in length the
anal segment, and scarcely more than 3 times as long as they are broad;
apical setae comparatively short; bristle of outer edge occurring at a short
distance from the apex. Antennae comparatively far less slender than in the
said species, the posterior ones being in particular distinguished by the unusu-
ally short and stout terminal joint. Last pair of legs very unlike those in
N. tenera, the proximal joint being nearly quadrate in form and finely denti-
culate inside, with the digitiform process extending straight backwards; distal
joint broadly oval in form and scarcely at all constricted at the base, spine
of inner edge rather strong.

Body of the living animal, according to Thorell, of a pale yellowish hue,
with the ripe ova fuscous green.

Lenght of adult female about 3 mm.

Remarks. — This species may be easily distinguished from the preceding
ones by the less slender form of the body and the shape of the incubatory
pouch. The structure of the posterior antennae, and more particularly that of
the last pair of legs, is also rather pecuHar. Moreover the caudal rami, as
usual, exhibit some well marked distinguishing characters.

Occurrence. — Two or 3 female specimens only of this form have as yet
come under my notice. They were selected from some material collected on
the south coast of Norway, the exact locality not being noted. Thorell found
this species within the branchial cavity of Styela intestinalis.

Distribution.— Coast of Bohuslan (Thorell), coast of France (Canu).

7. Notodelphys prasina, Thorell.

(PI. XVIII, 3).

Notodelphys prasina, Thorell, 1. c. p. 41, Pi. V, 7.

Syn: Notodelphys pusilla, Buchholtz.

Specific Characters. — Female. Body comparatively short and stout, con-
siderably dilated in its anterior part. Cephalic segment rather large, and
conically produced in front. Incubatory pouch subquadrangular in outline.

38

being of almost equal width throughout and transversely truncated behind.
Caudal rami very short, being scarcely as long as they are broad, and sub-
quadrate in form, with the outer edge densely hairy; apical setae rather strong,
the 2 middle ones considerably longer than the others and conspicuously
dilated at some distance from the base; bristle of outer edge occurring close
to the apex. Anterior antennae fully as long as the cephalic segment, and
having the setae rather long and slender. Posterior antennae of the usual
structure, with the terminal joint about the length of the other 2 combined.
1st pair of legs with the rami of nearly equal length, terminal joint of the
outer one bent abruptly outwards, at nearly a right angle to the preceding
part; joints of inner ramus triangularly produced at the end outside. Last
pair of legs very small, with the proximal joint extending inwards as a narrow
band-like plate finely spinulose at the edge, digitiform process recurved; distal
joint comparatively small and subfusiform in shape, being conically produced
at the end, spine of inner edge occurring about in the middle.

Body in the living animal rather pellucid, with the ovarial tubes and the
ripe ova of a bright grass-green colour.

Length of adult female scarcely exceeding 1.80 mm.

Remarks. — This is much the smallest of the species here recorded, and
may moreover at once be recognised by the very short caudal rami, as also,
when examined in the living state, by the bright green colour of the ovarial
tubes and the ripe ova. The form recorded by Buchholtz from the Mediter-
ranean under the name of N. pusilla is quite certainly identical with
Thorell's species.

Occurrence. — I have taken this form, often in considerable number, from
the branchial cavity of several kinds of Ascidians, most frequently however in
Phallusia meniula. It seems to be distributed along the whole south and
west coasts of Norway, at least to the Trondhjem Fjord.

Distribution.— CodiSi of Bohuslan (Thorellj, British Isles (Brady), Mediter-
ranean (Buchholtz).

Gen. 2. Agnathaner, Canu, 1892.

Generic Characters. — Body (of male) resembling in shape that in Noto-
delphys, being quite straight, with the anterior division somewhat dilated and
well marked off from the posterior; the latter narrow and composed of 5 seg-
ments. Caudal rami sublinear in shape, with the normal number of setae.

39

Antennae and legs built on the very same type as in Notodelphys. Oral parts
however (in male) considerably reduced, so as not to be adapted for mastication.
Anterior lip transformed to a somewhat tubular prominence containing the
outer part of the gullet. Mandibles with the palp normally developed, biramous,
masticatory part however reduced to a short simple point. Maxillae with the
masticatory lobe likewise much reduced, but having the other parts distinctly
defined. Anterior maxillipeds without any setiferous lobes inside, and termi-
nating in a single straight spine. Posterior maxillipeds extremely small and
rudimentary.

Remarks.— The exact limits of this genus cannot at present be stated, as
only the male sex is as yet known. It is very likely to believe that the female
will be found to exhibit several essential differences from the male, and it is
even not improbable that the structure of the oral parts, upon which the
present genus has chiefly been founded, will turn out to be rather different
in the female sex. Canu placed this genus, on account of the reduced oral
parts, next to the genus Enierocola. It is however otherwise very different
from that genus, and evidently so closely related to Notodelphys, that in any
case it ought to be included in the same family with it. Two different species
of this genus have been recorded by Canu, both of them only observed in the
male sex. The one of these species also occurs on the Norwegian coast, and
will be described below.

8. Agnathaner typicus, Canu.

(PI. IX).
Agnathaner typicus, Canu, Copdpodes du Boulonnais, p. 211, Pi. XVII, figs. 1 — 10.

Specific Characters. — Male. Body rather slender, with the anterior division
conspicuously dilated in the middle. Cephalic segment comparatively large,
occupying more than half the length of the anterior division, and gradually
somewhat contracted anteriorly, frontal part narrowly truncated and produced
below to a recurved rostrum. The 3 succeeding segments gradually diminishing
in size, and having the epimeral plates somewhat exstant and separated by
deep lateral incisions. Last truncal segment very small, with the lateral parts
not expanded. Tail rather slender, almost attaining half the length of the
anterior division, with the segments gradually diminishing in size behind; 1st
segment somewhat swollen, to receive the 2 usual spermatophores. Caudal
rami narrow linear in shape and not at all divergent, exceeding somewhat in
length the anal segment, and about 3 times as long as they are broad; apical

40

setae of very unequal length, the innermost but one being much the longest
and nearly attaining the length of the tail, the innermost seta considerably
smaller than the outermost; bristle of outer edge attached a little beyond the
middle, dorsal bristle near the end of the ramus. Eye well developed. An-
terior antennas of moderate size, not however attaining the length of the
cephalic segment, and composed of 13 well-defined joints rather densely clothed
with setae; hinge, as in Notodelphys, occurring between the penultimate and
antepenultimate joints. Posterior antennae almost of exactly same structure as
in Notodelphys. Natatory legs well developed, with both rami 3-articulate and
of about equal size, the outer one armed outside and at the tip with slender
cultriform spines. Last pair of legs very small and rudimentary, with the
proximal joint quite short and produced outside to the usual digitiform process;
distal joint rounded, scale-like, with a thin bristle at the tip and a very minute
spine inside.

Colour of the living animal not yet ascertained.

Length of the specimen examined 1.15 mm.

Remarks. — Though the figure of the animal (dorsal view) in Canu's work
does not fully agrees with that here given, I cannot doubt that these 2 forms
are identical, as no obvious difference could be detected in the structure of
the several appendages.

Occurrence. — A solitary male specimen of this form was found in some
dredged material taken af Grimstad, south coast of Norway, from a depth of
about 20 fathoms.

Distribution. — Coast of France (Canu).

Fam. 2. Doropygidae.

General Characters. — Body of female more or less compressed and curved
ventrally, with the anterior and posterior divisions sharply marked off from
each other; that of male more slender, with less sharply marked limit between
the 2 chief divisions. Head well defined from trunk, and produced in front
to a blunt rostral prominence, lateral parts deflexed and rounded off. 1st
segment of trunk distinctly defined both in front and behind, but of much
smaller size than the succeeding ones. The last 2 trunkal segments in female
united, to form dorsally the large and prominent incubatory pouch. Tail

41

cylindrical in shape, and in most cases only composed of 4 distinctly defined
segments. Caudal rami with the setae much obliterated, in some cases apparently
wholly absent, in other cases replaced by curved hooks. Anterior antennae
short and stout, deflexed, with the number of joints more or less reduced;
those in male, as a rule, of the very same structure as in female. Posterior
antennae distinctly prehensile, terminating in a more or less strong claw. Oral
parts on the whole well developed, though the posterior maxillipeds in some
cases may be rather reduced. The 4 anterior pairs of legs, as a rule, not
adapted for swimming, and of somewhat different structure in the different
genera. Last pair of legs generally less rudimentary than in the Notodelphyidce,
rarely quite absent.

Rernaiks. — This family was proposed in the year 1878 by Prof. Brady,
to include the 3 genera DoropyguSy Notopterophorus and Botachus, which
formerly were referred by Thorell to his family Notodelphyidce. I am of
opinion that this family ought to be maintained, although indeed some of the
forms apparently exhibit a rather close relationship to the genus Notodelphys.
However, as indicated in the above-given general characteristic of the family,
certain very conspicuous peculiarities are found, which are common to all the
forms, and by which the present family seems in reality to distinguish itself
pretty well. Several well marked types are comprised within the family, and
this has rendered it necessary to establish rather a great number of genera,
some of which have been formerly combined within the genus Doropygiis of
Thorell. Seven different genera belonging to the present family will be treated
of in the sequel, and 3 other genera, not represented in the Fauna of Norway,
are also evidently referable to the same family, viz., Goniodelphys Buchholtz,
Doroixys Kerschner, and Bonnierilla Canu. The family thus comprises at
present no less than 10 genera.

As to habits, the forms comprised within this family agree with the
Notodelphyidce in so far that they, like the latter, lead a symbiotic existence
within the branchial cavity of several kinds of Ascidians. Their mobility is
however far inferior, and they seem indeed in most cases to be wholly devoid
of swimming power, being only enabled to change their place within the
branchial cavity of their hosts by a slow ramping motion. This applies not
only to the females, but also to the males, with perhaps a single exception,
viz., Doropygopsls longicauda (see farther below).

6 — Crustacea.

42

Gen. 3. Doropygus, Thorell, 1859.

Generic Characters. — Body in female distinctly compressed, and exhibiting
a pronounced ventral curvature; that in male more cylindrical in shape, and
gradually tapered behind. Incubatory pouch very large and gibbously pro-
minent behind. Tail narrow cylindric in form, and more or less abruptly bent
downwards, last segment deeply cleft behind. Caudal rami more or less
produced, narrowed distally, and only provided with very small rudiments of
setae. Anterior antennae of the very same structure in the 2 sexes, being
composed of 8 or 9 joints, the first 2 of which are very broad and com-
pressed. Posterior antennae scarcely shorter than the anterior, but much
narrower, and highly chitinised, tapering distally, and armed at the tip with
an apparently immobile claw. Mandibular palp with the outer ramus well
developed, narrowly exerted at the end, and divided into 4 more or less
distinctly defined joints. Endopodal part of maxilte with a distinctly defined
terminal joint. Anterior maxillipeds with the terminal part bi-or 3-articulate.
Posterior maxillipeds more or less reduced. The 4 anterior pairs of legs with
the basal part very thick and muscular, rami generally 3-articulate and of
equal size. Last pair of legs with the proximal joint sub-quadrangular in form
and not produced outside to any distinctly defined process, distal joint more
or less slender, sub-linear in shape.

Remarks. — The present genus, being that established at the earliest date,
must of course be regarded as the type of the family Doropygidce. It is here
taken in a more restricted sense than done by Thorell and most other authors,
some of the species referred by them to this genus having turned out to
represent types of nearly allied genera. In the restriction here adopted, the
genus as yet comprises 6 species, 3 of which have been found on the Nor-
wegian coast and will be described below.

9. Doropygus pulex, Thorell.

(PI. XX).

Doropygus pulex, Thorell, 1. c. p. 46, PI. VI, 8.

Syn: Doropygus pullus, Buchholtz.

Specific Characters. — Female. Body comparatively short and stout, with
the anterior division, seen laterally, oblong oval in form and somewhat wide-
ning distally. Incubatory pouch gently curved and greatly prominent behind,
its posterior part being somewhat exerted and narrowly rounded at the end.

43

Tail about equalling in length half the anterior division, and apparently com-
posed of 5 segments, the last one cleft by a deep angular insision into 2
diverging triangular lappets, carrying on the tips the caudal rami. The latter
nearly twice as long as the anal segment, and of a narrow blad-llke shape,
tapering distally, and terminating in an obtuse point, on which slight rudiments
of 3 or 4 setae may be observed. Eye very small, but easily observable in
the living animal. Anterior antennae scarcely attaining the length of the head,
and apparently composed of 8 joints clothed with comparatively short setae,
some of the joints exhibiting slight traces of a sub-division, the first 2 much
larger than the others. Posterior antennae rather slender and quite smooth,
except at the tip, which is armed with a very strong curved claw accompanied
by a small bristle. Endopodal part of maxillae with 3 setae inside the base;
terminal joint comparatively small, quadrangular in form, and only provided
with 2 setae. Anterior maxillipeds with the terminal part well developed, and
composed of 3 well defined joints. Posterior maxillipeds much reduced in
size, each forming an undivided oval lamella clothed inside and at the tip
with a number of thickish plumose setae. The 4 anterior pairs of legs with
the rami comparatively short and broad, the inner one in 1st pair distinctly
3-articulate, in the succeeding pairs however only biarticulate, the 2 outer joints
being confluent. Last pair of legs with the distal joint somewhat cultriform
in shape, and armed outside near the end with 3 small denticles, apex blunted
and, as usual, provided with a spine and a very thin bristle.

Male of very small size, as compared with the female, and having the
body gradually tapered behind, though curved in a similar manner. Structure
of the several appendages much as in female.

Body of female, when alive, rather pellucid, with a slight whitish gray
hue, ripe ova in the incubatory pouch generally of a dark fuscous or violace-
ous colour.

Length of adult female attaining 3.80 mm.; that of male scarcely ex-
ceeding 1.50 mm.

Remarks. — The present species is the type of the genus Doropygus, and
may be easily recognised by the characteristic shape of the incubatory pouch
in the female. The form recorded by Buchholtz from the Mediterranean under
the name of D. pulhis is evidently identical with Thorell's species. On the
other hand, are the figures given by Brady on PI. XXVIII in his monograph
scarcely referable to the present species, but more properly to an immuture
specimen of D. porcicauda.

44

Occurrence. — I have met with this form in many different places on the^
Norwegian coast, from the Christiania Fjord at least to the Trondhjem Fjord.
It is found, often in considerable number, within the branchial cavity of several
kinds of Ascidians. When loosened from its hold, the animal rests nearly
immobile on the bottom, lying on the one or other side. Only from time to
time it is seen slowly to bend its body and to move the antennae and legs,
without however thereby to be enabled to change its place in any perceptible
manner.

Distribution.— CodiSi of Bohuslan (Thorell), British Isles (Brady), coast of
France (Canu), Mediterranean (Buchholtz.

10. Doropygus psyllus, Thorell.

(PI. XXI).
Doropygus psyllus, Thorell, 1. c. p. 49, PI. VII, 9.

Specific Characters. — Female. General form of the body rather like that
in the preceding species, though perhaps still shorter and stouter. Incubatory
pouch of very large size and quite evenly rounded behind. Tail scarcely
attaining half the length of the anterior division, and, as usual, composed of
4 segments, the last of which, as in D. pulex, is cleft into 2 diverging trian-
gular lappets. Caudal rami still more slender than in that species, otherwise
of a very similar structure. Anterior antennae composed of 9 well defined
joints, the 1st of which is much the largest, occupying almost half the length
of the antenna, 2nd joint much shorter but nearly as broad, and gibbously
expanded in front, being armed with 2 short spines in addition to the setae;
the remaining part of the antenna abruptly much narrower and extending at
an angle to the first 2 joints. Posterior antennae very slender, exceeding in
length the anterior ones, with the terminal joint considerably produced and
somewhat curved, apical claw very small. Endopodal part of maxills with 4
setae inside the base, terminal joint much larger than in D. pulex and of
rounded oval form, being fringed with 6 plumose setae. Anterior maxillipeds
about as in D. pulex. Posterior maxillipeds however more fully developed,
being composed of 2 well defined joints, distal joint however rather small, with
3 unequal setae on the end. 1st pair of legs about as in D. pulex, the succeeding
pairs however having both rami distinctly 3-articulate and rather slender, joints of
outer ramus remarkably produced at the end outside. Last pair of legs with
the distal joint comparatively narrower than in D. pulex, sublinear in form,

45

with the outer edge smooth, the inner clothed with a few bundles of small
spinules.

Body in the living animal, according to Thorell, of a whitish grey hue,
with the ripe ova fuscous green.

Length of adult female 2.30 mm.

Alale unknown.

Remarks.— This form exhibits in its general apearance a rather close
resemblance to D. pulex, and may indeed at the first sight easily be con-
founded with it. It is however of much inferior size, and, on a closer inspection,
is found to differ conspicuously in the shape of the incubatory pouch, hi the
structural details, moreover, several well-marked differences are found, as
indicated in the above diagnosis. The form recorded by Brady as D. Normani,
seem to be very closely allied to the present species, but, to judge from the
figures given by that author, it is scarcely the same species.

Occurrence. — Some few female specimens of this form were selected from
material collected, many year ago, on the western coast of Norway, the exact
locality not being ascertained.

Distribution. — Coast of Bohuslan (Thorell), coast of France (Canu).

11. Doropygus porcicauda, Brady.

(PI. XXII).

Doropygus porcicauda, Brady, Monogr. British Copepoda, Vol. I, p. 138, PI. XXVII, figs. 1—9,

PI. XXXIII, figs. 14—16.

Specific Characters.— Female. Body comparatively somewhat more slender
than in the 2 preceding species, with the hind edge of the head and the 3 ante-
rior trunkal segments elevated on each side dorsally to a small knob-like pro-
minence. Incubatory pouch of very large size and greatly prominent behind,
extending far beyond the limits of the tail, and terminating in an obtuse point.
Tail unusually short, scarcely exceeding in length Va o^ the anterior division,
and composed of 4 segments, the penultimate of which exhibits a slight indi-
cation to a subdivision; last segment not expanded distally, though, as in the
2 preceding species, deeply cleft behind in the middle. Caudal rami of rather
a peculiar shape, being greatly prolonged and terminating in a very flexible
thin lash, which may be curled up in a remarkable manner, as indicated in
the figure given by Brady. Anterior antennae rather elongated, being fully as
long as the head, and composed of 9 well defined joints, the first 2 of which,
as usual, are much the largest, though combined scarcely exceeding half the

46

length of the remaining very slender part of the antenna; 1st joint provided'
near the end with 3 remarkably strong and densely plumose setae, 2nd joint
with 2 short spines in addition to the setae. Posterior antennae resembling in
structure those in D. psyllus. Endopodal part of maxil-lae with the terminal
joint subfusiform in shape, and fringed inside with 5 setae gradually increasing
in length distally, its tip somewhat exerted and carrying 2 subequal setae^j
Anterior maxillipeds with the terminal part comparatively short and only com-
posed of 2 joints. Posterior maxillipeds distinctly biarticulate, distal joint slightly
constricted near the end. The 4 anterior pairs of legs with both rami distinctly
3-articulate, and gradually increasing in length behind, those of 4th pair remarldj
ably long and narrow, with most of the setae obliterated. Last pair of legs
of a similar structure to those in the 2 preceding species, but of comparatively
smaller size.

Colour of the living animal not yet ascertained.

Length of the specimen examined 3.40 mm.

Male unknown.

Remarks. — The present species may at once be recognised by the peculiar
structure of the caudal rami, a character which indeed has given rise to the
specific name proposed by Brady. The shape of the incubatory pouch is also
rather characteristic, and some peculiarities are moreover found in the structural
details, as indicated in the above diagnosis.

Occurrence. — A solitary female specimen only of this distinct species has
as yet come under my notice. It was obtained, many years ago, at Hvalor
outside the Christiania Fjord, and, as far as I remember it, was taken from
the branchial cavity of a Corella paralellogramma.

Distribution. — British Isles (Brady).

Gen. 4. Doropygopsis, G. O. Sars, n.

Generic Characters. — Body comparatively more slender than in Doropygus,
distinctly curved in female, straight in male. Incubatory pouch of moderate
size. Tail composed in both sexes of 4 segments, the last not cleft behind.
Caudal rami slender and narrow, with the apical setae less rudimentary than
in Doropygus. Anterior antennae in female of a similar structure to that in
the said genus; those in male however conspicuously transformed and distinctly
prehensile. Posterior antennae rather unlike those in Doropygus, and more
resembling in structure those in the Notodelpliyidce. Oral parts well developed

47

in both sexes. Mandibular palp with the outer ramus shorter than the inner,
forming a rather broad undivided plate fringed with the usual number of strong
plumose setae. Endopodal part ot maxillae with the terminal joint distinctly
subdivided. Posterior maxillipeds composed of 3 well defined joints. The 4
anterior pairs of legs more perfectly developed than in Doropygiis and appar-
ently adapted for swimming, at least in the male; both rami 3-articulate. Last
pair of legs built on the same type as in Doropygiis.

Remarks. — This new genus is established, to include the form recorded
by Aurivillius under the name of Doropygiis loiiglcauda. A closer examination
of this form, and more particularly of the hitherto unknown male sex, has
led me to the conclusion, that it more properly should be separated generically
from Doropygiis. The genus, though undoubtedly referable to the present
family, exhibits a closer affinity to the Notodelphyidce, than does any of the
other genera here treated of, and apears indeed in some respects to form a
connecting link between these 2 families.

12. Doropygopsis longicauda, (Aurivillius).

(PI. XXIII).

Doropygus longicauda, Aurivillius, Bidrag til kannedomen om Krustaceer, som lefva hos
Mollusker och Tunicater, p. 18, PI. III.

Specific Characters. — Female. Body rather slender and only slightly
compressed, exhibiting the usual ventral curvature. Head comparatively large,
fully attaining the length of the 2 succeeding segments combined, with the lateral
edges evenly curved in front, but almost straight in the middle; rostral pro-
minence very small. Incubatory pouch well developed and rather prominent
behind, with the extremity quite evenly rounded. Tail about half the length of
the anterior division, and narrow cylindrical in form, last segment smaller than the
others and nearly transversely truncated at the end. Caudal rami slender and
narrow about twice the length of the anal segment, and provided at the obtusely
pointed tip with 4 well defined, though comparatively small setae; 2 minute bristles
moreover present on each ramus the one attached to the outer edge at a short
distance from the base, the other occurring inside nearer the apex and somewhat
dorsally. Anterior antennae shorter than the head and, as usual, deflexed,
being composed of 9 well defined joints rather densely clothed with setae; 1st
joint with 2 very strong plumose setae near the end; 2nd joint without any
spines. Posterior antennae with the basal and terminal parts sharply marked

1

48

off from each other, the former provided at the end of the 1st joint behind
with a well developed plumose seta; terminal part a little shorter than the
basal one, and provided outside, at some distance from the end, with 2 small
juxtaposed setae; apical claw of moderate size and accompanied by 2 curved
bristles. Endopodal part of maxillae with the terminal joint rather produced
and fringed inside with 3 setae, its outermost part cut off as a well defined
apical joint carrying 4 setae. Posterior maxillipeds with the middle joint well
defined, and armed inside with a curved spiniform seta; terminal joint com-
paratively small and fringed with 4 setae. The 4 anterior pairs of legs with
the rami rather slender and somewhat unequal in size, the inner one being
the longer, especially in 1st pair; spines of outer ramus very thin, almost
setiform. Last pair of legs with the proximal joint very broad at the base;
distal joint slender, sublinear, with the edges somewhat waved and clothed
with small hairs and spinules.

Male of smaller size than female, and rather unlike it in its general
appearance, the body being very slender, attenuated behind, and quite straight,
with the 1st trunkal segment united with the head. Caudal rami still more
slender than in female, and having the apical setae more fully developed and
distinctly ciliated. Anterior antennae built on the very same type as in the
male Notodelphyidce, being composed of 10 joints, the last 2 of which are
much larger than in female and together form a movable terminal part admit-
ting to be impinged against the preceding part of the antenna. The remaining
appendages of exactly same structure as in female.

Body of female, in the living state, of an uniform light reddish hue;
ripe ova of a similar, though somewhat darker colour.

Length of adult female attaining 4,50 mm., of male 2.40 mm.

Remarks. — The above described form, the only species as yet known of
the present genus, may be easily distinguished from the other Doropygid^ by
its comparatively slender and less compressed body, as also by the unusually
long and narrow caudal rami. The female is at once recognised as a true
Doropygid by the characteristic ventral curvature of the body and the gib-
bously prominent incubatory pouch. The male, on the outer hand, may on
the first sight easily be taken for a Notodelphyid, exhibiting, as it does, a
much similar form of the body and a similar transformation of the anterior
antennae.

Occurrence. — Several specimens of this form have been collected by me
at different times and in different places, both on the south and west coasts
of Norway. Most of the specimens were taken from the branchial cavity of

49

Phallusia obliqua. The animal, when ahve, is rather more mobile than the
other Doropygidae, and even females encumbered with ripe ova are seen, when
loosened from their holds, moving to some extent freely in the water, though
in a rather clumsy manner. The males are much more agile and are scarcely
in this respect overmatched by the Notodelphyidae. Indeed, one of the male
specimens obtained was found out of his host, swimming quickly about
together with other free-living Copepoda.

Distribution. — Coast of Bohuslan (Aurivillius).

Gen. 5. Doropygella, G. O. Sars, n.

Generic Characters. — Body comparatively short and stout, being scarcely
at all compressed. Head remarkably large and broad, produced in front to a
deflexed conical rostrum. Incubatory pouch not much prominent. Tail composed
in both sexes of 4 segments, the last of which is transversely truncated behind.
Caudal rami quite simple, terminating in a blunt point, and without any
distinctly defined setae. Anterior antennae short and deflexed, with the proximal
joints very broad and compressed; those in male not transformed. Posterior
antennae strongly built and nearly smooth, apical claw well developed. Mandi-
bular palp with the outer ramus undivided. Endopodal part of maxillae with
a distinctly defined terminal joint extending outwards along the exopodal la-
mella. Anterior maxillipeds rather robuste, but with the terminal part poorly
developed. Posterior maxillipeds distinctly 3-articulate. The 4 anterior pairs
of legs of comparatively small size and not adapted for swimming, basal part
broad and flattened, rami in all the pairs 3-articulate, but rather short, with
the setae poorly developed. Last pair of legs small, with the distal joint scale-like.

Remarks. — This genus also is founded upon a single species detected by
Aurivillius and referred by him to the genus Doropygus. Several peculiarities
found in this species, both as regards the outward appearance of the body
and the structure of some of the appendages, have however led me to the conclu-
sion, that it more properly ought to be regarded as the type of a separate genus.

13. Doropygella Thorelli, (Aurivillius).

(PI. XXIV)
Doropygus Thorelli, Aurivillius, 1. c. p. 45, PI. V.

Specific Characters. —Female. Body of a rather short and clumsy form,
exhibiting the usual ventral curvature. Head unusually large and expanded,
exceeding both in height and width the adjoining part of the trunk, seen

7 — Crustacea

50

dorsally almost semicircular in outline ; rostral prominence terminating in a
knob-like point. The 3 succeeding segments gradually increasing in size, with
the lateral parts not extant. Incubatory pouch subquadrangular in shape and
scarcely dilated behind, with the extremity transversely truncated and slightly
overlapping the base of the tail. The latter about half the length of the
anterior division, with the last segment considerably larger than the preceding
one and not dilated distally. Caudal rami comparatively short, scarcely exceeding
half the length of the anal segment, and terminating in a blunt point. Eye
apparently absent. Anterior antennae scarcely attaining half the length of the
head, and composed of 8 joints, the 3 or 4 proximal ones lamellarly expanded,
Ihe 4 outer joints abruptly much narrower. Posterior antennae with the middle
joint somewhat dilated; apical claw well developed and accompanied by 2
very small bristles. Endopodal part of maxillae with 3 setae inside the base,
terminal joint somewhat fusiform in shape and edged with 6 setae, 2 of which
issue from the strongly convex inner edge, the 4 others from the tip. Anterior
maxillipeds with the claw-like spine issuing from the 2nd basal joint very strong,
terminal part short, biarticulate. Posterior maxillipeds with the middle joint
quite unarmed, terminal joint carrying 3 subequal setae. The 4 anterior pairs
of legs somewhat diminishing in size behind, and wanting the usual plumose
seta inside the 1st basal segment; outer ramus in all the pairs larger than the
inner and armed outside with strong spines. Last pair of legs with the proximal
joint rather broad at the base and provided at the end outside with the usual
small bristle; distal joint scale-like, with the outer edge boldly curved, tip
provided with a single small bristle.

Male resembling in shape the males of most other Doropygidae, being
however easily recognisable by the large size of the head.

Body in the living animal of an uniform whitish colour.

Length of adult female 2.10 mm., of male L50 mm.

Remarks. — The present form may be easily recognised from the other
known Doropygidae by its short and clumsy body, and more particularly by the
unusual development of the head and the characteristic shape of the incu-
batory pouch.

Occurrence. — I have taken this form not unfrequently in several places,
both of the south and west coasts of Norway. It is generally found within
the branchial cavity olPhallusia obliqaa, more rarely in that of other kinds of
Ascidians. The animal is very slow in its movements, and is quite unable to
move freely in the water.

Distribution. — Coast of Bohuslan (Aurivillius).

51

Gen. 6. Pachypygus, G. O. Sars, n.

Generic Characters. — Body of female very stout and compact, and pro-
nouncedly compressed, with the back boldly curved; that of male, as usual,
more slender and gradually attenuated behind. Head of moderate size and
rather deep. Incubatory pouch large and prominent, more or less exerted
at the end. Tail composed in both sexes of 4 segments, the last of which is
the smallest and peculiarly produced at the end both dorsally and ventrally.
Caudal rami claw-like- curved downwards, and tipped with a stout spine
accompanied by a number of smaller denticles. Anterior antennae comparatively
short and stout, with the number of joints somewhat reduced; those in male
not transformed. Posterior antennae quite smooth, terminating in a well developed
claw. Oral parts on the whole built on the same type as in the preceding
genus. The 4 anterior pairs of legs not adapted for swimming, both rami 3-
articulate and rather unequal, the outer one being the larger, and having the
setae more or less obliterated. Last pair of legs resembling in shape those in
Doropygus.

Remarks. — This genus is established to include the Doropygus gibber of
Thorell. The generic difference of this form from Doropygus was indeed
recognised by Giesbrecht; but I am not prepared to consent with him in
referring this species to the genus Notopierophorus Costa, as it differs very
conspicuously not only in the character from which that genus has derived
its name, but also in some of the structural details, as seen from the diagnoses
here given of the 2 genera. The genus Goniodelphys of Buchholtz seems to
come very near to the present genus, and should perhaps be united with it.

14. Pachypygus gibber, (Thorell).

(PI. XXV)
Doropygus gibber, Thorell, 1. c. p. 52, PI. VIII, 11.

Specific Characters.— Female. Body of a very robust and compact
appearance, and^ strongly curved ventrally, with the back boldly arched and
the tail more or less bent below the anterior division. Head comparatively
short, but rather deep, and produced in front to a short and obtuse rostral
prominence. The 3 succeeding segments rapidly increasing in size, the 3rd
being exceedingly large and deep; 1st trunkal segment only visible in its
dorsal part, being otherwise concealed by the adjoining segments. Incubatory
pouch large and prominent, with the hind extremity somewhat deflexed and

52

angular at the tip, the angle being more prominent in young specimens'
enclosed ova very numerous and densely accumulated. Tail not nearly attaining
half the length of the anterior division, and slightly tapered distally; last
segment rather short and remarkably produced at the end both dorsally and
ventrally. Caudal rami of rather a peculiar appearance, forming 2 somewhat
claw-like and very mobile lamellae curving downwards, each armed at the
narrowly exerted tip with a stout spine accompanied by 2 or 3 smaller den-
ticles. Anterior antennae comparatively short and stout, being only composed
of 7 joints clothed with rather small curved setae, the first 2 joints very large
and expanded, occupying combined -/a of the length of the antenna. Posterior
antennae strongly chitinised, with the terminal joint comparatively short, not
even attaining the length of the middle one. Endopodal part of maxillae with
3 somewhat unequal setae inside the base; terminal joint extending straight
outwards, and fringed on the inner edge with 4 very small setae, at the some-
what exerted knob-like tip with 3 considerably longer setae. Posterior
maxillipeds rather fully developed, 'with all the joints setiferous, the last one
exhibiting traces of a subdivision. 1st pair of legs with the rami nearly
equal-sized, the 3 succeeding pairs however having the outer ramus consider-
ably larger than the inner, with most of the setae obliterated and replaced by
tufts of small spinules. Last pair of legs with the distal joint cultriform, and
armed on the inner edge with small denticles.

Body in the living animal of a whitish gray hue, with the ripe ova dark
fuscous green.

Length of adult female attaining 5.00 mm.

Remarks. — This is much the largest of the known Doropygidae, and
moreover easily recognisable by its unusually robuste body. The male of
this species has been well described and figured by Canu.

Occurrence. — I have met with this form occasionally in several places,
both on the south and west coasts of Norway, It is found in several kinds
of Ascidians, most frequently perhaps in Phallusia meniula. The mobility
of the living animal is very restricted.

Distribution. —Coast of Bohuslan (Thorell), British Isles (Norman, Scott),
coast of France (Canu), Mediterranean (Buchholtz).

Gen. 7. Notopterophorus, Costa, 1852.

Generic Characters. — Body of female strongly curved ventrally, with the
free segments of trunk sharply defined and produced dorsally to more or less

53

prominent wing-like expansions in some instances divided into soft filiform
processes; that of male simple cylindric, without any dorsal expansions.
Incubatory pouch of moderate size and more or less produced at the end.
Tail composed in both sexes of 4 segments, the last of which is simple, truncate
at the end. Caudal rami forming 2 compressed pieces curving downwards
and each armed on the narrowly truncated end with 4 subequal hooks. An-
terior antennae alike in the 2 sexes, and comparatively more slender than in
Pachypygus. Posterior antennse and oral parts built on a similar type to that
in the said genus. The 4 anterior pairs of legs however conspicuously dif-
fering in the structure of the inner ramus, which in all the pairs is only com-
posed of 2 joints. Last pair of legs comparatively small with the distal joint
narrow linear in form.

Remarks.— This genus was established as early as the year 1852 by Costa,
and is chiefly characterised by the peculiar wing-like expansions of the free
trunkal segments in the female, these expansions attaining in some instances
quite an extraordinary development. Otherwise it comes very near to the
genus Pachypygus, yet differing from it also somewhat in the structure of the
legs and that of the caudal rami. Several species of this genus have been
recorded by different authors, and chiefly distinguished by the different deve-
lopment of the above-mentioned expansions. As however these expansions
appear to be subjected to some variation, the limits between the several species
are not always easy to fix exactly. Three Norwegian species referable to this
genus will be described below.

15. Notopterophorus auritus, (Thorell).

(PI. XXVI)
Doropygus auritus, Thorell, 1. c. p. 50, II. VII, PI. VIII, 10.

Specific Characters.— Female. Body moderately slender and gently curved,
with the free segments of trunk sharply defined by deep constrictions; wing-
like expansions only slightly prominent and quite evenly rounded at the end,
those of 1st segment confluent, the others well defined, though contiguous at
the base anteriorly. Incubatory pouch not very large, irregularly quadrangular
in outline, and terminating behind in an obtuse point. Tail about half the
length of the anterior division, and slightly tapering distally, with the last
segment the smallest. Caudal rami slightly curved and gradually attenuated
distally, with a small bristle somewhat beyond the middle of the upper edge;
tip narrowly truncated and armed with 4 hooks of equal size. Anterior an-

54

tennee somewhat shorter than the head, and composed of 9 well defined joints,
the first 2 of which, as usual, are the largest, though combined not much
longer than the remaining part of the antenna. Posterior antennae rather stout,
with the terminal joint much shorter than the middle one; apical claw very
strong. Mandibular palp with the outer ramus very short and broad, undivided.
Endopodal part of maxillae with 4 set« inside the base, one of them mucli
larger than the others; terminal joint fringed inside with 4 small setae and
carrying on the slightly exerted tip 3 somewhat longer setae. Anterior maxi-
lipeds with the terminal part rather slender, 3-articulate, middle joint consider-
ably longer than the others. Posterior maxillipeds distinctly 3-articulate, with
the last joint simple, fringed with 4 setae. 1st pair of legs with the rami not
much different in length, but rather unlike in structure, the inner ones being,
as in the 3 succeeding pairs, only composed of 2 joints, the distal one much
the larger and clothed with unusually long and slender setae. Outer ramus
of the 3 succeeding pairs longer than the inner and tapered distally, with
the 1st joint very large, setae much reduced, being wholly absent in the 4th
pair. Last pair of legs with the distal joint narrow linear in form and pro-
vided on both edges with small spinules.

Male much smaller than female and without any traces of dorsal expansions.

Body of female, in the living state, of a pale yellowish brown hue, with
the ripe ova fuscous green.

Length of adult female attaining 4.20 mm.; that of male scarcely exceeding
L40 mm.

Remarks. — This form was described in the year 1859 by Thorell and
referred by him to the genus Doropygus. In a note to his description he has
however alluded to its apparent relationship to the genus Notopterophonis of
Costa. Indeed, it ought evidently to be referred to that genus, though the
dorsal expansions of the body are far less conspicuous than in the other
known species.

Occurrence. — The present form is not seldom found in large Ascidians of
different kinds. I have noted it from many places on the Norwegian coast,
from the Christiania Fjord at least to the Trondhjem Fjord. Like most other
Doropygidae, it is very slow in its movements.

Distribution. — Coast of Bohuslan (Thorell), British Isles (Norman & Scott).

55

16. Notopterophorus papilio, Hesse.

(PI. XXVII).
Notopterophorus papilio, Hesse, Ann. Scienc. Nat., ser. 5, Vol, 1, p. 338, PI. XI, figs. 1 — 13.

Specific Characters. — Female. Body comparatively more slender than in
the preceding species and generally more strongly curved, being moreover
highly distinguished by the extraordinary development of the wing-like ex-
pansions, which are very delicate, hyaline, and divided at the end into soft
threadlike processes. The number of these expansions is 6 in all, the 4 middle
ones being arranged in pairs on the 2nd and 3rd trunkal segments, the other
2 forming median plates issuing the one from the 1st trunkal segment, the
other from the end of the incubatory pouch. Both these median expansions
are somewhat spatulate in form and divided at the end into 3 threadlike pro-
cesses, whereas only 2 such processes occur on each of the paired expansions.
Structure of the caudal rami and of the several limbs almost exactly as in the
preceding species.

Male of very small size, and exhibiting an appearance rather unlike that
in female, being wholly devoid of any dorsal expansions, and resembling in
shape the males of most other Doropygids.

Body of female, in the living state, semipellucid, of a light yellowish gray
hue, with the ovarial tubes and the ripe ova dark fuscous in colour.

Length of adult female attaining 4.30 mm.; that of male scarcely ex-
ceeding 1.20 mm.

Remarks. — The present species exhibits a most peculiar appearance by
the strongly prominent wing-like expansions surrounding the back of the body
and extending in different directions. Some variability of these expansions
may however be found to occur, and in younger specimens they are, as a rule,
much smaller than in fully adults, though always, unlike what is the case in
A^. auritus and elongatiis, distinctly divided at the end into well-marked thread-
like processes.

Occurrence. — I have only met with this remarkable form in a single
locality, viz., at Mold0en, west coast of Norway. It was found occasionally in
the branchial cavity of large specimens of Phallusia mentula. Most of the
specimens obtained were of the female sex; but on a closer examination of
the collected material, also some few male specimens were detected, one of
them still attached to the back of a young female by the aid of his rather
powerfully developed posterior antennae.

Distribution. — Coast of France (Hesse), British Isles (Brady).

56

17. Notopterophorus micropterus, G. O. Sars, ii. sp.

(PI. XXVIII. 1.)

Specific Characters. — Female. Body comparatively more robust than irf
N, paplllo, and more resembling in shape that of N. aiirltus, being gently
curved, with the segments very sharply marked of from each other. Wing-
like expansions much reduced in size and conspicuously differing in shape from
those in both the said species. The foremost expansion, issuing from the 1st
trunkal segment, very slight, hood-like, with the edge entire, the 4 succeeding
ones each exerted behind in a single thread-like point, the hindmost expansion,
issuing from the end of the incubatory pouch, likewise simple, being exerted
to a narrow point somewhat curved downwards. Structure of the several ap-
pendages scarcely differing from that in the 2 preceding species.

Colour of the living animal not yet ascertained.

Length of adult female 4.10 mm.

Remarks. — Though this form looks very different from N. paplllo, as
described and figured here, I am by no means fully convinced on its real
specific validity, and indeed I do not regard it as impossible, that on a closer
investigation it might turn out to represent only a peculiar variety of that
species. As I however have not found any decided transition between them,
I have found it advisable provisionally to record it as a separate species.

Occurrence. — Two female specimens only of this form have as yet come
under my notice. They were obtained in the same locality as the preceding species.

Gen. 8. Gunentophorus, Costa, 1843.

Syn: Sphaeronotus, Glaus.

Generic Characters. — Trunkal part of the body in female greatly inflated,
with the segments partly confluent, to form the large and prominent incubatory
pouch, the cavity of which is prolonged anteriorly over the 2nd and 3rd segments.
Head procumbent and well defined from the 1st trunkal segment, terminating
in a blunt rostral prominence. Tail nearly straight and only composed of 3
distinctly defined segments. Caudal rami curved outwards and armed at the
tip with small denticles. Anterior antennae very short and compressed, with
the joints imperfectly defined. Posterior antennae distinctly prehensile. Man-
dibles well developed. Maxillae with the endopodal part transversally truncated
and without any terminal joint. Posterior maxillipeds much reduced, uniarticulate.

57

1st pair of legs very unlike the others and closely applied to the oral parts,
both rami 3-articulate and provided with long plumose setae. The 3 succeeding
pairs of legs apparently immobile and without any armature whatever; outer
ramus elongate, 3-articuIate, inner very small and peculiarly contorted. 5th
pair of legs apparently absent.

Remarks. — This is a very anomalous genus, exhibiting some rather ex-
traneous characters. Yet in some respects, and more particularly in the
peculiar composition of the incubatory pouch, it shows an unmistakable
relationship to the genus Bonnlerilla Canu, which is a true member of the
present family. The genus as yet only comprises a single species, to be
described below.

18. 6unentophorus globularis, Costa.

(PI. XXVlll, 2)

Giinentophorus globularis, Costa, Fauna del regno di Napoli. Entomostraca, PI. 11.

Syn: Sphaeronotus Thorelli, Glaus.

Specific Characters.— Female. Body comparatively rather robuste, with
the anterior division distinctly curved, the posterior straight. Head not very
deep, with the lateral edges scarcely at all curved, and terminating in front in
an obtuse corner. 1st trunkal segment short and narrow; the 3 succeeding
segments wholly confluent dorsally, to form the greatly prominent, almost
hemispherical incubatory pouch; last trunkal segment well defined in its
posterior part. Tail considerably exceeding half the length of the anterior division,
and cyUndric in form, though slightly tapered distally, 1st segment much the
largest and a little protuberant below at the base, last segment exhibiting
dorsally, somewhat beyond the middle, a slight transverse suture indicating
a subdivision of the segment. Caudal rami comparatively small, slightly tapered,
and abruptly bent outwards, being armed on the tip with a few very small
denticles and on the outer edge, at some distance from the end, with a
minute bristle. Eye imperfectly developed, without any lenses, and only re-
presented by an irregular patch of a light yellowish red pigment. Anterior
antennae very short and stout, subtriangular in outline, and only clothed with
a few very small bristles, joints imperfectly defined and apparently 6 or 7 in
number. Posterior antennae strongly chitinised and rather powerful, with the
terminal joint comparatively short and somewhat tapered distally, apical claw
well developed. Mandibular palp with the inner ramus shorter than the outer
and less perfectly subdivided. Maxillae with 4 short, but densely plumose setae

8 — Crustacea.

H

58_

on the transversely truncated end of the endopodal part. Anterior maxilUpeds
with the terminal part very short, uniarticulate. Posterior maxillipeds forming ^|
each an oval undivided lamella clothed inside and at the tip with a number
of thickish plumose setae. 1st pair of legs with the rami of about equal size, M\
the outer one exhibiting only very slight traces of spines outside, its terminal
joint of a somewhat irregular shape, being expanded, inside the insertions of
the setae, to a rounded lobe edged with 3 short denticles. The 3 succeeding
pairs of legs much longer than the 1st, and of a very different structure, being
apparently quite immobile, as only very slight traces of muscular bands are
detected within them ; outer ramus considerably produced and conically tapered,
inner one extremely small, being composed of a short basal joint folloved by
a narrow, peculiarly twisted terminal piece, which in the 4th pair is simple, but
in the 2 preceding pairs divided by 2 successive circular crests as it were in
3 join'is. Of a 5th pair of legs not the slightest trace could be detected in
the specimens examined.

Body in the living animal of a pale yellowish grey colour, with a
slight bluish tinge; ovarial tubes and ripe ova of a somewhat darker
violaceous hue.

Length of adult female attaining nearly 5 mm.

Male unknown.

Remarks. The present form is easily recognisable from any of the other
Doropygidae, both as regards its outward appearance and the structure of the
several appendages. The large size of the Norwegian specimens is very
remarkable, and could led to the suggestion that they belonged to a
species different from that observed in the Mediterranean and on the
French coast. ^) As however no other reliable difference could be detected
to distinguish the Norwegian form, I have not felt justified to separate it
specifically. The Sphceronotus Thorelll of Claus is evidently identical with
Costa's species.

Occurrence. — Some few female specimens of this remarkable form were
obtained, many years ago, from large specimens of Phallusla mentula taken
in the upper part of the Trondhjem Fjord.

Distribution. — Mediterranean (Costa), coast of France (Canu), coast of
Bohuslan (Aurivillius).

1) Canu gives the length of the body to only 2.50 mm.

59

Gen. 9. Botachus, Thorell, 1859.

Generic Characters.— Bo Ay of female narrow, sub-cylindrical in shape,
with the matrical part remarkably elongate and the incubatory pouch only
slightly prominent. Tail short, deflexed, and composed of 4 segments, the
last of which is very short and conspicuously produced ventrally. Caudal
rami short, lamelliform, and armed at the end with strong claw-like spines.
Anterior antennae comparatively slender, attenuated, and rather densely clothed
with setse. Posterior antennae with a well developed plumose seta outside the
basal part, apical claw rather strong. Mandibular palp with the inner ramus
undivided, outer one narrow, sabre-like. Endopodal part of maxillae with a well
defined terminal joint. Anterior maxillipeds with the terminal part well developed,
3-articulate. Posterior maxillipeds small, uniarticulate. The 4 anterior pairs
of legs comparatively slender, but not adapted for swimming, both rami 3-
articulate, the outer one armed at the tip and outside with very slender spines,
setae on both rami much reduced in number. Last pair of legs very small and
rudimentary, resembling somewhat in structure those in the Notodelphyidce.

Remarks. — This is also a very distinct genus, though somewhat less
anomalous than Giinenterophoriis, and more agreeing with the usual Doropygian
type. In addition to the typical form described below, another nearly allied
species has been recorded by Buchholtz from the Mediterranean under the
name of B. fusiformis.

19. Botachus cylindratus, Thorell.

Botachus cylindratus, Thorell, 1. c p. 55, PI. IX, 12.

Specific Characters. — Female. Body extremely slender and narrow, with
the anterior division very little dilated and somewhat tapered anteriorly. Head
gradually contracted in front and terminating in a nearly horizontal, obtusely
rounded rostral plate. 1st trunkal segment very small and partly concealed by
the rounded lateral corner of the head. The 2 succeeding segments well
defined and slightly increasing in size behind. Matrical part of body, composed
of the last 2 coalesced trunkal segments, almost occupying half the length of
the body, and of oblong form, with the dorsal face only slightly vaulted and
encompassing the comparatively narrow incubatory cavity. Tail very short,
scarcely attaining in length Vs of the anterior division, and more or less
abruptly bent downwards; last segment very small, but produced below to a
rather prominent bifurcate lappet. Caudal rami forming 2 vertically placed

60

lamellae of sub-quadrangular shape, and armed at the upper corner with 2
strong claw-shaped spines, lower corner produced to an acute prominence
accompanied below by a slender bristle. Anterior antennae angularly bent in
the middle, and composed of 9 well defined joints, the first 3 of which are
much larger than the others and have the seta?, distinctly ciliated. Posterior
antennae rather strongly built and attached to the head by a short and thick
basal joint, terminal joint longer than the preceding one and finely ciliated on
both edges, apical claw only slightly curved and accompanied by 2 small bristles.
Mandibular palp with the basal part narrower than usual, inner ramus lamelli-
form, undivided, outer ramus more slender and provided in its outer part with
5 setae, the 2 outermost issuing from a small but well defined apical joint.
Endopodal part of maxillae with the terminal joint somewhat spatulate in form
and -provided at the end with 3 setae. Anterior maxillipeds not particularly
strong and gradually tapered distally. Posterior maxillipeds forming each an
undivided oblong oval lamella clothed at the tip and inside with a number
of partly ciliated setae. The 4 anterior pairs of legs gradually somewhat
increasing in length, 4th pair with the outer ramus considerably longer than
the inner and having the terminal joint rather produced. Last pair of legs
with the proximal joint produced outside to a conical process tipped with a
slender bristle; distal joint very small and narrow, with a single apical seta.

Body in the living animal rather pellucid, of a whitish grey hue with
the rather large ripe ova dark bluish or purplish.

Length of adult female 2.10 mm.

Male unknown.

Remarks. — The present form is at once distinguished from any of the
other known Doropygid^ by its very slender and narrow body, the short and
abruptly bent tail, and the shape of the incubatory pouch.

Occurrence. — I have met with this form not unfrequently in several places
on the Norwegian coast. It is found in several kinds of Ascidians and, as
observed by Thorell, almost exclusively between the lamellae of the branchial
sac, more or less firmly attached to these lamellae by the aid of its powerful
posterior antennae. When loosened from its hold, the animal rests nearly
motionless on the bottom, only a slight bending of the body being perceptible.

Distribution. — Coast of Bohuslan (Thorell), British Isles (Brady).

61

Fam. 3. Buproridas.

Remarks. — This very distinct family, established by Thorell, only comprises
as yet a single genus, the characters of which are given below.

Gen. 10. Buprorus, Thorell, 1859.

Generic Characters.— Body short and stout, unsegmented, and only com-
posed of head and trunk, the tail being wholly obliterated or only present as
a trifling rudiment. Ripe ova received into a roomy incubatory cavity formed
by the dorsal and lateral walls of the trunk in almost its entire extent, Anterior
antennae short and stout, with the number of joints much reduced. Posterior
antennae not prehensile, the terminal joint being only provided with simple
spines, none of which is unguiform. Oral parts of rather simple structure,
though apparently well adapted for mastication. The 4 anterior pairs of legs
poorly developed, with the rami short and stout, armed at the end with short
spines, the outer one biartieulate, the inner one uniarticulate. Last pair of
legs forming 2 simple conical prominences tipped with a few small spines.

Remarks. — This genus exhibits some very extraneous characters, by which
it seems to distinguish itself very sharply from any of the other genera com-
prised within the present division of Copepoda, and Thorell was certainly
quite right in regarding it as the type of a very distinct family. He was indeed
of opinion that this family was even more distinct than his family Ascldicolidce,
which latter he merely regarded as a subfamily of the Notodelphyidce. Yet,
on a closer examination, it will be found, that the present genus agrees with
those treated of in the preceding pages at least in one very essential character,
viz., in the presence of an incubatory cavity for the reception of the ripe ova.
Such a cavity, on the other hand, does not exist either in the Ascidicolidce or
in the other families treated of in the sequel, the ova pured out from the
ovarial tubes being here, as in most other Copepoda, accumulated in free
ovisacs appended to the body. The reception of the genus Enterocola within
the family Buprorldce, as proposed by Brady, cannot therefore by any means
be admitted. The present genus as yet only comprises a single species, to
be described below.

62

20. Buprorus Loveni, Thorell.

(PI. XXX)
Buprorus Loi)eni, Thorell, 1. c. p. 63, PI. X, 14.

Specific Characters. — Female. Body short and stout, bag-like, with the
head subquadrate in form and somewhat exerted, not being however distinctly
defined behind, rostral prominence short and obtuse at the tip. Trunk with
the dorsal face rather strongly vaulted and almost gibbously prominent in front,
seen dorsally, regularly oval or elliptical in outline. Eye wolly absent. An-
terior antennae about the length of the head, somewhat curved, and composed
of only 3 distinctly defined joints clothed with comparatively short, partly
spiniform setae, middle joint much the largest, terminal joint abruptly much
narrower and scarcely Vs as long. Posterior antennae 3-articulate, with the
1st joint about the length of the other 2 combined, and provided near the
end anteriorly with a curved seta, the 2 outer joints firmly connected and
forming with the 1st one a geniculate bend; middle joint armed outside with
3 strong spines, the outermost being accompanied by a slender seta; term-
inal joint shorter than the middle one and armed on the transversely truncated
extremity with 3 unequal spines and a simple seta. Mandibles with the
masticatory part not much expanded, but divided at the end into several
sharply pointed teeth; palp quite rudimentary, being replaced by a single
slender seta. Maxillse with the masticatory lobe well developed and armed
with strong spines, palp undivided, with 2 coarse spines at the tip and 2
juxtaposed setae attached to a distinct ledge of the outer edge. Anterior
maxilllipeds composed of 3 joints, the 1st of which is rather large and broad,
being provided at the end inside with a narrow cylindrical lobe tipped with
2 slender spines; 2nd joint produced inside to a quite similar bispinose lobe,
3rd joint very small and armed with 3 spines. Posterior maxillipeds undivided,
lamellar, and fringed inside in its outer half with 4 spines, each terminating
in' a blunt point. The 4 anterior pairs of legs of essentially same structure,
outer ramus somewhat larger than the inner one and having a short spine
outside the 1st joint, distal joint obliquely truncated and fringed at the end
with a row of 5 stout spines, inside which another row of somewhat more
slender spines is seen, the number of these spines varying in the different
legs; inner ramus in all the pairs provided at the end with 5 spines, one of
which is attached to the outer edge near the tip. Last pair of legs imperfectly
defined at the base, and armed at the narrowly exerted extremity with 4 short
spines. Between these latter legs a small triangular prominence occurs con-

63

taining the anal orifice, and apparently representing a trifling rudiment of
the tail.

Body in the living animal of an uniform whitish colour, with the rather
large ova, contained within the incubatory cavity, of same colour, but more
opaque.

Length of adult female 1.10 mm.

Male unknown.

Remarks.— The above-described peculiar form looks so very different
from any of the other known Copepoda, that at the first sight even its reference
to that order of Crustacea could be questioned. Indeed, in its outward appea-
rance it more resembles some kinds of mites, especially the Tardigrada.
On a closer examination however it is soon proved to be a true member of
the present division of Copepoda, its extraneous appearance being the result
of a close adaption to its sedentary life within Ascidians.

Occurrence. — I have found this peculiar form, often in considerable number,
within the branchial cavity of different kinds of Ascidians, most frequently
in Phallusia obliqiia. It may however easily escape attention, on account of
its small size and inconspicuous colour. The mobility of the animal is almost
wholly lost, and the only token of life perceptible is a slight fumbling move-
ment of the antennae and legs. I have carefully looked over the numerous
specimens collected, but have not succeeded in detecting even a single male
among them.

Distribution. —Co^si of Bohuslan (Thorell).

Fam. 4, Ascidicolidae.

Remarks. — This family was established by Thorell, to include his genus
Asctdicola, which indeed exhibits several well marked peculiarities distinguishing
it very conspicuously from the other Notodelphyoida. As to the relation of
this family to the other known families of the present division of Copepoda,
it is evidently more sharply defined from the preceding families than from
those treated of farther below, agreeing with the latter in one very essential
character not recognised by Thorell, viz., in the absolute absence of any true
incubatory cavity for the reception of the ripe ova. As the family only contains
a single genus, it may suffice to give the characters of the latter.

64

Gen. 11. Ascidicola, Thorell, 1859.

Syn: Coeliacola, Hesse.

Generic Characters.— Body of female slender, vermiform, with no sharp
demarcation between the anterior and posterior divisions. Head well defined
from trunk and terminating in a broad rostral plate. The last 2 trunkal seg-
ments in female not coalesced. Tail composed in both sexes of 4 segments.
Caudal rami simple, not clawed at the end. Anterior antennae short and thick,
alike in both sexes. Posterior antennae more slender and. distinctly prehensile.
Oral parts poorly developed and rather differing in structure from those in the
other Notodelphyoida. The 4 anterior pairs of legs in female only adapted
for crawling, the rami being very short, biarticulate, the inner one armed at
the end with exceedingly long and slender spines; those in male of quite
normal appearance and well adapted for swimming. Last pair of legs in female
transformed to large lamellae encompassing the genital region of the body,
those in male very small and rudimentary. Ripe ova accumulated in 2 juxta-
posed ovisacs appended to the dorsal face of the body and arched over by
the transformed last pair of legs.

Remarks. — The present genus comprises as yet only a single species, to
be described below.

21. Asc^dicola rosea, Thorell.

(PI. XXXI)

Ascidicola rosea, Thorell, 1. c. p. 59, PI. IX & X, 13.

Syn; Coeliacola setigera, Hesse.

Specific Characters. — Female. Body almost perfectly cylindrical in form,
the anterior division being very little broader than the posterior. Head
slightly contracted in front, and terminating in a broadly rounded rostral plate.
The first 2 trunkal segments imperfectly separated, the 2 succeeding ones
however well defined. Last trunkal segment not clearly defined from the 1st
caudal segment, both having the dorsal face somewhat hollowed to make an
underlayer for the ovisacs. Tail very fully developed, exceeding in length the
anterior division, and composed of 4 well defined segments gradually some-
what diminishing in size, the penultimate one having the ventral part of the
hind edge remarkably thickened and densely clothed with small pricks, last
segment transversely truncated at the end. Caudal rami a little shorter
than the anal segment, and narrow linear in form, tip somewhat obliquely

65

truncated and carrying 3 spiniform setae, the innermost but one much longer
than the others, outer edge provided with a well defined seta about in the
middle, and the dorsal face with another smaller seta at a short distance from
the tip. Eye inconspicuous. Anterior antennas short and thick, somewhat
curved and terminating in a blunt point, each antenna composed of 6 joints
densely clothed with comparatively short but rather strong curved setae. Posterior
antennae rather broad at the base, but rapidly tapered distally, the first 2 joints
each armed near the end anteriorly with a slender spine, terminal joint narrow,
sublinear in form, and provided with a short spine in about the middle* of
the outer edge, tip armed with a comparatively small claw slightly curved at
the end and accompanied by 2 or 3 small bristles. Anterior lip broad, almost
trapezoid in form. Mandibles with the masticatory part divided at the end
into several sharply pointed teath, partly bi- or tri-partite; palp very small
and apparently undivided with 3 or 4 short setae at the tip and one consider-
ably larger seta outside, apparently replacing the outer ramus. Maxillae divided
into 2 nearly equal triangular lobes, the inner one representing the masticatory
lobe, the outer the palp, both edged with a number of partly spiniform setae.
Anterior maxillipeds only composed of 2 distinctly defined joints, the proximal
one rather large and provided inside with a short lobe tipped with 2 small
spines; distal joint produced at the end to a strong claw-like spine accompanied
outside by another much narrower spine, its outer edge provided with 4 small
bristles arranged in pairs. Posterior maxillipeds very small and closely approx-
imate, each forming a narrow somewhat curved lamella, with 3 small setae at
the tip and 2 other similar setae in about the middle of the outer edge. The
4 anterior pairs of legs of essentially same structure, with both rami biarticulate,
the outer one somewhat incurved and without any setae inside, but armed
outside and at the tip with strong spines; inner ramus carrying on the extremity
3—4 exceedingly long and quite smooth spiniform setae extending backwards
along the median line of the belly. Last pair of legs transformed to 2 very
large curved lamellae ^) encompassing the middle part of the body and completely
arching over the ovisacs. The latter closely juxtaposed and of oblong oval
form, reaching nearly to the end of the 1st caudal segment. Ovarial tubes
very conspicuous in the living animal, and extending far into the tail.

Male of very small size, as compared with the female, and rather unlike
it in its outward appearance, the body being somewhat depressed in its anterior

0 It is the merite of Canu to have given a right interpretation of these lamellae, the
significance of which was wholly miscomprehended by Thorell and most other authors.
9 — Crustacea.

66

part and gradually attenuated behind, with the head comparatively of larger
size. Antennae, oral parts, and caudal rami of exactly same structure as in
the female. Legs however very different, the 4 anterior pairs exhibiting quite
a normal structure, with both rami 3-articulate and armed in the usual manner,
being all well adapted for swimming. Last pair of legs very small, knoblike.

Body of female, in the living state, of a light reddish hue, with the
ovarial tubes and the ripe ova of a deep rosy colour.

Length of adult female attaining 4.10 mm., that of male only 1.20 mm.
• Remarks. — The present form cannot be confounded with any of the other
known Notodelphyoidae, being at once recognised by its slender vermiform
body. The specimen described by Thorell as the .male of this species, is
quite certainly not a male, but an immature female, in which the 5th pair of
legs had not yet attained its full development. The form recorded by Hesse
under the name of Coeliacola setifem is apparently identical with the present
species.

Occurrence. — Several female specimens of this peculiar Copepod have
been collected by me at different times and in different places on the Norwegian
coast. They were found in the branchial cavity of several kinds of Ascidians.
Of males I have only as yet come across a single specimen, and this was
not found in Ascidians, but freely among some dredged material obtained at
Drebak, upper part of the Christiania Fjord.

Distribution.— Coasi of Bohuslan (Thorell), British Isles (Brady), coast of
France (Hesse, Canu).

Fam. 5, Botryllophilidae.

General Characters. — Body more or less distinctly segmented, with the
anterior division, as a rule, much broader than the posterior. Ripe ova not
received in any incubatory cavity, but accumulated to form one or 2 free ovi-
sacs appended to the dorsal face of the genital segment. Tail cylindric
in form, and composed of a varying number of segments in the different
genera. Caudal rami armed at the extremity with strong claw-like spines.
Anterior antennae short and compressed, narrowly exerted at the end. Posterior
antennae not prehensile. Oral parts well developed, but rather different
in structure from those in the preceding families. Posterior maxillipeds

67

exceedingly powerful, representing the chief attaching organs of the animal.
The 4 anterior pairs of legs more or less reduced and, as least in female,
quite unsuitable for swimming. Last pair of legs in female transformed
as supports for the ovisacs.

Remarks. — This family is established to include 3 nearly allied genera,
to be treated of in the sequel, that of the earliest date being Botryllophilus
Hesse. The family agrees with the Ascidlcolidce in the presence of free orisacs
in the female, but differs considerably in the structure of the several appen-
dages, the most prominent difference being the transfer of the affixing faculty
to the posterior maxillipeds.

Gen. 12. Botryllophilus, Hesse, 1864.

Generic Characters. — Anterior division of body in female very sharply
marked of from the posterior and rather tumid, carrying at the end, on each
side, the transformed 5th pair of legs. Tail narrow cylindric in form, and
composed of 4 well defined segments. Anterior antennae with the number of
segments rather reduced. Posterior antennae with the middle joint very short,
terminal joint elongate and armed with strong spines. Mandibles with the
masticatory part considerably expanded, palp biramous with the inner ramus
largely developed, the outer very small. Maxillae with the exopodal lobe
obsolete. Anterior maxillipeds comparatively feeble in structure, and divided
inside into a number of digitiform lobes, each tipped with a single curved
spiniform seta. Posterior maxillipeds very powerfully developed, and pro-
nouncedly prehensile, terminating in a claw-like biarticulate digit. The 4
anterior pairs of legs (in female) with the rami short, uni- or biarticulate, the
outer one spiniferous, the inner setiferous. Last pair of legs in female forming
2 narrow setiferous lappets attached to the sides of the last trunkal segment
and extending backwards, encompassing between them the single or double
ovisac. The latter more or less globular in form.

Remarks. — The present genus was established as early as the year 1864
by Hesse, to include a peculiar Copepod (B. ruber) found by him within a
compound Ascidian (Botrylliis). Subsequently 2 forms evidently referable to
the same genus were recorded, the one by Scott from the Scottish coast, the
other by Canu from the French coast. Scott identified, though with some doubt,
the form observed by him with Hesse's species, whereas. Canu regarded his
form as a new species and described it under the name of B. macropus. As

68

the original description and figures given by Hesse are very imperfect, it
remains still questionable, whether the one or the other of these 2 forms should
be regarded as identical with B. ruber Hesse. I should be inclined to believe
that these 3 forms in reality represent as many distinct species. They all
however agree in the peculiar shape of the transformed last pair of legs,
and this is indeed one of the most conspicuous characters distinguishing the
present genus from the other 2 genera treated of in the sequal. Scott has
described the adult male of the species observed by him. It is about half the
size of the female, and differs from it conspicuously, both as regards the general
form of the body and the structure of some of the appendages. Thus the
anterior antennae are densely clothed, especially at the base, with delicate band-
like setae («sthetasks?), and the legs are built on a quite different type, the
4 anterior pairs being apparently well adapted for swimming. A well defined
new species referable to the present genus will be described below.

22. Botryllophilus brevipes, G. O. Sars, n. sp.

(PI. XXXIII)

Specific Characters. — Female. Body comparatively short and stout, with
the anterior division oblong oval in form, and having all the segments con-
fluent, no traces of any dividing sutures being observable. Cephalic part
defined from the trunk above by a very slight depression, and gradually con-
tracted anteriorly, being produced in front to a very small, abruptly deflexed
rostral prominence. Dorsal face of trunk gently vaulted and abruply curved
behind. Tail considerably exceeding half the length of the anterior division,
and perfectly straight; 1st segment much the largest and rather tumid in its
proximal part; anal segment somewhat longer than the preceding one. Caudal
rami short and somewhat curved outwards, being armed at the extremity with
4 strong curved claws. Eye imperfectly developed, though easily observable
in the living animal. Anterior antennae short and compressed, very broad at
the base, but rapidly tapered distally, being composed of only 4 joints sharply
defined from each other, and clothed with a few rigid setae issuing from
knob-like prominences of the edge. Posterior antennae a little longer than the
anterior and abruptly bent in the middle, 1st joint fully as long as the other
2 combined and perfectly smooth; terminal joint linear in form and armed
on the outer edge with 2 strong spines, the obtusely rounded extremity of the
joint carrying 3 somewhat smaller spines followed by 2 slender setae. Mandibles
with the outermost tooth of the cutting edge distinctly bifurcate, palp rather

Notodelphyidae

Copepoda

Notodelphyoida

PI. XVII

e. O. Sars del.

1. Notodelphys rufescens, Thorel

2. ,, caerulaea, Thorell

3. ,, agilis, Thorell

Notodelphyidae

Copepoda

Notodelphyoida

PI. XVIII

e. O. Sars del

1. Notodelphys tenera, Thorell

2. ,, elegans, Thorell

3. „ prasina, Thorell

Notodelphyidae

Copepoda

Notodelphyoida

PI. XIX

i II irm

lW^^.^^A'

/fpiill

6. 0. Sars del.

Agnathaner typicus, Canu

Doropygids

Copepoda

Notodelphyoida

PI. XX

G. O. Sars del.

Doropygus pulex, Thorell

Doropygidae

Copepoda

Notodelphyoida

PI. XXI

G. O. Sars del.

Doropygus psyllus, Thorell

Doropygidae

Copepoda

Notodelphyoida

PI. XXII

G. O. Sars del.

Doropygus porcicauda, Brady

Doropygidae

Copepoda

Notodelphyoida

PI. XXIII

6. O. Sars del.

Doropygopsis longicauda, (Auriv.)

Doropygidae

Copepoda

Notodelphyoida

PI. XXIV

?-

K

-V

CM,

\ ,jlk^<^ 'M.

S\ {S.

2/0- 1/

itfi

-^<^. -ir

■m/i

?

fn,.

/', ■;;,■. : \

■^^^

N

^ ff;

o

%.

n

^.<:^^r^'-^^^^

v_i.,\^

vz-A^

-1

6. O. Sars del.

Doropygella Thorelli, (Auriv.)

Doropyg'da

Copepoda

Notodelphyoida

PI. XXV

A

//

■i

j^'

-^x

\ \

^

^ ^.do.

HS^f

X '' V

■'/

1 /

i %

6. O. Sars del.

Pachypygus gibber, (Thorell)

Doropygida3

Copepoda

Notodelphyoida

PI. XXVI

G. O. Sars del.

Notopterophorus auritus, (Thorell)

Doropygidae

Copepoda

Notodelphyoida

PI. XXVII

6. O. Sars del

Notopterophorus papilio, Hesse

Doropygidae

Copepoda

Notodelphyoida

PI. XXVIII

i-.U

//

{

m

/J

^

i.r

li iiii

G. O. Sars del.

1. Noiopterophorus micropterus, 6. O. Sars

2. Gunentophorus globularis, Costa

Doropygidae

Copepoda

Notodelphyoida

PL XXIX

G O. Sars del.

Botachus cylindratus, Thorell

BuproridaB

Copepoda

Notodelphyoida

PI. XXX

^

/A

?

Uo,

^■:

^

V^^

/ 'i>^ /r*-^

r\.

z-ai^^at

^v'.

'^.

i:^"\

/•'.<..:

vu

V

^

\

'¥\

,..':. //,

4

e. O. Sars del.

Buprorus Loveni, Thorell

Ascidicolidae

Copepoda

Notodelphyoida

PI. XXXI

G. O. Sars del.

Ascidicola rosea, Thorell

Botryllophilidae

Copepoda

Notodelphyoida

PI. XXXII

6. O. Sars del.

Botryllophilus brevipes, 6. 0. Sars

69

large, far exceeding in length the body of the mandible, rami however of very
unequal size, the inner one being much the larger and fully twice as long as the
basal part, proximal joint of this ramus imperfectly defined and without any setae,
distal joint oblong oval in form, and provided with 5 coarse setae, one of which is
attached to the outer edge, the other 4 to the obtusely rounded extremity; outer
ramus attached close to the base of the inner, and forming a small triangular lamella,
edged with 3 plumose setae. Maxillae with the masticatory lobe comparatively
small, with a restricted number of spines; endopodal part with 2 comparatively
short setae inside the base, terminal joint imperfectly defined and edged with
3 similar setae; exopodal lobe obsolete and replaced by 3 short setae attached
to the outer nearly straight edge of the palp, which is produced both prox-
imally and distally to a small knob-like prominence. Anterior maxillipeds with
the basal part imperfectly subdivided, and. exhibiting inside 5 digitiform lobes
and as many curved setae; terminal part small, uniarticulate, with a minute
apical spine and a densely ciliated seta outside the base. Posterior maxillipeds
composed each of a very large and massive basal part divided into 2 segments,
and of a comparatively short, but very mobile biarticulate dactylus curved in-
wards. The 4 anterior pairs of legs much reduced, with both rami quite
short and uniarticulate, the outer one narrow triangular in form, with the inner
edge perfectly smooth, the outer armed with 5 somewhat unequal spines;
inner ramus rounded oval in form and fringed with thickish, sparingly ciliated
setae, the number of which is somewhat varying in the different pairs. Last
pair of legs far less produced than in the other species, and attached to the
sides of the posterior part of the trunk, somewhat nearer the dorsal face;
each having the form of a narrow lanceolate lappet carrying on the tip a
rather strong curved seta accompanied by 2 much smaller bristles, another
still smaller bristle occurring on the upper edge somewhat beyond the middle.
Only a single comparatively large globular ovisac present, attached to the
dorsal face of the genital segment.

Body in the living animal of a pale reddish orange hue, with the ovarial
tubes and the ripe ova bright green in colour. Length of adult female 1.70 mm.

Male unknown.

Remarks. — The above-described species may be easily distinguished from
any of the other forms recorded by the quite unsegmented anterior division
of the body, as also by the poor development of the legs.

Occurrence. — Some few female specimens of this form were found, many
years ago, within the body cavity of a species of Botryllus, taken at Espevaer,
west coast of Norway.

10 — Crustacea.

70

Gen. 13. Pteropygus, G. O. Sars, n.

Generic Characters, — Body (of female) perfectly segmented, with the an-
terior division well marked off from the posterior, but less tumid than in
Botryllophiliis. Tail much narrower than the anterior division, and only com-
posed of 3 segments; caudal rami short, clawed at the end. Antenna and
oral parts of a structure similar to that in Botryllophiliis. The 4 anterior pairs
of legs with both rami short, uniarticulate, the outer one spiniferous, the inner
setiferous. Last pair of legs transformed to 2 large wing-like lamellae encom-
passing the last trunkal segment and meeting each other at the base dorsally,
partly obtecting the single cake-like ovisac.

Remarks.— The present new genus is nearly allied to Botryllophilus, but
differs conspicuously in the perfect segmentation of the anterior division of
the body, the 3-articulate tail, and more particularly in the very unlike appear-
ance of the last pair of legs, which are developed in a somewhat similar
manner to that in the genus Ascidicola. The genus comprises as yet only a
single species, to be described below.

23. Pteropygus vestitus, G. O. Sars, n. sp.

(PI. XXXIII).

Specific Characters.— Female. Body comparatively short and stout, with
the anterior division of nearly equal width throughout, and only very slightly
vaulted dorsally. Cephalic segment scarcely narrower than the succeeding
segment and evenly rounded in front, rostral prominence very slight. Last
trunkal segment well defined and abruptly narrowed behind. Tail about
equalling in length the trunk, and narrow cylindrical in form, with its 3 seg-
ments of nearly equal size. Caudal rami turned straight outwards, and armed
at the end with 4 strong curved claws arranged in pairs. Eye very small.
Anterior antennae short and compressed, broad at the base, but rapidly tapered
distally, being composed of 6 well defined joints clothed in front with numerous
unequal rigid setae. Posterior antennae very like those in Botryllophiliis, last
joint armed with 8 spines, 4 on the outer edge and 4 on the tip. Mandibles
with the 2 outermost teeth of the cutting edge much larger than the others;
palp very large, nearly twice the length of the body of the mandible, and of
a structure very similar to that in Botryllophiliis. Maxilla likewise rather
similar, though having the terminal joint of the palp distinctly defined at the
base. Anterior maxillipeds comparatively more fully developed than in that

71

genus, but built on the very same type. Posterior maxillipeds large and
massive, forming, as in Botryllophilus, the chief attaching organs. The 4 an-
terior pairs of legs very imperfectly developed, outer ramus cultriform, with
6 strong spines outside, inner ramus rather smaller and scarcely lamelliform,
being narrowed distally, and only provided with a restricted number of setae
at the tip. Last pair of legs forming 2 broadly oval lamellae encompassing
the body like a mantle, and extending nearly to the middle of the tail, each
lamella provided at the end below with a small bristle. Ovisac oval, flattened,
and extending almost to the end of the tail.

Colour whitish gray.

Length of adult female 1.80 mm.

Male unknown.

Remarks.— Ih^ above-described form cannot be confounded with any of
the other members of the present family. From the species of the genus
Botryllophilus it is at once distinguished by the very different appearance of
the transformed last pair of legs, in which respect it more resembles the form
next to be described.

Occurrence. — A few female specimens only of this peculiar form have as
yet come under my notice. They were taken at Risdr, south coast of Norway,
and, as far as I remember it, from the branchial cavity of Phallusia obliqua.

Gen. 14. Schizoproctus, Aurivillius, 1885.

Generic Characters. — Body of female fusiform in shape, with thin and
soft integuments and the segments only indicated by slight constrictions; that
of male more distinctly segmented and of extremely small size, as compared
with the female, to the ventral face of which it is found attached. Tail appa-
rently composed of 5 segments, and not very sharply marked off from the
trunk. Caudal rami small, curving outside, and minutely clawed at the end.
Antennae and oral parts built on the same type as in the 2 preceding genera,
but on the whole less fully developed. The 4 anterior pairs of legs very
small, with the rami uniarticulate and nearly of equal structure, both forming
small triangular pieces armed outside with short spines. Last pair of legs
(in female), as in Pteropygus, transformed to broad lamella extending on each
side along the base of the tail and separated dorsally by a deep and narrow
cleft. Ovisac not yet observed.

Remarks. — This genus, established by Aurivillius, is evidently referable
to the same family as the 2 preceding genera, though the outward appearance

74

found to exist, and it therefore may be allowed to include the present family
in the same great division. Moreower in habits these forms agree with the
other Notodelphyoida in so far that they are parasites of the same group"of
animals, viz., the Tunicata. The want of any true masticatory appendages
would seem to prove, that these Copepoda do not feed on any firm particles,
but only on some nourishing fluids licked up from their hosts. In fo far they
present an evident agreement with the poecilostomoiis Cyclopoida, from which
they indeed may be assumed to have been originally derived by a close adaption
to changed conditions of life, just as the other Notodelphyoida in all probabi-
lity by a similar adaption have taken their origin form gimthostonioiis Cyclopoida.
3 genera referable to the present family will be treated of below. Another
genus, Enteropsis, has been established by Aurivillius, and moreover several
of the peculiar forms recorded by Hesse, as found in compound Ascidians, may
in all probability be included in the same family.

Gen. 15. Cryptopodus, Hesse, 1865.

Syn; Aplostoma, Canu.

Generic Characters. — Body of female oblong, more or less curved ven-
trally, with the anterior division well marked off from the posterior and
terminating behind on each side in a short rounded lobe (the transformed 5th
pair of legs), the last 2 trunkal segments coalesced. Tail very small and
imperfectly segmented. Posterior antennae smaller than the anterior ones, distal
joint sublinear and minutely denticulate outside. Oral aperture forming a
transverse fissure limited in front by a slightly prominent bell-shaped anterior lip.
Maxillae only present as a very trifling rudiment on each side of the oral
aperture. Maxillipeds comparatively small, biarticulate, and terminating in a
minute hook. The 4 anterior pairs of legs very imperfectly developed, basal
part not distinctly defined, rami confluent at the base, the outer one forming
a simple rounded lobe, the inner knife-shaped, with a few short denticles inside.
Last pair of legs having the appearance of 2 simple conical lobes projecting
on each side somewhat dorsally from the last trunkal segment. Ovisacs large,
cylindrical in form.

Remarks. — This genus was established in the year 1865 by Hesse, but
very imperfectly characterised, and on that account it was not recognised by
subsequent authors. I think however I am right in identifying the genus
Aplostoma of Canu with Hesse's genus. In any case the generic name pro-
posed by Canu cannot be supported, as it has been long ago preoccupied.

75

The genus is prominently characterised by the small size of the posterior
antennae and the imperfect development of the oral parts, as also by the
structure of the legs. Hesse records 2 species of this genus, C. flavus and
viridis, none of which seems to be identical with the 2 Norwegian species
here described.

25. Cryptopodus brevicauda, (Canu)

(PI. XXXV)
Aplostoma brevicauda, Caiin, Copepodes cle Boulonnais, p. 223, PI. XX, figs. 5—18.

Specific Characters. — Female. Body rather slender, with the anterior
division nearly cylindrical in shape, though gradually narrowed in its anterior
part; limits of the segments indicated by well-marked constrictions. Cephalic
segment comparatively small and less distinctly defined, terminating in front
in a minute tuberculiform prominence. Tail very short, scarcely exceeding in
length \/6 of the anterior division, and only composed of 2 distinctly defined
segments, the 1st rather broad at the base and rapidly tapered distally, the
2nd very small. Caudal rami somewhat divergent, each with a minute bristle
in the middle of the outer edge and another still smaller one at the apex.
Anterior antennae conical in form and apparently, composed of 4 joints, the
outer 3 quite short and clothed with small bristles. Posterior antennae much
smaller than the anterior, with the distal joint narrow linear in form and armed
outside with 4 minute denticles. Anterior lip with the hind edge quite smooth.
Ovisacs fully as long as the entire body, cylindrical in form, and more or less twisted.

Body of the living animal rather opaque, of a pale rosy colour, with the
ovarial tubes of a somewhat darker hue.

Length of adult female 2.50 mm.

Remarks.— Th& above-described form is unquestionally identical with that
recorded by Canu as the type of his genus Aplostoma. Canu has also ob-
served the male of this species, and has given good figures of it in the above-
quoted work.

Occurrence. — Some few female specimens of this peculiar Copepod were
taken, many years ago, at Espevaer, west coast of Norway. They were found
in the compound Ascidian, Polycllnum luteiim, lying within a diverticle of the
branchial sac of the Zooids.

Distribution.— Coast of France (Canu).

76

26. Cryptopodus eruca, (Norman).

(PI. XXXV, 2)

Enterocola eruca, Norman, Last Shetland dredging Report, p. 300.

Specific Characters. — Female. Body resembling in shape that of the
preceding species, but (in the specimens observed) more strongly curved and
with the constrictions between the segments deeper. Tail comparatively still
smaller than in C. brevicaiida, with the caudal rami much shorter and without
any bristles. Anterior antennae apparently only composed of 3 joints. Posterior
antennae comparatively stouter than in that species, with the distal joint coarser
and only armed with 3 short denticles outside. Anterior lip with the posterior
edge divided into 6 very conspicuous tooth-like processes, 2 mediate and 2
on each side near the outer corner. The other appendages scarcely differing
in structure from ^those in C. brevicauda. Ovisacs of quite an extraordinary
length, being more than 3 times as long as the body, and of narrow cylin-
drical form.

Colour of the living animal not yet ascertained.

Length of adult female 2.30 mm.

Remarks. — My identification of the above-described form with Norman's
Enterocola eruca is only based on its occurrence in the same host. For the
remarks given by Norman are much too scanty for allowing any more exact
comparison. It is undoubtedly congeneric with Canu's species, but differs con-
spicuously in the structure of the anterior lip, and more particularly in the
enormous development of the ovisacs.

Occurrence. — Two female specimens, the one ovigerous, of this form were
taken, many years ago, from as many specimens of Styela intesiinalis collected
in the upper part of the Christiania Fjord. Norman also obtained his speci-
men from the same Ascidian.

Distribution. — Shetland Isles (Norman).

Gen. 16. Enterocola, v. Benden 1860.

Generic Characters. — Body (of female) more or less slender, with the
anterior division well marked off from the posterior and divided by slight
constrictions into the normal number of segments. Tail more perfectly
segmented than in C/yptopodus. Anterior antenna very small. Posterior
antennae much larger, with the terminal joint lamellar and fringed at the end
with spines or setae. Anterior lip rounded. Maxillae and maxillipeds rather

77

coarsely built, the former terminating in a stout conical process turned obliquely
inwards, and having outside a scale-like palp edged with coarse spines; the
latter imperfectly prehensile, with the distal joint produced at the end into 2
coarse spines. The 4 anterior pairs of legs more perfectly developed than in
Cryptopodus, the basal part being well defined and biarticulate; rami compar-
atively small, uniarticulate, the outer one simple mucroniform, the inner lamel-
liform and provided at the end with 2 setae; between each pair of these legs a
thin connecting plate present, of different form in the different species. Last pair
of legs transformed to 2 rather large curved lamellae projecting on each side
from the hind end of the trunk, and separated dorsally by a narrow cleft.
Ovisacs less produced than in the preceding genus.

Remarks. — This genus was established as early as the year 1860 by v.
Ben^den, and ought of course to be considered as the type of the present
family. It differs conspicuously from the preceding genus, especially as regards
the structure of the posterior antennae and the oral parts. Moreover the legs
are built on a somewhat different type, and the transformed last pair bear an
evident ressemblance to those m some of the Botryllophllldce (Pteropygus,
Schizoproctus). A quite peculiar character of this genus is also. found in the
presence of a well-marked connecting plate between each pair of the 4 anterior
pairs of legs. Two species of the present genus have been formerly recorded,
viz., E. fiilgens v. Beneden and E. Betencourti Canu. The Norwegian form
described below cannot be referred to any of these 2 species.

27. Enterocola bilamellata, G. O. Sars, n. sp.

(PI. XXXVI, 1)

Specific Characters. — Female. Body comparatively slender, with the an-
terior division almost perfectly cylindrical in shape, being scarcely at all narrowed
in front. Cephalic segment nearly as large as the succeeding segment, and
terminating in a blunt rostral prominence. Tail nearly attaining in length Vs
of the anterior division and rather swollen at the base, being composed of 4
well defined segments gradually narrowed behind. Caudal rami about the
length of the last 2 segments combined and rather narrow, without any arm-
ature whatever. Anterior antennae comparatively small, conical in form, and
apparently composed of 4 joints, the 1st much the largest, the last very small,
tuberculiform, without any bristles. Posterior antennae with the distal joint
remarkably large, forming a recurved oblong or linguiform plate divided at the
end into 7 thin setiform appendages of unequal length. Maxilles with a

11 — Crustacea.

78

small bispinose lappet inside turning towards the mouth, terminal prominence
very coarse, resembling somewhat in shape the molar process of the mandibles
in higher Crustacea ; palpe sub-spatulate in form, and armed on the broadly
rounded terminal edge with 5 coarse spines of equal size. Maxillipeds short
and stout, with a small conical process inside the large proximal joint; distal
joint strongly chitinised, incurved, and projecting at the end into 2 coarse and
somewhat unequal spiniform processes. The 4 anterior pairs of legs of essentially
same structure, 2nd basal joint well defined from the 1st and projecting outside
in a small, knob-like prominence ; inner ramus oval in form, with the 2 apical
setae rather slender and considerably exceeding the ramus in length; connecting
plate between these legs divided by a deep incisure into 2 rather prominent lingui-
form lamellae. Last pair of legs obliquely oval in form and slightly upturned,
advancing on each side somewhat over the base of the tail, each having on the
posterior edge 2 small bristles. Ovisacs not present in the specimen examined.

Colour of the living animal not yet ascertained.

Length of the body 2.60 mm.

Male unknown.

Remarks.— The above-described form is unquestionably referable to the
genus Enterocola of v. Beneden, but differs from the 2 other known species
by the comparatively narrow cylindrical form of the anterior division of the
body, as also in the structure of the posterior antennae and oral parts. Another
character by which this form is easily recognised is the peculiar bilamellar
shape of the connecting plates between the 4 anterior pairs of legs. The
specific name here proposed alludes to this character.

Occurrence. — A solitary specimen only of this form, an apparently fully
grown female, but without ovisacs, has as yet come under my notice. It
was found in a bottom-sample taken at Farsund, south coast of Norway, from
a depth of about 40 fathoms, and had undoubtedly by some accident been
thrown out from its abode within some compound Ascidian.

Gen. 17. Mycophilus, Hesse, 1865.

Generic Characters. — Body of female soft, vermiform, and more or less
strongly curved dorsally, with no sharp demarcation between the anterior and
posterior divisions. Trunkal segments indicated by slight constrictions of the
body. Tail however not at all segmented, sac-like, with 2 very small
lamellae (the caudal rami) on the blunted extremity. Anal orifice not, as usual.

79

occurring at the end of the tail between these lamellae, but transferred far in
front on the dorsal face of the body, on which account the posterior part of the
intestinal canal forms a peculiar coil within the caudal part. Antennae and oral
parts very imperfectly developed and densely crowded. Only 4 pairs of rudimentary
legs present, the 5th pair being wholly absent. Ovisacs not yet observed.

Remarks.— This is one of the many genera established by Hesse for the
peculiar parasites obtained by him from compound Ascidians. Indeed some of
the characters distinguishing the present genus are so strange, that it could seem
somewhat questionable if it might be included in the same family with the 2
preceding genera. Yet, some points of agreement are found to exist with the
genus Enteropsis of Aurivillius, which is regarded as a true Enterocolid. The
genus as yet only comprises a single species, to be described below.

28. Mychophilus roseus, Hesse.

(PI. XXXVI, 2)

Mychophilus roseus, Hesse, Recherches sur les Crustac^s tares on noiiveaiix des cotes de France.
Ann. d. sci. nat. Zoologie, Ser. 5, Vol. IV.

Syn : Enteropsis wararensis, Scott.

Specific Characters.— Female. Body slender, cylindrical in form, though
having its posterior part always strongly curved dorsally. Cephalic segment
comparatively small and somewhat contracted in front, terminating in a very
minute knob-like rostral prominence. Trunkal segments only faintly marked,
the last one confluent with the tail. Caudal part of body nearly occupying
half the entire length, and scarcely at all narrower than the anterior division,
its extremity bluntly rounded and carrying 2 very small blade-like caudal rami.
Anal orifice occurring nearly in the middle of the dorsal face of the body,
and defined by 2 distinctly projecting lips. Posterior part of the intestine rather
narrow and forming a more or less deep coil within the tail, ascending along
its dorsal face to the anal orifice. Anterior antennae very small, and apparently
only composed of 2 joints. Posterior antennae with the distal joint abruptly
recurved and terminating in an acute point. Maxillae of a somewhat similar
shape, but provided with a small lateral appendage (palp). Maxillipeds poorly
developed, imperfectly articulate, and terminating in a very small hook-like
point. Legs of uniform appearance, forming simple conical prominences extend-
ing laterally and each terminating in 2 very minute chitinous pieces (rudiments
of rami). Ovisacs not yet observed.

Colour of the living animal pale rosy.

80

Length of adult female 1.50 mm.

Male unknown.

Remarks. — The figure given by Hesse does not leave any doubt on the
identity of the above-described form with that observed by him, and it is like-
wise quite certain that the form recorded by Scott under the name of Enter-
opsis wararensis is the same species. Its very peculiar outward appearance
renders it indeed easily recognisable from any other members of the present
family.

Occurrence. — Some female specimens of this peculiar Copepod were ob-
tained, many years ago, at Espevasr, west coast of Norway. They were found
in a species of Botrylltis, taken up from a depth of about 20 fathoms.

Distribution. — Coast of France (Hesse), Scottish coast (Scott).

Supplement.

Gen. Buprorus, Thorell.

(See p. 61)

Of this remarkable genus, hitherto only represented by a solitary species,
B. Loveni Thorell, 1 have recently had an opportunity of examining a well
defined new species, to be described below.

29. Buprorus Nordgaardi, G. O. Sars, n. sp.
(PI. XXXVIl, 1.)

Specific Characters. — Female. Body exhibiting the short bag-like form
characteristic of the genus, though having the cephalic part considerably more
exerted, and the posterior part, limiting the incubatory cavity, greatly expanded
and broadly rounded off behind. Dorsal face of trunk exhibiting throughout
a dense clothing of small scale-like prickles. Anterior antennae resembling in
shape those in B. Loveni, being however divided into 7 well defined joints
clothed in front with rather strong and somewhat unequal curved setae, the 3
outermost joints much smaller than the others. Posterior antenna with the
terminal joint nearly as large as the middle one and armed on the transversely
truncated extremity with a stout spine followed by 4 somewhat curved setae.

_^1

Mandibles considerably stronger than in the type species, with 'the palp well
defined, conical in form, and provided at the tip with 2 unequal setae. Maxillae
and posterior maxillipeds nearly as in B. Loveni. Anterior maxillipeds, however,
somewhat different, being comparatively more powerfully developed, with only
a single bispinose lobe inside, and the terminal part undivided, claw-like,
carrying outside, about in the middle, a bundle of 3 curved setae. Legs on
the whole less robust than in the type species, with the rami narrower and
the spines on both of them uniseriate and much more slender, nearly setiform,
2 of them attached outside the terminal joint of the outer ramus; 4th pair
smaller than the preceding ones, and having the number of spines consider-
ably reduced. Last pair of legs about as in B. Loveni, but with the apical
spines more slender.

Colour of the living animal not yet ascertained.

Length of adult female scarcely exceeding 0.70 mm.

Male unknown.

Remarks. — The above-described form is unquestionably referable to the
genus Biipronis of Thorell, but differs from the type species decidedly both
as regards the general shape of the body and in the structure of some of the
appendages, as indicated in the above diagnosis. It is also of much inferior size.

Occurrence. — 2 female specimens of this form, the one with the incubatory
cavity filled with embryos in the last (Nauplian) stage, were found in a small
compound Ascidian (Amoroecium) taken by Mr. O. Nordgaard in the Trondhjem
Fjord and kindly sent to me for examination together with other kinds of
Ascidians. The species is named in honour of that distinguished naturalist,
who also otherwise has assisted me in my investigation of the Norwegian
Copepoda.

Fam. Anomopsyllidae.

Gen. Anomopsyllus, G. O. Sars, n.

Generic Characters. — Body (of female) divided into 3 sharply defined
sections: head, trunk and tail. Head comparatively small, triangular in form.
Trunk rather tumid and without any distinct segmentation. Tail comparatively
short and much narrower than the trunk, terminating in 2 diverging caudal

82

rami provided with the usual number of setcE. Antennse attached close together,
the anterior ones slender, multiarticulate, the posterior ones much smaller and
not prehensile. Oral parts imperfectly developed, except the posterior maxillipeds,
which are of a very peculiar structure and apparently prehensile, terminating
in a narrow and very mobile digit minutely clawed at the tip. Only 3 pairs
of legs present, all very imperfectly developed, forming small and simple tri-
angular lamella without any armature whatever. 2 ovisacs present in female
attached to the sides of the genital segment.

Remarks.— \i is very questionable, if this remarkable genus at all is refer-
able to the Notodelphyoida, and it is only provisionally recorded here, as I
am at present unable to determine with certainty its true systematic position.
In any case it ought to be regarded as the type of a quite distinct family,
AnomopsylUdce. The genus is founded on a single species, to be described below.

30. Anomopsyllus pranizoides, G. O. Sars, n. sp.
(PI. xxxvn, 2)

Specific Characters. — Female. Body moderately slender, exhibiting in its
general outline a perplexing similarity to a Praniza. Head rather small and
produced in front to a beak-like prominence, its lateral edges abruptly curved
behind. Trunk oblong oval in form, somewhat narrower in front than behind,
posterior extremity very slightly emarginated in the middle, with the lateral
corners evenly rounded off. Tail scarcely exceeding in length V^ of the trunk,
and apparently only composed of 3 segments, the 1st, or genital one, being
rather tumid at the base; anal segment larger than the middle one and not
dilated distally. Caudal rami narrow, sublinear in form, and considerably diver-
ging, being about as long as the anal segment, each carrying at the tip 4
setae, the 2 middle ones rather slender and abruptly bent outwards, the other
2 very small; seta of outer edge attached about in the middle. Anterior an-
tennae comparatively slender and attenuated, fully attaining the length of the
head, and composed of 7 joints clothed with a few slender setae. Posterior
antennae scarcely exceeding in length V^ o^ the anterior, and composed of 3
nearly equal-sized joints, the last one tipped with a number of somewhat un-
equal setae. Oral area exhibiting in the middle a rather wide hollowed space
limited in front by a slightly curved projecting border, probably answering the
anterior lip, and behind by a narrow oblong triangular plate (metastome).
Mandibles and maxillae undistinguishable, being replaced by an irregularly
twisted chitinous frame limiting the above-mentioned hollowed space on each

83

side and sending off inwards 2 short prominences. Anterior maxillipeds very
little prominent, and of a somewhat pyriform shape, converging anteriorly, and
each terminating in a knob-like point closely applied to the anterior extremity
of the metastomal plate. Posterior maxillipeds freely projecting and rather
fully developed, but very unlike in structure those in other Copepoda, being
doubly geniculate and composed of 4 joints, the 2nd of which is very large
and lamellarly expanded inside; last 2 joints much narrower and forming to-
gether a slender very mobile digit, which is allowed to impinge against the
inner sharpened edge of the preceding joint; proximal joint of this digit un-
armed, distal joint somewhat attenuated and armed at the tip with 2 very small
claws and, at some distance from the extremity, with another somewhat stronger
claw. Legs with a slight indication to a division in a basal and terminal part,
the latter exerted to an obtuse point without any traces of spines or setae;
1st pair somewhat larger than the other 2, which successively diminish in size.
Ovarial tubes in the specimen examined very conspicuous, extending through-
out the greater part of the trunk, 2 tubes present on each side connected
behind by a narrow commissure. Ovisacs broken off in the specimen exam-
ined, though indicated by a trifling piece of their coating still adhering to
each side of the genital segment.

Colour of the living animal not yet ascertained.

Length of the specimen examined about 3 mm.

Male unknown.

Remarks.— The above-described form may be at once recognised from
any of the hitherto known Copepoda. Indeed, the curious similarity it exhibits
in the general outline of the body with a Praniza is very striking, and has
given rise to the specific name here proposed. On the parasitic nature of
this Copepod, no doubt can arise.

Occurrence— k solitary specimen of this remarkable Copepod was found,
detached from its host, in a bottom-sample taken in the upper part of the
Christiania Fjord. In the same sample several other invertebrate animals were
contained, among them also some Annelids, and it seems to me not improb-
able, that the present Copepod had originally been attached to one of these
Annelids.

BIBLIOGRAPHY.

Monstrilloida.

Aiirivlllius, C. W. S. Vergl. thiergeogr. Untersuchungen uber die Plankton-
Fauna des Skageraks. K. Sv. Vetensk. Akad. Handl., Vol. 30.
1898.

Bourne, G. C. Notes on the genus Monstrilla, Dana. Qu. Journ. Micr. Sc. 2.
Vol. 30, 1890.

Breemen, Haag van. Nordisches Plankton. Copepoden 1908.

Caiman, W. T. A Treatise of Zoology. Appendiculata, Part. 3. Crustacea, 1909.

Claparede, A. R. Ed. Beobachtungen uber Anatomic und Entwickelungs-
geschichte wirbelloser Tiere an der Kiiste von Normandie an-
gestellt. 1863.

Clans, C. Die freilebenden Copepoden, mit besonderer Beriicksichtigung

der Fauna Deutschlands, der Nordsee und des Mittelmeeres. 1863.

Dana, J. D. Crustacea U. S. Expl, Exp. during the years 1838—42. 1855.

Giesbrecht, W. Pelagische Copepoden des Golfes von Neapel. Fauna & Flora
Golf. Neapel, Vol. 19. 1892.

Kroyer, H. Crustaces, in Gaimard, Voyage en Scandinavie etc. Atlas. 1845.

— Karcinologiske Bidrag. Nat. Tidsskr. Kjabenhavn. Vol. 20. 1849.
Lubbock, J. Description of eight new species of Entomostraca found at

Weymouth, Ann. Mag. Nat. Hist. (2) Vol. 20. 1857.
Malaquin, A. Parasitisme et evolution de deux Monstrillidae a I'interieur du
systeme vasculaire des Filogranes et Salmacynes. C. R. Acad.
Sc. 1896.

— Evolution des Monstrillides, C. R. Ac. Sc. 1897.

— Nouvelles recherches sur revolution des Monstrillides, C. R. Ac.
Paris. 1900.

12 — Crustacea.

86

Malaquin, A.
MObius, K.

Nordgaard, O.

Le parasitisme evolutif des Monstrillides. Arch. Zool. Exp. (3),

Vol. 9. 1901.

Syst. Darstellung der Thiere des Plankton gewonnen in der

westlichen Ostsee und auf eine Fahrt von Kiel in dem Atl.

Ocean. 5 Ber. Komm. wiss. Unters. Deutsch, Meere. 1887.

Unders0gelser i Fjordene ved Bergen 1899. Bergen Mus.

Aarbog. f. 1900.
Norman, A. M, & Scott, T. The Crustacea of Devon and Cornwall. 1906.
Poppe, S. A. Zur Literatur des genus Monstrilla, Dana. Nat Ver. Bremen.

Vol. 12. 1891.

Notes on Gatherings of Crustacea collected by the Fishery

Steamer "Garland" during the year 1901. 20th Ann. Rep. F.

B. Scotland. 1902.

Notes on some rare and interesting Marine Crustacea. 22th

Ann. Rep. F. B. Scotland. 1904.
Copepoda of Madeira and the Canary Islands. Journ. Linn.

Soc. London Vol. 20. 1888.

Monstrilla and the Cymbasomatidae. Trans. Biol. Soc. Liver-
pool. Vol. 4. 1890.

Beitrage zur Fauna der siidostlichen und ostlichen Nordsee.

Wiss. Meeresuntersuchungen. Vol. 1. 1896.

Scott, T.

Thompson, J. C.

Timm, R.

Notodelphyoida.

Allman. Description of a new genus and species of Entomostraca.

Ann. Mag. Nat. Hist., ser. 1. Vol. XX. 1847.

— On the development of Notodelphys, a new genus of Entomos-
traca. Rep. Brit. Assoc. 1847

Aurivillius, C. W. S. Bidrag til Kannedomen om Krustaceer, som lefva hos
Mollusker ock Tunicater. Akad. Afhandl. 1883.

— Krustaceer hos arktiske Tunicater. Vega Expeditionens vetensk.
lagttagelser. Vol. IV. 1885.

Beneden, P. J. van. Sur un nouveau genre de Crustace Lerneen. Bull. Acad.
Belg. ser. 2. Vol. IX. 1860

87

Brady, G. S.
Buchholz.

Canu, E.

Claus, C.

Costa, 0. G.
Delia Valle.

Giesbrecht. W.

Hesse.

Kerschner.

Norman, A. M.

Norman, A. M
Scott, T.

Thorell, T.

Monograf of the free and semiparasitic Copepoda of the Brit.
Isl. Ray Soc. London. Vol. 1. 1878.

Beitrage zur Kenntniss der innerhalb der Ascidien lebenden
parasitischen Crustaceen des Mittelmeeres. Zeitschr. f. wiss.
Zool. Vol. XIX. 1869.

Description de deux Copepodes nouveaux parasites des Syna-
scidies. Bull, scientif. Vol. XVII. 1886.
Sur quelques Copepodes semiparasites du Boulonnais. Compt.
rend. Acad. Paris. Vol. CXIII. 1891.
Les Copepodes de Boulonnais. 1892.

Ueber den Bau von Notodelphys ascidicola. Wiirzb. naturwiss.
Zeitschrift. Vol. 1. 1860.

Fauna del Regno di Napoli. Entomostraca. 1852.
Sui Copepodi che vivono nelle Ascidie coijiposta del Golfo di
Napoli. Akad. d. Linsei, ser. 3. Vol. XV. 1883 1).
Zur Kenntniss einiger Notodelphyiden. Mitt. zool. Stat., Neapel.
Vol. III. 18821).

Recherches sur les Crustaces rares ou nouveaux des cotes de
France. Ann. d. sc. nat. Zoologie, ser. 5. Vol. 1, IV, VI, XI.
1864—81.

Ueber zwei neue Notodelphyiden. Denkschr. d. k. k. Akad.
Wiss., Wien. Vol. XLI. 1897 1).

Last Report on Dredging among the Shetland Isles. Rep. Brit.
Assoc. 1860.

, & Scott, T. The Crustacea of Devon and Cornwall. 1906.
Notes on Gatherings of Crustacea. 19th Ann. Rep. of the
Fishery Board for Scotland. Part III. 1901.
Bidrag til Kannedomen om Krustaccer som lefva i Arter af
slagtet Ascidia. K. Sv. Vetensk. Akad. Handl. Vol. III. 1860.

1) I have not had an opportunity of consulting these papers.

SYSTEMATIC LIST

OF THE SPECIES DESCRIBED IN THE PRESENT VOLUME.

Monstrilloida.

Monstrlllolda cyclopimorpha.
Thaumatopsyilidae.

Thaumatopsyllus, G. O. Sars.
paradoxus, G. O. Sars.

Monstrilloida genuina.
Monstrillidss.

Monstrilla, Dana.

longicornis, Thompson.
longiremis, Giesbrecht.
clavata, G. O. Sars.
leucopis, G. O. Sars.
gracllicauda, Giesbrecht.
helgolandica, Glaus.
senicornls, G. O. Sars.

Cymbasoma, Thompson.
rigidum, Thompson.
Thompsoni, Giesbrecht,
longLspinosum, Bourne.

Monstriliopsis, G. O. Sars.
dubia, Scott,

Notodelphyoida.

Notodelphyldse.

Notodelphys, Allman.

Allmani, Thorell.

mfescens, Thorell.

caerulea, Thorell.

agllis, Thorell.

tenera, Thorell

elegans, Thorell.

praslna, Thorell.
Agnathaner, Canu.

typicus, Canu.

DoropygidaB.

Doropygus, Thorell.
pulex, Thorell.
psyllus, Thorell.
porcicauda, Brady.

Doropygopsis, G. O. Sars.
longicauda, Aurivillius,

Doropygella, G. O. Sars.
Thorelli, Aurivillius.

90

Pachypygus, G. O. Sars.

gibber, Thorell.
Notopterophorus, Costa.

auritus, Thorell.

papilio, Hesse.

microptems, G. O. Sars.
6unentophoru8, Gosta.

globularis, Costa.
Botachus, Thorell.

cylindratus, Thorell.

Buproridse.

Buprorus, Thorell.
Loveni, Thorell.
Nordgaardi, G. O. Sars.

AscidicolidaB.

Ascidicola, Thorell.
rosea. Thorell.

Botryilophilidae.

Botryllophilus, Hesse.

brevipes, G. O. Sars.
Pteropygus, G. O. Sars.

vesiitus, G. O. Sars.
Schizoproctus, Aurivillius.

inflatus, Aurivillius.

Enterocolidae.

Cryptopodus, Hesse.

brevicauda, Canu.

eruca, Norman.
Enterocola, v. Beneden.

bilamellata, G. O. Sars.
Mycophilus, Hesse.

rose us, Hesse

Anomopsyllidse.

Anomopsyllus, G. O. Sars.
pranizoides, G. O. Sars.

INDEX.

Page.

Agnathaner 38

typicus 39

Anomopsyllidce 81

Anomopsylliis 81

pranizoides 82

Aplostoma 74

brevicauda 75

Ascidicola 64

rosea 64

Bonnierilla 41, 57

Botachus 59

cylindratus 59

fusiformis 59

Botryllophilidoe 66

Botryllophilus 67

brevipes

macropus 67

ruber 67

Bnproridce 61

Buprorus 61

Loveni 62

Nordgaardi

Coeliacola .64

setigera 64, 66

Cryptopodns 74

brevicauda 75

eriica 76

flavus 75

viridis 75

Cymbasoma 9, 19

longispinosiim 23

rigidum 20

Thompsoni 22

Doroixys 41

Doropygella 49

Thorelli 49

Doropygidce 40

Doropygopsis 46

longicauda 47

Doropygiis 42

auritus 53

Page.

gibber 51

longicauda 47

Normani 45

porcicauda 45

psyllus 44

pulex 42

pullus 42, 43

Thorelli 49

Enterocola 76

betencourti 77

bilamellata 77

eruca 76

fulgens 77

Enterocolidce 73

Enteropsis 74

wararensis 79

Goniodelphys 41, 51

Gunentophorus 56

globularis 57

Haemocera 19

Danae 20

Monstrilla 10

anglica 16

clavata 14

Danae 22, 24, 27

dubia 26

gracilicauda 16

grandis 15

helgolandica 17

intermedia 11

leiicopis 15

longicornis 11

longiremis 13

longispinosa 23

rigida 20

serrlcornis 18

viridis 8

Monstrillidce 7

Monstrilloida 3

M. cyclopimorpha 4

M. genuina 7

Page.

Monstrillopsis 25

dubia 26

Mycophilus 78

roseus 79

Notodelphyidce 29

Notodelphyoida 28

Notodelphys 30

agilis 35

ascidicola 33

Allmani 31

caerulea 34

elegans 37

mediterranea 31, 33

rufescens 33

prasina 37

pusilla 37

tenera 36

Notopterophorus 52

auritus 53

elongatus 55

micropterus 56

papilio 55

Pachypygus 51

gibber 51

Pteropygus 70

vestitus 70

Schizoproctus 71

inflatus 72

Sphaeronotus 56

Thorelli 57

Thaumaleus 8, 9, 10, 19

Ciaparfedi 20

germanicus 20

longispinosus 23

rigidus 20

Thompsoni 22

typicus 8

Thaumatopsyllidce 4

Thaumatopsyllus 4

paradoxus 5

Botryllophilidae

Copepoda

Notodelphyoida

PL XXXIII

a.''^

L /ci$

^

\\

^■

k/V \

A :}

'%

\

(V

I

X

,^

r^

0. O. Sars del.

Pteropygus vesiitus, 6. 0. Sars

Botryllophilidae

Copepoda

Notodelphyoida

PI. XXXIV

''^'% % %

f.

^^®ui^

i

/'^

^

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^■'^■'^ /7lf^

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6. O. Sars del.

Schizoproctus inflatus, Auriv.

Copepoda

Enterocolidffi Notodelphyoida PI. XXXV

n-

6. O. Sars del.

rtt'fi

■y I'-i^xs

1%

c/^ '% •f.^-.n.=^^;

Mv

1. Cryptopodus brevicauda (Canu)

2. „ eruca (Norman)

Enterocolida

Copepoda

Notodelphyoida

PI. XXXVI

A en n-f'taU

6. O. Sars del.

1. Enterocoia bilamellata, G. O. Sars

2. Mychophilus roseus, Hesse

Copepoda

Buproridffi Anomopsyllidae Notodelphyoida

PI. XXXVII

\

\X

;\^ ^'''

i\

.r\

G. O. Sars del.

1. Buprorus Nordgaardi, 6. O. Sars

2. Anomopsyllus pranizoides, 6. O. Sars

AN ACCOUNT

OF THE

CRUSTACEA

OF

NORWAY

WITH SHORT DESCRIPTIONS AND FIGURES OF ALL THE SPECIES

BY

G. 0. SARS

PROFESSOR OF ZOOLOQY AT THE UNIVERSITY OF OSLO

VOL. IX

OSTRACODA

WITH 119 AUTOTYPIC PLATES

BERGEN
PUBLISHED BY THE BERGEN MUSEUM

SOLD BY

ALB. CAMMERMEYERS FORLAG, OSLO

1928

BERGEN. A/S JOHN GRIEGS BOKTRYKKERI

PREFACE.

Professor Georg Ossian Sars died after some weeks of ill-health on
April 9, 1927; on the 20th of the same month he would have filled his
ninetieth year. Among his papers were found the manuscript and the drawings
to Parts XV and XVI, which were intended to form the conclusion of
Volume IX, Ostracoda. Professor Sars had also written the 'Systematic List'
and the 'List of Plates' of this volume.

The proofs of Parts XV & XVI have been read by Mr. Sigurd Johnsen
(Zool. Dept., Bergen Museum), who has also prepared the Alphabetical Index
to Vol. IX. Mr. Johnsen wants to remark that in a few cases the names as
written in the manuscript of Syst. List differ from those used previously in the
text; in 'List of Corrections' these cases are noted together with some misprints
which were observed when preparing the index.

During his long and industrious life Professor Sars worked in many
branches of marine zoology (Whales, Fishes, Mollusks etc.) and ^everywhere
with singular success; in later years his special studies centred in the vast
field of the Crustacea. The first parts of "An Account of the Crustacea of
Norway" were published in 1890. Though Sars did not reach to complete
this work, the nine volumes published, comprising abt. 2400 pages of text and
more than 1100 plates, will always remain a standard source of knowledge to
all students of this group and a monument to the genius of G. O. Sars. The
Board of Directors of the Bergen Museum is proud of having been the medium
of presenting this work to the scientific world.

Bergen, January, 1928.

CORRECTIONS.

Page 97. Cypria opthalmica, read ophihalmica.
„ 109. Iliocyprella is in Manuscript Syst. List written Ilyocyprella.
„ 148. Llmnicy there (Limnicytherince) is in Man. Syst. List, written Lim-

nocythere (-ince).
„ 171. Leptocythera n. g., read Leptocy there n. g.
„ 194. Cythereis echinata, PI. LXXXIX, read PI. XC.
,, 195. Cythereis diinelmensis, PI. XC, read Pi. LXXXIX.

(From comparison oi the plates with the descriptions of these
two species, and also with Norman's figure of C. diinelmensis in
Nat. Hist. Trans. Northumb. & Durham, Vol. I, PI. VII, Figs. 1—4,
it is evident that the text on the plates are correct, the reference
number wrong; corrected by me in List of Plates).
PI. XLVL Jurine, read (O. F. Mulier).
„ C. Cythenirce dathrata, read Cytherura clathrata.

S. J.

PRINCIPAL WORKS ON OSTRACODA.

Aim, G. Monographic der Schwedischen Siisswasser-Ostracoden. 1915.

Balrdy W Natural history of the British Entomostraca. 1850.

Bosquet, J. Eiitomostraces fossiles des terrains tertiaires de la France et

de la Belgique. 1852.
Brady, G. S. Monograph of the recent British Ostracoda. 1866.

— Report on the voyage of "Challenger", Vol. 1, Part 3, Ostra-
coda. 1880.

— Many other publications both on indigenous and foreign
Ostracoda.

Brady, Crosskey & Robertson. Monograph of the post-tertiary Entomostraca

of Scotland. 1874.
Brady & Norman. Monograph of the marine and freshwater Ostracoda of the

north Atlantic and the north-western Europe. Part I. Podo-

copa. 1889.

Do, Part II. Myodocopa, Cladocopa, Platycopa. 1896.
Clans, C. Die Halocypriden des Atlantischen Oceans und Mittelmeeres.

1891.

— Beitrage zur Kenntniss der Siisswasser-Ostracoden. 1892.
Costa, O. G. Fauna del regno di Napoli. Crostacei. 1845.

Daday, E. v. Die Siisswasserfauna Deutsch Ost-Afrikas. 1910.

Dahl, F. Die Cytheriden der westlichen Ostsee. 1888

Dana, J. United States Exploring Expedition. Crustacea. 1853.

Bkman, S. Beitrage zur Kenntniss der Siisswasser-Ostracoden. Zool. Jahrb.

1912.
Fischer, S. Ueber das Genus Cypris und dessen in der Umgegend von St.

Petersburg vorkommenden Arten. Mem. Sav. etr. Vol. 7. 1851.
Hartwig, W. (Several papers relating to the gen. Candona inserted chiefly

in the Zool. Anzeiger.)

VIII

Jones, J. H.
J urine, L.

Kaufmann, A.

Koch, C. L.
Lilljeborg, W.
Mast, L.
Mailer, G. W.

Mailer, O. Fr.
Sars, G. 0.

Herrick & Turner. Synopsis of the Entomostraca of Minnesota. 1895.
Hirschmann, N. Beitrag zur Kenntniss der Ostracodenfauna des Finnischen

Meerbusen. 1909, 1912.

Monograph on the Tertiary Entomostraca of England. 1856.

Histoire des Monocles qui se trouvent aux environs de Geneve.

1820.

Die schweizerischen Cylheriden und ihre nachsten Verwandten.

1896.

Cypriden und Darwineliden der Schweiz. 1900.

DeutschlandsCrustaceen,Myriapoden undArachniden. 1837—41.

De crustaceis ex ordinibus tribus in Skania occurrentibus. 1853.

Contributo alia systematica delle Ilyocyprinae. 1906—07.

Die Ostracoden des Golfes von Neapel. 1894

Die Ostracoden der Voeltzker Expedition. 1898.

Deutschlands Siisswasser-Ostracoden. 1900.

Das Tierreich, L. 31, Ostracoda. 1912.

Entomostraca. 1785.

Oversigt af Norges marine Ostracoder. Chr. Vid. Selsk. Forh. 1865.

Ostracoda mediterranea. Arch. f. Math. Naturv. Vol. 12. 1888.

On some Ostracoda and Copepoda raised from dried Australian

mud. Chr. Vid. Selsk. Forh. 1889.

Oversigt af Norges Crustaceer II. 1890.

Contribution to the knowledge of the fresh water Entomostraca

of New Zealand. 1894.

Freshwater Entomostraca of South America. Part II. Copepoda

& Ostracoda. 1901.

Freshwater Entomostraca from China and Sumatra. 1903.

On the Crustacean Fauna of Central Asia. 1903.

Freshwater Entomostraca of the Cape Province. Part II Ostra-
coda. 1924.

Studies on marine Ostracoda. Part I. 1920.

Monographie der Ostracoden Behmens. 1891.

Die Siisswasser-Ostracoden Deutsch Ost-Afrikas. 1898.

Plankton Expedition der Humbolt-Stiftung. Ostracoda 1906.

Synopsis Crustaceorum Prussicorum. 1844.

Monographie der Ostracoden. Arch. Anat. Phys. 1850.

Skogsberg, T.
Vdvra, W.

Zaddach, G.
Zencker, W.

SYSTEMATIC LIST

OF THE SPECIES DESCRIBED IN THE PRESENT VOLUME.

Myodocopa.

Cypridinidas.

Cypridina, M-Edw.

norvegica, Baird.

megalops, G. O. Sars.
Philomedes, Lilljeborg.

globosus, Lilljeborg.

Lilljeborgi, G. O. Sars.
Asterope, Philippi.

mariae, Baird.

abyssicola, G. O. Sars.

Conchoeciid89.

Conchoecia, Dana.

elegans, G. O. Sars.
borealis, G. O. Sars.
obtusata, G. O. Sars.

Cladocopa.

Polycopidae.

Polycope, G. O. Sars.

orbicularis, G. O. Sars.

punctata, G. O. Sars.

areolata, G. O. Sars.

clathrata, G. O. Sars.

pustulata, G. O. Sars.

sublaevis, G. O. Sars.
Polycopsis, G. W. Miiller.

compressa, Brady & Robertson.

Platycopa.

Cytherellidae.

Cyiherella, Bosquet.

abyssorum, G. O. Sars.

Podocopa.

Cypridae.

Pontocy prince.

Pontocypris, G. O. Sars.

trigonella, G. O. Sars.
Erythrocypris, G. W. Miiller.

mytiloides, Norman.

hispida, G. O. Sars.

pallida, G. O. Sars.
Argilloecia, G. O. Sars.

cylindrica, G. O. Sars.

conoidea, G. O. Sars.

Macrocy prince.
Macrocypris, Brady.

minna, Baird.
Macrocypria, G. O. Sars.

angusta, G. O. Sars.

Bairdiince.
Bythocyprls, Brady.

bosquetiana, Brady,
obtusata, G. O. Sars.

X

Bairdia, M'Coy.

inflata, Norman.

Cyprince.

Paracyprides.

Paracypris, G. O. Sars.
polita, G. O. Sars.

Can don ides.

Candona, Baird.

Candida, O. Fr. Miiller.

neglecta, G. O. Sars.

lapponica, Ei<man.

caudata, Kaufmann.

Sarsi, Hartwig.

rostrata, Brady & Norman.

marchica, Hartwig.

stagnalis, G. O. Sars.

albicans, Brady.

compressa, Koch.
Cryptocandona, Kaufmann.

V^vrai, Kaufmann.

reducta, Aim.
Candonopsis, V^vra.

Kingsleyi, Brady & Robertson.

Cyclocyprides.

Cyclocypris, Brady & Norman.

globosa, G. O. Sars.

ovum, Jurine.

laevis, O. Fr. Muller.

serena, Koch.
Cypria, Zencker.

exsculpta, Fischer.

ophthalmica, Jurine.

lacustris, G. O. Sars.

Notodromides.
Notodromas, Lilljeborg.

monachus, O. Fr. Miiller.
Cyprois, Zencker.

marginata, Strauss.

Ilyocyprides.
Ilyocypris, Brady & Norman.
. biplicata, Koch,
gibba, Ramdohr.
Ilyocyprella, Daday.

Bradyi, G. O. Sars.

Eucyprides.
Cypris, O. Fr. Muller.

pubera, O. Fr. Muller.
Eucypris, Vavra.

virens, Jurine.

crassa, O. Fr. Muller.

elliptica, Baird.
Cyprlcercus, G. O. Sars.

fuscatus, Jurine.

affinis, Fischer.

hirsutus, Fischer.

obliqvus, Brady.
Cyprinotus, Brady.

salinus, Brady.

fretensis, Brady.
Heterocypris, Glaus.

incongruens, Ramdohr.
Dolerocypris, Kaufmann.

fasciata, O. Fr. Muller.
Herpetocypris, Brady & Norman.

reptans, Baird.
Prionocypris, Brady & Norman.

lutaria, Koch.

glacialis, G. O. Sars.

pigra, Fischer.

olivacea, Brady & Norman.

XI

Cypridopsides.
Pionocypris, Brady & Norman.

vidua, O. Fr. Muller.

helvetica, Kaufmanii.

obesa, Brady & Norman.

elongata, Kaufmann,

Almi, G. O. Sars.

picta, Strauss.
Cypridopsis, Brady.

aculeata, Costa.
Cypridopsella, Kaufmann.

villosa, Jurine.

Darwinulince .
Darwinula, Brady & Norman.

Stevensoni, Brady & Robertson.

Cytheridae.

Limnocytherince.
Limnocythere, Brady,

sancti-patricii, Brady & Robertson,
inopinata, Baird.

Cytheridei/icp.
Cytherissa, G. O. Sars.

lacustris, G. O. Sars.
Cyprideis, Jones.

lit'toralis, Brady.

sorbyana, Jones.
Cytheridea, Bosquet.

papillose, Bosquet.

punctillata, Brady.
Eucythere, Brady.

argus, G. O. Sars.

declivis, Norman.
Krithe, Brady & Robertson.

bartonensis, Jones.

Cytherltice.
Cythere, O. Fr. Muller.
lutea, O. Fr. Muller.

albomaculata, Baird.

viridis, O. Fr. Muller.
Leptocythere, G. O. Sars.

pellucida, Baird.

macallana, Brady.

castanea, G. O. Sars,

tenera, Brady.

crispata, Brady.
Cytheromorpha, Hirschman,

fuscata, Brady.
Xenocythere, G. O. Sars.

cuneiformis, Brady.
Kyphocythere, G. O. Sars.

limicola, Norman
Hemicythere, G. O. Sars.

villosa, G. O. Sars.

emarginata, G. O. Sars,

crenulata, G. O. Sars.

finmarchica, G. O. Sars.

qvadridentata, Baird.

angulata, G. O. Sars.

latimarginata, Speyer.

concinna, Jones.

oblonga, Brady.
Cythereis, Jones.

tuberculata, G. O, Sars.

echinata, G. O. Sars.

dunelmensis, Norman,

Jonesi, Baird.

mucronata, G. O. Sars.

Cytherurince.
Cytherura, G. O. Sars.
gibba, O. Fr. Muller.
nigrescens, Baird.
similis, G. O. Sars.
sella, G. O. Sars.
atra, G. O. Sars,

XII

intumescens, G, O. Sars.
afiinis, G. O. Sars.
striata, G. O. Sars.
producta, Brady,
acuticostata, G. O. Sars.
lineata, Brady,
undata, G. O. Sars.
fulva, Brady & Robertson.
• clathrata, G. O. Sars.
cellulosa, Norman.

Loxoconchince.
Loxoconcha, G. O. Sars.

impressa, Baird.

granulata, G. O. Sars.

tamarindus, Norman.

fragilis, G. O. Sars.
Cytheropteron, G. O. Sars.

latissimum, Norman.

alatum, G. O. Sars.

hamatum, G. O. Sars.

pundatum, Brady.

crassipinnatum, Brady & Norman,

angulatum, Brady.

subcircinatum, G. O. Sars.

testudo, G. O. Sars.

inflatum, Brady.

nodosum, Brady.

Bythocytherince.
Byihocythere, G. O. Sars.
turgida, G. O. Sars.
constricta, G. O. Sars.
Bradyi, G. O. Sars.

dromedaria, G. O. Sars.

insignis, G. O. Sars.
Pseudocythere, G. O. Sars.

caudata, G. O. Sars.
Macrocythere, G. O. Sars.

simplex, Norman.

Xestoleberlnce.

Xestoleberis, G. O. Sars.
aurantia, Baird.
depressa, G. O. Sars.

Paradoxostomince.

Sclerochilus, G. O. Sars.

contortus, Norman.
Paracytherois, G. W. Muller.

arcuata, Brady.

flexuosa, Brady.

producta, Brady & Norman.
Cytherois, G. W. Muller.

Fischeri, G. O. Sars.

vitrea, G. O. Sars.

pusilla, G. O. Sars.
Paradoxostoma, Fischer.

variabile, Baird,

ensiforme, Brady.

obliqvum, G. O. Sars.

Bradyi, G. O. Sars.

hibernicum, Brady.

pulchellum, G. O. Sars.

abbreviatum, G. O. Sars.-

Normani, Brady.

rostratum, G. O. Sars.

NTRODUCTION.

The Ostracoda form a very sharply defined order of Crustacea, the most
conspicuous feature of which is the presence of a bivalved shell, into which
the body with its several appendages may be wholly withdrawn, the valves
admitting of being closed by the aid of an adductor muscle traversing the body
and attached to the inside of the valves at about their centres. They thereby
at the first sight look rather like small mussels, and their popular name "mussel-
shrimps" is indeed derived from that character. The only other Crustacea in
which a somewhat similar feature is met with, is a group of the Phyllopoda
(Conchostraca). The Ostracoda are however very essentially distinguished from
these Crustacea by the want of any distinctly defined cephalic part or head,
as also by the considerable reduction of the postoral limbs. Whereas in the
conchostracous Phyllopoda more than 20 pairs of limbs may be found behind
the mouth, the number of these limbs in the Ostracoda never exceeds 4 pairs
and may be reduced to 3 (Cytherella) and even to only 2 pairs (Polycope);
nor do these limbs in any case assume the uniform foliaceous appearance
characteristic of the Phyllopoda. As to the preceding limbs, the anterior an-
tennae are far less rudimentary than in the above-named Crustacea, and the
mandibles are always provided with distinct, in some cases very powerfully
developed palps, whereas such palps are wholly absent in the Phyllopoda as
also in the nearly allied group Cladocera, at least in the adult stage of the
animal. The body, as a rule, terminates in 2 juxtaposed procurved rami, in some
cases very movable and strongly spinous or claved at the edges, in other cases
however much reduced. These rami evidently ansver to the so-called "post-
abdomen" in the Cladocera and the conchostracous Phyllopoda, but are
scarcely at all homologous with the "furca" of the Copepoda, though gene-
rally so termed by recent authors.

1 — Crustacea.

The greater number of the Ostracoda are of rather small size, the average
length of the shell only seldom exceeding a pair of millimeters. The largest
forms are found among the Cyprldinidce (Gigantocypris) and the freshwater
Cypridae (Megalocypris),

Ostracoda are found abundantly both in fresh waters and in the sea. But,
whereas the freshwater forms on the whole show a rather uniform appearance,
being almost exclusively referable to a single family (the Cypridae), the marine
Ostracoda are much more varied, exhibiting several very distinct types. As to
habits, some of the marine forms (Conchoeciidae) lead apparently a true pelagic
existence; but the great majority of Ostracoda are to be regarded as bottom-
animals, many of them (Cytheridae) being even quite devoid of swimming
faculty. We have not full evidence of the existence of true parasitisme within
the present order.

As the shell of most Ostracoda is of a rather firm consistency and in
many cases is even strongly calcareous, this part of the animal admits of being
rather well preserved also in the fossil state. Indeed, numerous species of
Ostracoda have been recorded from almost all fossiliferous formations even up
to the Cambrian period, though the true systematic relationship of the oldest
genera (Primitia, Leperditia, Beyrichia), by our wani of knowledge to the
anatomical details, may be regarded as somewhat doubtful.

As to the systematic arrangement of the Ostracoda, at first only a restricted
number of families were established, to comprise the known genera, 3 such
families being proposed in 1850 by Baird in his well-known work, viz., Cypii-
dinidce, Cypridce and Cytheridxe. The first attempt to a more exact systematic
grouping of the Ostracoda was made in the year 1865 by the present author^),
who proposed to divide the order into 4 principal groups or suborders, each
comprising one or more families. The arrangement proposed was as follow:
1. Myodocopa with the 2 families Cypridlnidce and Conchoeciidce, 2.
C/adocopa with the family Polycopidce, 3. Platycopa with the family
Cytherellidce, and 4. Podocopa with the 2 families Cypridce and Cytheridce.
This classification has been sanctioned by most subsequent authors. G. W.
Muller has however in his work on the Ostracoda of the gulf of Naple suggested
that the 2 suborders Cladocopa and Platycopa should more properly be wholly
rejected, the family Polycopidce being referred by him to the Myodocopa and
the family Cytherellidce to the Podocopa. I think however that the argumen-
tation given at some length by the said author in support to this view may

1) Oversigt af Norgcs marine Ostracodcr.

be foumd to be very little convictive, and indeed in the most recent system
presented by Dr. Skogsberg in his great work on the marine Ostracoda, the
2 said suborders have been fully admitted as such, though "designed with
other names, the only difference in his system from that proposed by me
being that the family Conchoeciidae (Halocypridae) has been wholly separated
from the Myodocopa and raised to the rank of a 5th suborder: Halicyprlformes.
As 1 am not prepared to consent with Dr. Skogsberg in this latter respect,
nor find any reasonable raison for changing the names at first given to the
suborders, I have felt justified to retain in the present Account my original
classification quite unaltered.

Suborder 1.

Myodocopa.

General Characters. — Shell exhibiting in front a persistent aperture, as ;
rule widened by a more or less deep insicure of each valve in this place, and allow
ing the antennae to be extruded and freely moved. A frontal tentacle always present
Anterior antenna never natatory, and more or less dissimilar in the two sexes
Posterior antennae constituting the sole locomotory organs of the animal, thei
basal part being remarkably large and muscular, outer ramus very movable
multiarticulate, and provided with strong natatory setae; inner ramus neve
natatory, being more or less rudimentary, and in male generally transforme(
to a grasping organ. Mandibular palps strongly developed, sub-pediform
geniculate on the middle, and clawed at the tip. 4 pairs of postoral limb
present, exhibiting a very varying structure. Caudal rami lamelliform, edge(
behind with strong claws. A well developed heart present in the middle o
the dorsal face. Intestine simple without any coecal appendages. Testicle;
likewise of a very simple structure.

Remarks. The most prominent feature distinguishing this suborder i:
unquestionably the restriction of the locomotory faculty to the posteririor an
tennae, the outer rami of which are in reality the only parts by which the bod\
is propelled. For this purpose of course a very powerful muscular apparatu:
is needed, and these muscles are found lodged within the basal part of th(
antennae, the remarkable size and massive shape of this part being thereb]
easily explained. During motion the said rami are extended from the fronta
opening of the shell and inserted at the base within the incisures of the valves
working like a pairs of oars by powerful strokes outwards and behind, thu;
propelling the animal.

The Myodocopa comprise 2 very sharply defined families, the Cypridinida
and the Conchoeciidce, which by some authors have been regarded even aj
groups of a higher systematic rank (see above). Both these families are wel
represented in the Fauna of Norway. All the known forms are exclusively marine

Fam. 1. Cyprtdinidae.

Characters of the family. Valves of rather firm consistency, in some
cases roughly sculptured and highly calcareous, frontal incisure as a rule rather
deep and defined above by a more or less projecting rostral prominence. Two
compound stalked eyes generally present, and moreover an unpaired central
ocellus, from the lower face of which the frontal tentacle issues. Anterior
antennae in both sexes well developed, distinctly geniculate at the base, and
carrying at the end strong annulated setae, one of which, attached posteriorly
at some distance from the tip, is generally pronouncedly sensory. Posterior
antennae with the basal part trigonal or cordiform in shape, inner ramus bi- or
triarticulate, very small in female, and having none of the joints conspicuously
expanded, in male generally larger and prehensile. Mandibles with the mastica-
tory part imperfectly developed, palp strong, with a small exopodal appendage
at the end of the 1st joint anteriorly. None of the postoral limbs pediform,
the 2nd pair being always provided at the base with a broad semilunar vibratory
plate; penultimate pair closely juxtaposed, each terminating in a vertical,
broadly triangular lamella; last pair very peculiar, slender vermiform in shape
and highly flexible, curving upwards and bakwards within the shell, and armed
in their outer part with a number of peculiarly modified spines. Caudal lamellae
without any spine in front of the marginal claws. Copulatory appendages in
male symmetrical, more or less coalesced at the base. Ripe ova received within
the cavity of the shell for accomplishing their first (larval) development.

Remarks. The type of this family is the genus Cypridina of M. Edwards,
to which in recent time several other genera have been added, more or less
differing from the type, though retaining most of the characteristic features
of that genus. Of these features may be named the presence of compound
stalked eyes and a well defined central ocellus, the comparatively full deve-
lopment of the anterior antennae, the peculiar reduction of the masticatory part
of the mandibles, and finally the anomalous structure of the 3 posterior pairs
of limbs. Especially is the appearance of the last pair of limbs highly remark-
able and unlike that found in any other Ostracods.

3 well defined genera referable to this family are represented in the
Fauna of Norway.

Gen. 1. Cypridina, M. Edwards, 1840.

Generic Characters.— Sexual dimorphism rather slight. Shell moderately
tumid and of a more or less oval shape, with the surface smooth and almosi
quite devoid of hairs; frontal incisure of valves rather deep and occurring
nearly in the middle of the anterior extremity; rostral part, as a rule, nol
much prominent and curved downwards. Eyes well developed in both sexes,
but larger in male than in female. Frontal tentacle short, clavate. Anterioi
antenna 7- articulate, and of nearly same structure in the two sexes. Posterioi
antennae with the inner ramus in most cases not transformed in male. Man-
dibles with the masticatory process small, conical in shape, and densely hairy
palp with the penultimate joint long and narrow, being densely clothed in
front with coarse setae, apical claws very short. Anterior lip forming in froni
a compressed somewhat securiform expansion finely crenulated at the edge,
and having moreover 2 more or less distinctly defined lateral lappets. Maxillae
with 3 well defined masticatory lobes inside the thickish basal part, palp rathei
strong biarticulate, and provided outside with a thin deflexed lamella terminating
in 3 finely ciliated setae, and apparently constituting the exopodite, distal joint of the
palp small, but armed with several strong diverging spines. Anterior maxillipeds
of a very compact and complicated structure, with the basal part broad and
flattened carrying on the one side the large vibratory plate, on the opposite
(inner) side 3 comparatively small subequal masticatory lobes, these lobes being
followed by 2 somewhat similar, but much stronger incurved lobes, which to-
gether with the adjoining part of the limb may more properly represent tht
endopodite, the distal lobe being clothed with numerous strong partly pectinate
setae, the proximal one with a row of short stout claws denticulated along the
one edge, — the remaining part of the limb apparently represents the exopodite
and is of a much more delicate structure, exhibiting a short proximal joini
which is produced on each side to'^'a setiferous lappet, the 2 lappets embracing,
as it were, the base of the succeeding quadrangular joint, to the outer cornei
of which in some cases a very small apical joint is added ^). Posterior max-
illipeds with 3 or 4 masticatory lobes, the outermost of which, together witli
the adjoining part, may perhaps represent the endopodite, terminal lamelk
(exopodite) richly fringed with ciliated setae, those issuing from the posterioi
corner being the largest. Last pair of limbs exhibiting the characteristic structure

') The 'interpretation here given somewhat differs from that set forth by Dr. Skogsberg
who described the whole outer part of the Hmb as the exopodite.

common to all the members of the family Cypridinidce. Caudal lamellae com-
paratively large, subtriangular in form, and armed with very strong claws
gradually increasing in size distally.

Remarks. — This genus was established as early as the year 1840 by M.
Edwards, to include a form (C. Reynaudi) captured in the Indian Ocean, and
conspicuously differing from any other Ostracods at that time known. Sub-
sequently many other species more or less closely agreeing with the form
recorded by M. Edwards have been detected, and though some of these have
been placed within separate nearly-allied genera, a good deal remain as true
members of the old genus Cypridlna. A grouping of the latter species has
recently been attempted by Dr. Skogsberg, who propose to divide the genus
into 5 subgenera, viz., Doloria, Vargiila, Macrocypridina, Cypridina (proper),
and Siphonostraca. The distinction of these subgenera seems however to me
to be in most cases based upon very slight and minutious differences. The
2 Norwegian species described below are both referable to the subgenus
Vargiila of Skogsberg.

1. Cypridina norvegica, Baird.
(PI. i-iii).

Cypridina norvegica, Baird, Notes on tlie genus Cypridina, witii description of some new
species, Proc. Zool. Soc. London 1860, pag. 200, Pi. LXXI, figs. 4, 4 a— d.

Specific Characters. —^Female. Shell, seen laterally, of a rather regular
broadly oval shape, greatest height in the middle and somewhat exceeding ^jz
of the length, dorsal margin quite evenly arched and joining the anterior and post-
erior edges without any trace of an intervening angle, vencral margin likewise uni-
formly curved, though somewhat less so than the dorsal one, posterior extremity
only slightly wider than the anterior and somewhat obliquely blunted, with
an indication to a rounded corner below; — seen dorsally or ventrally, oblong
oval in shape, with the greatest width in the middle and about equalling half
the length, both extremities obtusely pointed. Frontal incisure of the valves
rather deep and narrow, obliquely ascending, being defined below by a
rather projecting part of the valve bordered above by a thin transversely striated
lamella; rostral prominence narrow acuminate, curved downwards, and having
the upper edge quite continuous with the dorsal margin of the shell. Valves
semipellucid, with the surface smooth and polished, not exhibiting any obvious
sculpture. Eyes comparatively small, each with about 8 lenticular bodies em-
bedded in a dark pigment. Ocellus well developed, with the fronal tentacle

8

very short. Anterior lip with the lateral lappets conically produced. Inner
ramus of posterior antennae slender and attenuated, composed of 3 well defined
joints, the last very small and tipped with a long seta. Terminal plate of
posterior maxillipeds provided at the posterior corner with 3 (more rarely 4) den-
sely hairy setae separated from the other marginal setae by a rather wide interspace.
Caudal lamellae each with 9 claws more or less distinctly denticulated behind.

Male somewhat smaller than female and slightly differing in the shape
of the shell, the posterior part of which is comparatively lover and more exerted
below. Dorsal face of the enclosed body exhibiting behind a number of some-
what irregular conical projections not observed in female. Eyes much larger
than in female, each with up to 16 ommatidia. Structure of the several limbs
very little differing from that in female. Copulative appendages well developed
and confluent for about half their length, the outer part of each appendage
terminating inside in a linguiform lobe, outside in a peculiar incurved hami-
form process. Spermatozoa very small in the form of clear nucleated cells
produced at one end in a hair-like appendage (see PI. 111).

Colour whitish gray, some parts of the body shining through the shell
with a darker hue; ova in the incubatory cavity of the shell pale yellowish.

Length of adult female amounting to 3.60 mm., of male to 3.40 mm.

Remarks.— The present Ostracod was first described, though very imper-
factly by Baird in the year 1860. As the specimen examined by him was
taken off the Norwegian coast, I think that the identity of the above-described
form with Bairds species cannot properly be questioned. It is the type of the
subgenus Vargula proposed by Dr. Skogsberg.

Occurrence.— \ have met with this Ostracod not rarely in several places
on the western coast of -Norway in greater depths. Especially I found it very
abundant off the Lofoten islands, where it occurred on a soft muddy bottom
at depths ranging from 80 to 300 fathoms. Some specimens were also_ taken
during the Norwegian North Atlantic Expedition at Stat. 195 north of the Fin-
mark coast.

It. is a very active little creature, swimming about rather speedily in a
somewhat rolling manner. When disturbed, the animal emits a rather intense
phosphorescent light chiefly, it would seem, derived from a yellow fluid
secerned from the anterior lip. In habits it is pronuncedly rapacious, feeding
eagerly upon any carcass found in its way, and in some instances even attaking
living animals. Dr. 0stergreen found at one occasion several still living
specimens of this Ostracod within the cloaca and the uterine cavity of a
Spinax niger caught in the Trondhjem Fjord, and was thereby led to the

supposition, that this form lead a parasitic life in the said fish. This is however
by no means the case. The Ostracods had simply attaked the Spinax when
hanging on the fishing line in a dead or feeble condition, and had entered
the most accessible openings of the fish in order to feed upon its soft parts.
The finding of allied Ostracods on the gills or other places on recently captured
fishes, as mentioned by some other authors, may be explained in a similar
manner. On the other hand, the present Ostracod itself is not seldom found to
be infested with a peculiar parasit, Cyproniscus cypridlnce, described in the 2nd
Volume of the present work. The parasit is generally only found on female
specimens and occupies the place where otherwise the ova and embryos of
the Cypridina are carried during their developement.

Distribution.— W^si coast of Sweden (Skogsberg), Shetland Isles (Norman).

2. Cypridina megalops, G. O. Sars.
(PI. IV).

Cypridina megalops, G. O. Sars, Uiidersegelser over Hardangerfjordeiis Fauna. Chr- Vid.

Selsk. Forh. 1871, pag. 278.

Specific Characters.— Female. Shell comparatively shorter and stouter
than in the preceding species, seen laterally, of a less regularly oval shape,
being considerably higher behind than in front, dorsal margin strongly arched
in its posterior part, but more slowly declining in front, ventral margin evenly
curved, posterior extremity bluntly rounded, with the lower corner but very
slightly exerted;— seen dorsally or ventrally, ovale in shape, with the greatest
width somewath behind the middle. Frontal incisure of the valves of a similar
shape to that in C. norvegica; defining angle below however less prominent,
and the rostral projection comparatively broader. Surface of shell smooth and
polished. Eyes of considerably larger size than in the female of C. norvegica
and very conspicuous in the living animal. Anterior lip with only slight traces
of lateral lappets, hmer ramus of posterior antennae very small and only
composed of 2 joints, distal joint knob-like and terminating in a very long
and slender seta. Terminal plate of posterior maxillipeds fringed with an
uninterrupted row of about 18 plumose setae. Caudal lamellae each armed
with 11 claws. Structural details otherwise very little different from those in
C. norvegica.

Male rather like the female in its outward appearance, but slightly larger,
and having the posterior part of the shell less broad and somewhat more ex-

2 - Crustacea.

10

erted at the lower corner. Copulative appendages wfth the 2 terminal lappets
of a somewhat different shape from those in the male of C. norveqlca, the
outer lappet being scarcely hamiform.

Body semipellucid, of a similar whitish grey colour to that in the
preceding species; ova in the incubatory cavity of a pale orange hue.

Length of adult female amounting to 3.29 mm., of male to 3.35 mm.

Remarks. —The above-described form is nearly allied to C. norvegica, but
may be easily distinguished by the somewhat different shape of the shell, as
seen laterally, and more particularly by the large size of the eyes in both
sexes, the latter character having given rice to the specific name proposed.
Moreover some 'slight differences may be stated to occur also in the other
structural details, as pointed out in the above diagnosis.

Occurrence. ~On\y a limited number of specimens of this form have as
yet come under my notice. They were taken in moderate depths, partly in
the innermost part of the Hardanger Fjord at Utne, partly off the west coast
at Christiansund. Out of Norway this form has not yet been recorded.

Gen. 2. Philomedes Lilljeborg, 1853.

Syn: Cypridina Lilljeborg (not M. Edward).
Bradycinetus G. O. Sars.

Generic Characters. — Sexual dimorphism very strongly marked. Shell
much more elongate in male than in female, with the frontal sinus of quite
a different shape; rostral prominences in female large and procumbent, in
male almost horizontally porrected and obtuse at the end. Eyes in female
much reduced, in male largely developed. Frontal tentacle in both sexes
slender, styliform. Anterior antennae only composed of 6 joints and rather
dissimilar in the 2 sexes, those in male being considerably more elongate and
provided at the end of the 4th joint with a strongly developed sensory seta
(wanting in female); 2 of the apical setae moreover enormously prolonged and
very mobile, being more generally abruptly reflexed. Posterior antenna much
more powerfully developed in male than in female, with the 3rd joint of the
outer ramus remarkably prolonged and the outer joints provided with well
developed natatory setae, whereas these setae in the adult female are, as a rule,
found to be brocken off at some distance from the base; inner ramus in
female small, biarticulate, in male much larger and distinctly prehensile. An-

11

terior lip comparatively small, helmet-shaped. Mandibles with the masticatory
process cleft at the tip, and obsolete in male. Postoral limbs on the wohle
built on the same type as in Cypridina. Anterior maxillipeds however in
female (but not in male) distinguished by the remarkable development of the
proximal endopodal lobe, which projects in a large and highly chitinised bian-
gular or securiform piece carrying inside a row of stout claws. Copulative
appendages of male comparatively small, lobular at the end.

Remarks. — In the year 1853 Prof. Lilljeborg described 2 Cypridinids found
by him off the coast of Skane. The one of them was referred by him to
the genus Cypridina and named C. globosa, the other, of wich only a single
specimen was found, was regarded as the type of a new genus and recorded
under the name Philomedes longicornis. The first-named of these 2 forms
was subsequently found by the present author rather abundantly on the coast
of Norway, and was subjected to a closer anatomical examination, wich showed
it to be so decidedly different from the species of Cypridina that I felt justified
to establish for its reception a new genus, which I named Bradycinetus in
allusion to the slow movements of the animal. I was at that time still of
opinion, that the genera Bradycinetus and Philomedes were very distinct, the
one from the other, and it was only several years afterwards that the true re-
lationship between the 2 Cypridinids recorded by Lilljeborg was revealed to me.
In the year 1869^) I set forth the rather perplexing suggestion that these 2
apparently so widely different forms should more properly be combined into
the very same species, Philomedes longicornis being nothing else than the
adult male of Cypridina (Bradycinetus) globosa. This suggestion has since been
fully corrobonated both by myself and by other authors, and the remarkable
sexual dimorphism in the present genus thereby ratified. Of course the
generic name Bradycinetus ought to be wholly discarded and replaced by that
originally proposed by Lilljeborg for the male sex.

Several of the Cypridinid genera established in recent time approach the
present genus rather closely, and have by Dr. Skogsberg been grouped together
with it in a subfamily, Philomedince. The genus Philomedes proper comprises
only a limited number of species, 2 of which belong to the Fauna of Norway.

1) Uiidersegelser over Christianiafjordens Fauna.

12
3. Philomedes globosus (Lilljeborg).

(PI. V— VII).

Cvpridina globosa, Lilljeborg, De Crustaceis ex ordinibtis tribus i Skania occiirentibiis, p. 171,
Pi. XVII, figs. 2—10, Pi. XVIII, figs. 1, 2, 3, 7.

Syn: Philomedes longicornis Lilijeboig cT
„ Asterope grenlandica Fisher 2

Bradycinetus globosus, G. O. Sars $
„ bretida, Brady $

„ Philomedes brenda, G. O. Sars cf

Specific Characters.— Female. Shell rather tumid, seen laterally, of a
somewhat irregular rounded oval shape, greatest height in the middle and not
fully attaining ^4 of the length, dorsal margin almost straight in the middle,
sloping gently in front, more steeply behind, ventral margin evenly curved,
posterior extremity broader than the anterior and obliquely blunted, forming
below a slightly produced angular corner; — seen dorsally or ventrally, rather
regularly ovate, with the greatest width about in the middle and somewhat
exceeding half the length. Frontal incisure of valves moderately deep and
turned upwards, being overhung by the rather prominent rostral part, which
is obliquelly truncated at the end, with the upper angle rather slight, the
lower produced in a small procurved dentiform point. Valves of rather firm
consistency and only slightly transparent, surface evenly vaulted and minutely
punctate, being everywhere clothed with short stiff hairs; rostral prominences
fringed both in front and below by a hyaline finely ciliated border, selvage below
the incisure short and rounded off. Eyes scarcely visible in the living animal,
being in most cases quite devoid of pigment. Inner ramus of posterior
antennae very small, with the distal joint somewhat compressed and provided
in front with a slender ciliated seta, carrying moreover at the tip a peculiarly
tortouos thin bristle abruptly bent at the base; outer ramus very flexible and
having almost constantly the outer part of the natatory setae brocken off.
Last pair of limbs with a rather great number of cleaning spines, amounting
to 28 on each limb. Caudal rami each with 10 marginal claws.

Male very unlike the female in its outward appearance, the shell being
of a much more elongate, oblong oval shape, with the dorsal and ventral
margins only slightly arched. Frontal incisure of valves much wider than in
female, almost rectangular, and the rostral prominence far less procumbent,
whit the tip obtusely blunted and not exhibiting any trace of an angle below.
Eyes largely developed and very conspicuous in the living animal. Anterior
antennae with the 2 prolonged apical setae exceeding the stem of the antennae
by about half their length. Posterior antennae with the outer ramus much

13

more slender and elongated than in female, with the 3rd joint twice as long
as the 2nd and about equal in length to the remaining part of the ramus;
inner ramus distinctly 3-articulate, middle joint slender and somewhat arcuate,
with 3 subequal setae anteriorly; last joint transformed to a falciform claw ad-
mitting of being impinged upon the middle one. Postoral limbs on the whole
rather weaker in structure than in female. Copulative appendages comparatively
small, each terminating in 3 incurved digitiform processes. .

Body of female only slightly transparent, of a whitish grey colour with
a more or less distinct yellowish brown tinge; that in male much more pel-
lucid, the shell itself being almost colourless, whereas the enclosed body
exhibits in some places a vivid orange hue.

Length of adult female amounting to 2.60 mm., of male to 2.50 mm.

Remarks.— 'The present species has by most recent authors been identified
with Cypridina brenda of Baird; but it is very questionable if this identifi-
cation is correct. Indeed Dr. Skogsberg has found the identification quite inad-
missible, and has therefore proposed to retain the specific name given by Lillje-
borg to the female sex. In accordance therewith the species is here recorded
under the name by which it was distignated by me in the year 1869. It is
the type of the genus Philomedes and at the same time of the subfamily
Philomedince proposed by Dr. Skogsberg.

Occurrence.— ¥exm\ts of this form are by no means rare of the Norwegian
coast in moderate depths on a muddy bottom, and are noted from numerous
localities, from the Christiania Fiord up to Finmark. The adult males are much
more scarce, and are only quite occasionally captured. The behaviour of the
two sexes is very different. Whereas the males are very active animals, swim-
ming about with great spead, and in some cases even ascending to the very
surface of the sea, the adult females are constantly bound to the bottom,
dragging themselves slowly through the loose mud in search of food. This
sluggish behaviour is due to the peculiar imperfectness of the natatory setae on
the posterior antennae, rendering these limbs quite unserviceable for swimming. I
have examined numerous specimens, and have almost constantly found these
setae brocken in the very same manner. Only quite exceptionally I have met
with one or other specimen with these setae in an intact state, and such
specimens had never ova and embryos in the breading cavity, being in all
probability still young and virginal. I think that the supposition set forth by
G. W. Miiller in this regard is very likely to be accepted, viz., that the above
mentioned amputation of the natatory setae is a volontary act of the animal,
these setae being only of some use during the short period in which copulation

14

take place, but afterwards become useless or even inconvenient and therefore
are biten off by the aid of the strongly developed endopodal lobes of the
anterior maxillipeds, which indeed seem to be pretty well adapted for such
a purpose.

Distribution. — Kattegat, Skagerak, British Isles, Arctic Ocean : Newfoundland,
Greenland, Jan Mayen, Spitsbergen, Franz Joseph Land, Kara Sea, Murman coast.

/

4. Philomedes Lilljeborgi, G. O. Sars.

(PI. VIII)

Bradycinetiis Lilljeborgi, G. O. Sars. Oversigt af Norges marine Ostiacoder. Clir. Vid. Seisk.

Forh. 1865, p. 112.

Specific Characters. — Female. Shell, seen laterally, obtusely subquadrang-
ular in outline, greatest height in the middle and about equalling -,3 of the
length, dorsal margin straight in the middle, but abruptly declining both in front and
behind, ventral margin only slightly curved, posterior extremity scarcely broader
than the anterior, and exerted below to a rather prominent triangular corner;
seen dorsally or ventrally, oblong ovate in shape, about twice as long as broad,
and having the posterior extremity more pointed than the anterior. Frontal
incisure of valves occurring rather far below the longitudinal axis of the shell,
and exhibiting a similar shape to that in the preceding species; rostral part
however comparatively more prominent and strongly procumbent, being more-
over almost transversely truncated at the end, with the upper angle very
distinctly marked and the lower produced to a small procurved point; selvage
of this part rather broad. Surface of shell smooth and almost quite devoid of
hairs. Eyes, as in the female of the preceding species, imperfectly developed,
and scarcely visible in the living animal. Structure of the several limbs very
like that in P. globosus. hiner ramus of posterior antennae, however, provided
with 2 or 3 additional setae on the anterior edge of the distal joint, and last
pair of limbs having a much smaller number of cleaning spines, scarcely ex-
ceding 11 on each limb.

Male of somewhat smaller size than female, and differing from it in a
much similar manner to that in the preceding species, the shell being much
narrower, oblong in shape, and more abruptly truncated behind, with the
lower corner rather prominent. Frontal incisure of valves, as in the male of
P. globosus, very shallow, and the rostral part bluntly rounded at the end.
Eye large and conspicuous. Limbs transformed in the same manner as in the
male of the preceding species.

Colour of female whitish grey, with a pale yellow tinge.

15

Length of female amounting to 2.50 mm.

Remarks. — The present form is closely allied to the type species, but of
smaller size, and moreover easily distinguishable by the somewhat different
shape of the shell, the posterior corner of which is in both sexes considerably
more exerted. In the female, moreover, the rostral part looks rather different,
being still more strongly procumbent and transversely truncated at the end.

Occurrence. — This is a true deep-water form, occurring, as a rule, only
in depths below 100 fathoms. I have met with it occasionally in several places
on the Norwegian coast, from the Christiania Fjord up to the Lofoten islands.

Distribution.— West coast of Sweden, Beeren Island, Iceland, Atlantic
Ocean, down to 430 fathoms.

Gen. 3. Asterope, Philippi, 1840.

Syn: Cylindroleberis, Brady.
Copechaete, Hesse.

Generic Characters. — Sexual dimorphism rather strongly marked. Shell
in female of rather firm consistency and more or less oblong or elliptical in
shape, wi|h the frontal incisure of the valves very deep and narrow, arched
over by the rather large and evenly vaulted rostral part. Shell of male much
thinner and considerably differing in shape from that in female. Eyes in most
cases well developed in both sexes. Frontal tentacle slender. Anterior antennae
6-articulate and on the whole built on the same type as in the other Cypri-
dinidae, though having the outer part in female broader, with the joints pro-
nouncedly compressed and clothed with upturned ciliated setae generally projecting
from the shell in front; last joint small and provided, in addition to the setae,
with a short claw-like spine, seta attached to the posterior corner of antepenulti-
mate joint in both sexes distinctly sensory; same antennae in male transformed
in a much similar manner to that in the genus Philomedes, 2 of the apical
setae being enormously prolonged. Posterior antennae of quite normal structure,
with the inner ramus in female very small and in male distinctly prehensile.
Anterior lip small, lobular at the end. Mandibles with the masticatory process
very slender, falciform, and ascending along the inner face of the basal part
towards the gullet; palp rather powerfully developed, with the joints broad
and compressed, the 1st produced at the base below to a conical recurved
pocess clothed with several spiniform setae; last joint armed with a straight,
scarcely unguiform spine accompagned by a number of setae. Maxillae and
maxillipeds rather feeble in structure and without any distinctly defined mastic-

16

atory lobes, the former limbs in particular exhibiting a rather anomalous ap-
pearance, each of them having the form of a somewhat curved attenuated stem
provided at the base in front with a simple triangular lamella, and clothed
along the inner face with a dense, comb-like series of delicate recurving setae
the stem being terminated by a small decurved joint, apparently representing
the endopodite, and tipped with 2 small bristles. Anterior maxillipeds providec
at the base with the usual semilunar vibratory plate, their terminal part how-
ever far less complicated than in most other Cypridinids, forming a thin
somewhat tortuous lamella fringed on the one edge with delicate ciliated setae
Posterior maxillipeds almost wholly reduced to the triangular plate, by which
these limbs in other Cypridinids are terminated, the plate being considerabl)
more produced in front than behind and fringed with comparatively short setae
Last pair of limbs exhibiting the characteristic vermiform shape common tc
all the Cypridinidae. Caudal lamellae comparatively small, but armed with rathei
strong curved claws rapidly increasing in size distally. Copulative appendages
of male almost wholly confluent. Posterior part of body in both sexes pro
vided dorsally with a double row of well developed imbricate gill-blads, 7 ir
each row.

Remarks.— This is a very distinct genus, differing in some respects sc
conspicuously from the other Cypridinidae, that some recent authors (Brady
Skogsberg) have even removed it wholly as the type of a separate family
I think however that the present genus, in spite of these differences, ough
more properly to be retained within the family Cypridinidae, as the genera
type of that family is quite unmistakable both as regards the structure of the
shell and the composition of the enclosed body, and also in the manner ir
which the two sexes differ from each other. Yet the establishment of a sub
family, Asteropince, for its reception may be well justified. The most striking
feature distinguishing this genus is unquestionably the presence of true gilh
of a structure similar to that found in the higher Crustacea. By this charactei
indeed the present genus differs not only from the other Cyprtdlnldce, bu
from all hitherto known Ostracoda. The weak and apparently anomalom
structure of the maxillae and maxillipeds may be accounted for by the less rapacious
nature of the animal. The genus Cylindoleberls of Brady, as admitted by tha
author, is identical with Philippi's genus, which was established at a much
earlier date. Nor can I doubt that the genus Copechcete of Hesse ought tc
be adduced as a synonym, though Dr. Skogsberg, urging from some inaccurate
and evidently erroneous statements given by Hesse, find the identificatior
unadmissible.

17

A rather considerable number of species referable to this genus have
been recorded in recent times from different parts of the Oceans. Most of these
are so closely related, that their distinction is connected with no small difficulty;
but there are also a few forms, which exhibit more conspicuous differences,
and which on this cause have been removed as types of nearly allied genera,
though the systematic rank of subgenera perhaps would be more appropriate.
Two closely allied species, unquestionably referable to the present genus, are
represented in the Fauna of Norway.

5. Asterope marias (Baird).
(PI. IX, PI. X fig. 1.)
Cypridina marice, Baird, Proc. Zool. Soc. London, part XVIII, p. 257, Pi. XVII, figs. 5—7.
Syn: Cypridina oblonga, Grube

Cylindroleberis mariae, Brady
Asterope norvegica, G. O. Sars

, oblonga, G. O. Sars

Cylindroleberis oblonga, G. W. Miiller

Specific Characters. — Female. Shell very narrow, almost cylindrical in
shape, with the greatest height scarcely attaining half the length, dorsal and
ventral margins only very slightly curved, both extremities obtusely rounded
and nearly equal; — seen dorsally, narrow oblong in outline, with the greatest
width about equalling -/s of the length. Frontal incisure of valves rather deep
and narrow, occurring nearly in the middle of the anterior extremity; rostral
part moderately broad and terminating below in a beak- like point. Surface
of shell quite smooth and polished, without any obvious clothing of hairs.
Eyes well developed, and easily observable in the living animal, though not
of very large size. Inner ramus of posterior antenna very small, 3-articulate,
with only a single slender seta issuing from the tip. Last pair of limbs pro-
vided with only 12 cleaning spines. Caudal lamellae with about 10 claws, the
proximal ones very small, the others rapidly increasing in size distally.

Male very unlike the female in its outward appearance, and also of some-
what larger size. Shell, seen laterally, of a somewhat irregular oblong shape,
being considerably higher in front than behind, with the dorsal margin slightly
gibbous in front of the middle and the posterior extremity narrowly truncated;
seen dorsally, much wider in front than behind. Frontal incisure of valves
rather shallower than in female, and the rostral part more obtuse. Valves thin
and pellucid, each clothed behind with a number of well-marked hairs, arranged
in the manner as to form a wreath arround the posterior end of the shell.
Eyes rather larger than in female and very conspicuous in the living animal.

3 — Ciustasea.

18

Anterior antennae considerably more elongated than in female, with the outei
part less pronouncedly compressed and the sensory seta much more fully de-
veloped, the 2 prolonged apical setae almost attaining the entire length of the
shell. Inner ramus of posterior antennae with the middle joint about the length
of the 1st and somewhat widening distally, carrying beyond the middle an-
teriorly 3 subequal setae, terminal joint forming a somewhat compressed claw
impinging upon the preceding joint. Structure of the remaining limbs almosi
exactly as in female. Copulative appendage divided at the end into 4 obtuselj
rounded lobules. .

Colour in both sexes whitish grey.

Length of adult female amounting to 2.20 mm, of male to 2.40 mm.

Remarks. — As seen from the above-given list of synonymes, this form
has been recorded under several different names. On a closer comparison 1
have convinced myself, that the form described by me in 1869 as ^. norvegica
is in reality identical with the British species A marlce (Baird), and that the
Mediterranean form A. oblonga (Grube) is the same species. I should alsc
be much inclined to believe, that the form recently recorded by Dr. Skogsberg
as A. Grimaldi is not specifically distinct from the species here in question,
How far the Copechcete elongata of Hesse, as believed by. G. W. Miiller, is
identical with the present species, it is rather difficult to state with full certainty,
though I regard the identity by no means as improbable.

The present species may be easily recognised by the unusually narrow,
almost cylindrical shape of the shell in fully adult females. In youngei
specimens, however, the shell appears somewhat shorter and stouter, though
otherwise agreeing with that in the adults. The male exhibits a much similai
appearance to that of other species of the present genus.

Occurrence. — I have only met with this form quite occasionally, though
in several places, both on the south and west coasts of Norway. It is gene-
rally found in depths ranging from 20 to 60 fathoms, on a muddy bottom,
but never in any considerable number. Whereas the females almost constantly
keep themselves close to the bottom, the much more agile males in some
cases ascend to the very surface of the sea, being occassionally found afnong
plankton taken by the aid of the townet.

Distribution. — West coast of Sweden, British Isles, coast of France,
Mediteranean.

19
6. Asterope abyssicola, G. O. Sars.

Asterope abyssicola, G. O. Sars, Nye Dybvandscrustaceer fra Lofoten, Chr. Vid. Selsk. Forh.

1868, p. 170.

Specific Characters.— Female. Shell, seen laterally, of a somewhat irregular
oblong oval shape, with the greatest height a little in front of the middle and
exceeding half the length, dorsal and ventral margins gently curved, posterior
extremity somewhat narrower than the anterior and obtusely rounded; — seen
dorsally or ventrally, narrow oblong in outline, with the greatest width about
in the middle and the anterior extremity somewhat narrower than the posterior.
Frontal incisure of valves occurring rather far below the middle of the anterior
extremity and rather deep; rostral part very broad and curving downwards.
Surface of shell smooth and polished. Eyes quite inconspicuous in the living
animal. Structure of the several appendages very like that in the preceding
species; last pair of limbs however provided with a greater number of clean-
ing spines, amounting to 19 on each limb.

Colour uniformly whitish.

Length of shell 1.80 mm.

Male unknown.

Remarks. — In the shape of the shell this form resembles somewhat the
Mediterranean species, M. ellipiica Philippi. It is however of somewhat larger
size and differs both from this and the other known species by the absence
or at least quite rudimentary condition of the eyes. From the preceding species
it is moreover distinguished by the considerably greater number of cleaning
spines on the last pair of limbs.

Occurrence.— I'^o female specimens of this form were taken, many years
ago, off the Lofoten islands at the considerable depth of 120 fathoms, muddy
bottom. A 3rd female specimen was moreover obtained during the Norwegian
North Atlantic Expedition at Stat. 290, located about midway between Finmark
and Beeren Eyland, the depth being 191 fathoms. Out of Norway this form
has not yet been recorded.

Fam. 2. Conchoeciidae.

(Halocypridae auctorum)

Characters of the family. Shell of varying shape, with the valves, as a
rule, very thin and pellucid, scarcely exhibiting any trace of calcination, frontal
sinus generally well marked and arched over by 2 closely juxtaposed beak-like

20

rostral prominences. Eyes and ocellus wholly absent. Frontal tentacle, how-
ever, well developed, terminating, as a rule, in a more or less distinctly defined
club-like dilatation. Anterior antennae in female rather feeble and apparently
immobile, carrying on the tip a fascicle of delicate sensory filaments, in male,
as a rule, much more fully developed and freely mobile. Posterior antennae
powerfully developed and not essentially different in structure from those in
the Cypridinidae, inner ramus comparatively small, biarticulate, with the proximal
joint bulbously dilated, the distal one small and tipped with a fascicle of seifll
sory setae, being in male moreover armed with an abruptly curved hook. An-
terior lip more or less produced in front; posterior lip well marked, bilobed.
Mandibles with the body well chitinised, wedge-formed, and terminating below
in a complicated masticatory part; palp, as in the Cypridinidae, large, subpedi-
form, and abruptly bent in the middle, but without any distinctly defined
exopodal appendage, its 1st joint produced at the base below to a toothed
lobe adjoining the masticatory part of the mandibles. Maxillae built on the
very same type as in the more normal Cypridinidae, though having the outer
2 masticatory lobes coalesced. The 3 succeeding pairs of limbs more deviating
in structure and more or less pediform, the anterior pair being however sub-
servient to mastication, and thus more properly termed maxillipeds; last
pair very small, not vermiform. 2 pairs of trilobate vibratory plates present,
attached to the bases of the maxillipeds and the anterior legs, the latter limbs
more or less transformed in male. Caudal lamellae more or less rounded in
shape, with one of the claws inserted to a ledge of the anterior edge and
more slender than the others. Copulatory appendage of male single, sinistral.
Ripe ova, as a rule, not received within the cavity of the shell (sole exception
Euconchoecia) .

Remarks.— Ih^ present family is a very sharply defined one, exhibiting
some apparently rather essential differences from the Cypridinidce, though
evidently belonging to the same chief division. The proposal set forth by
Dr. Skogsberg, to remowe this family wholly from the Myodocopa as a distinct
suborder, I am quite unable to approve. In my opinion the 2 families Cypri-
dinidce and Conchoeciidce form together a very well defined and quite natural
group of Ostracoda, to which alone the systematic rank of a true suborder
can be assigned. Indeed, 1 think it may clearly appear from the diagnosis
given above of the Myodocopa, that all the fundamental characters by which
this suborder distinguishes itself from any of the 3 other suborders here recorded,
are equally well applicable to the Conchoeciidce as to the Cypridinidce. As I
am of opinion, that the several families in which the Cypridinidae has been

21

divided by recent authors, more properly only deserve the systematic rank of
subfamiHes, and no such division has been carried out of the Conchoeciidce, I
have come to the result, that only 2 true families are to be distinguished within
the suborder Myodocopa. The one of these families has been treated of in the
preceding pages, the other is that here in question. As to the name of the
family, I think that the one here given and proposed by me in the year 1865,
ought to be preferred to that generally used by recent authors, Halicypridce.
For, according to the general law in Zoology, the family-name should always
be derived from that of the genus at first established, and the generic name
Conchoecia was in reality proposed by Dana 2 years previous to that of
Haloeypris.

All the forms belonging to the present family lead a true pelagic life,
occuring not seldom in shoals near the surface of the sea, in other cases
however only at greater depths; but they are newer so strictly, bound to the
bottom as is the case witht the Cyprtdlnidce. The weak consistency of the shell,
in connection with the very powerfully developed swimming antennae, seems
indeed to be very apt for facilitating the free movements of the animal.

To the 2 genera, Conchoecia and Halocy pries originally established by
Dana, a limited number of additional genera have been recorded in recent
times, most of them closely allied to the first-named genus and in some cases
only founded on slight differences in the shape of the shell. Only the typical
genus is represented in the Fauna of Norway.

Gen. 4. Conchoecia, Dana, 1849.

Generic Characters. — Shell more or less elongate in shape and not very
tumid, with the dorsal face almost plain and continued anteriorly in the beak-
like rostral projections; subjacent sinus well marked and rather wide. Surface
of shell without any obvious clothing of hairs, in some cases apparently
quite smooth, but more generally sculptured with delicate curved striae often
crossing each other, so as to form a more or less dense net-work. Anterior
antennae in female straight, sub-cylindrical, imperfectly jointed, carrying on the
tip a bundle of generally 4 subequal sensory filaments accompanied in front
by a slender upward-curving seta; those in male much larger, and distinctly
4-articulate, with the apical appendages conspicuously transformed. Posterior
antennae with the basal part exceedingly large, obpyriform in shape, outer
ramus 7 — 9-articulate, with the 1st joint more than twice as long as the

i

22

remaining joints combined, all the natatory setae terminating in a thin lance
olate point; inner ramus with the proximal joint remarkably expanded behind
and produced anteriorly into 2 successive mamilliform processes, the lower of
which is tipped with 2 short bristles; distal joint in male with 2 of the apical
setae much elongated, and the hook constantly more strongly developed
on the right than on the left antenna. Anterior lip forming in front
large, hood-like prominence. Maxillipeds with the basal part produced anteri
orly to a well-marked masticatory prominence, palp 3-articulate and rapidly
tapered distally, its last joint very small and armed with 3 slender anteriorly
curved claws of unequal length. Anterior legs slender, 5-articulate, their out^l
part being in female of a similar structure to that of the palp of the maxillipeds
and generally projected from the shell below; those in male conspicuously
transformed, being more powerfully developed and as a rule, concealed within
the shell, terminating in 3 subequal, densely crowded setae more or less
abruptly bent in their outer part, and generally projecting from the shell,
at its upper posterior corner. Posterior legs very small, imperfectly biarticulate,
and terminating in 2 slender setae, the one of which is very elongate. Caudal
lamellae, each armed anteriorly with a slender spine, curving downwards in
front of the marginal claws. The latter somewhat compressed and gradually
diminishing in size proximally. Copulatory appendage in male oblong in shape
and scarcely lobular at the end.

Remarks. — This genus was established as early as the year 1849 by
Dana, and was subsequently divided by the same author into the 2 genera
Conchoecla (proper) and Halocypris, both being comprised within the sub-
family Halocyprince, which together with the subfamily Cypridinince constituted
his family Halocypridce. The genus may be easily distinguished from Halo-
cypris by the more elongated and far less tumid shell, as also by the very
distinct rostral prominences of the same. It comprises numerous species from
nearly all parts of the Oceans explored. To the Norwegian Fauna belong 3
well defined species, to be described in the sequel.

7. Conchoecla elegans, G. O. Sars.

(PI. XI & XII).

Conchoecla elegans, G. O. Sars, Oversigt af Norges marine Ostracoder, p. 117.

Syn : Paraconchoecla gracilis, Glaus.

Conchoecla quadrangularls, Aurivillius.

Specific Characters.— Female. Shell rather slender and elongated, seen
laterally, almost cuneiform in shape, being gradually narrowed from behind

23

forwards, greatest height quite behind and scarcely exceeding -/o of the length,
dorsal margin straight and horizontal, ventral slightly arcuate and ascending
in front, posterior extremity broadly truncated, with the upper angle well
marked, lower rounded off; — seen dorsally or ventrally, narrow oblong in outline,
tapering more in front than behind, greatest width behind the middle and but
little exceeding ^'3 of the length. Rostral projections rather prominent and
somewhat vaulted above, subjacent sinus very wide, seen laterally almost rect-
angular. Surface of shell exhibiting a very delicate decussated sculpture; right
valve with the upper posterior corner produced in a spiniform point, in front
of which 2 recurved denticles of the dorsal edge are always found. Anterior
antennae scarcely reaching beyond the basal part of the posterior ones, and
exhibiti-ng within their proximal part a number of dark yellow corpuscles, also
found in other species, and apparently visual in nature. Posterior antennae
with the basal part almost attaining half the length of the shell, outer ramus
7-articulate, inner ramus with 5 apical setae, one of them somewhat more
elongate than the others, which are all distinctly sensory. Frontal tentacle only
slightly dilated at the end and projecting a little beyond the anterior antennae.
Caudal lamella with the deflexed spine of the anterior edge rater slender,
claws of moderate length, 7 in number on each lamella, and gradually dimi-
nishing in size proximally.

Male of nearly same size as female and only sligtly differing in the shape
of the shell, though having the anterior part somewhat wider and the upper
posterior corner les prominent. Anterior antennae rather unlike those in female,
being much larger and divided into 4 well defined joints, the 2nd of which
is somewhat dilated at the base and filled with strong muscles acting upon
the 2 small' terminal joints, 3 of the apical appendages much prolonged, seti-
form, the other 2 sensory and very unequal in size, the anterior one bein very
small, the posterior elongated and extending backwards along the stem of the
antenna, outermost seta exhibiting, somewhat beyond the middle, a peculiar
dilatation in the form of a small oval disk finely striated radially and ap-
parently sucturial in nature. Inner ramus of posterior antennae with 2 of the
apical setae much elongated; prehensile hook well developed on the right
antenna, but much reduced on the left. Frontal tentacle with the extremity
conspicuously more dilated than in the female. Copulatory appendage of moderate
size, with the outer part slightly dilated and compressed.

Shell in the living animal very transparent, pale straw-coloured, enclosed
body of a darker hue and in some places exhibiting a more or less conspi-
cuous reddish brown pigment.

24

Length of adult female amounting to 2.30 mm., that of male about the sam?

Remarks. — The present species may be easily recognised from its nearest
allies by the comparatively very narrow, almost cuneiform shape of the shell
and by the rather prominent dentated upper posterior corner. The form
recorded by Glaus as Paraeonchoeeia gracilis is unquestionably identical with
the present species, and this is also the case with Conchoecia qiiadrangularis
of Aurivillius, this species being only founded on immature specimens of
C. elegans. On the other hand it seems to me rather questionable, if the
form taken in the antarctic Ocean, and recorded under the latter name, is in
reality identical with the northern form, though the identity has been admitted
by Dr. Skogsberg. HI

Occurrence. — I have met with this handsome species in several places on
the Norwegian coast, from the Chri'stiania Fjord up to the Lofoten islands,
but, as a rule, only in greater depths beyond 100 fathoms. The most suitable
method for catching it, is to attach a tow-net to the dredging line, at some
distance from the dredge or from a heavy lead to be dragged along the bottom.
In the tow-net thus several bathypelagic animals will be collected, an among
them the present Ostracod may often be found in great numbers. The move-
ments of the animal are exceedingly rapid and effected in adrupt bounds. I
have not observed any phosphorescence in the specimens examined by me in
the living state.

Distribution.— Wesi coast of Sweden (Skogsberg), British Isles (Brady),
Arctic Sea (Auiivillius) Atlantic Ocean (Glaus).

8. Conchoecia borealis, G. O Sars.

(PI. XIII, fig. 1).
Conchoecia borealis. G. O. Sars, Oversigt af Norges marine Ostracoder, p. 119.

Specific Characters.- Female. Shell, seen laterally, oblong subquadran-
gular in outline and rather expanded behind, greatest height nearly attaining
half the length, dorsal margin horizontal with a slight depression in the middle,
ventral margin strongly curved in its posterior part, but in front of the middle
more or less distinctly sinuated, posterior extremity broadly truncated, with the
lower corner evenly rounded off, the upper not produced, obtuse;— seen
dorsally, oblong oval in shape, with the greatest width about in the middle
and somewhat exceeding Va of the length, anterior extremity sub-truncate at
the end, posterior much contracted. Rostral projections rather smaller than in
the preceding species and less vaulted above, subjacent sinus about as in that

25

species. Dorsal face of shell flattened in its anterior half, or even somewhat
excavated, the excavation being defined on each side by an obtuse keel. Sur-
face of valves distinctly decussated by sharply marked striae crossing each other
and forming a very conspicuous net-work of quadrangular meshes, in some
places assuming a somewhat squamiform appearance; upper posterior corner
of each valve armed, somewhat within the edge, with 4 or 5 rather strong
deflexed denticles. Frontal tentacle more fully developed than in C. elegans,
with the extremity conspicuously club-shaped and finely hairy. Structure of the
several limbs very little different from that in the preceding species. Caudal
lamellae with the 3 anterior claws rather slender and elongate, the remaining
4 claws atruptly much shorter.

Male of rather smaller size than female, and having the shell com-
paratively narrower and m^re distictly sinuated below. Frontal tentacle with
the club-shaped extremity sharply defined behind, so as to form a well marked
capitulum. Outermost apical seta of the anterior antennae considerably longer
than the others and abruptly bent near the end, the middle part of the seta
being somewhat thickened and armed posteriorly with a dense series of recurved
somewhat squamiform spinules; posterior reflexed sensory filament tortuous
in a peculiar manner. Hook on the inner ramus of right posterior antenna
comparatively much larger than in the male of C. elegans.

Shell in the living animal rather pellucid, with only a very slight pale
yellow tinge; enclosed body exhibiting in some places a bright reddish orange
pigment.

Length of adult female amounting to 2.80 mm.; that of male scarcely
exceeding 2.30 mm.

Remarks. — The present species is easily distinguishable from the preceding
one, and has even by G. W. Miiller been placed within a separate group of
the genus, the so-called mollis-group. I think however that such a sharp
distinction of these 2 species may scarcely be justified, as both on the whole
agree rather closely in almost all structuial details. Yet the specific difference
is well expressed both in the general outward appearance and in the sculpture
of the shell.

The form recorded by G. W. Miiller from the antarctic Ocean under the
name of C. antipodiim, is closely allied to the present species, and has indeed
been regarded by Dr. Skogsberg as only a variety. The same belief Js_ also
expressed by that author as regards the arctic form, C. maxlmay Brady &
Norman. 1 feel however greet hesitation in approving these views.

Occurrence. — This form was first detected by the present author off the

4 — Crustasea

26

Lofoten islands, where it occurred, together with C. elegans, at the consfoer-
able depth of 250 — 300 fathoms. I have subsequently taken it occasionaUy in
the greater deeps of the Christiania Fjord, at Vallo and Hanke, and it hg^
also been recorded by Norman from tJie Trondhjem Fjord. j||

Distribution. — West coast of Sweden (Skogsberg), Arctic Ocean (Aurivil-
lius), Labrador current (Vavra).

9. Conchoecia obtusata, G. O. Sars.

(PI. XIII, fig. 2).
Conchoecia obtusata, G. O. Sars, Oversigt af Norges marine Ostracoder, p. 118,

Specific Characters.— Female. Shell, seen laterally, oblong oval in shape,
and scarcely broader behind than in front, greatest height about in the middle
and nearly attaining half the length, dorsal margin perfectly straight and hori-
zontal, ventral margin evenly arcuate throughout, posterior extremity narrowly
rounded and somewhat prominent in the middle; upper posterior corner rather
slight and quite unarmed; — seen dorsally or ventrally, narrow oblong in out-
ine, greatest width behind the middle and somewhat exceeding Va of the
length. Rostral prominences of moderate size and somewhat deflexed, subjacent
sinus comparatively narrower than in the 2 preceding species. Surface of
valves nearly smooth, though a slight concentric striation may be discerned in
their marginal parts. Structure of the several appendages very little different
from that in the 2 preceding species. j|

Male much smaller than female, and having the shell comparatively
shorter and stouter. Frontal tentacle with a well defined capitulum. Foremost
apical seta of the anterior antennae, as in the male of C. borealis, abruptly
bent near the end, and having the middle part somewhat thickened, but only
armed with scattered very small and simple spinules; posterior sensory appen-
dage distinctly flexuous. Hook on the inner ramus of right posterior antenna
of quite an extraordinary size, and exhibiting at some distance from the base
an abrupt elbow-like bend, its outer part forming on the middle another
though more even curvature; that on the left antenna, as usual, much reduced
in size. Copulatory appendage comparatively larger than in either of the 2
preceding species, but otherwise of a very similar appearance.

Colour of female specimens whitish grey, with a pale yellow tinge.

Length of adult female amounting to about 2 mm.; that of male only
to 1.40 mm.

Remarks. — This form cannot be confounded with any of the 2 preceding

27

ones, the shell differing conspicuously both in shape and in sculpture. It is
however a true member of the present genus, and my reference of it in the
year 1890 to the genus Haloeypris has turned out to be quite erroneous. I
was led to this supposition by a certain similarity in the shape of the shell
with a small Mediterranean form, which, on the authority of Claus, I took for
a member of Dana's genus, and which was described in my treatice on the
Mediterranean Ostracoda under the name of Haloeypris Clausi. This form is
however not at all a Haloeypris, but the type of a genus, or more properly
subgenus, closely allied to Conchoecia (Microconchoecia CI.).

The present spesies also has its representative in the Antarctic Ocean, a
form being found there, which so closely resembles the northern species, that
it has been considered both by G. W. Miiller and Dr. Skogsberg to be iden-
tical with that species, only representing a slight variety (antarctica). I must
however confess my doubt on the correctness of this identification.

Occurrence.— 01 this species at first only 2 female specimens were found,
the one at Flekkefjord, south coast of Norway, the other in the Trondhjem
Fjord. I have subsequently met with this form occasionaly in 2 other locali-.
ties, viz., at Risor, and in the middle part of the Christiania Fjord, at Hanko.
In the last-named locality it occurred together with C. elegans at a depth of
about 100 fathoms, in the other 3 localities it was found in rather shallower water.

Distribution. — West coast of Sweden (Skogsberg), North Atlantic Ocean
(Vavra).

Suborder 2.

Cladocopa.

General Characters. — Shell without any presistent aperture in front, the
valves admitting of being perfectly closed all around. Both pairs of antennae
distinctly natatory, the posterior ones having both rami developed for that
purpose. Mandibles with the palp of weak structure and not at all pediform,
nor clawed at the tip. 2 pairs only of postoral limbs present, the anterior
ones, representing the maxillae, largely developed, biramous, and partly nata-
tory; posterior pair (maxillipeds) of a much more delicate structure and chiefly
subservient to respiration. Posterior part of body strongly deflexed, and term-
inating in 2 short and broad juxtaposed lamellae, edged below with claw-like
spines, behind which an unpair, small setiform process occurs. Heart and
visual organs wholly absent. Frontal tentacle replaced by 2 juxtaposed
ciliated setae.

Remarks.— Ihis suborder was proposed in the year 1865 by the present
author, to include the very anomalous, and at that time wholly unknown genus
Polycope. the type of the family Polycopidce. I am still fully convinced, that
this suborder ought to be supported, and that the classing of the family Poly-
copidae within the suborder Myodocopa, as proposed by G. W. Miiller, is
quite inadmissible. True, a slight tendency towards the Myodocop type may
be found as regards the structure of the posterior antennae and in particular
the shape of their outer rami; but otherwise the differences are much to great
as to allow a closer association of that family to the Myodocopa. This has
also been fully conceded by the most recent author, Dr. Skogsberg, who has
restored this suborder, though under a different name viz , Polycopiformes.
The suborder comprises a yet only a single family, the general characters of
which are given below.

29

Fam. Polycopidae.

Characters of the family.— ShtW of more or less rounded shape, with
the valves subequal and wanting any obvious clothing of hairs. Anterior an-
tennae very movably connected with the body and of somewhat varying structure,
but always tipped with a fascicle of long natatory setse. Posterior antennae
with the basal part rather thick and muscular, though less so than in the
Myodocopa, rami not very unequal in size and both provided with long nata-
tory setae. Anterior lip comparatively small. Mandibles with the body well
defined and the masticatory part abruptly incurved, palp only composed of 2
distinctly defined lamellar joint, the proximal one carrying at the end anteriorly
a small exopodal appendage. Maxillae with the basal part divided into 2 seg-
ments, the 1st provided inside with a well defined masticatory lobe, the 2nd
with 2 much smaller setiferous lobes; terminal part, constituting the palp,
large and compressed, being divided at the end into 2 deflexed rami, the inner
3-articulate and clothed inside with numerous recurved, partly spiniform setae,
outer ramus much narrower, and not distinctly articulated, but tipped with a
dense fascicle of natatory setae. Maxillipeds lamellar in structure and each divided
into 3 more or less distinctly defined segments rapidly diminishing in size, the 1st
rather large and provided outside with a well developed semilunar vibratory plate,
2nd segment subtriangular in shape, with a small setiferous lobe at the end out-
side, last joint very small and in some case not distinctly defined. None of the
limbs transformed in male. Caudal lamellae with the claws inserted within more
or less deep incisions of the margin, left lamella in male more or less conspicu-
ously transformed and contributing to the formation of the very complicated
and pronouncedly asymmetrical copulatory apparatus.

Remarks. — This family was proposed by the present author for the reception
of the genus Poly cope, the only one at first known. In the year 1894 another
genus, Polycopsis, referable to the same family, was added by G. W. Miiller,
and I regard it as very probable, that the number of genera will be still more
increased in future. Both of the above mentioned genera are represented in
the Fauna of Norway.

Gen. 1. Polycope, G. O. Sars, 1865.

Generic Characters. —SheWy as seen laterally, more or less perfectly orbic-
ular in shape, with the 2 extremities very little dissimilar, the anterior one
being however in most cases somewhat more bowed in the middle than the

30

posterior. Valves generally thin and pellucid, with the surface in some cases
quite smooth, in other cases closely punctate or reticulate, lower edges scarcely
serrate, but, as a rule, fringed with very small and delicate spinules. Anterior
antennae each composed of 4 rather unequal joints, the first 2 very obliquely
connected with each other, 2nd joint considerably dilated at the base and filled
with strong muscles acting upon the small terminal part of the antenna, its
upper edge provided in the middle with a slender anteriorly-pointing seta;
3rd joint very movably articulated to the preceding joint and carrying a small
bristle at the end anteriorly; last joint so extremely small as only with diffi-
culty to be discerned, and tipped with 4 exceedingly long and slender subequal
natatory setae. Posterior antennae with the outer ramus 8 — 9 articulate, and
resembling in structure that in the Myodocopa; inner ramus not much shorter
than the outer and 3-articulate, with the 1st joint naked and much larger than
the other 2, which are densely clothed with natatory setae of the same appea-
rance as those on the outer ramus. Anterior lip rounded in front. Mandibles
with the cutting edge divided into 4 or 5 unequal teeth, proximal joint of palp
forming behind a rounded lobe clothed with 4 plumose setae, distal joint blunted
at the end, and provided with 4 slender apical setae arranged in pairs. Maxillae
with the rami of about equal length. Maxillipeds with the terminal joint well
defined and tipped with a single seta. Caudal lamellae in female without any
denticles of the anderior edge; left lamella in male sending off from the base
anteriorly a more or less produced spiniform process adjoining the copulatory
apparatus.

Remarks.— Oi this remarkable genus at first only a single species was
found, described by the present author in the year 1865 under the name of P.
orbicularis. In the next following years, however, 2 other nearly-allied species
were added, and in recent times the number of species has been considerably
increased by other authors. Thus G. W. Miiller records from the Mediterranean
no less than 9 different species referred by him to this genus. Some of these,
in particular the 3 species, P. dentata, rostrata and tuberosa, seem however
to me to differ so conspicuously from the typical species, both in the general
appearance and in the rough sculpture of the shell, that they perhaps more
properly should be placed within a separate genus. On a closer examination
of the material in my possession, I have been enabled to increase the number
of Norwegian species referable to the present genus to 6 in all.

31

1. Polycope orbicularis, G. O. Sars.

(PI. XIV, PI. XV, fig. 1)
Polycope orbicularis, O, O' Sars, Oversigt af Norges marine Ostracoder, p. 122.

Specific Characters. Female. — Shell rather tumid, seen laterally, nearly
circular in outline, greatest height in the middle and but little inferior to the
length, dorsal margin strongly and somewhat angularly arched in the middle,
ventral margin forming a more even and rather bold curve, anterior extremity
bluntly rounded, with a slight indication to an angle above; — seen dorsally
rather broad, almost rhomboidal in outline, the lateral edges being abruptly
curved in the middle, greatest width about equalling -/a of the length, anterior
extremity somewhat more pointed than the posterior. Valves thin and fragile,
though somewhat thickened along the dorsal face; ventral margin exhibiting
a narrow hyaline border crossed by a number of very small and delicate
spinules. Surface of valves finely punctate and moreover exhibiting a very
delicate reticulate pattern of polygonal meshes. Caudal lamellae each armed
with 7 claws finely ciliated behind and gradually diminishing in size proximally,
all the claws being inserted within deep incisions of the margin, which projects
between them as rather prominent triangular processes.

Male somewhat smaller than female, but otherwise very similar in its
outward appearance. Left caudal ramus conspicuously transformed; outermost
claw replaced by a thin bristle inserted high up on the side of the lamella,
subjacent excavation rather wide, with the anterior defining angle digitiform
produced; anterior upturned process broad at the base but rapidly tapered
distally and terminating in a tridentate point. Copulatory apparatus of such
a complicated structure as only with difficulty to be described in detail, its
most conspicuous part being a rather large piece, on the left side, curving
upwards in close approximation to the above-mentioned process of the cor-
responding caudal lamella, and terminating in a somewhat dilated bilobular
extremity.

Colour of shell pale yellow, variegated with irregular reddish orange patches
radiating from the centre of each valve towards the margins.

Length of adult female amounting to 0.70 mm; that of male to 0.50 mm.

Remarks. —Ihxs species, being the first described, ought of course to be
regarded as the type of the present genus. It seems to me somewhat questi-
onable, if the form recorded under this name by Brady in his Monograph of
the recent British Ostracoda is the same species, as the figure he gives of the
shell, as seen dorsally, is rather different. On the other hand, the figures given

1

32

in the subsequent work published by him in connection with Norman, are
unquestionably referable to the present species.

Occurrence. — This peculiar little Ostracod is by no means rare off the coast
of Norway. I have taken it in many different places, both on the south and
west coasts, from the Christiania Fjord at least to Trondhjem. It generally
occurs at moderate depths ranging from 6 to 20 fathoms, on a sandy bottom
covered with a thin layer of mud. The animal moves rather lively along the
bottom in a peculiar manner reminding somewhat on that of some Lynceidae
(Chydorus sphcericus) . During the swimming the slender natatory setae attached
to both pairs of antennas and to the outer ramus of the maxillae are seen
projecting from the shell anteriorly as dense diverging fascicles, which are
moved rapidly in a vertical plane, as in the Cypridce. When disturbed, the
animal at once withdraws its swimming appendages within the shell, the
valves of which then become firmly closed.

Distribution.— Bni\sh Isles (Brady).

2. Polycope punctata, G. O. Sars.

(PI. XV, fig. 2).

Polycope punctata, G. O. Sars, Nye Dybvandscrustaceer fra Lofoten.

Chr. Vid. Selsk. Forh. 1819, p. 171.

Specific Characters. — Female. Shell, seen laterally, resembling in shape
that of the preceding species, though having the margins somewhat more
regularly curved; — seen dorsally, very broad, the greatest width attaining ^U
of the length. Surface of valves sculptured with densely set and rather con-
spicuous pits, but without any trace of a reticulation. Anterior antennae less
densely hairy than in the preceding species, with the penultimate joint com-
paratively larger. Mandibular palp with the posterior lobe of the proximal
joint somewhat more prominent, and the distal joint broader, almost quadrang-
ular in shape; exopodal appendage only provided with a single thickish seta,
another small, but distinctly ciliated seta issuing just behind it from the outer
distal corner of the joint. Structure of the limbs otherwise very like that in
the preceding species. Caudal lamellae however somewhat dissimilar, being
more triangular in shape, with the lover edge almost straight and the anterior
corner rather produced; claws, as in P. orbicularis, 7 in number on each
lamella, intercurring projections of the margin, however, much smaller than
in that species. ^

Male closely resembling the female in its outward appearance, though
of somewhat smaller size. Left caudal lamella with the anterior corner not at

Cypridinidae

Ostracoda

Myodocopa

PI. I

6. O. Sars del.

Cypridina norvegica, Baird

n

Cypridinidae

Ostracoda

Myodocopa

PI. II

■O

^1

^ii

Mi'y'^>^.

'X'> '

?

l

M>^

:J

Wli

// 1/

:i^

G. O. Sars del

Cypridina norvegica, Baird
(continued)

CypridinidaB

Ostracoda

Myodocopa

PI. Ill

'hhy-

'm\

G. O. Sars del

Cypridina norvegica, Baird
(continued)

Cypridinidae

Ostracoda

Myodocopa

PI. IV

3ta

J Cf.cyy,^

6. O. Sars del.

Cypridina megalops, 6. O. Sars

Cypridinidae

Ostracoda

Myodocopa

PI. V

6. O. Sars del.

Philomedes globosus, (Lilljeborg)

CypridinJdae

Ostracoda

Myodocopa

PI. VI

6. O. Sars del.

Philomedes globosus, (Lilljeb.)
(continued)

n

Cypridinidae

Ostracoda

Myodocopa

PI. VII

6. O. Sars del.

Philomedes globosus (Lilljeb.)
(male)

Cypridinidae

Ostracoda

Myodocopa

PI. VIII

G. O. Sars del.

Philomedes Lilljeborgi, 6; O. Sars

^

^

Cypridinidae

Ostracoda

Myodocopa

PI. IX

6. O. Sars del.

Asterope Maria, (Baird)

Cypridinidffi

Ostracoda

Myodocopa

PI. X

Z-¥6

G. O. Sars del

1. Asterope Marias (Baird) contin.

2. „ abyssicola, 6. O. Sars

Conchoeciidae

Ostracoda

Myodocopa

PI. XI

-r^^^

-s

/;

r

;\ L,

G. O. Sars del.

Conchoecia elegans, 6. O. Sars

ConchoeciJdae

Ostracoda

Myodocopa

PI. XII

G. O. Sars del

Conchoecia elegans, 6. O. Sars
(continued)

^

Conchoeciidae

Ostracoda

Myodocopa

PI. XIII

' i^.^

6. O. Sars del.

1. Conchoecia borealis, 6. O. Sars

2.

obtusata, 6. O. Sars

Polycopidae

Ostracoda

Cladocopa

PI. XIV

.^^t

""--^ Z^>* '»-«'- jiSiA, '

^'<!V. ?-

;^

w

M

u

-^-:

/

\ si

-4^^^.^3E^

■V.

.7l>i

r

^■.

N N'Si^-.

'fa. ■ 'm^'(^-

y^

.Th

If-

G. O. Sars del.

Polycope orbicularis, 6. O. Sars

Polycopidae

Ostracoda

Cladocopa

PI. XV

G. O. Sars del.

1. Polycope orbicularis, 6. O. Sars (male)

2. ,, punctata, G. O. Sars

Polycopidae

Ostracoda

Cladocopa

PI. XVI

-$ /'

i.H^ /ir

z

N^r

^-^c^.

/^.•<

m^„.

6. O. Sars del.

1. Polycope areolata, 6. O. Sars

2. „ clathrata, 6. O. Sars

3. „ pustulata, 6. O. Sars

33

all produced, and the marginal claws comparatively thinner than in female;
anterior upturned process slender, falciform, and terminating in a thin setiform
point. Chief piece of the copulatory apparatus short and thick, almost globular
in shape, and clothed all over with small spikes.

Colour whitish gray, variegated with a light yellowish green pigment
forming irregular patches radiating, as in P. orbicularis, from the centre of
each valve to the margins.

Length of adult female amounting to 0.78 mm.

Remarks. — The above-described form is nearly allied to the typical species,
but of somewhat larger size, and moreover easily recognised by the closely
punctate sculpture of the valves and the wholly absence of any reticulation on the
same. In the fresh state it also distinguishes itself by a rather different colour.

Occurrence. — I have only met with this form in a single locality of the
Norv^egian coast, viz., off the Lofoten islands, where it occurred at the consider-
able depth of 120—250 fathoms.

DistrlbuUon. — ? British Isles (Brady).

3. Polycope areolata, G. O. Sars, n. sp.

(PI. XVI, fig. 1).

Specific Characters. — Female. Shell far less tumid than in the 2 pre-
ceding species, seen laterally, of a somewhat irregular rounded shape, with
the greatest height a little behind the middle and not attaining the lenght,
dorsal margin abruptly arched beyond the middle, ventral margin forming a
more even and rather bold curve, anterior extremity conspicuously bowed in
the middle, posterior bluntly truncated, with no trace of angle below;— seen
dorsally, regularly oval in outline, with the lateral edges quite evenly curved,
the greatest width scarcely exceeding half the length. Surface of valves con-
spicuously sculptured, exhibiting a very sharply marked areolation into com-
paratively wide polygonal meshes, ventral edges in the greater part of their
length fringed with delicate spinules; right valve armed, just above the most
prominent part of the frontal margin, with a well marked, though rather small
dentiform process. Structure of the several limbs not exhibiting any pronounced
difference from that in the type species. Caudal lamellae somewhat resembling
in shape those in P. punctata, but having the anterior corner far less produced,
whereas the marginal processes between the claws are rather more fully developed.

Male having the shell somewhat less high than in female, but otherwise
rather similar both in shape and sculpture. Left caudal lamella with the fore-
most claw very small and rudimentary, and the anterior corner not at all pro-

5 — Crustacea.

34

duced; upturned process not much elongated, simply spiniform, and sharply
defined at the base. Chief piece of the copulatory apparatus of a somewhat
similar shape to that in the male of P. orbicularis, but less elongated.

Colour not yet ascertained.

Length of adult female 0.53 mm., of male 0.48 mm.

Remarks.— Ih^ present species may be at once distinguished from either
of the 2 preceding ones by the far less tumid shell, and more particularly by
the very sharply marked areolation of the valves. Another rather conspicuous
difference is found in the frontal armature of the right valve.

Occurrence. — Some few specimens of this form were picked up from
samples collected at Korshavn, south coast of Norway, and taken at moderate
depths. I have not met with this form in any other place on the Norwegian coast.

4. Polycope clathrata, G. O. Sars, n. sp.

(PI. XVI, fig. 2)

Specific Characters. — Female. Shell very similar in shape to that in the
preceding species, but of smaller size and somewhat less high in proportion
to the length. Surface of valves very coarsely sculptured, exhibitin gan exceed-
ingly dense reticulation, the meshes being much smaller and more crowded
than in the preceding species, ventral edges nearly in their whole length fringed
with delicate spinules; right valve armed in front with a similar dentiform
process to that found in P. areolata, though of somewhat larger size. Caudal
lamellae not much different in shape from those in that species.

Male rather smaller than female, but resembling it very much both in its
general appearance and in the characteristic sculpture of the valves. Left caudal
lamella with the anterior corner blunted, and the 3 foremost claws (in the
specimen examined) wholly absent, upturned process rather slender and almost
straight, terminating in a somewhat tortuous point. Chief piece of the copuh
tory apparatus comparatively large and lamellarly dilated at the end.

Colour not yet ascertained.

Length of female 0.47 mm, of male 0.42 mm.

Remarks. — The present form is closely allied to the preceding specie
but of rather smaller size, and moreover at once distinguished by te mucf
denser reticulation of the valves. The transformed left caudal ramus of the
male and the chief piece of the copulatory apparatus also exhibit well markec
differences from those parts in P. areolata.

Occurrence. — Two specimens only of this form have as yet come und(
my notice. The male specimen was obtained from the same sample in whicl

35

the preceding species occurred; the female was found among some specimens of
P. orbicularis collected, many years ago, of the west coast of Norway, the exact
locality not being noted.

5. Polycope pustulata, G. 0. Sars.

(PI. XVI, fig. 3)
Polycope pustulata, G. O. Sars. Oversigt af Norges Crustaceer, Part II, Chr. Vid. Selsk.

Forh. 1890, p. 53.

Specific Characters.— Female. Shell, seen laterally, of the usual short
rounded shape, with the anterior extremity slightly bowed in the middle, the
posterior blunted and exhibiting above trace of an angle; — seen dorsally, of a
rather peculiar shape, being narrowed in front and much dilated behind, with
a very conspicuous pustuliform prominence on each side. Valves smooth,
without any obvious sculpture, and quite unarmed in front. Caudal rami resemb-
ling in shape those in P. orbicularis, the triangular processes of the margin
between the claws being rather produced.

Colour about as in P. orbicularis.

Length of shell 0.56 mm.

Male unknown.

Remarks.— Ih^ present form may at once be distinguished from any of
the other known species of the present genus by the peculiar pustuliform ex-
pansions of the hinder part of the shell, best seen in the dorsal or ventral aspect.
Otherwise it seems to be closely allied to the type species.

Occurrence. — A solitary female specimen only of this form has as yet
come under my notice. It was found, many years ago, off the west coast of
Norway, the exact locality not being noted. Out of Norway this form has
not yet been recorded.

6. Polycope sublaBvis, G. O. Sars, n. sp.

(PI. XVII, fig. 1)

Specific Characters. — Female. Shell, seen laterally, resembling in shape
that of the type species, though having the anterior extremity a little more
bowed in the middle;— seen dorsally, regularly oval in outline, with the lateral
contours quite evenly curved, and the greatest width only slightly exceeding
half the length. Surface of valves nearly smooth, though in some cases a very
faint reticulation may be discerned; anterior edges unarmed. Caudal lamellae
resembling in structure those in P. orbicularis, though comparatively somewhat
narrower, with the anterior corner more produced and the claws shorter.

Male, as usual, very like the female in its general appearance. Left
caudal lamella produced in front to a comparatively short and stout, almost

3e

straight prominence clothed at the somewhat obtuse point with small spikes.
Chief piece of the copulatory apparatus abruptly curved upwards, with the
outer part narrow cylindric in shape and obtusely blunted at the tip.

Colour not yet ascertained.

Length of adult female 0.50 mm.

Remarks. — The above-described form so closely resembles young specimens
of P. orbicularis, as easily at the first sight to be confounded with that species.
On a closer examination, however, it may at once be distinguished by the far
less tumid shell, its dorsal or ventral aspects being indeed very different in
the 2 species (compare the figures here given). Moreover well marked diffe-
rences are found in the shape of the transformed left caudal lamella in the
male, as also in that of the chief piece of the copulatory apparatus.

Occurrence. — It is only recently that I have been aware of this species,
which may be not uncommon, at least on the south coast of Norway, as 1
have succeeded in finding several specimens, both males and females, among
material collected partly at Risor, partly at Korshavn.

Gen. 2. Polycopsis, G. W. Miiller, 1894.

Generic Characters. — Shell of a somewhat similar shape to that in Polycope,
though more compressed, and having the anterior part of the ventral edges
distinctly serrate. Anterior antennae of a rather deviating structure, being com-
posed of a greater number of joints than in Polycope, amounting to 6 in all,
the first 2 of which are rather large and expanded, the 4 remaining joints
abruptly much smaller; 2nd joint much the largest and divided in front into
2 remarkable deflexed lappets, the distal one triangular in shape and highly
chitinised curving over the terminal part of the antenna. Posterior antennae
with the inner ramus in male distinctly prehensile, being armed at the end, in
front of the setae, with a slender recurved claw. Mandibles with the masticatory part
very narrow and imperfectly dentated at the end; distal joint of the palp some-
what differing in shape from that in Polycope, and having one of the apical setae
much stronger than the others, almost claw-shaped. Maxillipeds with the terminal
joint imperfectly defined. Caudal lamellae with the anterior corner bidentate.

Remarks. — This genus was established in the year 1894 by G. W. Muller,
to comprise the Polycope compressa of Brady «& Robertson and an additional
Mediterranean species, P. serrata. It is especially distinguished by the peculiar
structure of the anterior antennae, and exhibits also some other well marked
differences, as mentioned in the above diagnosis. Of the 2 as yet known
species, the one only is represented in the Fauna of Norway.

37

7. Polycopsis compressa (Brady & Robertson).

(PI. XVII, fig. 2)
Polycope compressa, Brady & Robertson, Ann. Mag. Nat. Hist. ser. IV, Vol. Ill, p. 20,

Pi. XXI, figs. 5—11.

Specific Characters. — Female. Shell rather compressed, seen laterally, of
a somewhat obliquely rounded shape, greatest height in the middle and only
little inferior to the length, dorsal and ventral margins evenly curved, anterior
extremity broadly rounded and only very slightly bowed in the middle, posterior
narrower and quite evenly rounded at the end, without any trace of an angle
above;— seen dorsally, narrow oblong in outline, with the lateral edges nearly
straight in the middle, greatest width somewhat behind the middle and not
nearly attaining half the length, anterior extremity more narrowed than the
posterior. Surface of valves smooth, of a dull appearance, not exhibiting any
obvious sculpture; anterior part of the ventral edges with about 16 well-marked
serratures, smaller however than in P. serrata. Anterior antennae with both
lappets of the 2nd joint well defined, the proximal one however much narrower
than the distal one, both tipped with a single seta; 2 other well-developed
ciliated setae, not found in Polycope, present, the one issuing from the upper
distal corner of the 1st joint, the other on the posterior edge of the 2nd joint
near its end; terminal part of the antenna distinctly 4-articulate and tipped
with 5 natatory setae. Caudal lamellae each armed, as in Polycope, with 7 claws,
intercurrent processes of the margin comparatively small.

Colour opaque whitish.

Length of the specimen examined 0.61 mm.

Remarks. — This form was at first described by Brady and Robertson as
a species of the genus Polycope, but was subsequently by G. W. Muller justly
removed as the type of a distinct genus. The latter author had also an oppor-
tunity of examining male specimens, and has stated the presence in them of
a well-developed apical claw on the inner ramus of the posterior antennae, a
feature not found in the species of Polycope. The present form may, also
without dissection, be easily recognised from any of the species of that genus
described in the preceding pages, by the much more compressed shell and by
the rather conspicuous serratures of the anterior part of the ventral edges.

Occurrence.— k solitary female specimen only of this form has as yet come
under my notice. It was taken at Korshavn, south coast of Norway in com-
paratively shallow water.

Distribution.— ^Briiish Isles (Brady), Mediterranean (G. W. Muller).

Suborder 3.

Platycopa.

General Characters. — Shell strongly calcareous, without any persistent
aperture in front, and in general appearance not very unlike that in some of the
Podocopa. Enclosed animal, however, built on a very different type. Both
pairs of antennae very powerfully developed and allowing to be extruded from
the shell in front, being however scarcely at • all natatory, the anterior ones
multiarticulate and abruptly geniculate at the base, the posterior ones exhibit-
ing a structure totally different from that in any other known Ostracoda, being
broad and flattened, biramous, and in their general appearance somewhat re-
calling the legs of Copepoda. All the other appendages of rather weak structure
and wholly concealed within the shell. 3 pairs only of postoral limbs present,
none of them pediform; last pair in female quite rudimentary. Caudal rami
rather feeble, and differing conspicuously both in shape and armature from
those in the other known Ostracoda. No frontal tentacle present, nor any
distinctly developed visual organs or heart.

Remarks. — This suborder also was founded by the present author in the
year 1865 on a single genus, viz., Cytherella, the species of which at that
time were only known in a fossil condition, and which of course only could
be determined from the characters of the shell, the genus being considered as
nearly allied to Cythere. By the' discovery of a recent species occurring off
the Norwegian coast, I had an opportunity of examining also the enclosed body,
and found it to my great astonishment so totally different in structure from
that in any of the other Ostracoda known to me, that I could not hesitate in
establishing for the reception of this genus not only a particular family,
Cytherellldce, but even a distinct group of higher systematic rank, named as
above in allusion to the peculiar structure of the posterior antennae. The state-
ments about the remarkable structural details in this genus given by me at
that time, though unfortunately without any accompanying figures, have since
partly been confirmed by 2 other authors, Brady and G. W. Miiller, who has
given figures of the limbs in 2 nearly allied recent species. The latter author,

39

however, did not consider the differences great ennough to justify the estab-
lishment of a distinct suborder, and proposed to include the family Cytherellidae
within the suborder Podocopa, placing it near the family Darwinulidce. I am
quite unable to consent with G. W. MuUer in this view, and the most recent
author, Dr. Skogsberg, also rejects it decidedly, fully admitting the present
suborder, though designing it with a new name, viz., Cytherellifotmes.

Fam. Cytherellidae.

Remarks.— k?, this family at present only comprises a single genus, it
may suffice to give the characters of that genus. I am however by no means
convinced that all the fossil forms referred to it are in reality congeneric.

Gen. Cytherelia, Bosquet, 1852.

Generic Characters.— SheW of very firm consistency, highly calcareous and
quite opaque, being more or less compressed and, seen laterally, of oval or
elliptical shape. Valves very unequal, the right one being much the larger
and overlapping the left around all the margins; muscular spots densely crowded
and arranged in a double vertical row near the centre of each valve; inner
duplicatures very narrow, almost obsolete. Anterior antennae strongly built,
7-articulate, all the joints sharply defined and more or less produced in front,
carrying tufts of comparatively short spiniform setae, the first 2 joints the largest
and forming together an abrupt geniculate bend. Posterior antennae with the
basal part divided into 2 sharply defined segments forming together a very
movable articulation, rami however apparently firmly connected to the end of
the basal part and of somewhat unequal size, the inner one the longer and
3-articulate, the outer biarticulate, both rami carrying numerous strong spini-
form setae. Anterior lip large, and somewhat bell-shaped. Mandibles rather
small, with the masticatory part obliquely truncated at the end and fringed with
a dense row of delicate spinules ; palp sub-cylindricat in shape, almost straight,
and only composed of 2 joints, the distal one small, bisetose, the proximal
one provided at the base anteriorly with a small setiferous lamella and clothed
along the inner face with a dense comb-like row of delicate recurved setae.
Maxillae carrying at the base a very largely developed vibratory plate, and

40

exhibiting inside the basal part 3 well defined masticatory lobes; palp slender
and somewhat resembling in shape and armature the mandibular palp, though
without any setose lamella at the base. Penultimate pair of limbs (maxillipeds)
only composed of 2 lamellar segments, the proximal one the larger and pro-
vided outside with a well developed vibratory plate, though rather smaller than
that on the maxillae, wanting however any trace of masticatory lobes, distal
joint narrow oblong in shape and clothed with a few irregularly arranged setae,
some of which are densely plumose. Last pair of limbs in female each only
represented by a simple rounded lamellae carrying a few setae on the end.
This and the preceding pair in male, however, provided with a strongly dev-
eloped prehensile appendage, that of the maxillipeds being of a very peculiar
appearance, somewhat hatchet-shaped, that of the last pair of limbs more
resembling in shape the prehensile palp of the maxillipeds usually met with
in male Cypridae. Posterior part of body in both sexes divided by transverse
chitinous stripes, as it were, into numerous short segments, some of which carry
dorsally long diverging setae. Caudal rami of rather delicate structure, forming
2 thin juxtaposed lamellae extending forwards below the body and fringed around
the somewhat dilated extremity with a number of peculiar flattened spines,
each terminating in a thin setiform lash. Copulatory appendages of male large,
symmetrical, forming 2 s'ender and attenuated pieces curving upwards. Ripe
ova received within the shell-cavity for farther development.

Remarks. — This genus was established in the year 1852 by Bosquet to
include some fossil Ostracoda found in the tertiary deposits of France and
Belgium. The genus was placed by him in the family Cytheridoe, near to
Cy there. The true systematic relation was first settled in the year 1865 by
the present author. |l

Several recent species have in the latter years been added to that observed
by me, all of them being found in considerable depths of the oceans; but
in almost every case the examination of these species has been limited to the
shell. The only additional informations about the structural details have, as
far as I know, been given by Brady for a species, C. serrulata, taken off the
coast of Marocco, and by G. W. Miiller for a Mediterranean species, C. sordidM\
The genus is represented in the Fauna of Norway by a single species only,
to be described below.

41

Cytherella abyssorum, G. O. Sars.

(PI. XVIII & XI^)
Cytherella abyssorum, G. O. Snrs, Ovcrsigt af Norges marine Ostracoder, p. 127,
Syn : Cytherella Beyrichi, Brady.
— scotica, Brady.

Specific Characters. — Female. Shell much compressed, seen laterally, of
a rather regular oval or elliptical shape, with the height somewhat exceeding
half the length, dorsal margin straight, ventral very slightly sinuated, both
extremities rounded off and nearly equal;— seen dorsally, very narrow, almost
cuneiform in outline, with the lateral margins scarcely at all bowed, anterior
extremity narrowly truncated, posterior abruptly dilated near the end and blunted
behind. Left valve much smaller than the right and fringed at its free edges
with a thin hyaline border, which fits closely in a groove of the right valve,
when the shell is closed. Surface of shell smooth, though exhibiting a some-
what dull appearance by numerous well-marked impressed pits, and in fresh
specimens clothed with scattered rigid hairs especially at the hind extremity.
Anterior antennae with the 1st joint rather massive and provided in front with
a number of somewhat unequal bristles, behind with a considerably longer
seta, 2nd joint abruptly bent upon the 1st ventrally and carrying in front 3
stout distinctly ciliated setae arising close together from a slight prominence
of the edge; 3rd joint comparatively simple, being quite unarmed in front and
only provided at the end behind with a thin bristle; 4th joint with 2 such bristles
and, like the 2nd, carrying in front 3 subequal stout setae attached to a well-
marked blunt prominence; 5th joint of a similar structure, though without any
bristles behind; 6th joint with only 2 setae in front, but provided at the end
behind with a small bristle; terminal joint much narrower than the others and
somewhat obliquely truncated at the end, carrying 4 unequal setae, one of them
rather small and attached to the anterior edge. Posterior antennae with the 2
segments of the basal part forming together generally an abrupt genicular bend,
2nd segment somewhat smaller than the 1st, but slightly widening distally and
exerted behind to a somewhat projecting corner tipped with 3 slender setae,
anterior edge of the segment clothed with tufts of fine hairs; outer ramus about
equal in length to that segment and having the proximal joint rather large,
quadrangular in shape, distal joint however very small, lamelliform; inner ramus

6 — Crustacea.

p

42

with its 3 joints gradually diminishing in size, the 1st being provided near the
base posteriorly with a bundle of small sensory filaments; setae of both rami
very coarse and more or less recurved. Caudal lamellae somewhat constricted
in the middle, and having the outer part slightly expanded, each with 9 — 10
marginal spines densely crowded around the blunted extremity, the middle
spines being the longest, the others gradually diminishing in length. 1

Male somewhat smaller than female and having the shell conspicuously
more compressed, with the posterior extremity far less abruptly dilated. Pre-
hensile appendage of maxillipeds with the basal part elongate subfusiform i
shape, exhibiting inside 2 successive, but rather remote bisetose prominence
and projecting at the end outside in a sharp corner; terminal mobile part much
shorter than the basal one, but somewhat dilated at the base which is exerted
in front to an angular corner followed by a number of well marked serratures
of the edge. Prehensile appendage of last pair of limbs rather different ifll
shape, forming a slender, distinctly 3-articulate stem bent in the middle in
an elbow-like manner, and provided outside the 1st (basal) joint with a dense
series of delicate finely ciliated setae. Copulatory appendages somewhat thickened
at the base, but terminating in a very narrow cylindrical extremity.

Colour in both sexes opaque whitish.

Length of adult female amounting to 0.95 mm., of male to 0.90 mm.

Remarks. — It may be that the above-described form in reality is identica
with one or other of the numerous fossil species recorded; but as I find it
impossible at present to decide this with certainty, I prefer to record the species
under the specific name given to it in 1865 and admitted by all subseque
authors. The 2 forms named by Brady as C. Beyrlchi and C. scotlca a
quoted here as synonyms on the authority of that author.

Occurrence. — Of this remarkable form at first only a few empty shells
were found off the Lofoten islands in depths ranging from 100 to 300 fathoms.
Subsequently, however, my late father succeeded in picking up a considerable
number of specimens from dried mud taken partly from the deeps off the
Lofoten islands, partly from several other places of the west coast off Norway.
Some of these specimens had still their 2 valves in situ, and on a cloS
examination I found the enclosed body in a few of them sufficiently w
preserved to allow a detailed investigation of the several limbs.

As to the habits of the animal, very little can be said, as I have not y
had an opportunity of observing it in the living state. It may however b
inferred from the heavy condition of the shell and the peculiar structure of thi

{

43

antennae, that the animal is quite incapable to move freely in the water, and
of course is always bound to the bottom, dragging itself slowly through the
loose mud chiefly by the aid of its powerful posterior antennae which may act
as a sort of shoving-implements for throwing away the mud in its route.

Destribution. — British Isles (Brady), Mediterranean at Nice (Marquis de
Folin), Atlantic Ocean down to 410 fathoms (Valorous Expedition).

Suborder 4.

Podocopa.

General Characters.— SheW without any persistent aperture in front, a
of very varying shape and sculpture, but always somewhat flattened below,
with the ventral edges of the valves in the oral region conspicuously bent
inwards and somewhat bowed, so as to overlap each other, when the shell is
closed. Both pairs of antenna well developed and partaking in the movements
of the animal, being in some cases adapted for swimming, in other case only
for crawling; the posterior ones very unlike those in the 3 preceding suborders,
being pronouncedly pediform, geniculate in front, and clawed at the tip.
Mandibles, as a rule, well developed and provided with a deflexed 4-articulate
palp of moderate size and provided at the base with a movable setiferous
lamella. 4 pairs of postoral limbs always present, the anterior ones (maxilla)
provided at the base with a large vibratory plate and terminating in 4 densely
crowded and more or less digitiform setiferous lobes, the outermost of which
represents the palp. The next pair of limbs in some cases subservient to
mastication and having the palp (endopodite) imperfectly developed, thus more
properly termed maxillipeds, in other cases however pronouncedly pediform,
like the 2 succeeding pairs. Caudal rami, when perfectly developed, forming 2
slender and very mobile pieces armed at the tip with 2 claws only, in many
cases however much reduced in size and apparently immobile. Compound
eyes wanting, but in most cases an ocellus, simple or bipartite, may be found
to exist. No frontal tentacle nor any trace of a heart present. Intestine divided
by a mediate constriction into 2 well defined compartiments, the anterior of
which may be provided with 2 more or less developed lateral coeca. Genital
organs of rather varying structure. Copulative appendages of male symme
trical and often very complex.

Remarks. — This suborder proposed by the present author in 1865, is
very natural one, exhibiting a number of well marked distinguishing characters
derived both from the shell and from the enclosed body. It has also been
approved by all subsequent authors, though its limits were somewhat altered

II

45

by G. W. Miiller by the reception within it of the family CytherelUdce. As
above shown, this family cannot however by any means find its place within
the present suborder. The name, as here given, alludes to the pronouncedly
pediform structure of the posterior antennae, the general appearance of which
is not unlike that of the mandibular palps in the Myodocopa. As to the shell,
the peculiar closure of the valves in the oral region is very characteristic, no
trace of such a closure being found in any of the forms belonging to the 3
preceding suborders, whereas in all the known Podocopa its existence may
easily be demonstrated.

The present suborder comprises the far greater bulk of the known
Ostracoda, and is represented both in the sea and in fresh water. We may
distinguish within it 2 well defined families, viz., the Cyprldce and the Cytheridce,
both established as early as the year 1852 by Baird and founded on the 2 old
genera Cyprls and Cythere. True, in recent times several other families have
been added; but in my opinion these new families only deserve the systematic
rank of subfamilies, to be classed under the head of the one or the other of
the 2 above-mentioned families. In the sequel a short characteristic of these
subfamilies will be given in addition to the diagnoses of the chief families.

Fam. 1. Cypridae,

Characters of the family. — Shell in most cases thin, corneous, only seldom
of a more solid consistency, surface smooth, never roughly sculptured, hing
simple, without any closing teeth. Ocellus, when present, generally simple,
not divided. Anterior antennae scarcely at all geniculate, basal part more or
less dilated and divided into 2 or 3 segments, terminal part attenuated, 4- or
5-articulate, and clothed with numerous more or less slender setae forming
together a dense apical brush. Posterior antennae originating by a short and
somewhat imperfectly defined root-joint followed by a much larger joint,
which constitutes the main part of the basal portion, the latter provided at<
the end outside with a small scale-like appendage carrying a slender anteriorly
curved seta accompanied by one or two very small bristles; terminal part
abruptly curved downwards and composed of 3 or 4 somewhat unequal joints,
the 1st of which is generally the largest and provided behind with a more or
less developed sensory appendage, at the end inside with 4 or 5 densely

46

crowded setae, which may attain a considerable length, rendering those limbs
well adapted for assisting the anterior antennae in the swiming motion of the
animal, these setae being however in some instances much reduced in size or
even wholly wanting; apical claws more or less slender, and generally 4 or 5
in number. Maxillipeds with the basal part produced in front to a well defined
masticatory lobe armed on the tip with curved spines or setae, and in most
cases carrying behind a more or less developed vibratory plate; palp, as a
rule, in female of inconsiderable size and in male transformed to a grasping
organ. Legs more or less dissimilar, the posterior one being as a rule, not
ambulatory, but upturned within the cavity of the shell. Caudal rami in some
cases much reduced, but in the great majority of the forms well developed
and very mobile. Germinal part of the genital organs in both sexes generally
lodged between the lamellae of the valves. A pair of more or less complicated
ejaculatory tubes added to the genital apparatus in male.

Remarks. — In the sense in which the family is here taken, it comprises
a considerable number of genera, both marine and freshwater, the former
deviating more or less conspicuously from the usual type prevailing in the
freshwater genera, though retaining most of the characteristic features disting-
uishing the present family from the Cytherldce. Yet a grouping of the genera
within subfamilies would seem to be fully justified. 5 such subfamilies will
be treated of in the sequel.

Subfam. 1. Pontocyprinae.

Characters of the subfamily. — Shell of somewhat varying shape, with the
valves nearly equal and more or less hairy. Antennae in some cases rather
slender and distinctly natatory, in other cases very short and stout and scarcely
adapted for swimming; the posterior ones 6-articulate; with the sensory appendage
.of 3rd joint very fully developed. Mandibles with the bristle attached outside
the masticatory part remarkably strong and distinctly pectinate; cutting teeth
simple, claw-like; palp comparatively large. Maxillae with the masticatory lobes
short and stout; palp however rather prominent and bowed in front. Maxillipeds
without any trace of a vibratory plate at the base; palp in female distinctly
3-articulate, sub-pediform, in male transformed in the usual manner. Anterior

47

legs of normal appearance, 5-articulate, and tipped with one or 2 slender claws.
Posterior legs rather unlike the anterior, though composed of the same number
of joints, last joint very small, and provided with 3 more or less unequal setae,
one of which is generally pectinated; none of the setae recurved. Caudal
rami well developed, but of somewhat different shape in the several genera;
in all of them, however, a very conspicuous triangular unpair prominence
occurs just behind their base, tipped with a thickish densely hairy seta. Ovaria
and testicles extending between the lamellae of the valves behind. Ejaculatory
tubes comparatively simple, wholly wanting the whorls of radiating spikes
found in other Cyprids; eferent ducts not convoluted.

Remarks. — The most characteristic feature of the present subfamily is
perhaps the comparatively simple structure of the ejaculatory tubes in the male.
Another character, which this subfamily shares with the next one, the Macro-
cyprince, may also here be named, viz., the sub-pediform structure of the palps
of the maxillipeds in the female. An attempt to a similar structure is however
also found in one of the genera belonging to the typical Cypridae, viz.,
Jlyocypris. Nor can the want of vibratory plates on these limbs be regarded
as a decisive character, as these plates in some of the typical Cypridae (Cy-
pridopsis, Potamocypris) are found to be nearly quite obsolete. In all other
respects the Cyprid type is pretty well manifested, and the present group
cannot therefore be considered to be so decidedly different from the other
Cypridae as suggested by G. W. Miiller.

3 genera referable to this subfamily will be treated of in the succeeding
pages, and a 4th genus, Pontocypria, has also been added by G. W. Miiller.

Gen. 1. Pontocypris, G. O. Sars, 1865.

Generic Characters. — Shell comparatively thin and pellucid, of a more or
less trigonal shape, with the valves unarmed on the edges, but rather densely
hairy. Eye well developed. Both pairs of antennae slender and distinctly
natatory; the anterior ones with the first 2 segments of the basal part
imperfectly defined, terminal part distinctly 5-articulate and clothed with rather
long setae. Posterior antennae with the first 2 joints of the terminal part long
and narrow, penultimate joint, on the other hand, quite short and, as usual,
produced at the end anteriorly to a claw-bearing prominence, last joint so very
minute, as easily to escape attention, though armed in the usual manner;
sensory appendage of 1st joint comparatively large, club-shaped, its extremity
being bladder-like dilated; natatory setae of same joint well developed; apical

4^

claws long and slender, 4 in number, the foremost one being somewhat shorter
than the others. Mandibular palp with the branchial appendage well defined,
though not of very large size. Palps of maxillipeds in female rather slender,
with the middle joint narrow linear, last joint small and tipped with a slender
claw-like spine accompanied by 2 small bristles; those in male of moderate
size and nearly equal. Anterior legs with a single slender claw on the tip.
Posterior legs with the penultimate joint very movably articulated to the
preceding joint, both distinctly serrate on the outer edge, last joint very small,
with the apical setae rather unequal, one of them being much more slender
than the others and exceeding considerably in length the pectinate seta.
Caudal rami well developed and somewhat exerted at the end, dorsal
edge of each ramus provided wit 3 slender setae, 2 of them placed close
together in about the middle, the 3rd in close approximation to the apical
claws. Ovarial tubes forming in the posterior part of the valves a sigmoid
curve. Spermatic vessels extending more or less forwards along the ventral
side of the valves, in some cases (according to G. W. Miiller) forming a dense
spiral coil in their anterior part.

Remarks. — This genus was established in the year 1865 by the present
author, to include 3 species found off the Norwegian coast. 2 of these species
have however subsequently been removed by G. W. Miiller and placed within a
new nearly-allied genus, Erythrocypris, the species recorded by me as P. trigonella
being considered by him as the type of the present genus. No less than 12
Mediterranean species referable to this genus have been recorded by G. W.
Miiller, all of them closely related to the northern form described below.

1. Pontocypris trigonella, G. O. Sars.

(PI. XX).
Pontocypris trigonella, G. O. Sars, Oversigt av Norges marine Ostracoder, p. 16.

Specific Characters.— Female. Shell, seen laterally, pronouncedly trigonj
in shape and somewhat narrowed behind, greatest height a little in front of
the middle and nearly attaining half the length, dorsal margin gibbously arched
in front of the middle and sloping rather steeply behind, ventral margin scarcely
at all sinuated, anterior extremity evenly rounded, posterior gradually tapered
and obtuse at the tip; — seen dorsally, oblong oval in outline, with the greatest
width in front of the middle and about equal to Vo of the length. Surface of
shell smooth and polished and rather densely covered with fine, mostly recui

J9

hairs. Eye comparatively large and very conspicuous in fresh specimens.
Caudal rami slightly tapered distally, and exerted at the end, in front of the
apical clav/s, to a digitiform process carrying a short deflexed bristle, distal
seta of the dorsal edge rather coarse, fully attaining the length of the apical
claws, the latter subequal in size.

Male of somewhat smaller size than female, and slightly differing in the
shape of the shell, which appears comparatively shorter and stouter. Prehensile
palps of maxillipeds with the propodus o51ong oval in form and provided near
the end inside with a short spine accompanied by 2 unequal bristles, dactylus
much curved and somewhat narrower on the left than on the right palp.
Copulatory appendages of moderate size, oblong oval in shape and blunted
at the end, without any, lateral lappets, but giving origin on the inner face
to a freely projecting highly chitinised apparently tubular string, abruptly bent
near the base and somewhat surpassing the terminal edge of the appendage.

Colour whitish, with a rather conspicuous dark brownish pigmentary patch
extending along each valve below its centre, and generally also with some
patches of the same colour at each extremity.

Length of adult female 0.70 mm, of male 0.62 mm.

Remarks. — It is very probable that one or other of the Mediterranean
species recorded by G. W. Miiller may prove to be identical with the present
form; but as these species have chiefly been characterised only by some slight
differences in the form and extension of the spermatic vessels of the male,
and these differences cannot be asserted except in quite fresh and still living
specimens, I am at present unable to decide the identity with full certainty.
In the shape of the shell the form named P. mediterranea seems to come nearest
to the present species and may perhaps in fact be identical with it.

Occurrence.— \ have met with this little beautiful Ostracod in several places,
both on the south and west coasts of Norway, and northwards up to the Lofoten
islands. . It is found in moderate depths on a muddy bottom, but nowhere in
any considerable number. The animal is a very habile swimmer, moving about
through the water rather speedily in the manner of the typical Cypridae, though
scarcely leaving the bottom for any longer distance. Male specimens are very
rarely met with, I have hitherto only come across 2 such specimens, the one
of which is figured on the accompanying plate.

Distribution.— British Isles (Brady), Mediterranean (Norman), Cape Verde
Islands (Brady).

Fossil in postglacial beds of Scotland.

Crustacea.

50
Gen. 2. Erythrocypris, G. W. Muller, 1894.

Syn: Pontocypris, Q. O. Sars (part).

(jeneric Charachters. — Shell of a more or less deep reddish or brownish
Coiour and rather more elongate than the in preceding genus, almost cuneiform
in shape, with the posterior extremity considerably exerted and terminating in
an obtuse point. Valves only slightly pellucid and more or less densely hairy,
the right one distinctly serrated at the hind corner below. Eye wholly wanting.
Both pairs of antennae comparatively shorter and stouter than in Pontocypris,
but otherwise of a very similar structure. The other limbs likewise built on
the very same type as in that genus. Prehensile palps of the maxillipeds in
male, however, considerably more powerfully developed and conspicuously
unequal. Posterior legs in both sexes with the pectinate apical seta much larger
than the other 2, which are very thin and subequal. Caudal rami rather stronger
than in Pontocypris and of more equal width throughout, distal seta of the
dorsal edge very small. Copulatory appendages in male of rather varying shape
in the several species. Spermatic vessels densely coiled within the posterior
extremity of the valves. Ovarial tubes forming a simple bend, their extremity
extending forwards along the ventral edge.

Remarks.— This genus, established by G. W. Muller in 1894, is close
related to Pontocypris, and indeed 2 of its species were formerly referred by
the present author to that genus. Yet, on a closer comparison, some well marked
differences, mentioned in the above diagnosis, between the 2 genera are found,
which would seem to corroborate the distinction of them. G. W. Muller records
7 species of this genus found by him in the gulf of Naples, one of them being
however identical with the form described below as E. mytiloides. 2 other
species belonging to the Fauna of Norway wiL also be treated of in the sequ

2. Erythrocypris mytiloides, (Norman).

(PI. XXI & XXll)

Cythere mytiloides Norman, Species of Ostracoda new to Britain. Ann. Mag. Nat. Hist. Vol. IX,

p. 50, Pi. Ill, figs. 1—3.

Syn : Cypris serrulata, G. O. Sars.

» Cy there avena, Noiman.

, Pontocypris serrulata G. O. Sars.

, Erythrocypris serrata G. W. Miiller.

Specific Characters. — Female. Shell much compressed, seen laterally, elong-
ate triangular or somewhat cuneiform in shape, highest in front and gradually
tapered behind, greatest height in the anterior third part and not nearly attaining

P

51

half the length, dorsal margin gibbously produced anteriorly and sloping rather
steeply both in front and behind, ventral margin almost straight, anterior ex-
tremity rounded off, posterior tapering to an obtuse point; — seen dorsally, narrow
lanceolate in outline, with the greatest width not nearly attaining V3 of the
length and occurring in front of the middle, both extremities pointed. Valves
very little pellucid and all over clothed with comparatively short hairs, right
valve armed at the posterior extremity below with 8 well marked and some-
what recurved denticles. Caudal rami comparatively large and only slightly
attenuated distally, apical claws somewhat unequal, the proximal one being
conspicuously stronger than the distal one, which is rather thin and also a
little shorter.

Male of about same size as female and scarcely differing in the shape of
the shell. Prehensile palps of maxillipeds very powerfully developed and con-
spicuously dissimilar, dactylus of the right palp remarkably short and broad,
subtriangular in form, that of left palp much thinner, falciform attenuated and
terminating in a fine point; propodus in both palps considerably dilated and
provided at the end inside with a peculiar thumb-like process of somewhat
different shape in the 2 palps. Caudal rami with a very conspicuous bulge
of the upper (ventral) edge in the middle not found in female. Copulative
appendages of large size and peculiar shape, exhibiting in the middle a prominent
lanceolate lappet and having the extremity triangularly produced or somewhat
helmet-shaped.

Colour in both sexes bright purplish brown.

Length of adult female amounting to about 1 mm.

Remarks.— TK\s form was shortly characterised by the present author as
early as in the year 1863 under the name of Cyprls serrulata, and was sub-
sequently (1865) referred by him to his genus Pontocypris. As pointed out
by Brady, this form had however been recorded at a still earlier date (1862)
by Norman under the name Cythere mytiloides, and though this name was
afterwards withdrawn by that author, on account of it having been preoccupied
for another species of the same genus, I think that Brady was quite right in
restoring the specific name originally proposed by Norman, since the present
form has turned out to be not a Cythere at all. The Mediterranean form
recorded by G. W. Muller as Erythrocypris serrata is unquestionably the same
species, as clearly seen from the figures given by that author. It may be
regarded as the type of the present genus.

Occurrence.— ki first only some few specimens of this form were observed,
taken partly at Christiansund, partly at Flekkefjord. More recently I have met

with it rather frequently in 2 other localities, viz., at Korshavn and Ris6r
Especially in the first-named locality it occurred very abundantly on a sandy
bottom in the laminarian region. The animal is not nearly so agile as the
Species of the preceding genus, though by no means devoid of swimming power.
The swimming movement is however rather slow, and look merely as a soft
gliding through the water generally close over the bottom. The bright purplish
colour of the shell renders this Ostracod easily discernible, and is even partly
retained in specimens preserved for a longer time in alcohol.

Distribution. — British Isles (Brady), coast of France (Fischer), Mediterrane
(G. W. MuUer). Fossil in the postglacial deposits of Norway and Scotland.

§

3. Ergthrocypris hispida, G. 0. Sars.

(PI. XXIII, fig. 1)
Pontocypris hispida, Q. O. Sars, Oversigt af Norges marine Ostracoder, p. 16.

Specific Characters. — Female. Shell rather more tumid than in the pre-
ceding species; but, seen laterally, of a much similar elongate triangular shape,
though scarcely so much exerted behind;- -seen dorsally, broadly lanceolate in
outline, with the greatest width in the anterior part, and considerably exceeding
Va of the length. Surface of shell densely covered with unusually long recurved
hairs, giving it a very hirsute appearance; right valve with only 5 serratures
below the posterior extremity. Structure of the several limbs very like that in
the preceding species. Caudal rami, however, comparatively less strong and
scarcely at all attenuated distally; apical claws less unequal and rather thin.

Male with the palps of the maxillipeds transformed in an analogous
manner to those in the type species, though scarcely as large, and having the
thumb-like process of the propodus far less prominent. Copulative appendages
rather unlike those in the preceding species, being of much smaller size and
more simple structure, without any lateral lappet, and with the extremity simply
rounded off; chitinous string of the inner face curved almost in a circk.
Caudal rami exactly as in female.

Colour yellowish brown.

Length of adult female scarcely exceeding 0.80 mm.

Remarks. — The above-described form is nearly allied to the preceding
but may at once be distinguished by the less compressed shape of the she i
and by its very coarse clothing of hairs, the latter character having given rise
to the specific name proposed. In the living state it is also readily distinguished
by the different colour of the shell.

53

Occurrence.— \ have met with this form not unfrequently in the upper part
of the Christiania Fjord in depths ranging from 10 to 20 fathoms, muddy
bottom. It also occurs occassionally at Risor, south coast of Norway in about
the same depth.

Distribution. — British Isles (Brady).

4. Erythrocypris pallida, G. W. Miiller.

(PI. XXIII, fig. 2)
Erythrocypris pallida. G. W. Muller, Die Ostracoden des Golfes von Neapel, p. 259, PI. 11,

figs. 12, 13, 43—45.

Specific Characters. — Female. Shell of a very similar shape to that in
the preceding species, but of rather smaller size, and with the surface far less
hirsute, the hairs clothing it being rather short and delicate. Right valve, as
in E. hispida. with only 5 serratures below the posterior extremity. Caudal
rami comparatively more slender than in that species, with the extremity some-
what produced in front of the apical claws, the latter moderately strong, but
scarcely exceeding half the length of the corresponding ramus.

Male with the palps of the maxillipeds of a similar structure to that in
E. hispida. Copulative appendages, however, somewhat differing in shape,
their outer part being conspicuously more expanded and forming inside a well
marked obtuse angle.

Colour much paler than in either of the 2 preceding species.

Length of adult female scarcely exceeding 0.70 mm.

Remarks. — The above-described form is unquestionably identical with the
Mediterranean species recorded by G. W. Muller, agreeing, as it does, pretty
well with the description and figures given by that author' Though closely
allied to the 2 preceding species, it may be readily distinguished by its smaller
size and much paler colour, the latter character having given rise to the specific
name proposed by G. W. Muller.

Occurrence.— \ have taken this form not unfrequently at Korshavn in the
same places where E. mytiloides occurred, occasionally also at Risor.

Distribution. — Mediterranean (G. W. Muller).

Gen. 3. Argilloecia, G. O. Sars, 1865.

Generic Characters. — Shell more or less elongate, and of firmer consi-
stency than in the 2 preceding genera, though scarcely calcareous, surface
smooth and almost bare of hairs. Valves subequal, each provided at the post-

54 .

erior extremity with a single excessively prolonged hair, and along the frontal edge
with a dense fringe of peculiarly transformed and very dehcate capillary appen-
dages. Eye wholly wanting. Both pairs of antennae short and stout, not adapted
for swimming (at least in female), the anterior ones with the basal part very
massive and sharply defined from the terminal part, the posterior ones with
the sensory appendage peculiarly transformed, pedicellate; some of the set«
on both pairs of antennas in male excessively prolonged and recurved. The
other limbs on the whole built on the same type as in the 2 preceding genera,
except that the branchial appendage of the mandibular palps is imperfectly
developed, and that the anterior legs are armed on the tip with 2 subequal
claws. Caudal rami comparatively small, conically tapered, with the apical cla
short and much curved.

Remarks. — This is a very distinct genus, differing in some respects con-
spicuously from the 2 preceding ones, though evidently referable to the same
subfamily. The genus was originally only founded on a single species described
by the present author in 1865; but in recent times several other species, more
or less agreeing with the typical one, have been added. Thus no less than
5 species, referable to this genus, have been recorded by G. W. Miiller from
the gulf of Naples, and I have myself had an opportunity of examining a 2nd
Norwegian species very distinct from that at first described.

i

5. Argilloecia cylindrica, G. O. Sars.

(PI. XXIV)

Argilloecia cylindrica, G. O. Sars, Oversigt af Norges marine Ostracoder, p. 18

Specific Characters. — Female. Shell very narrow, almost cylindrical in
shape, with the greatest height not nearly attaining half the length; seen
laterally, elongate oval or somewhat elliptical in outline, and scarcely broader
in front than behind, dorsal margin very little arched, ventral slightly sinuated
in the middle, anterior extremity rounded off, posterior abruptly blunted;— seen
dorsally, narrow oblong, with the side-edges almost straight in the middle, and
the greatest width about equal to ^/s of the length, both extremities obtuseh^
pointed. Valves only little pellucid, with the surface smooth and polished;
inner duplicatures not very broad and of quite normal appearance. Anterior
antennae with the terminal part about the length of the basal one and distinctly
5-articulate. Posterior antennae with the outer part of the sensory appendage
disciform and sharply defined from the narrow attaching stalk; natatory seta^
very small and rudimentary, though present in the usual number, Branchial

55

appendage of the mandibular palps replaced by a single strong seta. Palps of
maxillipeds short and stout, with the 2 outer joints very small. Posterior legs
with 3 apical sets, one of them very coarse, almost spiniform, and evenly
curved. Caudal rami rather broad at the base, but rapidly tapering to an obtuse
point carrying the very short, hamiform curved apical claws, and apparently
wanting the usual small bristle in front of the claws,

Male much smaller than female, and having the shell still narrower, with
the posterior extremity more exerted. 4 of the setae attached to the anterior
antennae in the middle of the terminal part much produced and generally re-
curved along the back of the shell. Natatory setae of the posterior antennae
prolonged in a similar manner. Palps of maxillipeds rather powerfully developed,
with the propodus considerably dilated at the base and the dactylus short and
stout, unguiform. Copulative appendages narrow oblong in form and obtusely
rounded at the tip.

Colour in both sexes a pure white. .

Length of adult female amounting to 0.69 mm., that of male scarcely
exceeding 0.60 mm.

Remarks. ~lh\s form, being that at first described, ought of course to be
regarded as the type of the present genus. It may be easily recognised from
any of the other species by the almost cylindrical shape of the shell in the
female, this character having indeed given rise to the specific name proposed.
Of the 5 Mediterranean species recorded by G. W. Muller, A. caudata seems,
in the shape of the shell, to come nearest to the present species.

Occurrence. — I have met with this Ostracod occasionally in several places
on the Norwegian coast, from the Christiania Fjord to Trondhjem, and Norman
also records it from Finmark (Hammerfest). It is generally found in moderate
depths ranging from 10 to 30 fathoms, on a muddy bottom, and, in spite of
its small size, may be easily detected by the pure white colour of the shell
and by a peculiarity which it has in common with some other Ostracoda, viz.,
that, on coming in contact with the air, it remains floating on the surface of
the water. The females are quite devoid of swimming power, crawling slowly
on the bottom, like the Cytheridae. The males, however, may perhaps lead a
more free existence, as could be inferred from the peculiar prolongation of
some of the setae attached to the antennae.

Distribution. — British Isles (Brady).

f^ossil in the postglacial beds of Scotlan4,

56
6. Argilloecia conoidea, G. O. Sars, n. sp.

(PI. XXV)

Specific Characters. — Female. Shell, seen laterally, very narrow, oblong
conoid in shape, greatest height in the middle and scarcely exceeding -/o of
the length, dorsal margin gently arched and sloping with a quite even curve
to the hind produced corner, ventral margin distinctly sinuated in the middle,
anterior extremity broadly rounded, posterior conically tapering to an obtuse
point lying below the longitudinal axis; — seen dorsally, oblong ovate in out-
line, with the greatest width behind the middle and only little exceeding Vs
of the length, anterior extremity more pointed than the posterior. Valves rather
pellucid, with the surface smooth and glabrous; inner duplicatures remarkably
broad and exhibiting a somewhat irregular highly chitinised marginal zone,
which in front projects in 2 opposit sharp corners, between which the inndll
edge of the duplicature is suspended. Structure of the several limbs very like
that in the typical species. Posterior legs, however, only provided at the tip
with 2 setae of unequal length, the shorter one distinctly pectinate. Caudal rami
comparatively narrower than in the preceding species and somewhat curved.

Male resembling in general appearance that of the type species, but of
considerably smaller size, and having the shell comparatively still narrower,
with the posterior extremity more produced. Some of the setae attached to
the 2 pairs of antennae, as in that species excessively prolonged and recurve
in the very same manner. Prehensile palps of maxillipeds with the propodu
almost quadrate in form and armed at the end inside with a short spine accom-
panied by 2 small bristles, dactylus of moderate size and slightly curved.
Copulative appendages rather slender and somewhat irregularly expanded
the end.

Colour not yet ascertained.

Length of adult female 0.59 mm, of male 0.50 mm.

Remarks. — Though agreeing pretty well in the essential structural details,
present species may readily be distinguished from the preceding one by th
rather different shape of the shell, especially in the female. It is also of rath
inferior size, hi its general appearance it looks rather like some of the Medite
ranean species recorded by G. W. Miiller; but I have been unable to ascertai
its identity with any of them.

Occurrence. — 3 specimens only of this form, an adult female and 2 male^
have as yet come under my notice. They were picked up from a gatherin
taken at Risor, south coast of Norway, from moderate deeps.

P

57

Subfam. 2. Macrocyprinae.

Characters of the snbf amity. SheW more or less elongate, tapered behind,
and of rather firm consistency, apparently calcareous, with the surface smooth
and almost bare of hairs. Valves pronouncedly unequal, the right one over-
lapping the left in the middle of the dorsal face; their closure in the oral
region very thorough, the edges being conspicuously expanded in that place.
Antennae not adapted for swimming; the anterior ones with the 3 seg-
ments of the basal part very distinctly defined, terminal part less sharply
marked of from the basal one, and having the set^e comparatively short. Post-
erior antennae, as in the Pontocy prince, distinctly 6-articulate" and armed at the
tip with the usual number of claws, sensory appendage of 3rd joint replaced
by a bundle of delicate filaments; natatory setae wholly absent. Mandibles
and maxillae on the whole normally developed. Maxillipeds without any vibra-
tory plate, masticatory lobe narrowly produced and sharply defined from the
basal part, palp in female sub-pediform, in male transformed in the usual manner.
Both pairs of legs slender, 5-articulate, but rather dissimilar, the posterior ones
being, as in the typical Cypridae abruptly bent upwards and concealed within
the shell, last joint of these legs well developed and carrying, in addition to
2 comparatively short setae, a remarkably elongate claw-shaped spine abruptly
reflexed along the leg. Caudal rami more or less imperfectly developed. Ovaria
and testicles not entering between the lamellae of Ihe valves. Ejaculatory tubes in
male largely developed, but rather differing in structure from those in the typical
Cypridae, their efferent ducts also dissimilar.

Remarks. — The most prominent characters distinguishing the present sub-
family are derived from the genital apparatus. In the structure of the maxillipeds
some resemblance to the Pontocy prince is found; but the posterior legs are
rather dissimilar, and the caudal rami exhibit an appearance even different
from that in all other known Cypridae. Yet, in most of the structural details
the Cyprid type may be found to be well manifested. 2 closely allied genera
referable to the present subfamily will be treated of below, and I am of opinion,
that the Mediterranean form recorded by G. W. Miiller as Macrocypris succinea
should more properly be regarded as the type of a 3rd genus.

8 — Crustacea.

58

Gen. 4. Macrocypris, Brady, 1866.

Generic Characters.— S>\\^\\ very solid, moderately elongate, and acufely
produced behind. Inner duplicatures of the valves rather broad, with a narrow
transversely striated marginal zone; muscular spots numerous and arranged
so as to form together a circular area. Eye wanting. Both pairs of antenna
short and robust, the anterior ones 7-articulate and gradually tapering distally,
without any sharp demarcation between the basal and terminal parts, setae of
the latter part short and stout. Posterior antennae with the terminal part scarcely
longer than the basal one, joints rapidly diminishing in size, apical claws slender
and elongate. Anterior lip forming in front a rather prominent compressed
expansion. Mandibles with the masticatory part rather expanded and coarsely
dentate at the edge, palp of moderate size, 4-articulate, and provided at the
base with a well developed branchial appendage. Maxilla with both the palp
and the masticatory lobes narrowly produced, vibratory plate of smaller size
than usual. Maxillipeds with the masticatory lobe very narrow, conical in shape ;
palp in female distinctly 4-articulate and armed with 3 slender spines, 2 apical
and 1 lateral. Anterior legs with the terminal joint unusually produced and
carrying on the tip 2 unequal claws accompanied by a thin bristle. Posterior
legs with the outer apical seta rather slender and elongated, recurved spine
almost extending to the base of the leg. Caudal rami very small and rudi-
mentary, in the form of 2 thin lappets hinging down from the end of the
body, and scarcely at all movable, each lappet provided with a limited number
of thin bristles. Copulative appendages of male lamellar, and of comparatively
simple structure. Ejaculatory tubes very long and narrow, extending along the
dorsal face of the body to beyond the middle of its length, each tube provided
with numerous short radiating spikes, which however do not form distinctly
defined whorls, proximal extremity of the tube bulbously dilated; efferent duct
very long, being immediately on its exit from the tube curled up in a dense
spiral coil with highly chitinised walls.

L^ Remarks. — This genus was established in the year 1866 by Brady, t)
include the form originally recorded by Baird as Cythere minna and subsequently
(1865) redescribed by the present author, but erroneously referred to the genus
Bairdia Mc Coy. As pointed out by Brady, the present Ostracod differs in
reality very decidedly from the species of that genus, and on the whole approaches
much closer to the typical Cypridae, than does the above-named genus. Only
a single 'species, strictly referable to the present genus, has as yet come uiidt:
my notice,

59

7. Macrocypris minna (Baird).

(PI. XXIV & XXV)

Cythere minna, Baird, Britisli Entomostraca, p. 171, Pi. 20, figs. 4, 4 a— d.

Syn : Bairdia minna, G. O. Sars.

Specific Characters. — Female. Shell moderately tumid, seen laterally, of
a somewhat irregular oblong trigonal shape, greatest height a little in front of
the middle and about equal to 75 of the length, dorsal margin forming a bold
and quite even curve sloping gradually behind to the posterior corner of the
shell, ventral margin nearly straight and horizontal, though exhibiting a slight
concavity in front of the middle, anterior extremity rounded off, posterior tapering
to an acuminate corner;— seen dorsally or ventrally, oblong fusiform in outline,
greatest width in front of the middle and somewhat exceeding Va of the length,
anterior extremity obtusely pointed, posterior gradually tapered to an acute
point; hing-line somewhat flexuous. Valves very little pellucid, with the surface
smooth and polished, being almost bare, except at the anterior extremity, where
a fringe of extremely fine and delicate hairs may be discerned. Caudal rami
sublinear in form, slightly tapered distally, and somewhat curved, each carrying
on the tip a slender, somewhat flexuous seta, and in the middle of the doral
edge a bundle of very small hair-like bristles.

Male of rather smaller size than female, but resembling it in the shape of
the shell. Prehensile palps of maxillipeds of moderate size and not much
dissimilar, propodus oval in form and armed at the end inside with 2 short
spines, dactylus somewhat broader on the right than on the left palp. Caudal
rami still more rudimentary than in female, and scarcely more than twice as
long as they are broad, each ramus tipped with 3 very small bristles. Copulative
appendages oblong triangular in outline and terminating in a thin lamella
rounded off at the end and somewhat bowed in front.

Colour of shell in both sexes milk-white, limbs more or less deeply tinged
with chestnut-brown.

Length of adult female amounting to about 3 millimeters; that of male
scarcely exceeding 2.50 mm.

Remarks.— l\\\s is by far the largest and finest of the marine Cypridae,
and is moreover easily recognisable by the characteristic shape of the shell
and its milk-white colour. It is the type of the present genus, in the restrict-
ion here adopted.

Occurrence.— Ihit present Ostracod is by no means rare on the Norwegian
coast. I have met with it not unfrequently in many places, from the Christiania
Fjord up to the Lofoten islands, but always only in greater deeps, from 50 to

300 fathoms. As could be inferred from the structure of the antennae, the
animal is quite devoid of swimming power, being only enabled to crawl slowly
on the bottom, at times burrying itself more or less deeply within the loose
mud. Male specimens are rather seldom to be found and may easily escape atten-
tion, as they do not differ in the shape of the shell from young female specimens^_

D/s/'n/^M/'/oAz.— Shetland Isles (Baird).

Fossil in posttertiary deposits of Calabria.

Gen. 5. Macrocypria, G. O. Sars, n.

Generic Characters. — Shell very narrow and elongated, acutely produce
both in front and behind, with the marginal zone of the valves highly chi-
tinised. Eye absent. Both pairs of antennae much more slender than in the
preceding genus, but, as in it, unadapted for swimming. Oral parts of nearly
same structure as in that genus. Maxillipeds with the palps in female less
robust, scarcely exceeding the basal part in length and distinctly 4-articulate.
Anterior legs very much elongated, with the terminal joint comparatively
small and tipped with a single exceedingly long and slender claw accompanied
by 2 small bristles. Posterior legs with the 2 apical setae very small, recurved
spine however well developed. Caudal rami movably articulated to the body,
and very unlike those in Macrocypris, being conspicuously asymmetrical, left
ramus much smaller than the right, which is produced in the shape of a
highly chitinised mucroniform piece without any armature whatever. Ejaculatory
tubes and their eferent ducts of essentially same structure as in Macrocypris.
Copulative appendages, however, rather dissimilar, not being lamellar, but ol
very compact structure, and clavate in shape. A pair of scopiform processes
present in male, issuing from the ventral face of the body between the bases
of the posterior legs. 1 1

Remarks. — This new genus is established, to include a species formerly
referred by the present author to the genus Macrocypris. On a closer exami-
nation I have however found this species to differ in some respects so deci-
dedly from the type of that genus that I now am of opinion that it more properlj
ought to be separated generically. The generic name here proposed alludei;
to the near relationship of this genus to Macrocypris.

61

8. Macrocypria angusta, G. O. Sars.

CPl. XXVIII).

Bairdia angusta, G. O. Sars, Oversigt af Norges marine Ostracoder, p. 22.
Syn : Macrocypris angusta, G. O. Sars.

Specific Characters.— Female. Shell, seen laterally, of a very narrow
and elongated form, almost lanceolate in outline, greatest height a little in
front of the middle and scarcely exceeding 7» oi the length, dorsal margin
evenly arched, though exhibiting near the posterior corner of the shell a slight
concavity, ventral margin distinctly sinuated in front of the middle and exhib-
iting a slight tendency to convexity behind, anterior extremity obliquely pro-
duced and terminating below in a sharp dentiform corner, posterior extremity
rather more exerted and produced to a narrow somewhat cultrate prominence;
—seen dorsally, narrow fusiform in outline, greatest width about in the middle
and not attaining Va of the length, both extremities sharply pointed. Valves,
as in Macrocypris, conspicuously unequal, rendering the hing-line somewhat
flexuous, surface smooth and polished, only clothed with scattered fine hairs,
marginal chitinised zone rather broad at each extremity and crossed by fine
striae. Anterior antennas with the basal part only slightly dilated, 1st joint of
terminal part unusually prolonged, attaining the length of the 3 remaining
joints combined, apical setae rather slender. Posterior antennae with the terminal
part almost twice the length of the basal one, and having "the 2nd joint con-
siderably longer than the 1st; apical claws comparatively short. Left caudal
ramus simply lanceolate and scarcely more than Va as long as the right, which
is considerably produced and terminates in a sharp somewhat hamate point.

Male, as usual, of somewhat smaller size than female, but resembling it
closely in the shape of the shell. Prehensile palps of maxillipeds with the pro-
podus rather narrow, oblong in shape and armed at the end inside with 2
short spines, dactylus abruptly bent at the base. Copulative appendages pro-
nouncedly club-shaped, being attached to the body by a narrow neck, and
almost globularly dilated in their outer part, each appendage sending off inside
2 apparently mobile beak-like processes, which give the appendage a certain
resemblance to a birds head.

Colour in both sexes pure white.

Length of adult female amounting to 1.80 mm.

Remarks. — The above-described form cannot be confounded with any of the
other Cypridae, exhibiting, as it does, a very characteristic outward appearance.
The peculiar asymmetry of the caudal rami, at first overlooked, is a quite
unique character not found, a far as I know, in any other Ostracoda.

62 ■

Occurrence. — I have met with this form not unfrequently in several places
on the Norwegian coast, from the Christiania Fjord to Trondhjem, in moderate
depths ranging from 20 to 100 fathoms muddy bottom. In its behaviour the
animal agrees with Macrocypris minna, being, like it, quite incapable tOj
move freely in the water.

Out of Norway this form has not yet been recorded.

Subfam. 3. Bairdiinae.

Characters of the subfamily. — Shell of somewhat varying shape and rather
firm in consistency, with the valves conspicuously unequal, the left one being
the larger. Antennae not adapted for swimming; the anterior ones with the
3 segments of the basal part well defined, terminal part short, 4 articulate,
but sharply marked off from the basal one, and densely setiferous. Posterior
antennae, as in the 2 preceding subfamilies, distinctly 6-articulate, penultimate
joint however firmly connected with the preceding joint and more or less pro-
longed; apical claws only 2 in number, both issuing from the terminal joint.
Mandibles and maxillae on the whole of normal structure. Maxiilipeds pro-
nouncedly pediform and, like the 2 succeeding pairs of limbs, ambulatory, though
differing from them in the presence of a well developed vibratory plate attached
to their base posteriorly. Caudal rami of small size, though well mobile, and
built quite on the type of most other Cypridae. Ovaria and testicles not
entering between the lamellae of the valves. Ejaculatory tubes wholly absent.

Remarks. — This is perhaps the most anomalous of the 5 subfamilies
comprised within the family Cypridce, and, indeed, on a closer examination of
a Mediterranean species belonging to the typical genus Balrdia, I found this
genus to differ so decidedly from the other known genera, that it appeared t
me requirable to establish for its reception a distinct family, Bairdiidce, inter-
mediate between the 2 other families of the Podocopa^). Although this family
has been generally accepted by recent authors, I am now of opinion, that the
systematic rank of a subfamily would be more appropriate, and that this sub-
family should be classed under the head of the Cypridce. Indeed, on a closer
examination, it may be recognised, that both in the structure of the shell and
in that of the appendages, the Cyprid type is more apparent than the Cytherid

IS c

1) Cfr. G. O. Sars, "Ostracoda mediterranea" Arch, f Math. & Naturvid. f. 1887.

«l

63

one. True, the presence of 3 pairs of apparently similarly constructed ambu-
latory legs would seem to approach the Bairdiince closer to the Cytheridae
than to the Cypridce, in which, as a rule, only a single pair of true ambula-
tory legs are found. On a closer comparison with the Cyprids treated of in
the preceding pages, it is however easily understood that the 1st of those
pairs answer to the maxillipeds in these Cypridae, and that their pediform
appearance is only due to an access of growth of the palps, rendering them
adapted for locomotion. These legs moreover exhibit a true Cyprid character
in the presence, at their base, of a well developed vibratory plate, never found
in any of the Cytheridae. Nor can the perfect similarity of the 2 last pairs of
legs be regarded as decisive for a classing of the present subfamily within
the Cytheridae. For in the genus Paracypris, which unquestionably is referable
to the typical Cypridae, the posterior legs only very little differ in structure
form the anterior ones and may indeed assist them in the crawling movements
of the animaP). Another character may here be named, which seems to
remove this subfamily from the Cypridce, viz., the absence of ejaculatory tubes
in the male. In the Pontocy prince however, as stated above, these tubes are
so imperfectly developed, as to be nearly said to be obsolete. After all, I
think that the arrangement here proposed may be found to be acceptable.

The present subfamily as yet only comprises 3 nearly-allied genera, 2 of
which are represented in the Fauna of Norway.

Gen. 6. Bythocypris Brady, 1888.

Generic Characters. — Shell more or less compressed, of oval or reniform
shape, and almost bare of hairs, edges unarmed. Both pairs of antennae com-
paratively shorter and stouter than in the type genus; the anterior ones with
the apical setae far less prolonged. Posterior antennae with the penultimate
joint moderately prolonged; apical claws very slender, but unequal in length.
Anterior lip only sligthly prominent and obtuse at the end. Mandibles with
the masticatory part not much expanded, but coarsely dentate; branchial
appendage of palp comparatively small, with only 3 setae, one of which
is much elongated. Maxillae with the masticatory lobes narrowly produced,
palp scarcely larger than these lobes and uniarticulate; vibratory plate exhibiting
at the base a well marked expansion edged with numerous very thin and

') Cfr. the description of this genus farther on.

64

slender setae. Legs of nearly equal length, each terminating in a very
slender claw and having the penultimate joint scarcely longer than the pre-
ceding joint; vibratory plate of the 1st pair (maxillipeds) somewhat resembling
in shape that of the maxillae, though of smaller size. Caudal rami narrow
sublinear in form, and armed on the tip with 2 thin claws, the distal of which
is the longer, dorsal edge with a slender seta about i the middle. fll

Remarks.— This genus, established by Brady in 1888, is closely allied to
Bairdla M'Coy, and its species were indeed formerly referred to that genus.
Yet, the shape of the shell is rather different in the 2 genera, and as also
some slight differences are found in the structural details, I think that the
genus ought to be supported. 2 well defined species referable to this genus_
will be described below,

9. Bythocypris bosquetiana (Brady).

(PI. XXIX).
Bairdia bosquetiana, Brady. On new or imperfectly known species of marine Ostracoc
Trans. Zool. Soc. Vol. 5, p. 364, PI. LVII, figs. 5, a— c,
Syn: Bairdia complanata, Brady.

Bythocypris reniformis, Brady.

Specific Characters. — Female. Shell much compressed, seen laterally, oval
reniform in shape, greatest height in the middle and about equal to half the
length, dorsal margin forming a bold and quite even curve sloping rather
steeply to the hind corner of the shell, ventral margin distinctly sinuated in
the middle, anterior extremity broadly rounded, posterior much narrower and
exerted to an obtuse corner; — seen dorsally, narrow lanceolate in outhne.
greatest width about in the middle and scarcely attaining 73 o\ the length,
both extremities obtusely pointed. Valves but very little pellucid, the left one
overlapping the right along the greater part of the dorsal face. Caudal rami
comparatively slender, with the apical claws abruptly curved in the middle
dorsal margin provided, in addition to the slender mediate seta, with a group
of 2 — 4 very small hair-like bristles between it and the base.

Colour pure whithe.

Length of adult female 1.30 mm.

Male unknown.

Remarks. — This form was originally recorded in the year 1865 by Bra(
as a species of the genus Bairdia, and was subsequently redescribed as tl
type of his genus Bythocypris, though with a different specific name, vij
reniformis. I am also of opinion that the form described by that author in '

group

i

6g

his well-known monograph as Bairdia complanata, and subsequently recorded
by the present author under this name, is the very same species.

Occurrence. — Only a few female specimens of this form have as yet come
under my notice. They were taken, many years ago, at Bekkervig, west coast
of Norwa}^ from the considerable depth of 150 fathoms. Norman has how-
ever recorded it from 3 other localities of the same coast.

D/s^n^tt/'/o/z.— Shetland Isles (Brady), Atlantic Ocean, down to 470 fathoms
(Brady), Mediterranean (G. W. Muller).

10. Bythocypris obtusata, G. O. Sars.

(PI. XXX, fig. 1).
Bairdia obtusata, G. O. Sars, Oversigt af Norges marine Ostracoder, p. 24.

Specific Characters. — Female. Shell somewhat less compressed than in
the preceding species, seen laterally, irregularly oval in outline, greatest height
in the middle and slightly exceeding half the length, dorsal margin evenly
arched throughout, ventral only very slightly sinuated, anterior extremity some-
what obliquely blunted below, with indication to an angle above, posterior
extremity with the lower corner only very slightly exerted; — seen dorsally, oblong
fusiform in outline, greatest width in the middle and about equal to ^s of the
length, both extremities obtusely pointed. Valves rather thin, but only little
pellucid, the left one overlapping the right almost along the whole dorsal face.
Structure of the several limbs vefy like that in the preceding species. Apical
setae of the anterior antennae, however, comparatively shorter, and the vibratory
plate on the 1st pair of legs (maxillipeds) of smaller size. Caudal rami some-
what less produced, and having the apical claws almost straight, seta of dorsal
edge accompanied above by a short bristle.

Colour whitish, with a slight pale yellow tinge.

Length of adult female 1.13 mm.

Male unknown.

Remarks. — The above-described form is evidently congeneric with the
preceding one, though easily distinguishable by the somewhat different shape
of the shell. It is also rather inferior in size.

Occurrence.— ki first I had at my disposal only an empty shell of this form
picked up by my late father from shell-sand taken up by the aid of the dredge
from a depth of 80—90 fathoms at Abelsnaes, south coast of Norway. Sub-
sequently however I succeeded in obtaining some perfect specimens in the same
locality where the preceding species occurred, and have thereby been enabled

9 — Crustacea.

66

to examine more closely the structural details. This species has also been
recorded by Norman from some localities on our western coast.

Distribution.— Briiish Isles (Brady).

Fossil — Calabria (Seguenza).

Gen. 7. Bairdia, M'Coy, 1844.

Syn- Nesidea, Costa.

Generic Characters. — Shell short and tumid, more or less pronounced^
rhomboid in shape, with the edges of the valves in most cases denticulate at
one or both extremities; surface in fresh specimens more or less densely clothed
with coarse recurved hairs. Both pairs of antennae considerably more slender
than in the preceding genus, the anterior ones carrying on the end a dense
fascicle of exceedingly long and slender setae; penultimate joint of the posterior
ones remarkably long and narrow. Mandibles and maxillae of essentially same
structure as in Bythocypris. Legs however still more slender, with the pen-
ultimate joint very long and narrow. Vibratory plate attached to the 1st pair
of legs (maxillipeds) rather larger than in that genus. Caudal rami with several
additional setae on the dorsal edge, apical claws very unequal in size, the proximal
one being much the longer and almost setiform. None of the legs in male
transformed; copulative appendages short and compact.

Remarks. — This genus was established as early as the year 1844 by M'Coy,
to comprise a number of fossil Ostracoda from the carboniferous limestone of
Ireland. Some of the forms included by him in that genus are however apparently
not congeneric, and for this raison most recent authors have found it advisabU;
to substitute the name Bairdia with that of Nesidea, proposed by Costa for
a species unquestionably belonging to the present genus. As however the forme'
name is the elder one, it ought certainly to be retained, though the genus
must be taken in a more restricted sense than done by M'Coy.

A single species only, referable to the present genus, is represented
the Fauna of Norway.

67

11. Bairdia inflata (Norman).

(PI. XXX, fig. 2)
Cythere injlnta, Norman, Species of Ostracoda new to Britain. Ann. Mag. Nat. Hist. Vol. IX,

p. 49, PI. Ill, figs. 6—8.

Syn: Bairdia obliqiiata, G. O. Sars.
, — subdeltoidea. White (not Miinster).

Specific Characters. — Female. Shell very tumid, seen laterally, oval
rhomboid in outline, greatest height about in the middle and somewhat exceeding
half the length, dorsal margin boldly arched and sloping rather steeply to the
hind corner of the shell, ventral margin nearly straight, anterior extremity obli-
quely truncated, projecting above in an obtuse corner, posterior extremity
somewhat exerted below, but obtuse at the end; — seen dorsally, broadly ovate
in outline, greatest width about in the middle and considerably exceeding half
the length, both extremities sharply pointed. Valves conspicuously unequal,
the left one overlapping the right considerably in the middle of the dorsal face,
hind edge of each valve irregularly dentated below; surface smooth, but of a
somewhat dull appearance from numerous small impressed pits.

Colour not yet ascertained.

Length of adult female 1.12 mm,

Male unknown.

Remarks. — This form was originally described in the year 1862 by Norman
as a species of the genus Cythere, and was subsequently erroneously identified
by White with the fossil species, B. subdeltoidea (Miinster). Nor can the
Mediterranean form described in detail by the present author under the latter
name be adduced to that species, but may more probably be identical with
one of the 10 closely allied species recorded by G. W. Miiller from the gulf of
Naples. As pointed out by Brady, the B. obliqvata of the present author is
identical with Norman's species.

Occurrence. — My knowledge to this form is confined to the examination
of 2 empty valves probably of the same specimen, found by my late father in
shell-sand from 0xfjord, on the Finmark coast. Norman has however recorded
this form from 3 localities on the west coast of Norway, and I have had an
opportunity of seing some of his specimens.

Distribution. — British Isles (Brady), Fosse de Cap Breton (Marquis de Folin).

Fossil in post-tertiary deposits of Scotland.

68

Subfam. 4. Cyprinae.

Characters of the subfamily. — Shell of very varying shape, and generally
thin, never calcareous. Antennae in some cases not serviceable for swimming,
but in the greater number of forms well adapted for this purpose; the anterior
ones with the first 2 segments of the basal part imperfectly defined and more
or less dilated, terminal part well marked off from the basal one, rather slender,
and generally 5-articulate. Posterior antennae with the terminal part, as a rule,
only composed of 3 joints, the 1st of which is much the largest and provided
behind with a comparatively small sensory appendage; apical claws 5 in number,
3 of them issuing from the penultimate joint. Mandibles and maxillae normally
developed. Maxillipeds with the masticatory lobe well defined and clothed
at the end with curved spines or setae, in most cases also provided at the base
behind with a more or less distinctly developed vibratory lamella; palp in
female poorly developed, not pediform, and forming, as a rule, a simple in-
articulate, and immobile lappet tipped with 3 unequal bristles, that in male,
as usual, transformed to a grasping organ. Anterior legs in some cases rather
slender, but more generally shorter and stouter than in the Cypridae treated of in the
preceding pages. Posterior legs more or less dissimilar, and generally upturned
within the shell. Caudal rami rarely rudimentary, being in most cases well
developed and very mobile, rod-like in shape, and armed at the tip with 2
more or less slender claws, dorsal edge generally provided with only a single
small bristle. Germinal part of ovaria and testicles, as also the coecal tubes
of the intestine, lodged between the lamellae of the valves. Ejaculatory tubes
always distinctly developed, and provided with numerous radiating chitinous
spikes arranged in well-defined whorls; eferent ducts simple, not convoluted,
as in the Macrocy prince.

Remarks.— This subfamily comprises the more typical Cypridae, nearly alt
of which are confined to fresh waters, only 2 genera, Paracypris and Agla
being as yet known as strictly marine.

Owing to the great number of genera referable to this subfamily, a systematic
grouping of them would seem to be desirable, and has indeed been attempted
by several authors, thoug in a rather different manner. In any case these groups
cannot deserve the systematic rank of subfamilies, but only that of subordinate
sections. In way of distinction from the true subfamilies, they are here spelt
with the termination "ides" instead of "inae". 6 such groups will be recorded
in the sequel, and to each of them a few short remarks will be added; but
I have not found it necessary to give full diagnoses of them,

%

69

Group 1. Paracyprides.

Remarks, —lo this group I provisionally refer the 4 following genera:
Paracypris G. O. Sars, Aglala Brady, Paracypria G. O. Sars, and Phlydenophom
Brady. These 4 genera seem to agree pretty well in the structure of the genital
apparatus, as also on the whole in that of the limbs, and exhibit some relations
to the next 2 groups, Candonides and Cyclocy prides, though being scarcely
referable to either of them. Only the 1st of these genera is represented in
the Fauna of Norway.

Gen. 8. Paracypris, G. O. Sars, 1865

Generic Characters. — Shell elongate compressed, narrowly produced behind,
and of rather firm consistency, with the edges highly chitinised. Eye well
developed. Antennae not adapted for swimming; the anterior ones slender,
but with the setae of the terminal part comparatively short. Posterior antennae
without any trace of natatory setae, sensory appendage of the 1st terminal joint
pronouncedly club-shaped; apical claws moderately slender. Anterior lip only
slightly prominent. Mandibles of quite normal structure. Maxillae with the
masticatory lobes narrowly produced, palp likewise narrow, with the apical
joint longer than broad. Maxillipeds provided at the base with a small, but
well defined vibratory lamella, palp (in female) simple; sub-linear in shape.
Both pairs of legs much elongated and only slightly differing in structure, each
carrying on the tip a long curved claw; the posterior ones, however, more
recurved, and having on the tip 2 unequal bristles in addition to the claw, the
one abruptly reflexed. Caudal rami rather fully developed, and resembling
somewhat in shape those in the genus Candona. though having 2 setae on
the dorsal edge.

Remarks. — This genus was established in the year 1865 by the present
author, to include a Cyprid, which, on a closer examination, was found to
approach the typical freshwater forms more closely than any of the other ma-
rine Cypridae observed; hence the generic name proposed. Indeed, the structure
of the posterior antennae and in particular that of the maxillipeds clearly proves
it to be referable to the subfamily Cy prince, as here defined. The genus Aglaia
of Brady seems to be very nearly related to the one here in question, though
differing rather conspicuously in the shape of the shell. A single species only
of the present genus is as yet known to me.

70

12. Paracypris polita, G. O. Sars.

(PI. XXXI)
Paracypris polita, G. O. Sars, Oversigt af Norges maFkie Ostracoder, p. 12.

Specific Characters. — Female. Shell much compressed, seen laterally, of
a very narrow, almost cuneiform shape, being gradually attenuated behind,
greatest height far in front of the middle and only slightly exceding Va of
the length, dorsal margin abruptly arched in front and sloping steeply behind,
ventral margin distinctly sinuated, anterior extremity well rounded, posterior
much exerted and tapering to an obtuse point;— seen dorsally, narrow lanceolate
in outline, greatest width somewhat in front of the middle and not nearly at-
taining Vs of the length, both extremities obtusely pointed. Valves nearly equal,
with the surface smooth and polished and almost devoid of any hairy clothing;
inner duplicatures rather broad, marginal zone highly chitinised and crossed
by fine arborescent stripes, being particularly broad ventrally. Caudal rami
somewhat curved and slightly tapering distally, apical claws rather strong, dorsal
setae subequal, somewhat recurved, and attached at a short distance from the end.

Colour of shell pale yellow, with an irregular flexuous band of a reddish
brown hue along the ventral side of the valves.

Length of adult female amounting to 1.30 mm.

Male unknown.

Remarks. — In the outward appearance this form bears a certain resemblance
to some of the Pontocy prince, particularly to the species of the genus Etythro-
cypris, but may be readily distinguished from these species by the perfectly
smooth and polished surface of the shell and by the want of any obvious
hairy clothing. In the structure of the limbs it differs very decidedly from any
forms of that subfamily, and it is only in the shape of the sensory appendage
the posterior antennae that some agreement with those forms is found.

Occurrence. — I have met with this handsome Ostracod in several localities
on the south and west coasts of Norway, at moderate depths, but nowhere
in any abundance. All the specimens obtained were of the female sex. Tht^
animal is quite devoid of swimming power, but crawls rather dexterely along
the bottom, at times burrowing more or less deeply into the loose mud.

Distribution.— Briiish Isles (Brady), Bay of Biskaye, Mediterranean (Normal^

FqssH in postglacial beds of Norway, Scotland and Sicily.

d

IS

n

Group. 2. Candonides.

Remarks. — The type of this group is the well-known freshwater genus
Candona, to which in recent time several other genera have been added, ex-
hibiting a more or less close relationship to that genus, and thus, together
with it, forming a well defined group of the subfamily Cyprinae. All the forms
referable to this group agree in their entire lack of swimming power, being
only found at the bottom of lakes or swamps. 3 genera of this group are
represented in the Fauna of Norway.

• Gen. 9. Candona, Baird, 1850.

Generic Characters. — Shell oval or reniform in shape, with the surface
smooth, of whitish colour, and often exhibiting a pearly lustre. Eye imperfectly
developed. Anterior antennae moderately slender, with the terminal part not
very sharply marked off from the basal one, and distinctly 5-articulate. Posterior
antennae without any trace of natatory setae, penultimate joint in male subdivided
and provided at the junction with 2 peculiar rod-like spines, apparently of
sensorial nature. Anterior lip evenly rounded in front. Mandibles quite normally
developed. Maxillae with the masticatory lobes short and stout, palp rather
prominent, with the apical joint broader than long and obliquely truncated
at the end. Maxillipeds whithout any distinctly defined vibratory lamella at
the base, palp in female simple, lash-shaped, in male, as usual, transformed
and prehensile, but with the dactylus and propodus confluent. Anterior legs
moderately slender and of normal structure; posterior ones rather dissimilar,
being of smaller size and upturned within the shell-cavity, last joint provided
with 3 setae, one of which is generally much smaller than the other 2, which
are not much different in length and extend in opposite directions. Caudal
rami slightly differing in shape in the different species, but armed in the usual
manner. Copulative appendages in male rather compact, exhibiting, as a
rule, one or two irregularly rounded lappets at the end. Ejaculatory tubes
comparatively large, but only provided with 7 whorls of radiating spikes;
proximal extremity of the tubes funnel-shaped.

Remarks.— This genus was established as early as the year 1850 by Baird,
to include 4 species, one of them (C. liicens,) being apparently identical
with Cypris Candida, O. Fr, Miiller. Subsequently many other species have
been added by different authors, and this genus has indeed proved to be one

of the most comprehensive of the Cypridae. On this raison a grouping of the
numerous species has been attempted by some recent authors; but it appears
to me that the Hmits of these groups are very difficult to define precisely.
All the species of the present genus seem to be confined to the northern
hemisphere. I have no knowledge of any true Candona being found south of
the line.

13. Candona Candida. (O. Fr. Mtiller).

(PI XXXII & XXXIII).
Cypris £andida, O. Fr. Miiller, Entomostraca, p. 62, PI. VI, figs. 7—9.
Syn: Monoculus Candidas Jurine.
„ Candona lucens, Baird.

Specific Characters.— Female. Shell moderately tumid, seen laterally,
irregularly oval or sub-triangular in outline, higher behind than in front, greatest
height considerably exceeding half the length, dorsal margin evenly arched,
sloping very steeply behind, but rather slowly in front, ventral margin slightly
sinuated, anterior extremity narrowly rounded, posterior obliquely deflexed and
terminating below in an obtuse corner; — seen dorsally, oblong oval in outline,
greatest width in the middle and nearly attaining half the length, both extremities
obtusely pointed. Valves only slightly pellucid and of rather firm consistency,
surface smooth and shining, with distant small pits, and only sparingly hairy
at each extremity; inner duplicatures moderately broad. Vibratory plate of
maxillipeds replaced by a single seta. Posterior legs only 4-articulate, the
penultimate joint not being subdivided, all 3 apical setae well developed, though
of somewhat different length. Caudal rami conspicuously curved and slightly
attenuated, apical claws rather strong, the distal one about half the length of
the ramus, dorsal seta well developed and attached at a distance from the tip
about equal to Vs of the length of the ramus. Genital lobes of moderate size
and produced behind to a subtriangular corner.

Male slightly larger than female, but scarcely differing in the shape of
the shell, except by the somewhat deeper ventral sinus. Prehensile palps of
maxillipeds not much dissimilar, both being subfusiform in shape, with 2
thickish setae inside the middle and the dactylar part somewhat thickened at
the end; right palp however a little broader than the left and more curved.
Caudal rami scarcely at all curved, but otherwise of same structure as in female.
Copulative appendages with one of the terminal lappets extending upwards at
almost right angle to the axis of the appendage.

Colour in both sexes pure white, with the dark contenta of the intestii
only faintly traced through the shell.

Polycopidae

Ostracoda

Cladocopa

PI. XVII

14.^.

>^^</

6. O. Sars del.

1. Polycope sublaBvis, 6. 0. Sars

2. Polycopsis compressa (Brady & Rob.)

n

\

Cytherellidae

Ostracoda

Platycopa

PI. XVIII

6. O. Sars del

Cytherella abyssorum, 6. O. Sars

Cytherellid«

Ostracoda

Platycopa

PI. XIX

^mw

e. O. Sars del

Cytherella abyssorum, 6. 0. Sars
(continued)

Cypridae

Ostracoda

Podocopa

PI. XX

G. O. Sars del.

Pontocypris trigonella, 6. O. Sars

Cypridae

Ostracoda

Podocopa

PI. XXI

6. O. Sars del.

Erythrocypris mytiloides (Brady)

L

CypridaB

Ostracoda

Podocopa

PL XXII

G. O. Sars del.

Erythrocypris mytiloides (Brady)
(Male)

I

Cyprid^

Ostracoda

Podocopa

PI. XXIII

G. O Sars de!

1. Erythrocypris hispida, 6. O. Sars

2. „ pallida, 6. W. MiJller

I

Cypridae

Ostracoda

Podocopa

PI. XXIV

6. O. Sars del.

ArgillcEcia cylindrica, 6. 0. Sars

Cypridas

Ostracoda

Podocopa

PI. XXV

e. O. Sars del.

Argilloecia conoidea, 6. 0. Sars

I

Cyprids

Ostracoda

Podocopa

PI. XXVI

!mc'}p

G. O. Sars del

Macrocypris minna (Baird)

I

Cypridae

Ostracoda

Podocopa

PI. XXVII

\\\^a(|.V/

A {

C ^

^^

;.^

US'

\^'

^J

i /r

/

/

W^ /

Qfih.n^p

\

/ / %

^'/

6. O. Sars del

Macrocypris minna (Baird)
(continued)

I

Cypridae

Ostracoda

Podocopa

PI. XXVIII

G. O. Sars del.

Macrocypria angusta, 6. O. Sars

Cypridae

Ostracoda

Podocopa

PI. XXIX

/'A'

6L.

m^'^\

Aim I v..

'^- '^y-

lii'^^.

'T/o

"J;

e

f

z.

6. O. Sars del.

Bythocypris bosqueiiana, Brady

1

CypridaB

Ostracoda

Podocopa

PI. XXX

6. O. Sars del.

1. Byihocypris obiusata, 6. O. Sars

2. Bairdia inflata (Norman)

3

Cypridae

Ostracoda

Podocopa

PI. XXXI

G. O. Sars del.

Paracypris polita, G. 0. Sars

i

Cypridae

Ostracoda

Podocopa

PI. XXXII

G. O. Sars del.

Candona Candida (O. Fr. MiJller)

73

Length of female amounting to 1.10 mm.; of male to 1.13 mm.

Remarks.— As some of the species distinguished in recent times bear a very
close resemblance to the one here in question, it is very likely to believe, that
a confusion of these forms with C Candida has formerly taken place. Indeed
it clearly appears from the several figures given in the most recent paper
published by Brady and Norman in 1889, that at least 3 different species have
been confounded and only regarded as simple varieties of C. Candida. The
statements uttered by some other authors on the great variability of the pre-
sent species seem also to point to a similar confusion. I have myself examined
a great number of specimens of this species from many different localities,
without having been aware of any obvious variability in the shape of the shell
in fully grown animals. In the immature state, it is true, the shape of the shell
may look somewhat different from that in adult specimens; but this is also the
case with most other species, and cannot of course be designed as variability
of the species.

Occurrence. — This Ostracod seems to be of very common occurrence over
the whole of our country, being found both in lakes and in small ponds and
ditches. Besides in many other places, I have taken it very abundantly in our
largest lake, Mjosen, at Hamar, at a few fathoms depth, on a muddy bottom
overgrown with aquatic plants. The animal is rather sluggish in habits, crawling
slowly over the bottom, and often burrying more or less deeply within the loose
mud and detritus. Yet, it may easily be detected, owing to its shining white
colour. Male specimens of this species seem to have been very seldom met
with. I have however found several such specimens in the gatherings taken
at the above-named locality in Mj0sen.

Distribution.— Troughoui Europe, Central Asia, Siberia, North America.

Fossil in postglacial deposits of Sweden.

14. Candona neglecta, G. O. Sars.

(PI. XXXIV, fig. 1).
Candona neglecta, G. O. Sars, Ostracoda mediterranea, Arch. f. Math. & Naturv. 1887, p. 107,

PI. XV, figs. 5—7, PI. XIX.
SyH : Candona Candida, Lilljeborg.

, „ var. Brady & Norman.

, fabceformis, VSvra (not Fischer)

Specific Characters,— Female. Shell conspicuously more elongate than
in C. Candida, seen laterally, oblong reniform in shape, greatest height behind
and scarcely attaining half the length, dorsal margin almost straight in the

9 — Crustacea.

74

middle, with a slight angular bend in the ocular region, and sloping ratBer
abruptly behind, ventral margin distinctly sinuated, anterior extremity rounded,
posterior obliquely deflexed, with the infero-posteal corner somewhat prominent,
though evenly rounded off at the end; — seen dorsally, narrow oblong in outline
with the greatest width not nearly attaining half the length. Surface of valv
smooth and shining, though exibiting a number of well marked scattered pit
and clothed at each extremity with short and delicate hairs. Posterior le
conspicuously more slender than in the type species, and having the penultimat
joint distinctly subdivided in the middle. Caudal rami rather slender an
attenuated and slightly curved, apical claws comparatively shorter than i
C. Candida, the distal one not nearly attaining half the length of the ramui
dorsal seta rather small and more approximate to the end. Genital lobes
rather inferior size, but distinctly angulated behind.

Male somewhat larger than female, and differing from it conspicuously
in the shape of the shell, the posterior part of which is broadly rounded off
and peculiarly expanded below, ventral sinus of the shell being moreover
considerably deeper. Prehensile palps of maxillipeds comparatively shorter and
stouter than in the preceding species, with the dactylar part less produced.
Caudal rami perfectly straight and still more narrowly exerted than in female.
Copulative appendages resembling in structure those in C. Candida, though
having the upturned lappet comparatively larger and subcordiform in shape

Shell in both sexes of the usual pure white colour, and somewhat les
opaque in male than in female.

Length of female amounting to 1.30 mm. of male to 1.40 mm.

Remarks. — This form was first described as a distinct species by the preset
author in the year 1887 from specimens taken in the Garda lake, upper Italj
It was however not recognised by subsequent authors, Brady & Norman havin
confounded it with C. Candida, and Vavra with C. fabceformis. It is howevt
evidently specifically distinct from either of these species, as admitted by a
recent authors. The form recorded by Lilljeborg as early as the year 185
under the name of C. Candida is quite certainly not that species, but is moi
properly referable to the form here under question.

Occurrence.— Tho^ present species, it is true, has not yet been found withi
the limits of Norway. As it however occurs in the immediately adjacent trac
of Sweden, it is very likely to believe that, on a closer investigation, it wi
be met with in one or other place of the south eastern part of our count
The figures here given are drawn from specimens raised in my aquaria ut
dried mud from Algeria.

75

Distribution. —Swedtn (Ekman), British Isles (Brady), Germany (G. W.
Mulier), Bohemia (Vavra), Switzerland (Kaufmann), Italy (G. O. Sars), Algeria
(G. O. Sars).

15. Candona lapponica, Ekman.

(PI. XXXIV, fig. 2). '

Candona lapponica, Ekman, Ostracoden aus den nordschwedischen Hochgebirgen. Unters.

Sarekgebirg. Vol. 4, p. 183, fig. 4.

Specific Characters.— Female. Shell, seen laterally, oblong subreniform
in outline, greatest height behind and scarcely attaining half the length, dorsal
margin somewhat arched in the middle and sloping rather steeply behind,
more slowly in front, ventral margin slightly sinuated, anterior extremity evenly
rounded, posterior obliquely deflexed, and terminating below in a narrowly
rounded corner; — seen dorsally, elliptical in outline, with the greatest width
about equal to V5 of the length, both extremities pointed. Surface of valves
smooth, glabrous, and clothed at each extremity with fine hairs. Posterior legs with
the penultimate joint distinctly subdivided. Caudal rami resembling in shape
those in C. neglecta, though somewhat less attenuated, distal claw exceeding
half the length of the ramus; dorsal seta rather small. Genital lobes produced
behind to a rather prominent triangular lappet.

Colour opaque white, with the usual pearly lustre.

Length of adult female scarcely exceeding 0.80 mm.

Male unknown.

Remarks.— Though the shape of the shell, as seen laterally, does not fully
agree with the outline figure given by Ekman, I think I am right in identifying
the above-described form with that recorded by the said author, as I have not
found any other difference either in the size or in the structural details. It is
one of the smallest species of the present genus.

Occurrence. — 3 female specimens only of this form have as yet come
under my notice, all exactly alike and evidently fully grown, as proved by the
well developed ova shining through the semipellucid shell. They were found
in a shallow ditch, at some distance from Christiania.

Distribution. — Swedish Lapmark (Ekman).

76

16. Candona caudata, Kaufmann.

(PI. XXXV).
Candona caudata, Kaufmann, Cypriden und Darwinuliden der Schweiz, p. 365, PI. 24,
figs. 16—20, PI. 26, figs. 17-23.
Syn: Candona acuminata. Brady & Norm, (not Fischer),
, — elongata, G. W. Miilier.

I

Specific Characters. — Female. Shell rather elongate, seen laterally, narrow
reniform in shape, with the greatest height not nearly attaining half the length,
dorsal margin gently arched, without forming any distinct angular bend either
in front or behind, ventral margin distinctly sinuated, anterior extremity evenly
rounded, posterior obliquely produced and exerted to a rather prominent
peculiarly deflexed corner more fully developed on the left valve, this corner
being however quite obsolete in immature specimens; — seen dorsally, narrow
elliptical in outline, with the greatest width only slightly exceeding Vg of the
length, both extremities obtusely pointed. Surface of valves smooth and po-
lished, though exhibiting a number of small scattered pittings and a few short
and delicate hairs at each extremity. Both pairs of antennae unusually robust,
the anterior ones with the terminal part scarcely longer than the basal one, and
having the setae very coarse, almost spiniform. Anterior legs likewise com-
paratively more strongly built than in most other species, with the apical claw
very coarse. Posterior legs with the penultimate joint distinctly subdivided.
Caudal rami comparatively large, gradually attenuated, and only slightly curved,
distal claw not attaining half the length of the ramus, dorsal seta of moderate
size. Posterior end of body produced, immediately above the insertion of the
caudal rami, to a slightly denticulated deflexed point, and carrying farther above
a short seta. Genital lobes forming behind a rather prominent conical lappet.

Colour white, with a pearly lustre especially very conspicuous in young
specimens.

Length of adult female amounting to 1.20 mm.

Male unknown.

Remarks. — This form was formerly identified by Brady and also by myself
with C acuminata (Fischer), which however, as shown by G. W. Miilier, isJI
different species. It has been recorded by the latter author under the nanre :
of C elongata Herrick; but the description and figures given by Herrick are
much too imperfect as to allow of a certain identification, and I therefore agree
with Dr. Aim in retaining for this species the name proposed by Kaufman^|
who has given a good description and easily recognisable figures of it, the
specific name alluding to the peculiarly exerted posterior corner of the shell

i

77

This latter character, however, is only to be observed in fully grown specimens;
in the immature state of the animal, scarcely any trace of such a corner is seen,
the posterior extremity of the shell being quite evenly rounded off, as seen
from the figure given on the accompanying plate. Such young specimens
resemble closely in shape the form recorded by Brady in his Monograph under
the name of C. detecta (O. Fr. Muller), which indeed may prove to be iden-
tical with the present species.

Occurrence. — I have taken this form rather abundantly in the 0stensj0
lake near Christiania at a depth of 2 or 3 fathoms on a muddy bottom. At
first only immature specimens were met with; but somewhat later in the summer
fully adult animals, with the characteristic produced posterior corner of the
shell, were captured, and such specimens were also found in another locality,
viz., in the Frogner dam located within the limits of the town. Only female
specimens of this species have as yet been observed.

Distribution. — Sweden (Aim), British Isles (Brady), Germany (G. W. Muller),
Switzerland (Kaufmann).

17. Candona Sarsi, Hartwig.

(PI. XXXVI).

Candona Sarsi, Hartwig, Zool. Anzeigcr, Vol. XXII, 1899, p. 544.

Syn: Candona pubescens, G. O. Sars (not Koch).

— dentata. G. W. Muller.

Specific Characters. — Female. Shell comparatively short and stout, seen
laterally, irregularly oval or somewhat subreniform in shape, with the greatest
height far behind and considerably exceeding half the length, dorsal margin,
nearly straight in the middle and somewhat ascending behind, then bent
downwards with a bold and quite even curve, ventral margin distinctly sinuated,
anterior extremity somewhat obliquely rounded, posterior much broader and
obtusely blunted, infero-posteal corner not at all exerted and broadly rounded
off; — seen dorsally, oblong oval in outline, with the greatest width somewhat
exceeding Va of the length, anterior extremity more pointed than the posterior.
Surface of valves of a somewhat dull appearance, being densely granular and
all over clothed with unusually long and coarse hairs, giving this form a more
hirsute aspect than in most other species; hyaline borders in front and behind
very narrow. Both pairs of antennae much more slender than in C. caudata.
Posterior legs with the penultimate joint distinctly subdivided, the shortest of
the apical setae very small and hamiform curved. Caudal rami comparatively
short and stout, perfectly straight and somewhat tapering distally, apical claws

]

er

1

78

distinctly denticulated and only curved in their outer part, the longer claw
considerably exceeding half the length of the ramus, dorsal seta of moderat
size. Genital lobes simply rounded off behind.

Male of about same size as female, but slightly differing in the shape
the shell, the posterior part of which is comparatively higher and more broadly
rounded off. Posterior antennae exhibiting the usual well-marked subdivisio;
of the penultimate joint and the characteristic sensory spines at the junction
the 2 joints. Prehensile palps of the maxillipeds somewhat unequal, the rig
one being conspicuously broader than the left and angularly bent at the en
dactylar part of both palps terminating in a sharp point. Copulative appendag
provided behind with 2 well defined thin lobes of nearly equal size, the upper
one somewhat securiform in shape, the lower broadly rounded.

Colour in both sexes opaque white.

Length of adult female amounting to 1.25 mm.

Remarks. — This form was described in the year 1890 by the present author^
and was at that time identified with Cypris pubescens of Koch. Subsequently
however Hartwig found the true Kochian species, and stated its difference from
the present species, which he proposed to rename as above. Yet, Dr. Kaufmann,
though admitting the specific difference of the 2 forms, has found it permissible
to employ for the present species the Kochian denomination with only the
necessary change of the authors name, as he is of opinion, that the form
recorded by Koch does not at all belong to Candona, but to a particular
genus, Pseadocandona. The validity of this new genus seems however to me
to be very questionable, the only difference from Candona being the supposed
want of a subdivision of the penultimate joint of the posterior antennae in tl^l
male. In any case the name pubescens cannot in my opinion be employed
to both these species, but must evidently be restricted to that originally recorde^i
by Koch. ^1

Occurrence. — The only place where I have met with this form is in a smaU
waterhole in the immediate neighbourhood of Christiania, from which seven
specimens, males and females, were collected, many years ago, and late in t
autumn. This water-hole is now filled up and, like many others of my best
finding-places, destroyed by new-building.

Distribution.— Briiish Isles (Brady), Switzerland (Kaufmann).

all

I

79

18. Candona rostrata, Brady & Norman.

(PI. XXXVII).
Candona rostrata, Brady & Norman, Monograph of the marine and fresh-water Ostracoda of the
North western Europe, 1889, p. 101, Pi. IX, figs. 11 & 12, Pi. XH, figs. 22-31.
Syn: Candona limbata. G. O. Sars

marchica, G. W. Miiller (part)

Specific Characters.— Female. Shell somewhat compressed, seen laterally,
angularly subreniform in outline, greatest height far behind and only slightly
exceeding half the length, dorsal margin straight in the middle and somewhat
ascending, with a slight trace of angle both in front and behind, ventral margin
rather deeply sinuated, anterior extremity bluntly rounded or almost transversely
truncated, posterior much higher and broadly rounded off, forming below a
rather conspicuous bowed expansion; — seen dorsally, oblong oval in outline,
with the greatest width about equal to ^/o of the length, anterior extremity
remarkably contracted at the end, forming, as it were, a sharp rostriform
prominence, posterior obtusely pointed. Valves somewhat unequal, the left one
overlapping the right slightly both in front and behind, hyaline borders at
each extremity very broad and conspicuous, surface of a somewhat dull ap-
pearance and all over densely hairy, the hairs being however less coarse than
in the preceding species. Antennae moderately slender, resembling in structure
those in that species. Posterior legs likewise of a very similar appearance.
Caudal rami somewhat more attenuated, with the apical claws comparatively
shorter. Genital lobes simply rounded behind.

Male, as a rule, somewhat larger than female, and having the posterior
part of the shell rather more expanded. Prehensile palps of maxillipeds conspi-
cuously unequal, the right one being much broader than the left and conside-
rably bowed outside. Caudal rami still more attenuated than in female, with
the apical claws less curved. Copulative appendages resembling in structure
those in C. Satsi, but having the upper terminal lappet smaller and simply
rounded.

Colour in both sexes whitish, semipellucid, wit a more or less distinct
orange tinge.

Length of adult female amounting to 1.10 mm., of male to 1.20 mm.

Remarks. — This form was described in the year 1889 by Brady and
Norman from some male specimens, the female sex not being observed. It is
evidently nearly allied to the preceding species, but may readily be distinguished
by the somewhat different shape of the shell and its less coarse hairy clothing,
as also by the very broad and conspicuous hyaline borders at each extremity.

80

In allusion to this latter character I had long ago noted this form under
provisional name C. llmbata. Another peculiar character distinguishing the
present species is the abrupt contraction of the anterior extremity of the shell
which, in the dorsal or ventral aspect of the animal, looke like a sharply
pointed rostrum; hence the specific name proposed, fll

Occurrence. — I have met with this form occasionally in the environs of
Christiania, especially in shallow grassy creeks at the borders of lakes and for-
med by the higher level of the water in the lakes during the spring. Unlike
what is generally the case, male specimens of this form are more frequently
met with than females.

Distribution.— Swtdtn (Ekman), British Isles (Brady) Germany (G.
Miiller), Bohemia (Vavra), Russia (Cronenberg).

19. Candona marchica, Hartwig.

(PI. XXXVIII, fig. 1).

Gandona marchica. Hartwig, Sitzungs Berichte de Gesellsch. naturf. Freunde in Berlin 18997

Nr. 8, p. 183.

Syn: Candona rostrata, G. W. Miiller (part).

Specific Characters.— Female. Shell comparatively shorter and stoute'
than in C. rostrata, though, seen laterally, of a somewhat similar shape,
greatest height as usual behind and considerably exceeding half the length,
dorsal margin somewhat ascending and joining the posterior edge by a bold
and quite even curve, ventral margin slightly sinuated, anterior extremity more
uniformly rounded than in C. rostrata, posterior blunted and less expanded
below; seen dorsally, oblong oval in outline, with the greatest width some-
what exceeding V5 of the length, anterior extremity more pointed than th
posterior, but scarcely rostriform produced. Surface of shell, as in the pr
ceding species, densely hairy, hyaline borders however rather narrower. Stru^
ture of the several limbs almost exactly as in C. rostrata. Caudal rami co
paratively shorter and stouter than in that species, with the apical claws more
unequal in length, the proximal one being very much shorter than the distal
one, which almost attains the entire length of the ramus. Genital lob
broadly rounded off behind.

Male of somewhat larger size than female and rather like the male of
C. rostrata in the shape of the shell, though heving the hyaline borders in
front and behind conspicuously narrower. Prehensile palps of maxillipeds com-
paratively shorter and stouter. Caudal rami with the proximal claw muc

I

ii

81

reduced in size, being scarcely half as long as the distal one and almost per-
fectly straight. Copulative appendages comparatively smaller than in C. rostmta
and slightly differing in shape, lower terminal lappet somewhat bilobed at the end.

Colour whitish, semipellucid, with a fainte yellow tinge.

Length of adult female scarcely exceeding 0.92 mm.; that of male
about 1 mm.

Remarks. — The present form is closely allied to C. rostrata, and seems
indeed often to have been confounded with that species. It is however rather
inferior in size, and has the shell, at least in female, conspicuously shorter
and stouter. Dr. Hartwig has moreover called attention to an easely observable
difference in the structure of the caudal rami in both sexes.

Occurrence. — I have found this form not unfrequently in similar localities
to those in which C. rostrata occurs, but only in the early part of the summer.

Distribuiion.-Sweden (Ekman), Germany (Hartwig), Switzerland (Kaufmann).

20. Candona stagnalis, G. O. Sars.

(PI. XXXVIIi; fig. 2).

Candona stagnalLi, G. O. Sars, Oversigt af Norges Crustaceer II, p. 65.

Syn: Candona Zenkeri, G. 0. Sars.
— rara, G. W. Miiller.
, — qvadrata, Aim.

Specific Characters.— Female. Shell, seen laterally, oblong subreniform
in shape, greatest height behind and scarcely exceeding half the length, dorsal
margin straight and nearly horizontal, joining the posterior edge by an abrupt,
almost angular bend, ventral margin distinctly sinuated, anterior extremity
obliquely rounded, posterior much broader and obtusely blunted, forming
below a rather conspicuous bowed expansion;— seen dorsally, narrow oblong
in outline, with the greatest width about equal to -/s of the length, both
extremities obtusely pointed. Surface of valves smooth, without any obvious
sculpture, and clothed at each extremity with comparatively short and fine
hairs, posterior expansions flanked by a rather broad pellucid border. Posterior
legs with the penultimate joint not subdivided, shortest apical seta about the
length of the terminal joint and not hamiform curved. Caudal rami com-
paratively slender and attenuated, almost straight, apical claws of moderate
size and not much unequal, the distal one scarcely exceeding half the length
of the ramus, dorsal seta small and attached not far from the end. Genital
lobes of unusual size, subquadrate in shape and forming behind an angular
corner.

10 — Crustacea.

82

Male of about same size as female, but having the posterior part of the
shell more broadly rounded off. Prehensile palps of maxillipeds resembling
in structure those in C. marchica. Caudal rami about as in female. Copulative
appendages with 3 well defined terminal lappets of nearly equal size, though
somewhat differing in shape.

Colour whitish, with a fainte yellow tinge.

Length of adult female amounting to 0.86 mm.

Remarks.— The above-described form was shortly characterised by the
present author in the year 1899; but the structural details were not sufficiently
made out, for which cause the species was not recognised by subsequent
authors, it having been recorded as new under 2 different names, viz., as
C. ram by G. W. Miiller and as C. quadrata by Aim. The latter author has
however in his most recent treatise admitted the identity of these 2 forms
with the Norwegian species. The form recorded by me under the name of
C. Zenkeri I am now disposed to consider as only a variety of the present
species.

Occurrence. — I found this form, many years ago, rather abundantly in
some small ditches located in the immediate neighbourhood of Christiania.
These ditches are now destroyed by new-building; but I had fortunately secured
a sufficient preserved material for a renewed examination, and have thus been
enabled to confirm the statement given by Dr. Aim about the remarkable size
and peculiar shape of the genital lobes in the female.

Distribution. — Sweden (Ekman), British Isles (Brady), Germany (C. W. Miiller).

21. Candona albicans, Brady.

(PI. XXXIX, fig. 1).

Candona albicans, Brady, Monograph of recent British Ostracoda, p. 381, PI. XXV, figs. 20—25).]

Syn: Candona parallela, G. W. Miiller.

Specific Characters. — Female. Shell, seen laterally, oval subreniform ini
shape, only slightly higher behind than in front, greatest heigt somewhat
exceeding half the length, dorsal margin perfectly straight and nearly horizontal,
with a fainte indication to an angle both in front and behind, ventral margin
only very slightly sinuated, anterior extremity obliquely rounded, posterior
obtusely blunted and scarcely expanded below; — seen dorsally, oblong oval or]
elliptical in outline, with the greatest width about equal to ^/r, of the length
and both extremities obtusely pointed. Valves only slightly pellucid and clothed]
at each extremity with short and delicate hairs, surface of a dull appearancej

I
I

i

83

exhibiting numerous densely crowded areolae or pits, especially very sharply
marked in yoiing specimens. Posterior legs with the penultimate joint distinctly
subdivided, shortest apical seta not hamiform and nearly twice the length of
the terminal joint. Caudal rami resembling in shape those in C. siagnalis,
though perhaps a little shorter. Genital lobes of moderate size and simply
rounded, not forming any projecting corner behind.

Male of about same size as female and only slightly differing from it in
the shape of the shell. Prehensile palps of maxillipeds and copulative appen-
dages not essentially differing in structure from those parts in C stagnalis.

Remarks. — I have felt justified in restoring the species originally established
by Brady as C. albicans, although that author in his more recent publications
has questioned its validity, supposing it to have been merely founded on
immature specimens of an earlier known Candona, C. compressa (Koch). True,
in very young specimens of this and also of some other Candonae a slight
areolation of the valves similar to that described by Brady in his C albicans,
may be traced; but in none of them this areolation is so strongly marked as
in this species and very soon disappears wholly by the growth of the animal.
In the present species, however, it is well observable also on the valves of
fully adult specimens, though somewhat less conspicuous than in the immature
state. I have compared young specimens of the present species with the
description and figures given by Brady, and find the agreement quite complete,
both as to the shape of the shell and to its sculpture. The C. parallela of
G. W. Miiller is unquestionably identical with Brady's species.

Occurrence. — This form is rather common in the environs of Christiania,
being generally found in small ditches and pools with muddy bottom. During
the early part of the summer, as a rule, only immature specimens are met with,
but somewhat later, under favourable circumstances, also fully adult animals
may be captured. Male specimens seem to be rather scarce. I have as yet
only come across 2 such specimens, the one of which is figured on the
accompanying plate.

Distribution.— Swtden (Aim), British Isles (Brady), Germany (G. W. Miiller).

22. Candona compressa, (Koch).

(PI. XXXIX, fig. 2).
Cypris compressa, Koch, Deutschlands Crustaceen, p. 171, PI. 17.
S y n : Candona pubescens, Vavra (not Koch).
fallax. G. W. Miiller.

Specific Characters. — Female. Shell somewhat compressed, seen laterally,
angularly subreniform in shape, much higher behind than in front, greatest

84

height slightly exceeding half the length, dorsal margin straight in the middle
and conspicuously ascending behind, joining the posterior edge by an abrupt
angular bend, ventral margin scarcely at all sinuated, anterior extremity narrowly
rounded, posterior very broad and obliquely deflexed, with the lower corner
evenly rounded off; — seen dorsally, narrow oblong in outline, with the greatest
width scarcely exceeding Vs of the length, anterior extremity more pointed than
the posterior. Valves rather densely hairy and having the hyaline borders in
front and behind very narrow; surface in most cases apparently quite smooth,
though in some specimens a very delicate and dense reticulate pattern may
be traced over the whole of the shell. Posterior legs with the penultimate
joint distinctly subdivided, shortest apical seta not hamitorm and more than
twice as long as the terminal joint. Caudal rami comparatively slender and
attenuated, with the apical claws of moderate size and distinctly denticulate,
the distal one scarcely attaining half the length of the ramus. Genital lobes
of a rather peculiar and characteristic shape, being divided by a deep median
sinus into 2 lanceolate lappets, the posterior one the larger.

Male somewhat smaller than female, but resembling it in the shape of
shell. Prehensile palps of maxillipeds rather unequal, the right one being
much broader than the left, with the outer edge considerably bulging. Copu-
lative appendages differing somewhat in shape from those in the other species
and exhibiting 2 sub-erect terminal lappets of rounded form. Ejaculatory tubes
also somewhat deviating in structure, the central duct being unusually wide^
whereas the radiating spikes are very short.

Colour opaque white.

Lenght of adult female amounting to 1.05 mm.

Remarks. — I am by no means assured, that the identification of this species
by other authors has in every case been correct. Thus it appears to me quite
evident, that the form so named by Ekman cannot be this species, as the
female genital lobes are described and figured as quite simple, rounded off;
nor seems the outline figure of the shell given by Dr. Aim to be in any full
accord with the present species. Yet, it may be assumed as tolerably certain,
that both the form recorded by Lilljeborg and that described and figured by
Brady are in reality identical with the species here in question. By none of
the authors I find any mention of the peculiar shape of the genitale lobes, as
described above, though this character alone will suffice for distinguishing the
present species form any of the other known Candonae. As to the C. fallax
of G. W. Muller, it has recently been mentioned by Dr. Aim as a synonym
of C. compressa. Wheter this is correct or not, I am unable at present to decide

wide«j

J

85

Occurrence. — The only place where I have as yet met with this species,
is in a shallow muddy swamp located on the Fornebo peninsula, at some
distance west of Christiania. Male and female specimens occurred here in about
equal number.

Distribution. — Sweden (Lilljeborg), British Isles (Brady), ? Germany (G. W.
Miiller), Bohemia (Vavra).

Gen. 10. Cryptocandona, Kaufmann, 1900.

Generic Characters. Shell thin and much compressed, with the valves
nearly equal and having the inner duplicatures rather broad. Antennae, mandibles
and maxillae about as in Candona. Maxillipeds however with the vibratory
plate less rudimentary, carrying 3 well developed plumose setae. Anterior legs
rather slender. Posterior legs with 2 additional setae inside, not found in
Candona, the one attached in the middle of the penultimate joint, the other at
the end of the preceding joint; apical setae, as in Candona, 3 in number, but
exhibiting a somewhat different mutual relation, the outermost seta being much
longer than the other 2 and more abruptly reflexed. Caudal rami comparatively
large, but with the dorsal seta extremely small, almost obsolete. Male specimens
not yet observed of any of the species.

Remarks. — This genus proposed by Kaufmann is nearly allied to Candona,
and has indeed not been admitted as such by the most recent author. Dr. Aim,
who regards it to represent only a subsection or group of that genus. I think
however that this genus ought to be supported, as it exhibits some well-marked
differences from Candona found in all the species. As observed by Kaufmann,
the genus shows in several respects an approach to the next genus, Candonopsis,
occupying, as it were, an intermediate place between it and Candona. The
male characters remain to be made out, and will no doubt present some
peculiarities. 5 species referable to the present genus are as yet known, 2 of
them being represented in the Fauna of Norway.

23. Cryptocandona Vavrai, Kaufmann.

PI. XL, fig. 1).

Cryptocandona Vavrai, Kaufmann, Cypriden und Darwinutiden der Schweiz, p. 391, PI. 24,

figs. 12—15, PI. 26, figs. 10—16.

Specific Characters.— Female. Shell, seen laterally, oblong reniform in
shape, only slightly higher behind than in front, greatest height about equal
to half the lenght, dorsal margin straight in the middle and somewhat abruptly

d

86

bent both ind front and behind, ventral margin distinctly sinuated, anterior
extremity evenly rounded, posterior somewhat obliquely deflexed and round-
ded off below; — seen dorsally, narrow oblong in outline, with the side-edges
almost straight in the middle, greatest width scarcely attaining Vs of the length,
both extremities obtusely pointed. Valves smooth, glabrous, and clothed at
each extremity with short and delicate hairs; inner duplicatures remarkabl^
broad both in front and behind. Anterior antennae with the terminal part
scarcely as long as the basal one, and having the 4 first joints comparatively
short, last joint however remarkably slender and narrow, being fully as long
as the 2 preceding joints combined. Maxillipeds with the palp comparatively
short and stout, bluntly rounded at the tip. Posterior legs with the penulti-
mate joint not subdivided, shortest apical seta scarcely longer than the terminal
joint and hamiform curved. Caudal rami perfectly straight and gradually tape-
red, apical claws moderately strong and slightly curved, the distal one scarcely
exceeding half the lenght of the ramus. Genital lobes evenly rounded

Shell semipellucid, of whitish or light grey colour.

Length of adult female 0.90 mm.

Remarks. — This form, being that described at the earliest date, ought of
course to be regarded as the type of the present genus. It is readily recog-
nised from any of the species of Candona by the very much compressed and
rather regularly reniform shape of the shell.

Occurrence. — I have taken this form, many years ago, in a shallow ditsh
at some distance west of Christiania (Bogstad), and have more recently also
met with in another locality, viz., at Grimstad, south coast of Norway. All
the specimens collected were of the female sex und fully grown.

Distribution. — Sweden (Ekman), Switzerland (Kaufmann).

24. Cryptocandona reducta, (Aim).

(PI. XL, fig. 2.
Condona reducta, Aim, Monographic der Schwedischen Siisswasser Ostracoden, p. 137."

Specific Characters. — Female. Shell, seen laterally, narrow oblong in
shape, scarcely higher behind than in front, greatest height in the middle and
not nearly attaining half the length, dorsal margin well arched, without any
abrupt bend either in front or behind, ventral margin only very slightly sinu-
ated, anterior extremity evenly rounded, posterior somewhat exerted and obtusely
blunted at the end; — seen dorsally, narrow lanceolate in outline, with the«j
side-edges evenly curved and both extremities sharply pointed. Valves very '

11

87

thin and pellucid and sparingly hairy at each extremity, surface quite smooth
and polished, inner duplicatures less broad than in the preceding species.
Anterior antennae with the terminal part fully as long as the basal one, and
having the last 2 joints rather elongated and subequal in size, setae comparati-
vely shorter than in the preceding species. Posterior legs with the penulti-
mate joint distinctly subdivided, shortest of the apical setae not hamiform.
Caudal rami somewhat less strong than in the type species and slightly cur-
ved, apical claws rather thin, the distal one exceeding somewhat half the length
of the ramus.

Colour transparent whitish.

Length of adult female amounting to 0.95 mm.

Remarks. — Though the outline-figures of the shell given by Dr. Aim. do
not fully agree with those here drawn, I cannot doubt that the above-described
form is identical with Aim's species, as otherwise no difference could be detec-
ted. The species is readily distinguishable from C. VCLvral by the very nar-
row and elongated shell, the shape of which, as seen laterally, exhibits a per-
plexing resemblance to that in Candona anceps, Ekman.

Occurrence.—SomQ few specimens of this pretty species were found in the
same localities in which C. Vdvrai occurred. I have moreover taken it occasio-
nally in the Maridal lake near Christiania and in the Van lake near Moss at
depths varying from 2 to 20 fathoms.

Distribution. — Sweden (Aim).

Gen. 11. Candonopsis, Vavra, 1891.

Generic Characters. — Shell thin, compressed, more or less reniform in
shape, with the inner duplicatures of the valves very broad in front. Both
pair of antennae, and particularly the anterior ones, very slender, but not adap-
ted for swimming, the posterior ones in male with the penultimate joint subdi-
vided, as in Candona. Mandibular palp unusually produced, with the terminal
joint long and narrow. Maxillipeds with a well defined vibratory plate carrying
3 thickish plumose setae, palp in female slender and attenuated, in male trans-
formed in a similar manner to that in Candona. Posterior legs resembling in
structure those in Cryptocandona, except that the seta inside the end of the
penultimate joint is wanting. Caudal rami very slender and narrow, without
any trace of a dorsal seta.

Remarks.— This genus was established in the year 1891 by Vavra, to in-
clude the form recorded by Brady and Robertson under the name of Candona

88

Kingsleyi, and has been admitted by all recent authors. Indeed, this genus
exhibits some very conspicuous differences from the true Candonae and appears
to approach more nearly to Crypocandona, being however well distinguished
also from that genus. It comprises only a single European species, but ij
represented in more southern latitudes by several nearly-allied forms.

25. Candonopsis Kingsleyi (Brady & Robertson).

(PI. XLl).

Candona Kingsleyi, Brady & Robertson The Ostracoda and Foramlnifora of Tidal Rivers. Ann
Mag. Nat. Hist. Vol. VI, ser. 4, p. 17, PI. IX, figs. 9-12.

Syn: Candona fabceformis G. O. San; (not Fischer).

. Ann.

Specific Characters. — Female. Shell, seen laterally, rather regularly
reniform in shape, greatest height a little behind the middle and about equal
to half the length, dorsal margin forming a quite even curve throughout,
without any trace of an angular bend either in front or behind, ventral
margin distinctly sinuated, both extremities evenly rounded off, the anterior
a little broader than the posterior; — seen dorsally, narrow lanceolate in
outline, with the greatest width behind the middle and about equal to Vd
of the length, anterior extremity more pointed than the posterior. Valves
rather pellucid, with the surface smooth and polished, being clothed at
each extremity with delicate hairs; inner duplicatures of the anterior extremity
remarkably broad, with the inner edge almost straight and vertical. Anterior
antennas with the terminal part exceedingly slender, almost twice as long
as the basal one, and having all the joints narrow cylindrical in shape and
equal in size, setae rather slender. Posterior antennae with the penultimate
joint nearly as long as the antepenultimate one, and narrower than usual.
Terminal joint of the mandibular palp nearly of same length as the pre-
ceding joint, but much narrower, slender cylindrical in shape. Palp of maxilli-
peds gradually tapered and exhibiting trace of a small terminal joint. Caudj
rami excedingly narrow and slightly flexuous, apical claws slender and curve<
in their outer part, the distal one exceeding half the lenght of the ramuj
Genital lobes evenly rounded off.

Male of somewhat larger size than female, and having the posterior par!
of the shell comparatively broader. Prehensile palps of maxillipeds rather
short and stout and, as usual, somewhat unequal, the right one being con-
spicuously broader than the left, whih the outer edge strongly bowed through-
out. Copulative appendages terminating in 2 unequal lappets, the upper one

89

rather large and triangularly produced. Ejaculatory tubes very large and
distinctly observable through the pellucid shell.

Colour transparent whitish.

Length of female 0.95 mm., of male about 1 mm.

Remarks.— This form was first recorded in the year 1870 by Brady and
Robertson as a species of Candona, and description and figures of it were also
given in the more recent Monograph published by the first-named author in
connection with Norman; but its true relation to Candona was first made out
in the yar 1891 by Vavra. I had myself long ago been aware of this beautiful
Ostracod, but had erroneously identified it with Candona fabceformis (Fisher),
a species not yet found within the limits of Norway.

Occurrence. — I have taken this form rather abundantly in some muddy
creeks at the border of the 0stensj0 lake near Christiania, and more recently
also at Grimstad, south coast of Norway. Male specimens seem to be fully
as frequent as females and are readily recognised by the translucent large ejacula-
tory tubes.

Distribiition.—Swdden (Aim), British Isles f Brady), Germany (G. W. Muller),
Bohemia (Vavra), Switzerland (Kaufmann), Siberia (G. O. Sars).

Group 3. Cyclocyprides.

Remarks. — This group as yet comprises 3 genera, viz., Cyclocypris, Cypria,
and Physocypria, the validity of the last-named genus being however some-
what questionable. Owing to a certain resemblance found in the structure of
the ejaculatory tubes and in the subdivision of the penultimate joint of
the posterior antennae in the male, G. W. Muller has combined this and the 2
preceding groups, to form a particular subfamily of the Cypridae, Candonlnce,
and Dr. Aim has recently adopted the same view, though proposing to change
the name of this subfamily to Candocy prince. I think however that the arrange-
ment here proposed might be found to be more appropriate, and in particular
I must insist on the necessity of keeping the present group sharply apart from
the Candonides, with which it scarcely exhibits any closer affinity, except in
the 2 above-named characters. In habits, too, the forms comprised within the
present group widely diverge from the Candonides, being, quite in contrast
to the latter, exceedingly agile animals, more perfectly indeed equiped for
swimming than most other Cypridae.

11 - - Crustasea.

90

Gen. 12. Cyclocypris, Brady & Norm., 1889.

Generic Characters. — Shell rather tumid, of a more or less rounded oval
shape, with the dorsal face evenly vaulted. Valves subequal, with the inner
duplicatures comparatively narrow. Eye well developed, with dark pigment.
Both pairs of antennae powerfully developed, and perfectly adapted for swim-
ming. Natatory setae of the posterior ones unusually prolonged, extending far
beyond the tips of the apical claws; penultimate joint of these antennae in
male distinctly subdivided, but wilhout any traces of sensory spines. Mandi-
bular palp of quite normal structure. Maxillae with the masticatory lobes com-
paratively short, palp of moderate size. Maxillipeds provided at the base with
a rather fully developed vibratory plate edged with the normal number (6) of
plumose setae; palp in female comparatively small and simple, in male trans-
formed in the normal manner, the dactylus being well defined from the pro-
podos and of different shape in the 2 palps. Anterior legs not much elongated.
Posterior legs rather larger, with 2 setae inside the penultimate joint, and the
terminal joint unusually produced, apical setae 3 in number and very unequal,
the outermost one being greatly prolonged and abruptly reflexed. Caudal rami
well developed, sublinear in form, with the apical claws comparatively strong,
dorsal seta small and rather remote from the apex. Copulative appendages
of moderate size, terminating in one or 2 broadly rounded lappets. Ejacula-
tory tubes with I more or less densely crowded whorls of radiating spikes,
proximal end of the tubes transversely truncated. H

Remarks. — This genus was proposed in the year 1889 by Brady and
Norman, to include the species recorded by the present author as Cypris
globosa, the other species now comprised within this genus being retained by
them in the genus Cypria of Zenker. From the latter genus, in the restriction
at present adopted, it may at once be distinguished by the much more tumid
shell, and in the structural details also some well marked differences are found.
4 species referable to this genus will be described in the sequel.

26. Cyclocypris globosa, G. O. Sars.

(PI. XLll).

Cypris globosa, G. O. Sars, Zool. Reise i Christianias og Trondhjems Slifter 1862, p. 27.

Syn: Cypris cinerea, Brady.
, Cyclocypris dispersa, G. W. Miiller.

Specific Characters. — Female. Shell very tumid, seen laterally, rounded
oval in shape, greatest height in the middle and about equal to 73 of tl

91

lenght, dorsal margin boldly arched, without any abrupt bend, ventral margin
scarcely at all sinuated, anterior extremity obliquely rounded, posterior rather
broader and obtusely blunted; — seen dorsally, broadly ovate in outline, with
the greatest width somewhat behind the middle and about equal to the height,
anterior extremity obtusely pointed, posterior rounded off. Surface of valves
smooth and clothed with short hairs more conspicuous at each extremity,
hyaline borders in front and behind rather slight. Anterior antennae with the
terminal part about the length of the basal one, and having the joints gradually
diminished in size, last joint very small, setae much elongated and distinctly
ciliated. Posterior antennae with the penultimate joint scarcely more than half
as long as the preceding joint; apical claws very slender and almost straight.
Posterior legs with the terminal joint considerably exceeding half the length
of the penultimate one, shortest apical seta comparatively small. Caudal rami
considerably produced and perfectly straight, with the dorsal edge in its greater
extent fringed with minute spinules, apical claws remarkably short and stout,
the distal one scarcely exceeding V^ of the length of the ramus.

Male, as a rule, slightly larger than female, but scarcely differing from
it in the shape of the shell. Prehensile palps of maxiilipeds rather dissimilar,
the right one having the propodos slightly narrowed distally, and the dactylus
remarkably broad, sublamellar, and almost angularly curved; left palp with the
propodos somewhat broader and exhibiting near the end inside a dentiform
prominence, dactylus narrow falciform. Copulative appendages comparatively
large, terminating in a broadly rounded lobe. Ejaculatory tubes remarkably
short and massive, with the whorls of radiating spikes densely crowded and
somewhat obliquely disposed in relation to the central duct.

Colour bright yellowish brown, somewhat darker in male than in female.

Length of adult female amounting to 0.88 mm.

Remarks. — This form was recorded as early as the year 1863 by the
present author, but was not described in detail or figured. Yet, it has been
well recognised by most subsequent authors, its comparatively large size
rendering it indeed readily distinguishable from any of the other known species.
The form recorded by Brady in his Monograph under the name of Cypris
cinerea is evidently identica with the present species, the figures given having
apparently been drawn from an immature specimen. G, W. Miiller has proposed
to change the specific name globosa to dispersa, but I do not find that such
a change is required..

Occurrence.— \ have taken this form in several places around Christiania
in small pools and ditshes liable to exsiccation during the summer. It is a

92

very actiwe little animal, svimming about in the water with great dexterity,
and is readily detected by its bright brownish colour. Male specimens occur
in nearly same number as females.

Distribution .-"^Sweden (Aim), British Isles (Brady) Germany (G. W. Miiller
Bohemia (Vavra), Switzerland (Kaufmann).

27. Cyclocypris ovum, (Jurine).

(PI. XLIII, fig. 1).

Monoculus ovum, Jurine, Hist, des Monocles, p. 179, PI. XIX, figs. 18, 19.

Syn: Cypris minuta, Baird.
, — Icevis, G. O. Sars (not Miiller).

» — pygmcea, Cronenberg.

Specific Characters.— Female. Shell, seen laterally, rather regularly oval
or elliptical in shape, greatest height in the middle and scarcely attaining -/a
of the length, dorsal margin quite evenly arched, sloping however more steeply
behind than in front, ventral margin nearly straight, both extremities evenly
rounded off, the posterior somewhat more obtuse than the anterior; — seen dor-
sally, regularly oval in outline, greatest width in the middle and about equal
to V3 of the length, both extremities somewhat blunted. Valves only slightly
hairy, with the surface smooth and polished. Posterior legs with the terminal
joint about half the length of the penultimate one, middle apical seta comj
paratively small, scarcely half as long as the terminal joint, and sigmoid curve
Caudal rami less produced than in C. globosa, dorsal edge exhibiting at
some distance from the base a few extremely small denticles, apical claws of
moderate size, the distal one nearly attaining half the length of the ramus.

Male resembling the female both in size and in the shape of the she
but exhibiting the usual sexual differences.

Colour of both sexes a more or less bright chestnut brown.

Length of adult female scarcely exceeding 0.50 mm.

Remarks. — The identity of the above-described form with Jurine's Mono-
culus ovum seems to me to be beyond doubt. This species has however by
several authors, and also by myself been formerly recorded under the name applied
here to the next species, and in some cases quite new specific names have
been introduced. It is one of our smallest fresh-water Ostracoda, and the name;
applied to it by Baird and Cronenberg allude indeed herto.

Occurrence.— \ have met with this small Ostracod rather abundantly in
many places around Christiania, and it is most probably distributed over the

P

1

ii

93

greater part of our country. In spite of its small size, it may easily be detected
by the bright chestnut brown colour of the shell.

Distribution. — Sweden (Lilljeborg), British Isles (Brady), Germany (G. W.
Muller), Switzerland (Kaufmann), Siberia (G. O. Sars), North America (Turner).

28. Cyclocypris laBvis (O. Fr. Muller).

(PI. XLIII, tig. 2).

Cypris Icevis, O. Fr. Muller, Entomostraca, p. 52, PI. Ill, figs. 7—9.

Syn: Cypris minuta, G. O. Sars (not Baird).
, — pantherina, Fischer.

, Cyclocypris serena, G. O. Sars (not Koch).

Specific Caracters. — Female. Shell very short and high, seen laterally,
rounded trigonal in shape, greatest height in the middle and almost attaining
^/4 of the length, dorsal margin gibbously arched in the middle, ventral margin
straight, both extremities rounded off, the posterior blunter than the anterior;
—seen dorsally, broadly ovate in outline, greatest width behind the middle and
about equal to the height, anterior extremity somewhat narrowed, posterior
broadly rounded. Valves more densely hairy than in the preceding species,
and exhibiting a peculiar tessellated pattern of the surface. Posterior legs with
the terminal joint about half the length of the penultimate one, middle apical
seta comparatively longer than in C ovum and distinctly sigmoid. Caudal
rami of about same shape as in that species, but distinguished by a rather
peculiar armature of the dorsal edge at the base, consisting of a knob-like
prominence exerted into 3 sharp points and followed proximally by a row of
4 well marked denticles.

Male scarcely differing from the female, except by the usual sexual
characters.

Colour dark brownish grey, with a more or less distinct olivaceous tinge.

Length of adult female 0.50 mm.

Remarks. — Though the identity of the above-described form with Cypris
Icevis of O. Fr. Muller appears to me to be very questionable, it is here
recorded under that specific name, as it has been so named by most recent
authors. It is of about the same small size as C. ovum, with which it indeed
seems often to have been confounded. On a closer examination, it may hoivever
easily be distinguished from that species by the comparatively higher and more
tumid shell, and in the fresh condition also by its rather different colour. The
peculiar armature of the caudal rami at the base, described above, seems to

94

have quite escaped the attention of eadier authors. I have found it perfectly
constant in all the specimens more closely examined by me.

Occurrence. — This species is of very common occurrence around Christi-
ania, being found, often in great abundance, in shallow ditches and pools with
grassy bottom. In habits it ressembles the preceding species, though being
perhaps somewhat less agile.

Distribution. — Throughout Europa, Central Asia, North, America.

29. Cyclocypris serena (Koch).

(PI. XLIII, fig. 3).

Cypris serena, Koch, Deutsch lands Crustaceen, H. XXI. 22.

Syn: Cvpris Icevis. Brady (not O. Fr. Miiller).
, Cpclocypris ovum serena, Aim.

Specific Characters. — Female. Shell seen laterally, broadly oval in shape,
greatest height in the middle and almost attaining 7* o^ the length, dorsal
margin boldly and rather evenly arched throughout, ventral margin not at all
sinuated, both extremities blundtly rounded and nearly equal; — seen dorsally,
broadly ovate in outline, greatest width somewhat behind the middle and equal
to the height, anterior extremity somewhat more narrowed than the posterior.
Surface of valves smooth and polished, being clothed at each extremity with
delicate hairs. Posterior legs with the terminal joint scarcely half as long as
the penultimate one, middle apical seta about the length of the terminal joint
and simply curved at the end. Caudal rami of moderate size and slightly
curved, dorsal edge nearly smooth, with only very slight trace of an armature
at the base, apical claws comparatively more slender than in the preceding
species, the distal one fully attaining half the length of the ramus.

Male closely resembling the female both in size and in the shape of the
shell. Prehensile palps of maxillipeds less conspicuously unequal than in ^|
globosa, the dactylus of the right one being comparatively smaller, though much
broader than on the left palp. Copulative appendages and ejaculatory tubes
likewise differing in shape conspiciously from those parts in the said species.
Colour in both sexes dark olivaceous brown. _,

Length of adult female amounting to 0.60 mm. H

Remarks. — I am by no means convinced that the above-described form
is in reality identical with Cypris serena of Koch, which I should be more
inclined to refer to the preceding species. As I however feel some reluctance
in augmenting the long list of specific names proposed within the present

95

genus with a new one, I have preferred to record it here under the name by
which it has been very recognisably described by Kaufmann and more recently
also mentioned by Dr. Aim. The latter author has however questioned its true
specific validity, regarding it merely as a variety or subspecies of C. ovum and
naming it, in accordance therewith, C. ovum serena. In my opinion the pre-
sent form ought to be regarded as a well defined species, differing, as it does,
from C. ovum rather conspicuously both in size and in the shape of the shell,
and moreover exhibiting some well marked differences in the structural details,
as pointed out in the above diagnosis.

Occurrence.—SevQTal specimens of this form, both males and females,
were taken, some years ago, in our largest lake, Mjesen, at Hamar. They
occurred together with some other Ostracoda in a few fathoms deep, on a
muddy bottom overgrown with aquatic plants.

Distribution. — Sweden (Aim), British Isles (Brady), ? Germany (Koch),
Switzerland (Kaufmann).

Gen. 13. Cypria, Zenker, 1854.

Generic Characters. — Shell short and high, but much compressed, with
the valves slightly unequal, the left one being the larger and somewhat over-
lapping the right at both extremities; pellucid borders well observable. Eye
large and conspicuous. Antennae well adapted for swimming, and on the whole
resembling in structure those in Cyclocypris, except that the subdivided penul-
timate joint of the posterior ones in the male is provided with 2 well-marked
sensory spines, as in the Candonides. Mandibular palp with the terminal joint
unusually produced. Maxillae with the masticatory lobes much reduced in size,
palp however rather large, with the proximal joint somewhat lamellar and
bowed behind, distal joint small. MaxiUipeds with the vibratory plate per-
fectly developed, palp in female simple lash-shaped, in male, as usual, pre-
hensile and very unequal on each side, the right one being much more pow-
erfully developed than the left. Anterior legs of moderate size. Posterior legs
with only a single seta inside the penultimate joint, terminal joint les produced
than in Cyclocypris, with the 2 innermost setae very small and subequal, the
outermost much prolonged and abruptly reflexed. Caudal rami resembling in
structure those in the said genus, but without any armature of the dorsal edge
at the base. Copulative appendages comparatively small, terminating in 2
juxtaposed narrow lappets. Ejaculatory tubes, as in the preceding genus, with
7 whorls of radiating spikes, but having the proximal end bladderformy produced.

96

Remarks. — This genus was proposed as early as the year 1854 by Zenker,
but was taken by that author in a much wider sense than now generally
admitted. In the restriction at present adopted it is nearly allied to Cyclocy-
pris, but at once recognised from that genus by the much more compressed
shape of the shell, and also in the structural details some well marked diffe-
rences are found, as pointed out in the above given diagnosis. Several species
referable to this genus have been recorded from different parts of the world.
To the Norwegian Fauna belong 3 species, to be described in the sequel.

J

30. Cypria exsculpia, (Fischer).

(PI. XLIV)

Cypris exsculpta, Fischer, Beitrag zur Kenntniss der Ostracoden, p. 18, PI. XIX, figs. 36—38.

Syn : Cypris elegantula, Lilljeborg (not Fisclier).
„ Cypria punctata var. striata. Zenker.
, Cypris striolata, Brady.

c>t>— de.

Specific Characters. — Female. Shell, seen laterally, rounded trigonal in
shape, greatest height in the middle and equal to ^/^ of the length, dorsal
margin boldly arched throughout, ventral margin not at all sinuated, being
even somewhat convex in the middle, both extremities evenly rounded off; —
seen dorsally, narrow oblong in outline, with the greatest width scarcely
exceeding Vs of the lenght, side-edges almost straight, both extremities
obtusely pointed. Surface of valves very finely striated longitudinally and
clothed at each extremity with scattered delicate liairs. Caudal rami compara-
tively narrow and almost straight, with the dorsal edge smooth, apical claws
rather slender, the distal one somewhat exceeding half the length of the ramus.

Male of somewhat smaller size than female and having the posterior part
of the shell comparatively more expanded. Right prehensile palp of max-
illipeds with the propodos conspicuously dilated at the end, forming inside a
thumb-like acuminate projection, to the side of which a thin spiniform appen-
dage is attached, dactylus very strong and evenly curved, with a dentiform
prominence in the middle of the concave edge; left palp less strongly built,
with the propodos not at all dilated at the end, and the dactylus much smaller.
Copulative appendages with the terminal lappets not much produced, the upper
one narrower than the lower.

Colour light olivaceous brown.

Lenght of adult female amounting to 0.85 mm.

Remarks. — This form, first described by Fisher under the above name,
may be easily distinguished from the other 2 species here recorded by its

i

97

considerably larger size and by the delicate longitudinal striation of the valves,
this latter character having indeed given rise to the specific names proposed
by Fischer and Brady.

Occurrence. — I have met with this form occasionally in shallow grassy
swamps near Christiania, and in some cases rather abundantly. The animals
are very habile swimmers, moving about in the water rather quickly. Male
specimens are by no means rare, and are often seen in copulation with
the females.

Distribution. — Sweden (Lilljeborg), British Isles (Brady), Germany (Zenker),
Switzerland (Kaufmann), Russia (Fischer), North America (Turner).

W
31. Cypria opihalmica, (Jurine).

(PI. XLV, fig. 1).

Monoculns opthalmicus, Jurine, Hist, des Monocles, p. 178, Pi. XIX, figs 16, 17.

Syn: Cypris punctata, Kocli.
„ Cypris compresso, Baird.
Cypris elegantula, Fischer.

Specific Characters.— Female. Shell very short and high, seen laterally,
broadly and somewhat irregularly rounded in shape, greatest height in the
middle and almost attaining ^U of the length, dorsal margin very strongly
arched, forming a bold an even curve sloping steeply both in front and behind,
ventral margin straight or very slightly sinuated in the middle, both extremities
evenly rounded off and somewhat deflexed;^seen dorsally, narrow oblong in
outline, with the greatest width about equal to Vs of the length, anterior ex-
tremity more pointed than the posterior. Surface of valves quite smooth,
without any trace of a striation, but all over adorned with dark pigmentary
speeks; pellucid border in front and behind more conspicuous than in the
preceding species. Caudal rami comparatively broader than in that species and
having the dorsal edge in its greater extent fringed with delicate spinules, apical
claws moderately strong, the distal one about half the length of the ramus.

Male, as in the preceding species, somewhat smaller than female, with
the posterior part of the shell comparatively broader and more bluntly rounded
behind. Right prehensile palp of niaxillipeds conspicuously expanded distally,
with a well-marked conical prominence inside at the base of the thumb, the
latter terminating in a spiniform process somewhat swollen at the base; dactylus
almost attaining the length of the propodos, and having the inner edge slightly
bowed in the middle; left palp resembling in shape that in the preceding

12 — Crustacea.

I

98

species. Copulative appendages with the terminal lappets rather produced, the
upper one somewhat larger than the lower and more obtuse at the end.

Colour in both sexes pale yellowish, with a more or less distinct chccolat
tinge especially dorsally; speeks of the valves dark brown.

Length of adult female scarcely exceeding 0.65 mm. ■^

Remarks.— This form was recorded as early as the year 1820 by Jurine
as Monoculus ophthalmicus, and has subsequently been described under several
other specific names, as mentioned in the above-given list of synonyms. It is
readily recognised from the other 2 species here recorded by the very conspi-
cuous dark speeks, with which the valves are adorned, and which scarcely i
any case are wanting.

Occurrence. — The present little beautiful Ostracod is found rather com-
monly around Christiania in small ponds and ditches and has probably a wide
distribution over our country. In habits it perfectly agrees with the preceding
species.

Disttibution. — Throughout Europe, North Africa, Siberia, North Americ

32. Cypria lacustris, G. O. Sars.

(PI. XLV, fig. 2).
Cypria lacustris. G. O. Sars, Oversigt af Norges Crustaceer 11, p. 54.

1

est

Specific Characters.— Female. Shell not nearly so strongly vaulted abov
as in the preceding species, seen laterally, suboval in shape, with the greatest
height scarcely exceeding ^/a of the length, dorsal margin forming a quite ev
curve throughout, ventral margin slightly sinuated in the middle, both extrem;
ties rounded off;— seen dorsally narrow lanceolate in outline, with the greatest
width scarcely exceeding ^3 of the length, both extremities obtusely pointed.
Valves very pellucid, with the surface smooth and polished, wanting any traces
of the dark speeks, so conspicuous in the preceding species, hyaline borders
in front and behind remarkably broad. Caudal rami conspicuously more slend4§
than in that species and somewhat curved, apical claws less unequal, the distal
one about half the length of the ramus.

Male, as usual, smaller than female and having the posterior part of th
shell broader and more deflexed. Right prehensile palp of maxillipeds rather
abruptly expanded at the end, but without any trace of the conical prominence
found in the preceding species inside the thumb, the latter simply lanceolate
in shape; dactylus coarser than in either of the 2 preceding species, with tnl
inner edge strongly bulging in the middle. Left palp conspicuously narrowed

|i

99

in its outer part, with the dactylus quite short, hamiform curved and exhibiting
at the base inside a knob-like prominence. Copulative appendages with both
terminal lappets lanceolate in shape and nearly equal-sized.

Colour in both sexes transparent white, with a fainte yellowish tinge.

Length of adult female scarcely exceeding 0.60 mm.

Remarks. — This form was briefly announced by the present author in 1890
under the manuscript name lacustris proposed by Lilljeborg. The validity of
the species has however not been admitted by Dr. Aim, who regards it as
merely a slight variety of C ophthalmica. In order to settle this question, I
have subjected both these forms to a renewed detailed examinarion, and have
thereby convinced myself on their specific distinctness.

Occurrence. — I have found this form very abundantly in severals of our
larger lakes, down to very codsiderable depths. Though the animals are well
equipped for swimming, they keep constantly near the bottom, over which they
move in the usual manner.

Distribution.SwQdtn (Lilljeborg).

Group 4. Notodromides.

Remarks.— In accordance with Dr. Kaufmann, I refer to this group the 2
anomalous genera Notodromas Lilljeborg and Cyprois Zenker, which, though
rather sharply defined the one from the other, yet exhibit some characters in
common not found in the other groups here recorded. To these genera may
moreover be added the genus Newnhamla King, which evidently is closely
allied to Notodromas, and the genus Hiingarocypris Vavra, which shows some
relations to Cyprois. Only the 2 first-named genera are represented in the
Fauna of Norway.

Gen. ]4. Notodromas, Lilljeborg, 1853.

Generic Character s.— Sh^W short and stout, with the dorsal face evenly
vaulted, ventral flattened and exhibiting in the middle a sharply defined navi-
cular area, surface of valves otherwise quite smooth. Eye distinctly divided
in the middle so as to appear double. Antennae well adapted for svimming,
the posterior ones with the penultimate joint distinctly subdivided in both sexes,
the 3 outer joints remarkably slender and narrow, apical claws imperfectly
developed. Mandibles of normal structure. Maxillae with the palp of moderate

1

100

size, outermost masticatory lobe comparatively large and armed on the end
with 6 coarse unguiform spines of equal size. Maxillipeds without any trace
of a vibratory plate, palp in female simple, lash-shaped, in male, as usual,
prehensile and very unequally developed on each side. Anterior legs compa-
ratively small, with the basal part quite simple, 1st joint of terminal part rather
dilated and provided anteriorly with a remarkably strong plumose seta, apical
claw not much prolonged. Posterior legs with the penultimate joint not subdi-
vided and provided with a single slender seta inside in the middle, terminal
joint comparatively small and tipped with 3 setae not very unequal in length.
Caudal rami attenuated and connected with each other in the greater extent
of their length, each carrying on the tip 3 closely set setiform claws, the proximal
one apparently answering to the dorsal seta in other Cyprids; apical bristle
wanting. Copulative appendages of male rather massive and each provided
with a movable band-like lappet curved upwards. Ejaculatory tubes with both
extremities pronouncedly funnel-shaped, radiating spikes arranged in numerous
densely crowded whorls, with scarcely any distinctly visibles interspaces be,
tween them.

Remarks.— This genus was established in the year 1853 by Lilljeborg, to
include the form recorded by O. Fr. Miiller as Cypris monacha and subsequently
adduced by Zenker to his genus Cyprois. From this genus, in the restriction
now adopted, it is however very sharply defined. In addition to the European
species described below, 2 other species have been recorded from more southern
latitudes, the one from Sumatra, the other from Ceylon. As above mentioned,
the genus Newnhamla of King is closely allied to the present genus, from
which it only seems to differ by the rough sculpture of the shell.

33. Notodromas monachus, (O. Fr. Muller).

(PI. XLVI, PI. XLVII, fig. 1).

Cypris monacha, O. Fr. Muller, Entomostraca, p. 60, PI. V, figs. 6—8.

Syn: Monoculus monachus, Jurine.
„ Cypris bimuricata, Koch.
, Cyprois monacha, Zenker.

Specific Charactets. — Female. Shell moderately tumid, seen laterall}^
rounded subquadrangular in shape, greatest height a little behind the middle
and about equal to 7^ oi the length, dorsal margin strongly curved behind^
but sloping rather slowly to the anterior extremity, ventral margin pe
fectly straight and sharply defined both in front and behind, anterior extremity
broadly rounded, posterior obtusely blunted; — seen dorsally or ventrally, regularly

nd.

*m

101

ovate in outline, greatest width behind the middle and about equal to ^,3 of
the length, anterior extremity sharply pointed, posterior obtuse. Ventral im-
pressed area of a somewhat navicular shape and occupying the greater length
of the shell, being defined on each side by a well marked keel. Surface of
valves smooth, with scattered delicate hairs at each extremity, infero-posteal
corner of left valve produced to a short tooth-like prominence; both valves
exhibiting in front a rather broad pellucid marginal zone. Anterior antennae
with the basal part rather dilated, terminal part slightly longer and having the
1st joint much larger than the others, almost occupying half the length of
that part. Posterior antennae with the last joint fully as long as the penulti-
mate one and carrying on the tip a slender setiform claw accompanied by 2
or 3 small bristles, claws of the penultimate joint replaced by 3 setae one of
which is peculiarly bent at the tip; natatory setae of these antennae extending
as far as the apical claw. Caudal rami of moderate size and only slightly
curved, apical claws gradually diminishing in length proximally, the distal one
somewhat exceeding half the length of the ramus.

Male of somewhat larger size than female, and conspicuously differing
from it in the shape of the shell, which, seen laterally, appears conspicuously
dilated behind the middle, with the ventral margin in that plase considerably
bowed, the posterior extremity exerted to an obtuse lappet and wanting any
trace of a dentiform projection. Prehensile palps of maxillipeds very power-
fully developed and conspicuously dissimilar both in size and shape; propodos
of left palp somewhat lamellar, sub-oval in form, with the inner edge angularly
bent near the middle and the outer edge terminating in a somewhat securi-
form lamella; propodos of right palp almost twice as long and narrow fusi-
form in shape, with a small seta at the end inside; dactylus of both palps
slender, somewhat compressed at the base and exerted to a thin setiform lash.
Caudal rami considerably more curved than in female and also compara-
tively narrower.

Colour in both sexes rather peculiar: upper part of the shell of a pale,
opaque whitish hue gradually passing over below to a dark, almost black
shadow, which extends along the lower part of the shell and curves upwards
in front, so as to occupy the greater part of the anterior extremity.

Length of adult female amounting to 1.10 mm., of male to 1.20 mm.

Remarks. — This easily recognisable Ostracod was described as early as
the year 1785 by O. Fr. Muller, and has subsequently been observed by many
other authors, all of them having adopted for it the specific name originally
proposed, with the only exception of Koch, who did not recognise this form,

102

but recorded it as a new species of the genus Cypris under the name C.
blmuricata.

Occurrence. — I have tal<:en this form very abundantly in some small creeck
with clear water and rich bottom vegetation, located at the border of the
0stensj0 lake near Christiania, and I have also met with it in 2 other localities
of our country, viz., at Hamar and at Sandosund. The swimming power o
this form is very highly developed, and the animals are almost found in con
stant motion, swimming about in the water with great dexterity, hi som
cases, especially at sunny weather, they ascend to the very surface, movin
below it in a more or less gyrating manner, with the back downwards an
the belly in immediate contact with the surface, the boat-shaped ventral are
apparently serving as a suspending apparatus for that purpose. This peculiar
behaviour of the animal, also described by King in the case of Newnhamia,
has indeed given rise to the generic name proposed by Lilljeborg. Male
specimens occur in about same number as the females, and are easily
recognised from them by the rather different shape of the shell.

Distribution. — Throughout Europe, Central Asia (G. O. Sars), North
America (Turner).

Gen. 15. Cyprois, Zenker, 1854.

Generic Characters. — Shell short and high, somewhat exerted behind
without any sharply defined ventral area, pellucid borders of the waives verj
conspicuous and closely striated transversally. Eye simple, not divided. An
tennae well adapted for swimming, the posterior ones of normal structure
though more slender than usual, penultimate joint not subdivided in either o
the sexes, last joint comparatively small, apical claws normally developed
Mandibles of usual structure. Maxillae with the outermost masticatory lobe, aj
in Notodromas, very coarse, and armed with 6 unguiform spines. Maxillipedi
provided at the base with a well defined vibratory plate; prehensile palps ir
male far less powerfully developed than in Notodromas and less unequal of
both sides. Anterior legs of quite normal appearance. Posterior legs wit
the terminal joint extremely small and partly embraced by the end of th
preceding joint; apical setae only 2 in number, the 3rd being replaced by
small dentiform prominence. Caudal rami resembling in structure those i
Notodromas, but having a well defined apical bristle in front of the claw
Copulative appendages of male very complicate, with several freely projectin

I

i

103

lappets. Ejaculatory tubes more slender than in Notodromas, but, as in that
genus, provided with numerous densely crowded whorls of radiating spikes,
ends of the tubes funnel-shaped, but less sharply marked off than in the
said genus.

Remarks.— lh\s genus was proposed in the year 1854 by Zenker, to
include 2 species, the one of which is that described below, the other being
Cypris monacha O. Fr. Miiller, which now is removed as the type of a dif-
ferent genus, Notodromas. The differences between these 2 genera are indeed
very conspicuous, though in the structural details they have some characteristic
features in common, as pointed out in the above diagnosis,

34. Cyprois marginata, (Strauss).

(PI. XLVII, ffg. 2, PI. XLVHl).

Cypris marginata, Strauss, Mem. Mus. Paris, Vol. 7, p, 59, Pi. 1, figs. 20—22.

Syn : Cypris flava, Zaddach.

„ — dispar. Fischer.

, Cyprois dispar, Zenker.

, — flava, Brady & Norm.

Specific Characters. — Female. Shell somewhat compressed, seen laterally,
broadly ovate or more properly subtriangular in shape, being considerably
higher in front than behind, greatest height about in the middle and some-
what exceeding ^/3 of the length, dorsal margin strongly arched in the middle
and sloping rather steeply behind, more slowly in front, exhibiting in the ocular
region a fainte concavity, ventral margin very slightly sinuated or nearly straight,
anterior extremity remarkably broad, almost semicircularly rounded off, posterior
obliquely deflexed and gradually narrowed, to form below a somewhat pro-
jecting obtuse corner;— seen dorsally, oblong ovate in outline, greatest width
behind the middle and only slightly exceeding 7^ o^ the length, anterior
extremity narrowly produced, posterior more obtuse. Valves subequal, with
the surface quite smooth and clothed at each extremity with scattered delicate
hairs, pellucid border very conspicuous in front and behind, being continued
also dorsally and ventrally as a narrow stripe, thus encircling the whole shell;
inner duplicatures rather broad in front. Eye comparatively small, but with
dark pigment. Anterior antennae with the terminal part considerably longer
than the basal one, its 1st joint about the length of the 2 succeding joints com-
bined. Posterior antennae with the penultimate joint very narrow and fully as
long as the preceding joint, apical claws rather slender and present in the
usual number, the outermost one however much reduced in size; natatory

104

setae extending to the tip of the claws. Caudal rami almost straight and
gradually attenuated, apical claws slender, the distal one considerably exceed-
ing half the length of the ramus, proximal claw (the transformed dorsal seta)
nearly as long as the middle one.

Male of somewhat smaller size than female, but resembling it in the general
shape of the shell, except that the posterior corner appears somewhat less pro-
duced and more evenly rounded off. Prehensile palps of maxillipeds of almost
equal size and only slightly differing in shape, propodos of left palp howev^Bj
exhibiting at the end inside a rather conspicuous sinus not found on the right,
dactylus of the latter palp rather broader and more compressed than on the
left. Caudal rami considerably more curved than in female. Copulative appen-
dages strongly chitinised, of a more or less dark brown colour, with 2 of th^|
projecting lappets very conspicuous and somewhat spoon-shaped, the one issuing
from the lower face and curving anteriorly, the other from the upper face and
curving in the opposite direction, a 3rd lappet of a more simple shape extending
from the posterior end of the appendage.

Colour in both sexes pale yellow, being in old specimens somewhat
darker, ochraceous.

Length of adult female amounting to 1.70 mm., of male to 1.52 mm

Remarks.— ^Th'\s is the only as yet known species of the present genus.
Its identity with the form recorded by Strauss was first settled by the present
author in the year 1890 and has been admitted by all recent authors. Pr
viously this form had been described under 2 different specific names quote
in the above given list of synonyms.

Occurrence.— \ have taken this form, many years ago, rather abundant!
in some small ponds and ditches near Christiania, now destroyed by ne
building, and I have also met with this Ostracod in 2 other localities of our
country, wiz., at Moss and near Nevlunghavn, outside the Christiania Fjor
The animals are rather active, svimming quickly about in the usual manne
but never showing any attempt to the peculiar behaviour described above i
Notodrothas. Male specimens are not seldom found, but appear on the who
to be more scarce than female ones. I have taken this form as late in the
year as in October, and it cannot therefore be considered to be an exclusive
vernal form, as believed by Dr. Aim.

Distribution.— Ihxowghoni Europe, North America (Turner).

it

I

Cyprids

Ostracoda

Podocopa

PI. XXXIII

6. O. Sars del.

Candona Candida, (O. Fr. Miiller)
(continued)

Cyprids

Ostracoda

Podocopa

PI. XXXIV

G. O. Sars del.

1. Candona neglecta, 6. O. Sars

2. ,, lapponica, Ekman

CypridaB

Ostracoda

Podocopa

PI. XXXV

G. O. Sars del.

Candona caudata, Kaufmann

Cypridae

Ostracoda

Podocopa

PI. XXXVI

G. O. Sars del.

Candona Sarsi, Hartwig

Cyprids

Ostracoda

Podocopa

PI. XXXVII

G. O. Sars del.

Candona rostrata, Brady & Norman

CypridaB

Ostracoda

Podocopa

PI. XXXVIII

^■n

i^.

^:^l^'))t\^

JiC

G. O. Sars del.

1. Candona marchica, Hartwig

2. „ stagnalis, 6. O. Sars

Cypridae

Ostracoda

Podocopa

PI. XXXIX

^-n- ^

Suoff/

G. O. Sars del.

1. Candona albicans, Brady

2. „ compressa, Koch

Cyprids

Ostracoda

Podocopa

PI. XL

G. O. Sars del.

1. Cryptocandona Vavrai, Kaufmann

2. „ reducta, Aim

Cyprids

Ostracoda

Podocopa

PI. XLI

6. O. Sars del.

Candonopsis Kingsleyi, Brady ^ Rob.

Cypridae

Ostracoda

Podocopa

PI. XLII

6. O. Sars del.

Cyclocypris globosa, 6. O. Sars

Cyprids

Ostracoda

Podocopa

PI. XLIII

\^

JIU

6. O. Sars del.

1. Cyclocypris ovum, (Jurine)

2. ,, laevis, (O. Fr. Muller)

3. „ Serena, (Koch)

Cypridae

Ostracoda

Podocopa

PI. XLIV

6. O. Sars del.

Cypria exsculpta, (Fischer)

Cyprid£B

Ostracoda

Podocopa

PI. XLV

"^r /.t.

o.<i6.

G. O. Sars del.

1. Cypria ophthalmica, (Jurine)

2. „ lacustris, 6. O. Sars

Cyprid^

Ostracoda

Podocopa

PI. XLVI

6. O. Sars del.

Notodromas monachus, (Jurine)

Cypridae

Ostracoda

Podocopa

PI. XLVII

/.c^^

G. O. Sars del.

1. Notodromas monachus (continued)

2. Cyprois marginata, (Strauss)

Cypridae

Ostracoda

Podocopa

PI. XLVIII

^■'6Ut- X',

6. O. Sars del.

Cyprois marginata, (Strauss)
(continued)

105

Group 5. Ilyocyprides.

Remarks.— This group appears to be a very sharply defined one, differing,
as it does, in some respects rather conspicuously from the other groups here
treated of, and on this cause it has indeed by moost recent authors been
considered as a distinct subfamily of the Cypridae, Ilyocyprince. I think how-
ever that the systematic value of the above named differences has been rather
overestimated, and that it might be more appropriate to regard it as merely
a subsection of the subfamily Cyprinae, as here defined. The group as yet
only comprises 2 closely related genera, both of which are represented in the
Fauna of Norway.

Gen. 16. Ilyocypris, Brady & Norm. 1889.

Generic Characters. — Shell of rather firm consistency, more or less oblong
quadrangular in shape, with the anterior part of the dorsal face compressed
and exhibiting on each side 2 successive vertical folds, the posterior part some-
what flattened along the middle; surface of valves sculptured with numerous
closely set pits, edges highly chitinised and finely denticulate, but without any
pellucid border. Eye small, simple. Antennae adapted for swimming, the
natatory setae in both pairs very long and slender. Mandibles of normal
structure. Maxillae with the masticatory lobes short and stout, none of the
spines on the outermost lobe remarkably strong, palp of moderate size, with
the distal joint short and broad, sub-spatulate in shape. Maxillipeds with a
well defined vibratory plate at the base, palp in female very small, but distinctly
biarticulate; palps in male, as usual, transformed and nearly symmetrical, both
unusually slender and narrow, with the propodus not at all dilated and the
dactylus rather feeble. Anterior legs of moderate size, with the penultimate
and antepenultimate joints, as a rule, confluent. Posterior legs comparatively
short and generally bent in a zigzag manner, penultimate joint undivided and
provided inside with 2 slender setae, terminal joint somewhat conical in shape,
and carrying 3 well defined setae, 2 of which issue from the dp, the 3rd from
the outer edge of the joint. Caudal rami comparatively small, but built in
the usual manner. Copulative appendages of male terminating in 2 unequal
lappets, the lower one narrow cylindrical in shape, the upper rather produced
and securiform expanded at the end. Ejaculatory tubes slender, with about
20 well defined whorls of radiating spikes, number of spikes in each whorl
rather small; proximal end of the tubes somewhat bulbously produced.

13 — Crustacea.

106

Remarks. — This genus was established in the year 1889 by Brady and
Norman, to include the Cypris gibba of Ramdohr, and has been admitted by
all subsequent authors. Several additional species of this genus have in recent
times been recorded both from Europe and from more southern latitudes; but
some of these are so closely related, both as to the ex*ernal appearance and
to the structural details, that their specific validity has been often questioned.
2 such closely allied species will be described below.

35. Ilyocypris biplicata (Koch).

(PI. XLIX).

Cypris biplicata. Kocli, Deutschlands Crustaceen, H. 21, PI. XVI.

Syn: Ilyocypris gibba var. (auctorum).

Specific Characters. — Female. Shell rather compressed, seen laterally,
oval quadrangular in shape, somewhat higher in fiont than behind, greatest
height in the ocular region and slightly exceeding half the length, dorsal
margin nearly straight and a little sloping behind, forming a somewhat pro-
minent convexity in the ocular region and joining the hind edge by a well-
marked angular bend, ventral margin rather deeply sinuated in the middle,
anterior extremity broadly rounded off, posterior obtusely blunted; — seen
dorsally, narrow oblong in outline, with the greatest width scarcely exceeding
-It, of the length and occurring behind the middle, anterior extremity obtusely
pointed, posterior rounded off. Valves subequal, with the 2 vertical folds in
front very conspicuous, but without any traces of projecting lateral protuberances,
anterior edges very finely denticulated in their whole extent, posterior edges
likewise denticulate, but with the denticles less densely crowded, both extremities
moreover rather densely clothed with fine hairs. Surface of shell coarsely
granular, with densely set small rounded pits. Anterior antennae with tdl
terminal part about the length of the basal one, joints gradually diminishing
in size, setae very long and slender. Posterior antennae with the penultimate
joint much shorter than the preceding joint, natatory setae much elongated,
extending far beyond the tips of the claws. Posterior legs with the shorter of _
the 2 apical setae about half the length of the other, which equals the out
seta in size. Caudal rami slightly curved and gradually attenuated, api(
claws rather thin, the distal one about half the length of the ramus, dors
seta attached at about the outer ^/3 of the ramus.

Male of smaller size than female, but resembling it in the general shaj
of the shell. Prehensile palps of maxillipeds with the propodus not at

107

dilated and carrying inside near the end a small seta, dactylus rather feeble.
Copulative appendages with the lower terminal lappet very small, upper well
developed, lamellar. Ejaculatory tubes with about 18 whorls of radiating
spikes, proximal end rather produced, bottle- shaped.

Colour opaque whitish grey, generally with a more or less distinct brow-
nish tinge.

Length of adult female attaining 1.10 mm.

Remarks. — I think I am right in identifying the form here described with
that recorded by Kock under the above specific name. It has generally been
combined with /. g'lbba (Ramdohr); but I find it convenient to keep it apart
as a nearly allied species, since no true transitions between these 2 forms have
occurred to me. The specific name proposed by Koch is fairly well applic-
able to the present form, the 2 transverse folds of the valves being more
sharply marked off than in any other species known to me.

Occurrence.— \ have taken this form occasionally in small ponds and
ditches near Christiania. In some cases it occurred in company with /. gibba:
but in other places only this form was met with. On the whole it would
seem to be less common in our country than /. gibba, whereas in other coun-
tries it is by far the predominant form. In habits the animal is rather sluggish,
being more generally found creeping slowly on the bottom more or less
deeply hurried within the loose mud. It is however by no means devoid of
swimming power, as could be expected from the well-developed natatory setae
on the antennae. Indeed, at times it is seen moving freely in the water in a
peculiar abrupt manner; but these movements are never carried on for any
longer time, and the animal very soon sinks back to the bottom. Evidently
the heavy shell, which moreover is often thickly covered with mud, con-
siderably encumbers the free movements of the animal. Male specimens seem
to be very rare. Indeed, I have not come across this sex among the Norwegian
specimens examined, nor has it been observed by any of the Swedish authors.
My knowledge to the male of this species is due to some few specimens
which, together with numerous females, were raised, many years ago, from
dried mud taken in Algeria and kindly sent to me from Dr. Chevreux.

D/s//'/7;////o/7.— Throughout Europe, Algeria, North America.

J08
36. Ilyocypris gibba (Ramdohr).

(PI. L, fig. 1).

Cypris gibba, Ramdolir, Magaz. d. Gesellsch. naturf. Freunde zu Berlin 1808,

Vol. II, p. 41, PI. III.

Syn: Ilyocypris gibba var. bicornis, Kaufmann.

Specific Characters. — Female. Shell resembling in general shape that o
the preceding species, though perhaps a little more elongate in proportion tc
the height, being however highly distinguished by the presence of 3 pairs o
well-marked lateral projections, especially very conspicuous in the dorsal oi
ventral aspect of the shell. Of the projections the one pair, located in from
of the middle, is slightly umboniform, the other 2, located farther behind, arc
more sharply marked off, but rather unequal in size, the smaller one occurring
near the ventral face, the larger more dorsally and forming a very prominen'
recurved horn-like process. Structure of the several limbs almost exactly as ir
the preceding species.

Colour whitish grey, generally lighter than in /. biplicata.

Length of adult female about 1 mm.

Male unknown.

Remarks. —This form was recorded as early as the year 1808 by Ram-
dohr as a species of Cypris, the specific name proposed by him alluding
apparently to the peculiar gibberiform lateral projections of the shell. B>
Kaufmann and Masi it has been described as merely an occasional variety
(bicornis) of the preceding species, which is regarded by them as the typical
/. gibba. This I think cannot properly be sanctioned. In our country and also
according to Dr. Aim, in Sweden the present form is much the predominant
and as it unquestionably is the same as that originally observed by Ramdohr,
it ought in any case to be regarded as the typical /. gibba. In my opinion
it should moreover be kept apart from the preceding form as a particular,
though closely allied species. True, in some cases, especially in quite younjj
specimens, the peculiar lateral projections of the shell distinguishing the pre-
sent species may appear much reduced in size; but I have never found thj
to be wholly absent as in the preceding species.

Occurrence. — This form is very common around Christiania, occurring
often in great abundance in small shallow ponds and ditches with clayey
bottom. In behaviour it agrees with (he preceding species, though it has
appeared to me to be somewhat more agile, being often seen to swii
rather quickly through the water.

Distribution. — Throughout Europe, ? North America.

IMJ

109 , K^c, ^"^'' \^-^

Gen. 17. Iliocyprella, Daday, 1900.

Generic Character s.—SheW resembling in shape that in the preceding
genus, though as a rule somewhat more elongate and compressed. Valves
with the 2 vertical folds in front of the middle well marked, but without any
lateral projections, surface roughly granulated as in llyocypris. Antennae not
adapted for swimming, the setae in both pairs being rather short and not
ciliated. Anterior legs with the terminal part distinctly 4-articulate, the penul-
timate joint being sharply divided in the middle. Structure of the remaining
appendages not essentially different from that in llyocypris.

Remarks. — This genus was proposed in the year 1900 by Daday, to
include the form recorded by Vavra as llyocypris gibba var. repens, and was
chiefly characterised by the rudimentary condition of the natatory setae on the
posterior antennae, rendering the animal quite uncapable to move freely in the
water. Another well-marked difference from llyocypris is found in the distinct
subdivision of the penultimate joint of the anterior legs. As generally a
generic value has been assigned to both these characters, I think that the
genus ought to be supported, though in other respects approaching closely to
llyocypris. In addition to the species observed by Daday and described below
2 other forms recorded by Kaufmann as llyocypris Inermls and /. iners are
apparently referable to this genus.

37. Iliocyprelia Bradyi, G. O. Sars.

(PI. L, fig. 2).
llyocypris Bradyi, G. O. Sars, Oversigt af Norges Crustaceer II, p. 59.
Syn: llyocypris gibba var. repens, Vavra.
Iliocyprella repens, Daday.

Specific Characters. — Female. Shell rather compressed, seen laterally,
oblong quadrangular in shape, greatest height in front and scarcely exceeding
half the length, dorsal margin perfectly straight and nearly horizontal, being
only little prominent in the ocular region, ventral margin deeply sinuated,
anterior extremity well rounded off, posterior obtusely blunted:— seen dorsally,
narrow oblong in outline, the greatest width scarcely exceeding -/o of the
length, anterior extremity more pointed than the posterior. Valves with the
inner duplicatures very sharply defined and rather broad, borders in front and
behind finely denticulated. Anterior antennae with the terminal part scarcely
as long as the basal one, none of the set« exceeding this part in length.

110

Posterior antennae with the natatory setae reduced to slight rudiments, the
longest of them scarcely extending beyond the middle of the penultimate joint.
Caudal rami rather slender and scarcely at all curved, apical claws very thin,
subequalj.and exceeding somewhat in length half the ramus.

Colour dark brownish grey.

Length of adult female about 1 mm.

Male unknown.

Remarks.— This form was first described as a distinct species by the
present author in the year 1890, it having previously been confounded with
Ilyocypris bipltcata (or gibba). The form described by Vavra in 1891 as
Ilyocypris gibba var. repens. and subsequently recorded by Daday as the type
of the present genus, is unquestionably identical with the species here under
question.

Occurrence. -\ have met with this form rather abundantly near Christiania,
in some shallow ditches with grassy bottom and slowly floating water. The
animal is rather sluggish, being quite devoid of swimming power and only
adapted for slowly crawling on the bottom or along the aqvatic plants growing
on it. In the fresh state it is moreover easily recognised from the species of
the genus Ilyocypris by the dark brownish colour of the shell.

Distribution. — Sweden, British Isles, Germany, Switzerland, Hungary,
Turkistan.

Group 6, Eucyprides.

Remarks.- lo this group I refer the more typical forms of the sub-
family Cyprinae, all of which were formerly included in the genus Cypris. In
recent times however several nearly-allied genera referable to this group have
been established, 8 of which will be treated of in the sequel, as represented
in the Fauna of Norway.

Gen. 18. Cypris, O. Fr. Muller 1776 (sens, strict.).

Syii: F.urycypris, O. W. Muller.

Generic Characters. — Shell very tumid and of rather firm consistency,
with the dorsal face more or less gibbously vaulted, the ventral flattened.
Valves subequal, with the anterior and posterior edges in most cases coarsely
dentate and the inner duplicatures moderately broad. Both pairs of antennae
powerfully developed and well adapted for swimming, the posterior ones with

Ul

the penultimate joint rather slender and attenuated, natatory setae densely
plumose and extending to the tips of the apical claws. Mandibles normally
developed. Maxillae with the masticatory lobes attenuated, the outermost one
armed with 2 strong denticulated spines in addition to the usual curved
bristles; palp narrow, with the distal joint cylindrical in shape. Maxillipeds
with the vibratory plate well developed, palp (in female) comparatively small,
not subdivided. Anterior legs remarkably short and stout, with the penulti-
mate and antepenultimate joints wholly coalesced. Posterior legs much more
slender, with only a single seta inside the penultimate joint, which terminates
in several irregular lobules partly embrasing the minute terminal joint; the
latter provided outside with a slender seta and at the tip with a much smaller
hamiform bristle accompanied inside by a knob-like projection of the joint.
Caudal rami very narrow, linear in shape, with the apical claws slender and
almost straight, dorsal seta small and not far remote from the tip. Propagation
chiefly parthenogenetical.

Remarks. — In the restriction here adopted this genus only comprises a
limited number of species chiefly distinguished by the coarse, ventrally flattened
shell and by the structure of the anterior legs. The type of the genus is the
well-known C. pubera O. Fr. Miilier, and in Europe only one additional species,
the magnificent C. bispinosa Luccas, has as yet been found, the other species
being from more southern latitudes. Only the type species is represented in
the Fauna of Norway.

38. Cypris pubera, O. Fr. Miilier.

(PI. Ll).
Cypris pubera, O. Fr. Miilier, Entomostraca p. 56, PI. V, figs. 1—5.
Syn: Monocuhis ovatiis, Jurine.
„ Cypris striata, Zaddach.
„ „ cuneata, Baird.

„ „ pnnctillata. Brady.

„ Eiirycypris pubera, G. W. Miilier.

Specific Characters. — Female. Shell very tumid, seen laterally, oval
triangular in shape, greatest height somewhat in front of the middle and con-
siderably exceeding half the length, dorsal margin gibbously arched in its
anterior part and sloping rather steeply both in front and behind, ventral
margin almost straight, though slightly bowed in the oral region, anterior
extremity obliquely rounded, posterior gradually narrowed, with the lower
corner rounded off;— seen dorsally, broadly ovate, with the greatest width in

112

the middle and about equal to the height, both extremities obtusely pointed
and nearly equal. Valves with the lateral faces evenly convex and all over
densely clothed with comparatively short but rather coarse hairs, anterior
margin of both valves armed with a row of about 8 coarse somewhat lanceo-
late denticles originating somewhat inside the edge; right valve moreover ex-
hibiting at the infero-posteal corner below 2 very conspicuous successive
denticles, the distal one rather long, spur-like. Armature of the valves in young
specimens rather dissimilar, the anterior extremity wanting the submarginal
denticles, but having the edge itself finely serrate, posterior corner of right
valve with a continuous row of coarse nearly equal denticles. Anterior
antennae with the basal part very massive, terminal part a little shorter, and
having the joints rapidly diminishing in size, the 1st being about as long as
the 2 succeeding ones combined. Posterior antennae with the penultimate
joint fully as long as the preceding joint, but much narrower, apical claws
slender and coarsely denticulated. Caudal rami exceedingly slender and narrow,
perfectly straight, with the apical claws very unequal in length, the distal one
being almost twice as long as the proximal one and about half the length of
the ramus.

Colour dark green, in some cases with a brownish tinge, ovarial tubes
shining through the shell with a bright orange hue.

Length of adult female amounting to 2.50 mm.

Remarks. — This form was recorded as early as the year 1776 by O. Fr.
Miiller under the above name, and has subsequently been observed by many
other authors, though some of them did not recognise it and described it
under other specific names, as seen from the above given list of synonyms.
It is one of our largest freshwater Ostracods, and may moreover be easily
recognised by its strongly vaulted and densely pubescent shell. The armatu^
of the valves is also highly characteristic. V

Occurrence. — I have taken this form rather abundantly in small ponds
and swamps with grassy bottom, both around Christiania and in several other
localities of our country as far North as Tjote on the Nordland coast,
spite of the heavy shell, the animal is well adapted for svimming, though
movements are not nearly so rapid as in most species of the next gem
Male specimens have never been met with of this species.

Distribution. — Throughout Europe, Siberia, North America.

113

Gen. 19. Eucypris, Vavra, 1891.

Generic Characters. — Shell of somewhat varying shape, but as a rule of
less firm consistency than in the preceding genus, and not particularly flattened
ventrally, edges of valves smooth, inner duplicatures comparatively broader than
in Cypris. Antennae well adapted for swimming and, like the oral parts, of
a very similar structure to that in the preceding genus. Legs however, some-
what different, the anterior ones having the penultimate and antepenultimate
joints well defined, and the posterior ones terminating in a more or less
distinctly developed minute chela formed by a small hook-like projection of
the apical joint impinging against a projecting lobute of the preceding joint.
Caudal rami comparatively shorter than in the preceding genus. Propagation,
as a rule, exclusively parthenogenetical.

Remarks. — This genus was proposed in the year 1891 by Vavra, but was
taken by him, as also by most other authors, in a much wider sense than
admitted in the present account. In the restriction here adopted only 6
European species are referable to this genus, 3 of which will be described
below, the other 3 species not yet found in Norway being E. ornata (Jurine),
E. clavata (Baird) and E. Lilljeborgl (G. W. Muller). In more southern lati-
tudes, however, the genus seems to be very abundantly represented.

39. Eucypris virens (Jurine).

(PI. Lll).

Monociiliis virens, Jurine, Hist, des Moncles, p. 174, PI. XVllI, figs. 15, 16.

Syn: Cypris tristriata, Baird.

„ „ ornata, Fischer (not Jurine).

Specific Characters. — Female. Shell moderately tumid, seen laterally,
suboval or slightly reniform in outline, greatest height about in the middle and
equal to ^/o of the length, dorsal margin boldly archeil, forming in the middle
an abrupt, almost angular bend, and sloping at a nearly equal rate to each
extremity, ventral margin slightly sinuated in the middle and a little bowed
in the oral region, both extremities rounded off and nearly equal; — seen
dorsally, oblong ovale in outline, greatest width somewhat behind the middle
and about equalling half the length. Surface of valves smooth and clothed
with short and fine hairs more conspicuous at each extremity; inner duplica-
tures of moderate size, rather broader in front than behind. Anterior antennae
with the terminal part about the length of the basal one, joints gradually
diminishing in size. Posterior antennae with the penultimate joint somewhat
shorter than the preceding joint and about of equal width throughout, apical

14 — Crustacea.

claws slender and distinctly denticulated, natatory setae extending to the tips
of the claws. Spines on the outermost masticatory lobe of the maxillae smooth.
Palp of maxillipeds of moderate size, with the apical setae unusually prolonged,
the middle one exceeding the palp in length and distinctly ciliated in its
outer part. Anterior legs moderately slender, with the terminal part distinctly
4-articulate and the apical claw rather elongated. Posterior legs with the apical
chela well developed. Caudal rami almost straight and gradually attenuated,
apical claws only slightly curved and rather unequal in size, the distal one
considerably exceeding half the length of the ramus.

Colour dull grassy green.

Length of adult female amounting to 2.30 mm.

Alale unknown.

Remarks. — The present species, the identity of which with Monocnliis
virens of Jurine seems to me to be indoubitable, may be regarded as the type
of the genus Eiicyprls. It is easily distinguished from the other 2 species
here described by its much larger size, as also by the rather different shape
of the shell. In these respects it comes however very near to some of the
exotic species described. G. W. Miiller distinguishes of the present species 3
varieties or subspecies named media, obtusa and acuminata. Of these the
1st agrees pretty well with the Norwegian specimens observed by me; the other
2 I am much inclined to regard as particular species, having had an oppor-
tunity of examining both of them from specimens raised out of dried mud
from Algeria. Young specimens of the present species, as usual, differ some-™
what from the adults in the shape of the shell, and are moreover highly
distinguished by a most peculiar and beautiful sculpture of the valves exactly
agreeing with that described and figured by Brady in his Cypris tessellata.^
(see the figures on the accompanying plate). fl

Occurrence. ~l\\\s is one of our commonest freshwater Ostracoda, being
found often in great abundance in grassy ponds and swamps, especially in the
early part of the summer. In. habits the animal is rather active and is ofter^Hj
seen to swim about in the water with considerable speead, though as usual,
more generally keeping at the bottom for search of food. Male specimens
have never been met with either of this or any other species referable to the,
present genus in the restriction here adopted, and the exclusive partensgenitical
propagation may thus be mentioned as a distinguishing character of the genuj
from some of the succeeding nearly allied genera.

Distribution. — Throughout Europe, North America, Greenland.

115

40. Eucypris crassa (O. Fr. Miiller).

(PI. LlII, fig. 1).

Cypris crassa, O. Fr. Miiller, Entomostraca, p. 61, Pi. 6, figs. 1 & 2.

Syn : Cypris dromedaria, Fisclier.

! Specific Characters. — Female. Shell rather tumid, seen laterally, of quite

an unusual shape, being somewhat gibbous in front and narrowly produced
behind; greatest height anteriorly and about equalling half the length, dorsal
margin forming in front a bold gibberiform curve and sloping obliquely
behind, with a slight concavity above the posterior extremity, ventral margin
rahter deeply sinuated, anterior extremity broady rounded off, and rather
sharply defined above by a conspicuous depression in front of the ocular region,
posterior much narrower and obtusely blunted at the end; — seen dorsally,
regularly oblong oval, greatest width in the middle and nearly attaining half
the length, both extremities remarkably contracted at the ends, which project
ns sharp rostriform points. Valves rather thin, with a well-marked pellucid
marginal zone; inner duplicatures remarkably broad both in front and behind;
surface smooth and shining. Anterior antennae with the terminal part some-
what longer than the basal one, joints successively diminishing in size.
Posterior antennae with the penultimate joint almost as long as the preceding
one, apical claws rather slender, natatory setae not fully extending to the tips
of the claws. Maxillae with the masticatory lobes less attenuated than in the
other species, palp likewise somewhat dissimilar, its distal joint being com-
paratively shorter and broader. Caudal rami rather strong, with the distal
claw very long and slender, almost attaining the entire length of the ramus.

Colour light greenish.

Length of adult female amounting to 1.90 mm.

Male unknown.

Remarks. — This is a very distinct and easily recognisable form, differing

i conspicuously from any of the other known species in the shape of the shell,
as also somewhat in the structure of the maxillae, though being apparently
referable to the present genus. The specific name dromedaria, under which
it has been recorded by Fischer, alludes to the peculiar shape of the shell,
as seen laterally.
Occurrence.— IhQ only place where I have hitherto met with this form,
is on the high-plateau of Ekeberg, near Christiania. It occurred here early in
the spring very abundantly in a shallow grassy swamp, which later in the

116

summer becomes wholly dried up. The animals were seen swimming about
in the water rather quickly in the usual manner.

Distribution. —Sweden (Aim), British Isles (Brady), Germany (G. W. Miiller),
Russia (Fischer).

41. Eucypris elliptica, Baird.

(PI. LlII, fig. 2).
Cypris elliptica, Baird, Nat. Hist, of Britisli Eiitomostraca, p. 158, PI. XIX, fig. 12.

Specific Characters. — Female. Shell rather tumid, seen laterally, oval
trigonal in outline, greatest height a little in front of the middle and slightly
exceeding -/a of the length, dorsal margin gibbously arched and sloping with
an almost straight course to each extremity, ventral margin very slightly sinuated
in the middle and conspicuously bowed in the oral region, both extremities
evenly rounded off, the anterior somewhat broader than the posterior;— seen
dorsally, oblong ovate in outline, greatest width behind the middle and slightly
exceeding half the length, anterior extremity more narrowed than the posterior.
Valves nearly equal, with the surface smooth and clothed with delicate hairs;
inner duplicatures very narrow. Structure of the several limbs not exhibiting
any noticeable peculiarity. Caudal rami of moderate length, slightly attenuated
and nearly straight, though a little curved downvards at the end, distal claw
about equal in length to '■^j-a of the ramus.

Colour light yellowish green.

Length of adult female amounting to 1.50 mm.

Male unknown.

Remarks.— \ think that G. W. Miiller was quite right in identifying th
form examined by him with Cypris elliptica Baird. At least the figures give
by Brady and Norman of this form seems to me to agree pretty well with
the present species, and I am by no means prepared to assent with Dr. Aim
in his opinion that these figures are more properly applicable to Eucypris
afjinis hirsuta of that' author, which belongs to the next genus, Cypricerciis.
True, a certain resemblance between these 2 forms may be found in the shape of
the shell, as seen laterally; but the dorsal aspect is conspicuously different,
and the figure given by Brady and Norman in this aspect agrees perfectl
with that here reproduced.

Occurrence.— \ have only once met with this species, viz., some years
ago in a small pond near Christiania. At first I indeed thought it to be
large variety of Cypricercus offinis (see further on), to which it bears a p(

I

117

plexing similarity both in its general appearance and in its behaviour. I very

soon however became convinced of the fundamental difference of these 2 forms.

Distribution.— Sweden (Aim), British Isles (Brady), Germany (G. W. Muller).

Gen. 20. Cypricercus, G. O. Sars, 1895.

Generic Characters. —SheW tumid, of more or less elliptical shape, higher
in front than behind, with the left valve overlapping the right more or less
conspicuously along the anterior extremity. Antennae well adapted for swimming,
the posterior ones unusually slender and attenuated. Mandibles normal. Max-
illae with both the palp and the masticatory lobes narrowly produced. Max-
illipeds with the vibratory plate well developped, palp in female of the usual
lash-shaped appearence; those in male slightly unequal. Anterior legs of
moderate length. Posterior legs with the terminal joint very small, apicale
bristle unguiform curved. Caudal rami long tnd slender, attached to the body
by a very mobile jointing. Copulative appendages of male terminating in 2
unequal lappets, the lower rounded, the upper very prominent, beak-shaped.
Ejaculatory tubes slender, with numerous whorls of radiating spikes, proximal
extremity cup-shaped. Spermatic vessels forming within the anterior part of
each valve a dense spiral coil.

Remarks. — This genus was established by the present author in the year
1895, to include a South African species, C. citneaius G. O. Sars, and was
chiefly characterised by the powerfully developed caudal rami and by the
peculiar arrangement of the spermatic vessels of the male. It is nearly allied to the
genus Strandesia of Claus (Neocypris G. O. Sars), and indeed G. W. Muller has
combined the 2 into one, though in my opinion they ought to be kept apart. I
have felt justified to include in the present genus the 4 succeeding Norwegian
species, which by recent authors have been referred to the genus Eucypris. True,
one of the most characteristic feature of this genus, viz., the peculiar arrange-
ment of the spermatic vessels, has not been stated, because in none of them
as yet male specimens have been met with. But in a closely allied species
from Algeria I have succeeded in examining that sex, and have found the
above named character perfectly as in the type species. The remarkable
development of the caudal rami is in all of them in full accordance with
that in the South African species.

118

42. Cypricercus fuscatus (Jurine).

(PI. LIV).
Monoculiis fuscatus, Jurine, Hist, des Monocles, p. 174, PI. 19, figs. 1, 2.
Syn: Cypris hispida, Baird.
„ — adusta, Koch.

„ — fusca, Brady.

„ Eucypris fusca ta major, G. W. Miiller.

Specific Characters. — Female. Shell, seen laterally, oval or elliptical in
shape, greatest height a little in front of the middle and somewhat exceeding
half the length, dorsal margin rather evenly arched, ventral not at all sinuated,
curving somewhat upwards behind, anterior extremity broadly rounded off,
posterior much narrower and terminating in an obtuse corner;— seen dorsally,
broadly ovate in outline, greatest width nearly equal to the height, anterior
extremity more pointed than the posterior. Valves somewhat less unequal
than in most of the other species, though the left one overlaps the right a
little along the anterior extremity, surface rather densely hairy and somewhat
uneven by numerous small knobs, from which the hairs arrise; inner duplica-
tures not very broad. Posterior antennae very slender and attenuated, natatory
setae extending about to the ends of the terminal claws. Spines on the outer-
most masticatory lobe of the maxillae coarsely denticulated in their outer part.
Caudal rami exceedingly slender and narrow, distal claw scarcely attaining
half the length of the ramus.

Shell of a light yellowish brown hue, with a very conspicuous dark
chocolate brown band across the nuchal region, extending obliquely down the
sides of the valves to somewhat beyond the muscular spots.

Length of adult female amounting to 1.50 mm.

Male unknown.

Remarks. — The identity of the above described form with Jurine's Mono-
culiis fuscatus seems to me to be undoubitable, and I should also be much
inclined to believe that Cypris adusta of Koch is the same species. Brady
and Norman moreover quote Cypris hispida Baird as a synonym. It is th
largest of the Norwegian species, and may moreover be easily recognised b
the characteristic colour of the shell, which even in specimens for a longer
time preserved in alcohol is well observable.

Occurrence. — The only locality where I have hitherto met with this form,
is on Maerdo, outside Arendal. It occurred here very abundantly in small
water-holes peopled with larvae and youngs of Limnadia lenticularis.

Distribution. — Throughout Europe, North America.

1 the
h

I

ii

i

119

43. Cypricercus affinis (Fischer),

(PI. LV, fig. 1).
Cypris affinis, Fischer, Mem. Acad., St. Petersburgh, Vol. 7, p. 32, Pi. X, figs. 9--11.
Syn : Cypris reticulata, Zaddach.
„ — fitscata minor, G. W. Miiller.

„ Eucvpris fnscata affinis, G. W. Miiller.
„ — affinis hirsiita. Aim.

Specific Characters. — Female. Shell, seen laterally, oval or somewhat
club-shaped in outline, greatest height considerably exceeding half the length,
dorsal margin somewhat gibbously arched in front of the middle and sloping
with an almost straight course both in front and behind, ventral margin very
slightly sinuated in the middle and gently curved upwards behind, anterior
extremity well rounded off, posterior rather narrower and obtuse at the end;
— seen dorsally, regularly oval in outline, with the greatest width about equal
to the height, both extremities obtusely pointed. Valves more unequal than
in C. fuscata, the left one considerably overlapping the right along the anterior
e.xtremity; surface smooth and clothed with delicate hairs; inner duplicatures
comparatively broader than in the preceding species. Natatory setae of the
posterior antennae extending somewhat beyond the apical claws. Spines on
the outermost masticatory lobe of the maxillae indistinctly denticulated. Caudal
rami of the structure characteristic of the genus, but somewhat less slender
than in the preceding species, distal claw attaining half the length of the ramus.

Colour light yellowish, with a slight olivaceous tinge, and without any
sharply marked dark patches.

Length of adult female amounting to 1.20 mm.

Male unknown.

/^^/war^s.— The specific name reticulata proposed by Zaddach and assigned
by some recent authors to this species must, I think, be wholly discarded, as
only applying to immature specimens, and I have shown above, that the
Cypris tesselata Fisher is of a similar kind, being in all probability only
founded on immature specimens of Eiicypris virens. It remains to consider
the 2 species described by Fischer as Cypris affinis and C. hirsuta, which
both are unquestionably referable to the present genus. These 2 species have
by most recent authors been combined and only regarded as varieties of one
species, which is named by Dr. Aim Eucypris affinis-hirsuia. I have however
convinced myself that these 2 forms are in reality specifically distinct, and
that of course the 2 names proposed by Fischer ought to be supported in the
sense originally taken by that author. To the present species the specific

120

name af finis ought to be fixed, whereas the next species must bear the
name hirsuta.

Occurrence. — This form is rather common around Christiania in small
ponds and ditches, but is as a rule only met with in the early part of the
summer. The animals are very active, swimming about in the water rather
quickly.

Distribution. — Throughout Europe, North America.

44. Cypricercus hirsuius (Fischer)..

(PI. LV, fig. 2).
Cypris hirsuta, Fischer, I. c. p. 159, PI. 10, figs. 6—8.
Syn: Cypris elliptica, G. O. Sars (not Baird).
„ ? Eucypris affinis-hirsuta. Aim (part).

Specific Characters.— Female. Shell conspicuously less high than in the
preceding species, seen laterally, oblong oval in shape, with the greatest height
scarcely exceeding half the length, dorsal margin gently arched, without showing
any gibbous bend in front, ventral margin distinctly sinuated in the middle
and somewhat bowed in the oral region, anterior extremity well rounded off,
posterior narrowed and obtuse at the end; — seen dorsally, broadly oval in
outline, with the greatest width exceeding the height, both extremities obtuse
and subequal. Valves conspicuously unequal, the left overlapping the right
considerably along the anterior extremity; surface rather densely hairy. Nata-
tory setae of the posterior antennae not extending as far as the apical claws.
Spines of the outermost masticatory lobe of the maxilla smooth. Caudal
rami comparatively more slender than in the preceding species, distal claw n(
attaining half the length of the ramus.

Colour dark bluish green.

Length of adult female scarcely exceeding 1.10 mm.

Male unknown.

Remarks. — I think I am right in identifying the above-described forrfT
with Cypris hirsuta of Fischer. It was formerly erroneously regarded by me
as identical with Cypris elliptica Baird, which has proved to belong to the
preceding genus (see above). Dr. Aim does not however admits its specific
difference from C. affinis, combining both under the name Eucypris affinal
hirsuta. 1 think however that its distinction may be found in reality to be
beyond doubt, as it differs from the preceding species, both in the shape of
the shell and in the structure of the appendages, as also very conspicuousj
in colour.

121

Occurrence. — I have taken this form in several places, both near Chri-
stiania and elsewhere in the country, in small ponds and ditches with muddy
bottom. In habits it differs notably from the preceding species, being by far
not so active, as could indeed be inferred from the less fully developed nata-
tory setae on the posterior antenna. More generally the animals keep close to
the bottom, over which they are seen mowing rather slowly, very seldom
ascending to the surface.

Distribution. — ? Sweden (Aim), Russia (Fischer), probably also in many
other parts of Europe.

45. Cypricercus obliqvus (Brady).

(PI. LV, fig. 3).
Cypris obliqva, Brady, Monogr. of British Ostracoda, p. 364, PI. XXIII, figs. 33—38.

Specific Characters. — Female. Shell, seen laterally, of the usual oval
shape, greatest height a little in front of the middle and considerably exceeding
half the length, dorsal margin rather boldly and evenly arched, ventral very
slightly sinuated in the middle and curving upwards both in front and behind,
both extremities rounded off, the anterior more broadly than the posterior;—
seen dorsally, regularly ovate in outline, with the greatest width in the middle
and not fully attaining the height, both extremities gradually narrowed and
terminating in an obtuse point; — end view remarkably oblique, the right valve
being in a higher level than the left. Natatory setae of the posterior antennae
extending about to the tips of the apical claws. Spines of outermost mastic-
atory lobe of maxillae indistinctly denticulated in their outer part. Caudal
rami very slender, distal claw not nearly attaining half the length of the ramus.

Colour light greenish.

Length of adult female amounting to 1.26 mm.

Male unknown.

Remarks.— l\\\s form was described by Brady in his well-known Mo-
nograph and chiefly characterised by the peculiar oblique shape of the shell,
as seen from the ends. In the lateral aspect it does not look very different
from that of C. afflnls, though on a closer comparison some slight differences
may be found also in this case. The specific distinctness of this form is
however quite unquestionable.

Occurrence. — I have taken this form, often in great abundance, both near
Christiania and in several other places of our country, and always only at the
borders of larger lakes, never in such small ponds and ditches, which are

15 — Crustacea.

122

peapled by the other species of this genus. It is very perplexing that this
form has not yet been recorded from Sweden, the Ostracod Fauna of which
has been so thoroughly investigated both by earher and recent authors.
Probably it has been overlooked, owing to its external resemblance to C. affinis.
Distribution. — British Isles (Brady), France (Monier).

Gen. 21. Cyprinotus, Brady, 1885.

Generic Characters. — Shell compressed, more or less gibbously arched
dorsally, with the valves conspicuously unequal, the left overlapping the right
anteriorly and also somewhat dorsally, right valve with the free edges in their
whole extent minutely tuberculated. Antennae well adapted for swimming and,
like the mandibles, of normal structure. Maxillae with the masticatory lobes
less attenuated than in the preceding genus. Maxillipeds and legs about as
in that genus. Caudal rami however far less powerfully developed. Copulative
appendages of male resembling in shape those in Cypricercus. Ejaculatory
tubes with numerous whorls of radiating spikes, proximal extremity truncate.

Remarks. — This genus was established in the year 1885 by Brady, to
include a Ceylon species C. cingalensis, distinguished by a most unusual
dorsal gibbosity of the shell. Two Australian species, with the dorsal gib-
bosity of the shell less strongly marked, but otherwise agreeing with the type,
were subsequently described by the present author, one of them, C. dentato-
marginatus, having previously been recorded by Brady from India as a species
of Cypris. The 2 Northern species described below are unquestionably refer-
able to the present genus in the restriction here adopted.

46. Cyprinotus saiinus (Brady).

(PI. LVI, fig. 1).
Cypris salina, Brady, Monograph of British Ostracoda, p. 368, Pi. XXVI, figs. 8—1
Syn: Cypris strigata, Baird (not O. Fr. Miiller).
„ „ prasina, Brady & Norm, (not Fischer).

„ Eiicypris palcermitana, Daday.

Specific Characters. — Female. Shell, seen laterally, broadly oval in shape,
greatest height in the middle and almost attaining V3 of the length, dorsal
margin boldly arched, ventral slightly sinuated, anterior extremity somewhat
deflexed and obliquely rounded, posterior conspicuously produced, forming
below a rounded expansion defined above by a slight concavity of the dorsal
margin; — seen dorsally, oblong ovate in outline, with the greatest width behind

123

the middle and scarcely attaining half the length, anterior extremity gradually
narrowed to an acute point, posterior obtuse. Valves conspicuously unequal,
the left one overlapping the right in their greater extent; marginal tubercles
of right valve very small an densely crowded; surface of shell smooth and
clothed with short and delicate hairs. Anterior antennae with the terminal
part scarcely exceeding the basal one in length, joints successively diminishing
in size. Posterior antenuce with the penultimate joint about equal in length
to - 3 of the preceding one; natatory setae extending to the tips of the apical
claws. Caudal rami comparatively small, nearly straight, and gradually attenuated
towards the end; distal claw exceeding half the length of the ramus.

Ground colour of the shell pale yellowish, but clouded with a number
of very conspicuous dark brown band-like patches, partly surrounding the
valves, partly extending down their sides, so as to leave 3 lighter vertical
areas, the middle one joining below a 4th horizontal area.

Length of adult female 1.25 mm.

Male unknown.

Remarks. — This form was described as early as the year 1866 by
Brady as a species of the genus Cyprls. It is however unquestionably referable
to the genus Cyprinotus, in the restriction here adopted, being closely allied
to the southern species, C. dentaio-marginata mentioned above. When
examined in the fresh state, this form may be at once recognised by the
peculiar colouring of the shell, wich is unlike that in any of the other known
Ostracoda.

Occurrence. — I have met with this form in 2 localities of our country,
viz., at Sandviken, west of Christiania, and at Valle, on the western border
of Christiania Fjord. In both localities it occurred in pronouncedly brackish
water, and it has also elsewhere only be found under similar conditions. The
^animals are rather active, swimming quickely about in the water.

Distribution.— Sweden (Aim), British Isles (Brady), Pommeria (Miiller),
'ranee (Monier).

47. Cyprinotus fretensis (Brady).

(PI. LVl, fig. 2).

Cypris fretensis, Brady & Roberlsen, Ann. Mag. Nat. Hist., Ser. IV, Vol. VI, p. 13,

Pi. IV, figs. 7-9.

Specific Characters. — Female. Shell very like in its general appearance
that of the preceding species, though comparatively less high, with the dorsal
margin more evenly arched and the infero-posteal corner less produced.

124^

Structure of the several appendages scarcely exhibiting any more pronounced
differences from that in C. salUius.

Colour of the shell however very dissimilar, being uniformly light yellow-
ish, without any traces of the dark band-like patches adorning the shell of
that species.

Length of adult female scarcely exceeding 1.20 mm.

Male unknown.

Remarks. — The above-characterised form so closely resembles the pre-
ceding one, both in the general shape of the shell and in the structure of the
several appendages, that its specific distinctness might look somewhat questi-
onable, and indeed in his more recent publications Brady has withdrawn the
species, finding it undistinguishable from C. salinus. Yet, I think that these
2 forms ought to be kept apart, as they differ very conspicuously in the colour
of the shell, as also notably in habitat. On a closer comparison moreover some
slight differences are found to exist in the shape of the shell, as seen laterally.

Occurrence. — I have only met with this form in a single locality, viz., in
a ditche near Moss, where it occurred rather abundantly together with other
Entomostraca. The water in the ditch was perfectly fresh, and as the situation
of the ditch is considerably above the level of the sea, no mixture of salt
water can ever have taken place. Brady has found it under quite similar
conditions.

Distribution.— Bniish Isles (Brady).

Gen. 22. Heterocypris, Glaus, 1892.

Generic Characters.— Shell moderately tumid and more or less reniform
in shape, with the dorsal face not gibbously arched; its colour in all the known
species uniformly yellow. Valves conspicuously unequal, the left one being
the larger, and overlapping the right anteriorly as also somewhat ventrally;
edges of right valve roughly tuberculated along the anterior extremity and
along the posterior part of the ventral side. Structure of the several appeta
dages rather like that of the preceding genus. "

Remarks.— This genus was proposed in the year 1892 by Glaus, to include
the well known European species Cypris incongruens Ramdohr. It has how-
ever not been admitted by subsequent authors, who regard it as identical with
the genus Cyprinotus of Brady, to which it certainly shows a close affinity.
Yet, I find it appropriate to keep these 2 genera apart, as they differ con-
spicuously in the shape and partly also in the structure of the shell. More

125

over in recent times several additional species, closely agreeing with the type of
the present genus, and exhibiting the very same differences from Cyprinoius,
have been detected. To the Norwegian Fauna only belongs a single species,
to be described below,

48. Heterocypris incongruens (Ramdohr).

(PI. LVII).

Cypris incongruens, Ramdohr, Magazin. naturf. Freundc in Berlin, 2 Jalirg. 1808, p. 86,

PI. Ill, figs. 1—12, 15-20.
Syn: Monoculiis aurantius, Jurine.
„ Cypris fiisca, Strauss.
,, Cyprinotiis incongruens, G. O. Sars.
„ Eucypris incongruens, Daday.

Specific Characters. — Female. Shell, seen laterally, oval subreniform in
shape, distinctly higher behind than in front, greatest height not fully attaining
-/;3 of the length, dorsal margin sloping gradually in front and quite evenly
arched behind, ventral margin very slightly sinuated in front of the middle,
anterior extremity somewhat obliquely rounded, posterior obtuse, with the lower
corner not at all produced; — seen dorsally, oblong-ovate in outline, with the
greatest width behind the middle and about equal to half the length, anterior
extremity gradually narrowed to an acute point slightly turned to left side,
posterior obtuse. Surface of shell smooth and polished, with scattered small
puncta and clothed with short and delicate hairs; left valve overlapping the
right in front by a well-marked pellucid border wanting on the right valve,
marginal tubercles of the latter obtusely rounded and in some cases not easy
to discern, though apparently never wholly absent. Anterior antennae with the
terminal part about the length of the basal one, its 1st joint fully as long as
the 2 succeeding ones combined. Posterior antennae with the penultimate
joint much shorter than the preceding one, natatory setae extending somewhat
beyond the tips of the apical claws. Caudal rami rather narrow and nearly
straight, distal claw about half the length of the ramus, dorsal seta rather
longer than the apical one.

Colour pale yellow, in older specimens passing over to an orange hue,
ripe ova shining through the shell with a brick-red colour.

(Length of adult female amounting to 1.60 mm.
? Male unknown.
Remarks. — This form was recorded as early as the year 1808 by Ram-
dohr, and has subsequently been observed by almost every one of the authors
who have studied the fresh water Ostracoda, though described under several

126

other names. When examined in the fresh state, it may at once be recognised
from the other indigenous Cypridae by the bright yellow colour of the shell,
and the same characteristing colouring is also found in all the other known
species of the present genus.

Occurrence. — This is perhaps the most common of our fresh water Ostra-
coda, occurring often in great abundance in ponds and ditches during the
greater part of the year. Though more generally keeping at the bottom, the
animals are at times seen swimming about in the water with great dexterity.
The exlusive parthenogenatical reproduction of this form seems to me to be
indubitable. I have examined immence numbers of specimens, both from
Norway and from abroad, but have never come across even a single male
specimen, arid I have also watched the species in my aquaria for many suc-
sessive generations with the very same result. True, Dr. Varra describe what
he believe to be the male of this form; but I am by no means assured that
the specimen examined by him had in reality belonged to the present species.
In some other species more or less closely allied to the present one, are indeed
male specimens not rarely met with, and I have examined this sex in both of
the 2 South African forms; H. capensls (G. W. Muller) and H. anrea G. O. Sars.

Distribution. — Throughout Europe, Central Asia, North and South Africa,
North America, Brazil.

Gen. 23. Dolerocypris, Kaufmann, 1900.

Generic Characters. Shell very narrow and elongated, with both extremi-
ties rather produced. Valves somewhat unequal, the right overlapping the
left both in front and behind, edges unarmed; inner duplicatures very broad.
Antennae well adapted for swimming. Maxillae with both the masticatory lobes
and the palp narrowly produced. The other limbs on the whole of normale
structure. Caudal rami rather powerfully developed, with the apical claws
very unequal in length, both coarsely denticulated, dorsal seta very small a
attached near the end.

Remarks.— This genus was proposed in the year 1900 by Kaufmann, to
include Cypris fasciata O. Fr. Muller, and has been admited by the more
recent authors. In addition to the European species described below, 4 other
nearly allied species have in recent times been recorded from more southCj
latitudes.

I

127

49. Dolerocypris fasciata (O. Fr. Muller).

(PI. LVIIl).
Cypris fasciota, O. Fr. Muller, Entoniostraca, p. 53, PI. IV, figs. 1 — 3.
Syn : Monocnliis fasciatiis, Juriiie.
Cypris ephippiata. Koch.
„ Herpetocypris fasciata, Brndy & Normad.

Stenncypris fasciata. G. O. Sars.
,, Eucypris fasciata, Daday.

Specific Characters- — Female. Shell, seen laterally, narrow oblong in
shape, greatest height in the middle and only slightly exceeding ^/u of the
length, dorsal margin evenly arched in the middle and sloping slowly to each
extremity, ventral margin almost straight, anterior extremity narrowly rounded
off at the end, posterior rather narrower and drawn out to an obtuse corner;
— seen dorsally, narrow fusiform in outline, with the greatest width not fully
attaining V3 of the length, both extremities gradually narrowed and nearly
equal. Surface of shell smooth and finely hairy; right valve with a well
defined marginal area in front, wanting on the left valve. Caudal rami straight,
sublinear in form, with the dorsal edge very finely ciliated in its outer part,
distal claw fully half the lenght of the ramus and almost twice as long as the
proximal one, both armed behind with a double row of coarse denticles; dorsal
seta so very small as easily to escape attention; apical bristle well developed.

Colour light olivaceous, with a very conspicuous dark, saddle-like band
across the back behind the ocular region, extending down to about the centre
of the shell. Ripe ova and ovarial tubes shining through the shell with a
bright orange hue.

Length of adult female 1.60 mm.

Male unknown.

Remarks. — The present form is readily recognised from any of our other
fresh water Ostracoda by the extremely narrow and elongate shape of the
shell and, when examined in the fresh state, also by its characteristic colour.
It was formerly erroneously referred by me to the genus Stenocyprls, from
which it in reality differs essentially in several respects. Nor can it, as done
by Brady and Norman, be referred to the genus Herpetocypris, as it is by no
means devoid of swimming power.

Occurrence. — I have only met with this form in 2 localities of our country,
viz., in a small grassy pool at Lysaker and in a similar pool at the border of
0stensj0 lake, both localities in the neighbourhood of Christiania. The

128

movements of the animal are not particularly rapid, though it is often seen
to swimm freely about in the water in the usual manner.

Distribution. — Throughout Europe, Siberia, Sumatra (O. O. Sars).

Gen. 24. Herpetocypris, Brady & Norman, 1889.

Generic Characters. — Shell elongate, more or less reniforme in shape,
with the dorsal face scarcely at all arched. Valves conspicuously unequal, the
left being the larger and considerably overlapping the right both in front and
behind, edges smooth. Antennae not adapted for swimming, the natatory setae
of the posterior ones being quite rudimentary. Maxillae with the masticatory
lobes rather produced, spines on the outermost lobe distinctly denticulated, palp
with the distal joint slightly widening at the end. Maxillipeds with the vibra-
tory plate small, but well defined, palp slender and attenuated. Both pairs
of legs rather elongated. Caudal rami comparatively strong, sublinear in form,
with the dorsal edge minutely spinulose, apical claws rather unequal in size
and distinctly denticulated, dorsal seta very small and attached close to the apex.

Remarks. — This genus was proposed in the year 1889 by Brady and
Norman, to include Cypris reptans Baird and some other species considered
by them to be congeneric with it, and was chiefly caracterised by the rudi-
mentary condition of the natatory setae on the posterior antennae, causing the
animal to be quite devoid of swimming power; hence the generic name proposed.
The genus is here taken in a much more restricted sense than done by Brady
and Norman, only the type |^ species being left in this genus, whereas the
other species referred to it by the said authors have been discarded and trans-
ferred to the next genus. Dr. Kaufmann has also confined the limits of this
genus in a similar manner, though one of his species, H. peregrina must be
removed from the genus. Only the type species is represented in the Fauii^
of Norway.

50. Herpetocypris reptans (Baird).

(PI. LXIX).
Candona reptans, Baird, British Entomostraca, p. 160, PI. XIX, figs. 3, 3 a.
Syn: Cypris reptans, Lilljeborg.
— virescens, Brady.

Specific Characters. — Female. Shell, seen laterally, oblong renifon
shape, height almost equal throughout and not attaining half the length, dorsa^
margin nearly straigt and horizontal, with a slight angular bend in the ocull

129

region, ventral margin gently sinuated, anterior extremity somewhat deflexed
and obliquely rounded, posterior blunted, with the lower corner rounded off;
— seen dorsally, narrow oblong, with the greatest widht behind the middle
and about equal to -lb of the length, anterior extremity gradually narrowed to
an acute point, posterior extremity more obtuse. Valves conspicuously unequal,
the left one considerably overlapping the right in front as also along the
ventral face, exhibiting moreover a well defined marginal zone closely striated
transversally; inner duplicatures rather broad in front and of somewhat diffe-
rent shape in the 2 valves; surface of shell smooth and clothed anteriorly with
delicate densely crowded hairs, posteriorly with scattered rather long bristles.
Natatory setae of posterior antennae much reduced, scarcely extending to the
middle of the succeeding joint. Caudal rami rather slender and slightly curved,
with the base somewhat thickened, dorsal edge fringed with 4 — 5 successive
rows of very minute spinules, distal claw not attaining half the length of the
ramus, but nearly twice as long as the proximal one, both distinctly denti-
culated, dorsal bristle very small, apical one very much longer.

Colour more or less olivaceous green, clouded with darker shadows.

Length of adult female amounting to 2.60 mm.

Male unknown.

Remarks.— This form vas described as early as the year 1850 by Baird,
but was erroneously referred by that author to the genus Candona. It is one
of our largest fresh water Ostracoda, and easily recognisable from any of them
by its elongate reniform shell, resembling however in this respect closely some
of the foreign species, for instance the African species, H. Chevreuxl G. O.
Sars, yet exhibiting some well marked differences, in particular as to the relative
developpement of the natatory setae on the posterior antennae.

Occurrence. — I have met with this Ostracod occasionally both in the
neighbourhood of Christiania and near Trondhjem. It is generally found in
teams and ditches with muddy bottom, and always close to the ground, along
which it is seen crawling rather slowly, at times hurrying more or less deeply
within the loose mud. I have never seen it to make even the slightest attempt
to move freely in the water.

Distribution. — Throughout Europe.

16 — Crustacea.

Gen. 25. Prronocypris, Brady & Norman, 1896.

Generic Characters. — ^\\q\\ of somewhat varying shape in the different
species but as a rule higher in front than behind. Valves subequal, with the
edges in some cases serrate, though more generally smooth; inner duplicatures
of moderate size, broader in front than behind. Antennae not adapted for
swimming, the natatory setae of the posterior ones being quite rudimentary.
Maxillae with the masticatory lobes not much produced, palp narrow, with the
distal joint comparatively small and scarcely widening at the end. Legs rather
slender. Caudal rami of moderate size, with the apical claws less unequal
than in Herpetocypris, dorsal bristle somewhat remote from the apex, apicale
one very minute.

Remarks.— Ihis genus was proposed in the year 1896 by Brady and
Norman, and only founded on a single species, P. serrata, the generic name
alluding to the serrated edges of the valves in that species. The genus was
subsequently admitted by Kaufmann, who refers to it also the form recorded
by Brady under the name Cypris tiimefacta. In the present account 3 other
species are provisionally included in the same genus.

51. Prionocypris lutaria (Koch).

(PI. LX).
Cypris lutaria, Koch, Deutschlands Crustaceen etc.
Syn : Cypris Jurini, Zaddack.
— lucida, Lilljeborg.
„ Herpetocypris strigata, Brady & Norman.
„ — Jurini, G. O. Sars.

„ — peregrina, K'Jufmann.

„ Eucypris lutaria. Aim.

Specific Characters. — Female. Shell, seen laterally, oblong oval in shape,
greatest height somewhat in front of the middle and about equalling half the
length, dorsal margin gently arched, with a slight indication to an angle behind
the ocular region, and rather steeply sloping behind, ventral margin very
slightly sinuated, anterior extremity broadly rounded off, posterior much nar-
rower and obliquely blunted; — seen dorsally, elliptical in outline, with the
greatest width in tne middle and about equalling ^jh of the length, both efl
tremities pointed and nearly equal. Surface of shell smooth and polished,
clothed with short and delicate hairs; inner duplicatures of valves not very
broad. Natatory setae of posterior antennae scarcely extending beyond the
middle of the succeeding joint. Spines on the outermost masticatory lobe of

131

maxillae coarsely denticulated. Apical claw of anterior legs very slender and
elongated. Caudal rami almost straight and slightly attenuated, with the dorsal
edge very finely spinulose, apical claws rather slender and not much unequal,
the distal one about half the length of the ramus, dorsal bristle more than
twice as long as the apical one.

Colour pale yellow with an olivaceous tinge and clouded with irregular
bluish green shadows.

Length of adult female amounting to 2.50 mm.

Male unknown.

Remarks.— This form has by some authors been identified with Cypris
strlgata of O. Fr. Miiller; but this identification is certainly wrong, and is
also decidedly rejected by the most recant author, Dr. Aim. On the other
hand no doubt can arise on the identity of Cypris lutaria of Koch with the
present species, and as the specific name proposed by that author is of earlier
date than either Jurlni or lucida, it ought of course to be retained for the
present form. As to its systematic position, it has generally by recent authors
been placed in the genus Eucypris Vavra. But this cannot by any means be
admitted, as it differ^ very essentially from the species of that genus in the
rudimentary condition of the natatory setae on the posterior antennae and the
consequent absolute want of swimming power. Nor can it, as done by Brady
and Norman, be referred to the genus Herpetocyprls. as the structure of the
shell is very different. On the other hand I do not find any objection for
including it in the genus Prionocypris, as here defined. It is one of our
largest fresh water Ostracoda, and moreover easily recognizable by the general
form of the shell and its colour.

Occurrence.— \ have taken this handsome Ostracod, early in the summer,
rather abundantly in some ditches with grassy bottom near Christiania (Ule-
vold). The animals were found constantly keeping at the bottom, they being
quite unable to move freely in the water.

Distribution.- -IhioMghowi Europe, Central Asia.

52. Prionocupris glacialis, G. O. Sars.

(PI. LXI, fig. 1).
Herpetocyprls glacialis, G. O. Sars, Oversigt af Norges Crustaceer II, p. 61.

Syn: Cypris Jiirini, G. O. Sars (noii Ziiddacli).
„ Eiuypris glacialis. Aim.

Specific Characters.— Female. Shell rather tumid, seen laterally, oblong
oval in shape, greatest height in front of the middle and exceeding somewhat

132

half the length, dorsal margin rather evenly arched and sloping gently behind,
ventral margin almost straight, anterior extremity broadly rounded off, posterior
somewhat narrower and obtuse at the end;— seen dorsally, broadly fusiform
in outline, with the greatest width in the middle and about equal to half the
length, both extremities pointed and nearly equal. Surface off shell densely
clothed with rather coarse hairs. Natatory setae on the posterior antennae
scarcely extending beyond the middle of the succeeding joint. Spines on
outermost masticatory lobe of the maxillae armed near the extremity on each
side with 2 opposite strong denticles. Caudal rami resembling in structure
those of the preceding species.

Colour dark fuscous, with a bluish green shadow dorsally behind the
ocular region.

Length of adult female 1.60 mm.

Male unknown.

Remarks. — This form was at first (1866) confounded by me with the
preceding species, to which it certainly bears some ressemblance in its general
appearance. It was however subsequently subjected to a closer examination,
and its specific distinctness thereby ascertained. It is of much smaller size and
moreover distinguished by its more tumid and densely hairy shell, as also by
its somewhat different colour.

Occurrence. — This is a true arctic species, being almost exclusively con-
fined within the polar circle. The specimens at first observed vere taken
during the Norwegian North Atlantic Expedition in small water-holes at Advent
Bay, Spitsbergen. Subsequently I was enabled to include this form also in
the Norwegian Fauna, having taken some specimens at Smelroren, on the
mainland inside Vard0, East Finmark. According to Dr. Aim, this form has
also been met with, as a glacial relict, on the high-plateau of Filefjeld (Jotun-
heimen).

Distribution.— Greenland, Spitsbergen, Bear Island, Nowaja Zembla, Swe-
dish Lapmark.

53. Prionocypris pigra (Fischer).

(PI. LXI, fig. 2).
Cypris pigra, Fischer, Mem. Soc. Imp. de St. Petersbourg, Vol. 7, p. 158, PI. 9, figs. 11 — 1

Syn: Cypris tume facta. Brady.
„ Herpetocypris tumefacta, Brady & Norman.
„ Eucypris pigra. Aim.

d

Specific Characters. — Female. Shell very tumid, seen laterally, oval
trigonal in shape, greatest height nearly in the middle and considerably ex-

133

ceeding half the length, dorsal margin gibbously arched in the middle and
sloping rather steeply both in front and behind, ventral margin very slightly
sinuated, anterior extremity obliquely rounded, posterior somewhat broader and
likewise obliquely rounded off;— seen dorsally, very broady ovate in outline,
with the greatest width in the middle and somewhat exceeding the height,
both extremities pointed, the anterior more so than the posterior. Surface of
shell smooth and clothed with fine hairs. Natatory setae on posterior antennae
very much reduced, not nearly extending to the middle of the succeeding joint.
Spines on outermost masticatory lobe of the maxillae quite smooth. Caudal
rami rather narrow and nearly straight, with the dorsal edge smooth, distal
claw about half the length of the ramus, dorsal bristle slightly longer than the
apical one.

Colour pale whitish yellow, slightly clouded dorsally behind the ocular
region.

Length of adult female about 1 mm.

Male unknown.

Remarks. — The identity of the above-described form with Cypris pigra
of Fischer seems to be quite ascertained, and the specific name tumefacia,
under which this form has generally been recorded, must of course cede the
older name proposed by Fischer. It is a very distinct and easily recognisable
species, differing considerably in its general appearance from the other forms
included in the present genus, though its place within it may be regarded as
unquestionable.

Occurrence. — \ have taken this form very abundantly in a shallows ditch
near Christiania, and have also met with it in our largest lake, Mjesen at
Hamar, where it occurred not rarely on a woody bottom at a depth of 2 — 4
fathoms. The animals are found slowly crawling on the bottom, being quite
unable to move freely in the water.

Distribution. — Sweden, British Isles, Germany, Switzerland, Russia.

54. Prionocypris olivacea (Brady & Norman).

(PI. LXU).

Herpetocypris olivacea, Brady & Norman, Monograph of Mar. and Freeh water Ostracoda 1889,

p. 89, PI. 1, figs. 3, 4.

ISyn: llyodromiis oiivaceiis, Brady & Norman 1896.
Specific Characters. ^F emale. Shell, seen laterally, oval reniform in shape,
' greatest height a little in front of the middle and about equalling half the
length, dorsal margin gently arched, ventral slightly sinuated, anterior extremity

134_

somewhat obliquely rounded, posterior scarcely narrower and obtuse at the
lower corner; — seen dorsally, oblong oval in outline, slightly constricted in
front of the middle, greatest width behind and not attaining half the length,
both extremites obtusely pointed, the anterior narrower than the posterior.
Surface of shell of a somewhat dull appearance, and clothed with short hairs.
Natatory setae of posterior antennae extremely rudimentary and easily over-
looked, apical claws rather strong and coarsely denticulated. Spines on outer-
most masticatory lobe of the maxillae armed with 2 strong denticles on each
side of the terminal part. Caudal rami comparatively strong and quite straight,
with the dorsal edge minutely spinulose, apical claws remarkably stout, the
distal one not nearly attaining half the length of the ramus, dorsal bristle
replaced by a thickish spine somewhat similar to the apical claws, but much
shorter.

Colour uniformly dark olivaceous green.

Length of adult female 1.25 mm.

Male unknown.

Remarks. — The reference of this form to the Australian genus Ilyodromiis
G. O. Sars, proposed by Brady and Norman, and also sanctioned by Kauf-
mann, seems to me to be quite inadmissible, and is in reality only founded on
the somewhat similar transformation of the dorsal bristle on the caudal rami.
In other respects this genus diffejs very conspicuously both as to the structure
of the shell and to that of some of the appendages. On the other hand,
apart from the above-named particularity, I find that the agreement of the
present species with the preceding ones is quite unmistacable.

Occurrence. — I have hitherto only met with this form in a single place,
viz., in a shallow ditch near Christiania. The animal is rather sluggish, and
keep constantly at the bottom.

Distribution.— Briiish Isles, Hungary, Bohemia, SwitzeHand.

Group 7. Cypridopsides.

n

Remarks. — The forms referable to this group are in particular distinguished
from the other fresh water Cypridae by the rudimentary condition of the caudal
rami. True, in 2 of the genera, Cypretia Vavra and Paracypretta G. O. Sars,
the reduction of these rami appears somewhat less complete than in the other
genera; but also in this case the reduction is great ennough to distinguish
them from the more typical Cypridae. Several genera have been established

135

within this group; but their right definition is by no means in every case
quite clear. In the Fauna of Norway 3 of these genera are represented.

Gen. 26. Pionocypris, Brady & Norman, 1896.

Syn: Cypridopsis, auctorum (part).

Generic Characters. — Shell tumid and more generally short and high, with
the ventral face more or less flattened. Valves only slightly unequal, the left
one being a little larger than the right, with the shelf-like expansion of the
ventral edge strongly marked; inner duplicatures moderately broad in front
and continued along the ventrale side to the hind extremity. Antennae power-
fully developed and well adapted for swimming. Maxillae with both the palps
and the masticatory lobes narrowly produced. Maxilliped^ with the vibratory
plate more or less reduced. Anterior legs strongly built, with the apical claw
very long and slender. Caudal rami quite rudimentary, and apparently immo-
bile, forming 2 small justaposed lappets, each terminating in a slender seti-
form flagellum.

Remarks. — This genus was proposed in the year 1896 by Brady and
Norman, to comprise some of the species previously referred to the genus
Cypridopsis, the type of the genus being Cypris vidua of O. Fr. Miiller. The
above-named authors included in this genus also the Australian species, Cy-
pridopsis i^lobiiliis G. O. Sars. But this form has turned out to be referable
to an other genus, viz., Cypretta Vavra, differing essentially in the structur eof
the caudal rami.- Several species of the present genus have been recorded,
both from Europe and from other continents. To the Fauna of Norway belong
6 species, to be described in the succeeding pages.

55. Pionocypris vidua (O. Fr. Miiller).

(PI. LXIII).

Cypris vidua. O. Fr. Miiller, Entomostraca, p. 55, PI. IV, figs. 7—9.
Syn : Cypris sella, Baird.
„ Monoculiis vidua, Jurine.
„ Cypridopsis vidua. Brady.

H Specific Characters.— Female. Shell very tumid, seen laterally, short ovoid
in shape, greatest height in the middle and almost attaining -/a of the length,
dorsal margin boldly arched in the middle, ventral margin very slightly sinuated
and somewhat bowed in the oral region, anterior extremity well rounded off,
posterior a little narrower and obtuse at the end;— seen dorsally, broadly ovate,

136

or somewhat rhomboid in cutline, the lateral edges being abruptly curved in
the middle, greatest width exceeding somewhat the height, both extremities
obtusely pointed, the anterior narrower than the posterior. Surface of shell
rather densely hairy, and distinctly sculptured with closely set small impressed
pits.— Natatory setae on posterior antennae densely ciliated and extending beyond
the tips of the apical claws. Vibratory plate of maxillipeds provided with 5
setae. Caudal rami very small, lash-shaped, with a minute bristle on the dorsal
edge, terminal flagellum longer than the stem.

Colour yellowish white, with 3 dark, somewhat irregular, band-like patches
running down the valves from the dorsal face to about their middle, the fore-
most patch lying immediately inside the anterior edge, the other 2 connected
dorsally on each side by a longitudinal band.

Length of adult female 0.70 mm.

Male unknown.

Remarks. — This form was described and figured as early as the year
1785 by O. Fr. Miiller, and has generally been recorded by recent authors
under the name Cypridopsis vidua. It is the type of the genus Pionocypris,
as here defined.

Occurrence.— I have taken this little Ostracod in many places of our
country in ponds and ditches with clear water and grassy bottom. Though
in most cases keeping at the ground, the animals are very well adapted for
swimming, and are seen at times moving rather quickly through the water.

Distributions. — Throughout Europe, Central Asia, North America.

56, Pionocypris helvetica (Kaufmann).

(PI. LXIV, fig. 1).

Cypridopsis helvetica, Kaufmann, Cypriden und Darwinoliden der Scliweitz, p. 363,
PI. 19, figs. 4, 5; Pi. 22, figs. 10, 11.

Specific Characters.— Female. Shell, seen laterally, of a shape rather
similar to that of the preceding species, though comparatively somewhat less
high in proportion to the length; — seen dorsally, however, far less broad, and
regularly ovoid in outline, with the lateral edges quite evenly curved, and the
greatest width scarcely exceeding the height, anterior extremity narrower than
the posterior, which is rounded off at the end. Surface of shell quite smooth
and finely hairy, without any trace of the impessed pits characterising the
shell of the preceding species. Natatory setae on the posterior antennae still
more prolonged. Vibratory plate of maxillipeds with only 3 setae. Caudal
rami with the terminal flagellum very long and slender.

Cyprida

Ostracoda

Podocopa

PI. XLIX

G. O. Sars del.

Ilyocypris biplicata, (Koch)

Cypridae

Ostracoda

Podocopa

PI L

/. ?/.

G. O. Sars del.

1. Ilyocypris gibba, (Ramdohr)

2. Iliocyprella Bradyi, 6. O. Sars

CypridsB

Ostracoda

Podocopa

PI. LI

I

G. O. Sars del

Cypris pubera, O. Fr. Muller

Cypridae

Ostracoda

Podocopa

PI. Lll

e. O. Sars del.

Eucypris virens, (Jurine)

^

CypridaB

Ostracoda

Podocopa

PI. Llll

nj

6. O. Sars del.

1. Eucypris crassa (O. Fr. MiJller)

2. „ elliptica, (Baird)

Cyprids

Ostracoda

Podocopa

PI. LIV

G. O. Sars del.

Cypricercus fuscatus, (Jurine)

Cyprids

Ostracoda

Podocopa

PI. LV

6. O. Sars del.

1. Cypricercus affinis, (Fischer)

2. „ hirsutus, (Fischer)

3. „ obliqvus, (Brady)

Cypridae

Ostracoda

Podocopa

PI. LVI

6. O. Sars del.

1. Cyprinotus salinus, (Brady)

2. „ freiensis, (Brady)

Cupridae

Ostracoda

Podocopa

PI. LVil

6. O. Sars del.

Heterocypris incongruens, (Ramdohr)

Cypridae

Ostracoda

Podocopa

PI. LVIII

£

m T h, i

'I )■'.

G. O. Sars del.

Dolerocypris fasciata, (O. Fr. MiJller)

Cypridas

Ostracoda

Podocopa

PI. LIX

I

G. O. Sars del.

Herpetocypris reptans, (Baird)

Cypridae

Ostracoda

Podocopa

PI. LX

e. O. Sars del

Prionocypris iutaria, (Koch)

Cypridae

Ostracoda

Podocopa

PI. LXI

r

6. O. Sars del

1, Prionocypris glacialis, G. O. Sars

2. ,, pigra, (Fischer)

Cypridas

Ostracoda

Podocopa

PI. LXII

G. O. Sars del.

Prionocypris olivacea, (Br. & Norm.)

Cypridae

Ostracoda

Podocopa

PI. Lxm

G. O. Sars del.

Pionocypris vidua, (0. Fr. Miiller)

Cypridae

Ostracoda

Podocopa

PI. LXIV

0-7M,

6. O. Sars del.

1. Pionocypris helvetica, (Kaufm.)

2. „ obesa, (Brady & Rob.)

3. „ elongata, (Kaufm.)

137

Colour very similar to that in P. vidua, the ground-colour of the shell
being pale whitish, and the band-like patches very dark, almost black. In
addition to the 3 patches found in the said species, a 4th patch is to be traced
close to the hind extremity of the valves.

Length of adult female 0.65 mm.

Male unknown.

Remarks. — This form has generally been confounded with the preceding
species, to which it certainly bears a close resemblance. Dr. Kaufmann has
however pointed out some well-marked differences, which prove it to be in
reality specifically distinct. I have raised both these forms together from a
parcel of dried mud kindly sent to me by Mr. Johansen and taken from a
pool near Ottawa, Canada. On examining more closely the specimens abound-
ing in my aquaria, I at once became aware of the marked difference between
these 2 forms in the shape and sculpture of the shell, making it very easy
to distinguish them, the one from the other, even at a rather low magnifying
power.

Occurrence. — This species is rather frequently met with, both in small
pools and at th.:; borders of greater lakes, and I have taken it as far North
as Matsjok in East Finmark. In its behaviour the animal agrees with the
preceding species, being however comparatively more active in its movements.

Distribution .—Swiizerland, and probably in many other places of Europe,
North America.

57. Pionocypris obesa (Brady & Robertson).

(PI. LXIV, fig. 2).

Cypridopsis obesa, Brady & Robertson, Ann. Mig. Nat. Hist. Ser. 4, Vol. Ill, p. 12,

Pi. XVIII, figs. 5-7.
Syn: Cypridopsella tumida, Kaufmann,

Specific Characters. — Female. Shell of a very obese appearance, seen
laterally, broadly ovoid in shape, greatest height in the middle and exceeding
^ 5 of the length, dorsal margin boldly arched, with indication to an angle in
the middle, ventral margin slightly sinuated and distinctly bowed in the oral
region, anterior extremity broadly rounded off, posterior somewhat narrower
and obtuse at the end;— seen dorsally, broadly ovate in outline, with the
greatest width behind the middle and considerably exceeding the height,
anterior extremity obtusely pointed, posterior evenly rounded off.— Surface of
shell finely hairy, and of a somewhat dull appearance, being very distinctly

17 — Crustacea.

138

sculptured with rather coarse rounded pits. — Vibratory plate of maxillipeds
with only 2 setae. Caudal rami about as in P. vidua.

Colour of shell uniformly greenish, without any dark patches across the
valves.

Length of adult female 0.72 mm.

Male unknown.

Remarks. — This species was recorded in the year 1869 by Brady and
Robertson, but was subsequently withdrawn by the same authors, being only
considered to be a variety of P. vidua, and this opinion has also been sanc-
tioned by the most recent author, Dr. Aim. Yet, the specific distinctness of
this form seems to me to be unquestionable, as it distinguishes itself, not only
in the shape and colour of the shell, but also in some of the structural details
(maxillipeds). The form recorded by Kaufmann as Cypridopsella tumida is
apparently identical with the present species. The reference of this form to
the genus Cypridopsella is quite unreasonable, being only founded on the
small number of set« on the vibratory plate of the maxillipeds. In all other
respects it shows itself as a true member of the present genus.

Occurrence. — I have only met with this form quite occasionally in some
shallow grassy swamps near Christiania.

Distribution. — British Isles, Germany, Switzerland, and probably many
other parts of Europe.

58. Pionocypris elongata (Kaufmann).

(PI. LXIV, fig. 3).

Cypridopsella elongata, Kaufmann, Cypriden und Darwinuliden der Schweiz, p. 314,
PI. 19, figs. 14, 15; PI. 22, figs. 20-23.

Specific Characters. — Female. Shell unusually elongated, seen laterally,
oblong oval in shape, greatest height a little in front of the middle and
scarcely exceeding half the length, dorsal margin quite evenly arched, ventral
slightly sinuated in the middle and conspicuously bowed in the oral region,
anterior extremity somewhat obliquely rounded, posterior narrower and obtuse
at the end;— seen dorsally, oblong ovate in outline, with the greatest width
behind the middle and slightly exceeding half the length, anterior extremity
obtusely pointed, posterior rounded off. — Surface of shell smooth and finely
hairy, without any obvious sculpturing. Left valve exhibiting, inside the anterior
edge, a row of very conspicuous rounded thickenings. — Vibratory plate of
maxillipeds with only 2 setse. Caudal rami of the usual appearance.

139

Colour of the shell cinereous green, with a dark shadow dorsally, behind
the ocular region.

Length of adult female 0.76 mm.

Male unknown.

Remarks. ^The above-described form is unquestionably identical with
CypridopseUa elongaia of Kaufmann, agreeing pretty well with the figures
given by that author. It ought in my opinion to be referred to the genus
Pionocypris, in spite of the somewhat anomale shape of the shell. A character
very distinctive of the present species, but overlooked by Kaufmann, is the
peculiar thickenings occurring inside the anterior edge of the left valve.

Occurrence. — I have only met with this form in a single place of our
country, viz., in a grassy pond at Asker, West of Christiania; but I have, many
years ago, raised the same species rather plentifully from dried mud taken in
Algeria and kindly forwarded to me by Mr. Chevreux.

Distribution. — Switzerland, Germany, Algeria.

59. Pionocypris Almi, G. O. Sars, n. sp.
(PI. LXV, fig. 1).

Cypridopsis elongata, Aim, Monographic der Schwedischen Siisswasser Ostracoden, p. 79

(not Kaufmann).

Specific Characters, — Female. Shell less elongated than in the preceding
species, seen laterally, ovoid in shape; with the greatest height in the middle
and considerably exceeding half the length, dorsal margin boldly and rather
evenly arched throughout, ventral margin slightly sinuated in the middle and
scarcely bowed in the oral region, anterior extremity obliquely rounded,
posterior a little broader and obtusely blunted at the lower corner;— seen
dorsally, ovate in outline, with the greatest width in the middle and about
equalling ^/o of the length, anterior extremity obtusely pointed, posterior rounded
off at the end. Surface of shell smooth and finely hairy; left valve vithout
any traces of .the marginal areolae in front, found in the preceding species.
Vibratory plate of maxillipeds with 2 setae. Caudal rami of the usual shape.

Colour of shell uniformly light greenish, without any obvious dark patches.

Length of adult female 0.59 mm.

Male unknown.

Remarks. — This form has been erroneously identified by Aim with the
preceding species, from which it differs decidedly in the far less elongated
form of the shell, as also in she absolute absence of the peculiar marginal

140

areolae found in that species inside the anterior edge of the left valve. It is
also very different from the next species, which Dr. Aim suppose to be the same.

Occurrence. — Only a few specimens of this form have as yet come under
my notice. They were taken, many years ago, from a grassy pond near
Christiania.

Distribution. — Sweden (Aim).

60. Pionocypris picta (Strauss).

(Pt. LXV. fig. 2).

Cypris picta, Strauss, Mem. du Mus. d'Hist. Nat., Vol. VII, p. 59, PI. 1, figs. 17—19.

Syn: Cypridopsis picta, G. O. Sars.

Specific Characters. — Female. Shell rather tumid, seen laterally, short
ovoid in shape, greatest height behind the middle and about equalling ^j:> of
the length, dorsal margin boldly arched behind the middle and sloping rather
steeply behind, more slowly in front, ventral margin very slightly sinuated,
anterior extremity obliquely rounded, posterior broader and obtuse at the lower
corner;— seen dorsally, broadly ovate in outline, with the greatest width behind
the middle and about equal to the height, anterior extremity gradually nar-
rowed to an obtuse point, posterior broadly rounded off. — Valves smooth and
rather densely hairy. Caudal rami with the stem comparatively short, scarcely
half the length of the flagellum.

Colour of shell light bluish green, with a rather conspicuous dark patch
on each side arching over the muscular spots, and continued down the valves
both in front and behind, extremities of valves tinged with a similar dark hue.

Length of adult female 0.43 mm.

Male unknown. H

Remarks. — This small Ostracod was recorded as early as the year 1821
by Strauss, and has subsequently also been noted by some other authors on
the continent, though not observed either in Sweden or on the British Isles.
Besides by its small size, it is easily recognised form the other species of the
present genus by the shape of the shell and its peculiar colour.

Occurrence. — I have taken this form occasionally in grassy ponds and
swamps near Christiania. The animals are rather activ, swimming about in
the water with considerable speed.

Distribution. — France, Holland, Belgium,

141

Gen. 27. Cypridopsis, Brady, 1866.

Generic Characters. — Shell of somewhat varying shape in the different
species, but, as a rule, far less tumid than in Pionocypris. Valves only slightly
unequal, the right being however a little larger than the left, and overlapping
it in front by a narrow pellucid border; surface more generally rough by
numerous densely set impressed pits, and in some cases armed with stout
spines. Antennae well adapted for swimming, but comparatively less strongly
built than in Pionocypris. Maxillae with the masticatory lobes narrowly pro-
duced; palp rather feeble, with the distal joint narrow and longer than broad.
Maxillipeds with the palp comparatively short, and in male prehensile; vibratory
plate more or less reduced. Anterior legs more slender than in Pionocypris.
Caudal rami very small and of a structure similar to that in the said genus.
Copulative appendages of male with the outer lappet boot-shaped. Ejaculatory
tubes with numerous whorls of radiating spikes, proximal extremity truncate.
Spermatic vessels forming in each valve dense coils both in front and behind.

Remarks. — The present genus is here taken in a more restricted sense
than done by Brady and most other authors. Indeed the 3 species comprised
by Brady, in his genus represent in my opinion as many separate genera, one
of them, C. vidua, being the type of the genus Pionocypris treated of in the
preceding pages, and another, C. villosa, that of the genus Cypridopsella Kauf-
mann, to be spoken of farther below. It is thus only left in the genus Cyprid-
opsis the 3rd species recorded by Brady, viz., C. aculeata. Although rather
nearly allied to Pionocyptis, the present genus is well distinguished by the far
less tumid shell, and by the right valve (and not the left) being the larger.
Moreover slight differenses are to be found in the structure of some of the
appendages. — The genus is represented in the Fauna of Norway by only a
single species, to be described below; but in other parts of the world numerous
species referable to this genus have been recorded.

61. Cypridopsis aculeata. (Costa).

(PI. LXV., fig. 3).
Cypris aculeata, Costa, Fauna del regno di Napoli.

Specific Characters. — Female. Shell, seen laterally, broadly oval or some-
what trigonal in shape, greatest height in the middle and nearely attaining -/s
of the length, dorsal margin boldly arched and almost angular in the middle,
sloping rather steeply both in front and behind, ventral margin distinctly sinu-

142

ated in the middle, anterior extremity well rounded off, posterior somewhat
narrower and obtuse at the lower corner; — seen dorsally, oblong ovate in
outline, with the greatest width behind the middle and about equalling half
the length, anterior extremity gradually narrowed to an obtuse point, posterior
rounded off. — Surface of shell distinctly pitted and rough from numerous short
and stout spines, being moreover rather densely hairy. Natatory setae on
posterior antennae finely ciliated and extending somewhat beyond the tips of
the apical claws. Vibratory plate of maxillipeds with 4 setae. Caudal rami
very small, with the flagellum twice as long as the stem.

Colour of shell dark bluish green.

Length of adult female 0.72 mm.

Male unknown.

Remarks.— This form was recorded as early as the year 1852 by Costa,
and was the following year described by Lilljeborg as new, but with the same
specific name as that given to it by Costa. It is easily recognised from oui
other fresh water Ostracoda by the very dark bluish green colour of the shell
and by its spiny armature. In the latter respect it comes however very neai
to some of the exotic species.

Occurrence. — I have taken this form rather abundantly in several places
of our country, but always in more or less brackish water. The reproduction
seems to be exclusively parthenogenetical, as I have newer come across even
a single male specimen among the many hundred examined. The animals
are rather activ, swimming about in the water with great dexterity.

Distribution. — Throughout Europe, Island, Central Asia, North and South
Africa.

Gen. 28, Cypridopsella, Kaufmann, 1900.

Syn: Potamocypris, Aim (not Brady). ^|

Generic Characters. —Shell much compressed, more or les reniform ir
shape and densely hairy. Valves very unequal, the right overlapping the lef
more or less conspicuously along the dorsal face. Antennae well adapted fo)
swimming. Maxillae with the masticatory lobes short and stout, palp rather large
with the distal joint spatulate in shape and armed at the end with coars(
spines. Vibratory plate of maxillipeds quite rudimentary. Anterior legs rathe
slender. Caudal rami of a structure similar to that in the 2 preceding genera
Genital lobes of female provided in front with a peculiar hooked process.

143

Remarks. — This genus was proposed in the year 1900 by Kaufmann, and
as its type was considered Monoculiis vlllosus of Jurine, which by most recent
authors had been referred to the genus Cypridopsis Brady, Kaufmann, how-
ever included in that genus 2 other species which evidently are not congeneric,
and which have been described above as members of the genus Pionocypris.
The present genus is in particular distinguished by the very asymmetrical valves
and by the structure of the maxillae. From the genus Potamocypris Brady it
differs essentially by the well developed natatory setae on the posterior antennae,
hi addition to the typical species described below, Cypridopsis smaragdina
Vavra and Potamocypris maculata Aim are apparently referable to the present
genus.

62. Cypridopsella villosa, (Jurine).

(PI. LXVI)

Monoculus villosus, Jurine, Hist, des Monocles, p. 178, PI. XIX, figs. 14, 15.

Syn: Cypris Westwoodi. Baird.

, Cypridopsis villosa, Brady.

, Potamocypris villosa. Aim.

Specific Characters. — Female. Shell, seen laterally, triangular reniform
in shape, greatest height in the middle and about equaling ^/s of the length,
dorsal margin boldly arched in the middle and sloping rather steeply both in front
and behind, ventral margin deeply sinuated, anterior extremity obliquely rounded,
posterior rather narrower and somewhat deflexed, with the lower corner obtuse;
— seen dorsally, narrow oblong or lancet-shaped, with the greatest width in
the middle and not nearly attaning half the length, both extremities pointed
and nearly equal. — Surface of shell finely dotted and clothed with coarse recurved
hairs.— Natatory setae on posterior antennae finely ciliated and extending some-
what beyond the tips of the apical claws. Maxillae with the distal joint of
the palp broader than long and armed with 4 spines, one of them forming
the immediate continuation of the joint; spines on outermost masticatory
lobe smooth. Vibratory plate of maxillipeds replaced by 2 small bristles. Caudal
rami with the flagellum very slender and about twice as long as the stem.
Genital lobes rather large, oblong in shape and somewhat widening in front,
hooked process strongly chitinised.

Colour of shell light grass-green.

Length of adult female 0.72 mm.

Male unknown.

Remarks. — The identity of the above-described form with Jurine's Mono-
culus villosus seems to me to be indoubitable, and has also been admitted

144

by most recent authors, though Dr. Ahn has uttered some doubt thereon. The
said author refers this species to the genus Potamocypris, Brady (= Para-
cypridopsis, Kaufmann); but this can scarcely be sanctioned, because that ge-
nus is characterised by the quite rudimentary condition of the natatory setae
on the posterior antennae and the consequent want of swimming power.— The
very conspicuous asymmetry of the valves renders the present Ostracod easily
recognisable from most of our other Cypridae; but this asymmetry is only
apparent in fully grown specimens, hi the immature state of the animal the
valves are nearly equal (see the fig. given on the plate of such a specimen).

Occurrence.— \ have taken this form in several places of our country, and
as far north as Selsavik, lying just within the polar circle. It is found in
shallow grassy ponds and swamps, and, though more generally keeping at
the bottom, the animals are seen at times swimming rather quickly about in
the water. All the specimens examined by me were of the female sex, and
I do not have any notice of the male of this form having ever been observed.

Distribution. — Throughout Europe, Central Asia, (?) South America.

Subfam. 5. Darwinulinae.

Remarks. — This subfamily only comprises a single genus, Darwinula,
which by most authors has been recorded as the type of a distinct family of
the suborder Podocopa. Yet referring the reader to the considerations set forth
in the earlier parts of the present Volume and to my proposal of only admit-
ting 2 real families of the Podocopa, I have found it more appropriate to
record this genus as the type of only a subfamily, which I have felt justified
to class within the family Cypridae, as here defined. True, the Cyprid characters
would seem so be somewhat less clearly manifested in this subfamily than in
most of the preceding ones; but jet I think that there is full evidence of its
nearer approach to the Cyprid than to the Cytherid type. The characters of
the genus given below will, I think, show this more clearly.

Gen. 29. Darwinula. Brady & Norm. 1889.

Syn: Polycheles, Brady.
„ Darwinella, Brady.

Generic Characters. ShtW more or less cuneate in shape, narrowed in
front, expanded behind. Valves thin and pellucid, smooth, without any obvious
sculpture, inner duplicatures narrow; muscular spots rather in front of the middle.

145

and arranged in form of a rosette. A single eye present. Antennae not adapted
for swimming, both pairs remarkably short and stout, the anterior ones 6-arti-
culate, with the terminal part not sharply marked off from the basale cne,
and armed with strong spiniform setae; the posterior ones with a small bisetose
exopodal lobule at the end of the basal part, terminal part 3-articulate, 1st joint
the largest and provided behind with a group of small sensory threads,
penultimate joint, as in other Cypridae, produced at the end in front to a claw-
bearing prominence. Anterior lip lamellarly produced in front. Mandibles
with the cutting edge straight and finely dentate, palp large geniculate, 3-arti-
culate, basal joint provided inside with a pectinate row of slender ciliated
setae, and in front with a small vibratory plate edget with short setae. Maxillae
with the masticatory lobes short and stout, proximal joint of palp thickened and
produced in front, distal joint small; vibratory plate large and broad. Max-
illipeds produced in front to a well developed masticatory lobe, and provided
outside with a rounded vibratory plate edged wit numerous setae; palp pedi-
form, 3-articulate. Legs elongate, both pairs of similar structure, the posterior
ones however, as a rule, extended backwards and somewhat upwards within
the cavity of the shell. Caudal rami quite absent, the body terminating in a
simple conical process. Ripe ova received within the posterior roomy part of
shell-cavity for further development.

Remarks. — This genus was established in the year 1870 by Brady and
Robertson; but as the name Polycheles proposed had been preoccupied, it was
subsequently (in 1872) changed to Darwlnella, and again in 1889 to Dar-
winula, because also the name Darwinella had turned out to be preoccupied.
The genus as yet only comprises 2 species; but I have had an opportunity
of examining one or 2 additional species from South America (Peru). Only
the type species is represented in the Fauna of Norway.

63. Darwinula Stevenson! (Brady & Robertson).

(PI. LXVII).

Polycheles Stevensoni, Brady & Robertson. Ann. Mag. Nat. Hist. ser. IV, Vol. VI, pag. 25,

PI. VII, figs. 1—7, Pi. X, figs. 4—14.
Syn: Argilloecia aurea, Brady & Robertson.
„ Darwinella Stevensoni, Brady & Robertson.
„ Darwinula improvisa, Turner.
„ — aurea, G. W. Miiller.

Specific Characters. — Female. Shell, seen laterally, narrow cuneiform in
shape, gradually tapered in front, greatest height far behind and about equal
to Vo of the lenght, dorsal margin almost straight and gently sloping in front,

18 - Crustacea.

146

ventral margin very slightly sinuated and curving evenly upwards behind,
anterior extremity narrowly rounded, posterior much broader and somewhat
obliquely blunted, more prominent above;— seen dorsally, elongate ovale or
lanceolate in outline, with the greatest width behind, and about equalling the
height, anterior extremity gradually narrowed to an obtuse point, posterior ob-
tusely rounded off. — Valves slightly unequal, the right somewhat encompassing
the left in the posterior part; surface smooth and polished, with a pearly lustre,
and almost bare from hairs; muscular spots 9 in number, somewhat wedge-shaped
and arranged regularly around a common centre. Eye well marked and oc-
curring far in front.

Colour of the shell whitish pellucid, with a dark patch just above the
muscular spots.

Length of adult female 0.72 mm.

Remarks.— This remarkable form is eastily recognised from any of our
other freshwater Ostracoda by the narrow cuneiform shape of the shell, and
still more by the anomalous structure of the several appendages. The form
recorded by Turner from North America, under the name of D. improvisa, is
certainly identical with the present species.

Occurrence. — The only place, where I have met with this Ostracod is in
the lower part of the Vansje near Moss. It occured here occasionally on a
muddy bottom, at a depth of about 2 fathoms. The specimens were not easy
to detect, as they were mostly hidden within the mud, through which they
move very slowly, chiefly by the aide of their powerful antennae. All the
specimens captured were of the female sex, and were mostly loaden wit ova
and embryos in their shell-cavity. Brady has also observed the male, and has
given a figure of the copulative appendages, no other structural details being
however noted.

Distribution. — Sweden, British Isles, France, Switzerland, North America.

Fam. 2. Cytheridae.

Characters of the family. — Shell much varying in shape and structure,
but more generally of rather firm consistency, more or less calcareous, and
not seldom roughly sculptured. Valves, as a rule, not much unequal, and
connected dorsally by a more or less perfect hinge; muscular spots arranged
in a vertical row. 2 eyes generally present, in some cases however confluent

147

or quite wanting. Antennae never adapted for swimming, the anterior ones
generally sub-pediform and geniculate, like the posterior, the geniculation
occurring between the 2 segments of the basal part, the distal of which is always
powerfully developed, terminal part having the number of joints more or less
reduced and clothed with scattered setae often mingled with strong spines.
Posterior antennae provided at the end of the basal part with a long rod-like
flagellum, curving downwards in front of the terminal part, and containing the
efferent duct of a gland lying on each side of the front part of the body,
terminal part generally 3-articulate, 1st joint short, and without any sensory
appendages behind or any fascicle of setae at the extremity, penultimate joint
never, as in the Cypridae, produced at the end in front to a claw-bearing process.
Mandibles and maxillae on the whole built on the same type as in the Cypridae,
though in some few cases (Paradoxostoma) conspicuously transformed. 3 pairs
of ambulatory legs present, all of a rather similar structure and freely projecting
from the shell, the anterior pair answering to the maxillipeds iu the Cypridae,
but never partaking in the mastication, nor provided with any true vibratory
plate. Caudal rami rudimentary and quite immobile. Germinal part of genital
organs not lodged within the valves. Ejaculatory tubes absent. Copulatory
appendages more or less complicated. Brush-like ventral appendages always
present in male.

Remarks.— This family comprises a vast number of various forms, both
fossil and recent, all of which originally were referred to a single genus, Cythere.
The far greater bulk of them, are strictly marine, only a comparatively small
number of forms being found in fresh water, and some few species exclusively in
brachish water. They all are of comparatively small size, seldom exceeding a
length of 1 millimeter and, as a rule, very much smaller. Owing to this circum-
stance, and to the specimens being in most cases picked up from dried material,
the examination of the species has more generally been confined to the shell alone.
Indeed, previous to my account in 1865, only a few of the more common
littoral forms had been subjected to an anatomical examination of the enclosed
animal, and it was supposed that the structural details in the other Cytheridse

I were of a quite similar kind. On a carefull examination of the limbs in the
various forms observed by me off the Norwegian coast, I found so many
essential differences in their structure, that a subdivision of the genus Cythere
into several distinct genera appeared to me quite necessary. 14 such genera
were of course established, and characterised in my account, both according
to the structure of the shell and to that of the limbs. Of these genera 3 had
been previously proposed, but only founded on fossil shells, and a 4th genus

148

(Paradoxostoma) had been established by S. Fischer on account of some per-
plexing peculiarities found in the structure of the oral parts. All these genera
have been admitted by subsequent authors, and their number has in recent
time been still more increased, especially by G. W. Miiller, amounting at pre-
sent to about 30 in all. Owing to this considerable number of genera, it
would seem to be very desirable, that a grouping of them within subfamilies
should be effected, as done In the family Cyprids, and indeed some slight
attempt to do so has been made by a few authors. Thus in the year 1889
Brady and Norman discarded wholly from the other Cytheridae the genus Para-
doxostoma of Fischer as the type of a distinct family, Paradoxostomaiidce.
G. W. Miiller has accepted this group, but rightly reduce its systematic rank to
that of a subfamily of the Cytheridae. The said author mentions also another
subfamily under the name of Cytherurlnce, but the exact limits of this sub-
family is not clarly indicated, nor has any further subdivision of the family
been effected. I have endeavoured in the present Account to carry out the
classification of the present family in a more complete manner, grouping the
several genera into 7 subfamilies, the characters of which will be exposed in
the sequel.

Subfam. 1. Limnicytherinae.

Characters of the subfamily. — Shell in most cases of rather feeble con-
sistency, scarcely at all calcareous, and only faintly sculptured. Hinge imperfect.
Valves subequal, with the marginal zone crossed by scattered simple pore-chan-
nels. Only a single eye present, as in most Cypridas.-Both pairs of antennae di-
stinctly geniculate and subpediform; the anterior ones with the terminal part
firmly connected with the distal segment of the basal part, and generally com-
posed of 3 joints armed with scattered spiniform setae. Posterior antennae with
the flagellum well developed in both sexes. Mandibular palp short and stout,
distinctly triarticulate and having the vibratory plate rather fully developed.
Legs not much different in length an generally of same appearance in the 2
sexes. Caudal rami of somewhat different structure in the different genera.

Remarks.— lh& Cytherids comprised within this subfamily are all true
freshwater forms, and have generally been referred to a single genus, Limni-
cythere. Kaufmann has ht)wever distinguished another liearely allied genus
Leiicocythere, and a 3rd genus, apparently referable to the same subfamily,
has recently been established by the present author under the name of Goni^

149

phocythere, to include 2 South African species. Besides by their confinement
to fresh water, the forms comprised within the present subfamily distinguish
themselves from most other Cytheridae by the thin corneous shell, the imper-
fectly developed hinge, and by the presence of only a single eye, as in most
of the Cyprid«.

Gen. 30. Limnicythere, Brady, 1866.

Generic Characters. — Shell more or less reniform in shape and rather tumid,
in some cases provided with tuberculiform lateral prominences. Valves thin
and fragile, with the surface smooth or obscurely reticulate, and only sparingly
hairy at each extremity; inner duplicatures comparatively narrow. Anterior
antennae with the terminal part triarticulate, last joint very narrow and pro-
longed. Posterior antennae with 3 apical claws, all issuing from the terminal
joint; ,lagellum distinctly biarticulate. Vibratory plate of mandibular palp with
7 setae, 5 apical and 2 lateral. Masticatory lobes of maxillae comparatively
short, palp with the distal joint small, quadrangular in shape, and hawing one
of the apical spines, claw-like. Legs moderately slender, with 2 well-developed
setae on the anterior edi^c of the basal part, apical claw of last pair much
prolonged in male. Caudal rami well defined at the base and more or less
conical in shape, with one apical and one lateral bristle. Copulative appen-
dages of male with the basal part very large and protuberant in front, terminal
part comparatively small, and very sharply marked off from the basal one.

Remarks. — This genus was established in the year 1866 by Brady, to
comprise 2 genuine fresh water species formerly referred to the genus Cy there.
The genus was characterised by that author chiefly by the thin and fragile
shell, and by the uniform appearence of the spiniform setae on the anterior
antennae. Several species referable to this genus have in more recent times
been recorded, both from Europe and from other continents. Two of these
species are represented in the Fauna of Norway and will be described in the sequel.

64. Limnicythere sancti-patricii, Brady & Robertson.

(PI. LXVIII, PI. LXIX, fig. 1.)

Limnicythere sancti-patricii, Brady & Robertson.

Ann. Mag. Nat. Hist., ser. IV, Vol. IH, p. 17.

Pi. XVIII, figs. 8—11; PI, XXI, fig. 4.

Specific Characters.— Female. Shell seen laterally, oblong reniform in
shape, scarcely higher in front than behind, greatest height about equalling
half the length, dorsal margin nearly straight or very slightly concaved in the

150

middle, forming in front, just above the eye, an obtuse angle, and curving
behind evenly to the posterior extremity, ventral margin deeply sinuated in the
middle, anterior extremity broadly rounded off, posterior a little narrower and
likewise evenly rounded;— seen dorsally, broadly ovate or somewhat rhomboid
in outline, with a slight constriction in the middle bounded anteriorly by an
obtuse prominence, greatest width behind and somewhat less than the height,
both extremities acutely pointed, the anterior narrower than the posterior.
Valves thin and pellucid, with the edges quite smooth, surface faintly reticulated
and provided at each extremity with scattered hairs. Anterior antennae with
the distal segment of the basal part rather dilated and finely ciliated in front,
terminal part almost twice as long, with the last joint very narrow and pro-
longed, linear, bearing on the tip 3 sets, the innermost one bifurcate. Posterior
antennae with the apical claws rather slender and successively diminishing in
length posteriorly. Caudal rami directed downwards and somewhat club-shaped,
with the apical bristle scarcely longer than the lateral one. Genital lobes heart-
shaped, slightly lobular below.

Male of rather larger size than female, and having the shell narrower
and more elongated, with the ventral margin more deeply sinuated and the
posterior extremity more expanded. Copulative appendages very large, with
the basal part oval pyriform in shape, produced in front to an obtusely conical
prominence, and exhibiting inside several variously formed highly chitinised
processes; terminal part issuing from about the middle of the lower side of the
basal one, and having the form of a thin plate divided into 3 unequal lobules.

Colour of shell in both sexes light yellowish brown, antennae and legs
bright yellow.

Length of adult female 0.79 mm, of male 0.82 mm.

Remarks. — This species was first described in the year 1869 by Brady
and Robertson, and has subsequently been observed by several other authors.
It is easily recognised from the other species of the present genus by its com-
paratively large size and by the shape of the shell in the 2 sexes. fl

Occurrence.— The only place where I have hitherto met with this form,
is in our greatest lake, Mjesen, at Hamar. It occurred here on a woody
bottom, at a depth of 2 — 3 fathoms. Males specimens were almost as frequent
as femals, and could readily be distinguished from the latter by the rather different
shape of the shell. The animals crawl slowly on the bottom in the usual
manner of other Cytheridae.

Distribution. — Sweden, British Isles, Bohemia, Hungary, Switzerland.

Fossil. — Sweden, England.

151

65. Limnicythere inopinata, (Baird).

(PI. LXIX, fig. 2.)

Cy there inopinata. Baird, British Entomostraca, p. 172, Pi. XX, fig. 1, 1 a— c.

Syn: Limnicythere incisa, Dahl.

Specific Characters. — Female. Shell, seen laterally, oval quadrangular
or short reniform in shape, greatest height exceeding somewhat half the length,
dorsal margin almost straight and horizontal, forming in front, above the eye,
a slight indication to an angle and joining the hind edge by an abrupt curve,
ventral margin deeply sinuated in the middle and rather bowed at the posterior
corner, both extremities broadly rounded off, the posterior a little broader than
the anterior; — seen dorsally, more or less irregularly ovate in outline and
somewhat constricted in the middle, anterior extremity narrowly pointed, posterior
more obtuse. Valves in most cases (but not always) provided with 2 very con-
spicuous obtuse protuberances, best seen in the dorsal aspect of the shell, the
one occurring a little behind the middle and near the ventral face, the other,
somewhat larger, placed more behind and more approximate to the dorsal face;
anterior and posterior edges finely denticulated, the denticles being rather more
conspicuous on the hind edge; marginal zone rather broad and crossed by
scattered striae. Structure of the several appendages very like that in the
preceding species. Caudal rami however somewhat different, being conical
in shape and directed more forwards, with the apical bristle much prolonged.
Genital lobes very small, reniform in shape.

Colour of shell whitish pellucid, with a slight bluish or yellowish tinge.

Length of adult female 0.62 mm.

Male unknown.

Remarks. — This form was described and figured as early as the year
1850 by Baird as a species of Cythere, and may properly be regarded as the
type of the present genus. It is of smaller size than the preceding species,
and moreover easily distinguished by the shorter and more regularly quadran-
gular shape of the shell, the distinctly denticulated posterior edge of the valves,
and in most cases also by the very conspicuous lateral protuberances, which
give to the shell a rather irregular appearence. These protuberances are
however in some cases much reduced or may even be quite absent, and this
has led to the establishment of a spurious species, viz. L. incisa, Dahl.

Occurrence. I have taken this species occasionally in 2 small tarns near
Christiania, and moreover rather abundantly in a grassy swamp at Tj0t0, on
the Nordland coast. The specimens taken in the neigbourhood of Christiania

152

were all provided with strongly marked lateral protuberances, whereas those
found at Tjeto were mostly missing such protuberances, and thus agreeing with
the form recorded by Dahl under the name of L. inclsa. On a closer examina-
tion of the specimens collected in the latter locality I have found in some of
them distinct traces of protuberances in the same places as in the typical form,
and as no other differences could be detected between the 2 forms, I am now
of opinion that they should be combined in one species. All the specimens
observed were of the female sex.

Distribution. —Sweden, British Isles, Baltic, Germany, Switzerland.

Fossil.Sweden, Scotland.

Subfam. 2. Cytherideinae.

Characters of the subfamily. — Shell, as a rule of firm consistency, more
or less calcareous, with the surface generally distinctly sculptured. Hinge more
perfect than in the Limnocytherince, though wanting distinct closing teeth in
front and behind. Eye distinctly divided, in some cases absent. Antennae
built on the same type as in the preceding subfamily. Mandibular palp more
slender, with the first 2 joints confluent, vibratory plate less perfectly developed.
Legs successively increasing in length, with only a single seta on the anterior
border of the basal part, being, as a rule, conspicuously transformed in male.
Caudal rami extremely small, and imperfectly defined at the base.

Remarks. — This subfamily is established to comprise the genus Cytheridea
Bosquet and allied forms, which seem to me to present some particular charac-
ters distinguishing them both from the Limnicytherince and from the next sub-
family, Cytherince. 4 genera referable to this subfamily will be treated of in
the sequel.

Gen. 31. Cytherissa, G. O. Sars, n.
Syn: Cliyteridea (pirt).

Generic Characters. — Shell club-shaped, very solid, with the surface
roughly sculptured. Valves subequal, with the marginal zone thickened and
the inner duplicatures narrow. Hinge showing slight traces of closing teeth
in front and behind, but without any crenulation of the edges. Eyes well
defined, though rather approximate. Antennae powerfully developed; the an-
terior ones with the terminal part 3-articulate and armed in front with 3 claw-

153

like spines; the posterior ones with the flagellum well developed, and with 3
apical claws on the terminal joint. Vibratory plate of mandibular palp more
fully developed than in the other genera. Maxillae with the masticatory lobes
rather short and stout. Legs comparatively robuste, with a slight rudiment of
a proximal bristle on the front edge of the basal part, and with the seta on
the infero-posteal corner remarkably developed. Caudal rami forming 2 oval
thickened pieces placed vertically, and each provided behind with 2 extremely
small simple bristles. Genital lobes remarquably produced below. Reproduction
exclusively parthenogenetical.

Remarks. — This new genus is established, to include the form at first
recorded by the present author as Cythere lacustrls, and subsequently generally
referred to the genus Chyteridea of Bosquet. On a closer examination of the
said form, I have found it to present some rather notable particularities
distinguishing it both from Cytherldea and from the nearly-allied genus
Cypridels, and have therefore felt justified to keep it apart from both these
genera as the type of a separate genus.

66. Cytherissa lacustrls, G. O. Sars.

(PI. LXX.)

Cythere lacustrls, G. O. Sars, Zool. Reise i Sommeren 1882, p. 30.

Syn: Cytherldea lacustrls, Brady.
„ Acanthopus reslstans, Vernet.
, Cypridels torosa, Jones (part).

Specific Characters. — Female. Shell rather tumid, seen laterally, oval
subtriangular or somewhat clavate in shape, much higher in front than behind
greatest height about equalling ^/s of the length, dorsal margin forming above
the eyes a gibbous prominence, thence sloping obliquely backwards and joining
the hind edge by an abrupt bend, ventral margin slightly sinuated in front
of the middle and curved evenly upwards behind, anterior extremity broadly
rounded off, posterior much narrower and obtusely blunted at the end; — seen
dorsally, irregularly oval in outline, with the sides waved, greatest width about
half the length, both extremities obtuse at the end and nearly equal. Surface
of shell very uneven, exhibiting on each side 3 or 4 more or less conspicuous
obtuse protuberances and on the ventral face a number of irregularly waved
longitudinal ridges. Valves very solid and but little pellucid^ being sculptured
with densely set irregular pittings and scattered tubercles, each composed of a
group of small nodules; marginal zone very narrow and indistinctly striated,
edges smooth and clothed with fine hairs. Anterior antennae with the basal

19 — Crustacea.

154

segments considerably expanded, terminal part scarcely longer than the dista
segment, and having the 3 articles of about equal length. Posterior antennae with
the apical claws slender and successively diminishing in length behind. Vibrator}
plate of mandibular palp oblong quadrangular in shape and edged with 5 setae.
3 apical and 2 much smaller lateral. Legs with the basal seta very coarse
and densely hairy, apical claw almost straight. Genital lobes terminating below
in a rounded lappet.

Colour of shell dark brownish, limbs bright yellow.

Length of adult female amounting to 0.95 mm.

Remarks. — This form was described as early as the year 1863 by the
present author as a species of Cythere, and was subsequently referred by Brady
to the genus Cytheridea Bosquet. It has generally been regarded as nearly
allied to Cyprideis iorosa Jones, and indeed G. W. Muller records it only as a
variety of that species. This is certainly quite erroneous. The present form
is in reality so considerably different, that in my opinion it cannot even be
placed in the same genus with it.

Occurrence. — I have taken this form rather abundantly in severals of our
larger lakes, for instance in Mjosen, Tyrifjord, Aarungen, Noklevand etc., and
have also met with it in one of our montain lakes, viz., in Afsio, on the high-
plateau of Dovre. It occurs generally in a depth of some fathoms, on a muddy
bottom, along which the animals crawl slowly in the usual manner of the
Cytheridae. Though I have examined carefully many hunderds of specimens
from different localities, I have never come across any male, and the same
absolute want of this sex has also been ascertained by other authors. It would
thus seem to be sufficiently proved, that the reproduction of the present form,
unlike what is generally the case with Cylheridae, is exclusively parthenogenetical.

Distribution.— Sweden, British Isles, Switzerland.

Fossil. — Scotland.

Gen. 32. Cyprideis, Jones, 1856.

Syn: Cytheridea, auctornm (part).

Generic Characters. — Shell of somewhat various shape, rather solid, and
distinctly sculptured, in some cases provided with lateral protuberances. Valves
somewhat unequal, the right one armed at the infero-posteal corner with a denti-
form process, marginal zone densely striated. Hinge exhibiting a more
less distinct crenulation of the edges. Eyes distinctly separated. Anteri^
antenna2 about as in Cytherissa; posterior comparatively less robust, and or

155

provided with 2 apical claws. Vibratory plate of mandibular palp less fully
developed than in Cyiherlssa. Legs of right series in male conspicuously
transformed, 1st leg distinctly prehensile, 2nd leg with the terminal part very
feeble, though apparently 3 articulate. Caudal rami extremely small, in form
of 2 thin bisetose lamellae. Genital lobes likewise very small and not produced
below. Ripe ova received within the shell-cavity for further development.

Remarks. — This genus, proposed by Jones, has by most recent authors
been rejected, and regarded as identical with Cytheridea Bosquet. I think
however that the genus ought to be supported, though it is here taken in a
sense somewhat different from that formerly adopted by me. It differs from
the preceding genus in the general appearance and sculpture of the shell, as
also somewhat in the structure of the appendages, and very essentially in the
fact, that the ripe ova are received within the shell-cavity for further develop-
ment. The peculiar transformation of the legs in the male is a character,
which this genus shares with the succeeding one. The type of the present
genus is C. torosa Jones, a species closely allied to that described below.

67. Cyprideis litioralis, Brady.

PI. LXXI. PI. LXXII, fig. 1.

Cytheridea littomlis, Brady, Nat. Hist. Trans. Northumb. and Durham, Vol, III, p. 6.

Syn: Cytheridea torosa, Brady (not Jones).
„ Cyprideis torosa, G. O. Sars (not Jones).
„ Cytheridea torosa, var. teres, Brady & Norm.

Specific Characters. — Female. Shell, seen laterally, oval reniform in shape,
almost equally high behind as in front, greatest height exceeding somewhat
half the length, dorsal margin nearly straight in the middle and joining the
hind edge by a quite even curve, being more abruptly bent in front, with a
slight indication to an angle above the eyes, ventral margin scarcely at all
sinuated, anterior extremity well rounded off, posterior obtusely blunted; — seen
dorsally, oblong ovate in outline, slightly constricted in the middle, with the
greatest width far behind and about equalling half the length, anterior extre-
mity obtusely pointed, posterior much broader and blunt at the end. Surface
of shell evenly convex, without lateral protuberances, but of a dult appearance,
being marked with closely set rounded pittings; marginal zone of the valves
closely striated: right valve produced at the infero-posteal corner to a short
dentiform projection pointing backwards, edges otherwise quite smooth and
finely hairy. Anterior antennae with the terminal part about as long as the
distal segment of the basal one, middle joint scarcely longer than the 1st.

156

Flagellum of posterior antennae well developed. Vibratory plate of mandibular
palp rounded in shape and edged with 5 setae. Legs slender and considerably
increasing in length behind. Posterior part of body flattened, spoon-shaped
and terminating in an upturned spiniform projection.

Male. — Shell comparatively more elongate and more evenly compressed
than in female, being distinctly higher in front than behind, with the posterior
extremity much less tumid and, seen laterally, obliquely rounded. Right 1st leg
distinctly prehensile, with the terminal joint considerably thickened and evenly
curved, seta of 1st joint transformed to a strong curved spine with a small
bristle outside, apical claw very powerful. Right 2nd leg with the terminal
part 'scarcely longer than the basal one, and of very feeble consistency, without
any armature whatever. Right 3rd leg with a dense brush of hairs on the
1st joint of the terminal part. Copulative appendages with the basal part very
large and tumid, rounded oval in shape, and sending of inside, at the junction
with the terminal part, a highly chitinised rodlike process pointing obliquely
forwards, terminal part not sharply defined from the basal one, and of some-
what triangular shape, being produced in front to an acuminate lappet, posterior
extremity irregularly rounded.

Colour of shell in both sexes dark brownish; limbs bright yellow

Length of adult female 1.03 mm., of male 1.10 mm.

Remarks. — The above-described form has generally been considered as
only a variety of Cypridels iorosa Jones. In this view I am not prepared to
assent. The form originally described by Jones differs conspicuously by the
strongly marked lateral protuberances of the shell, which indeed have occasioned
the specific name given to it by its detector. Moreower the shape of the
shell is rather different, as seen from the figures given by Brady in his
Monograph of post-tertiary Entomostraca. The specific name littoralis was
assigned to the present form by Brady as early as the year 1868, and must
of course be retained for this species. ■I

Occurrence. — The only place where I have hitherto met with this form,
is in a brackish lake, Engervand, at Sandviken, West of Christiania. It occurrec
here rather abundantly at the borders of the lake together with Cypridop.
aeuleata.

Distribution. — Baltic, British Isles, Holland, France, See of Azow, Centra
Asia, North Africa.

Fossil. — Sweden, Scotland.

i

II

157

68. Cyprideis sorbyana (Jones).

(PI. LXXII, fig. 2).

Cytheridea sorbyana, Jones, Monograph of Tertiary Entomostraca, p. 44, Pi. IV, fig. 6.

Syn: Cytheridea dentata, G. O. Sars.
„ — inermis, G. O. Sars.

Specific Characters.— Female. Shell rather tumid, seen laterally, short
subtriangular in shape much higher in front than behind, greatest height nearly
equalling ^/a of the length, dorsal margin boldly arched in front of the middle
and sloping steeply behind, more slowly in front, ventral margin almost straight,
anterior extremity broadly rounded, posterior much narrower, tapering below
to an obtuse corner; — seen dorsally, broadly oval in outline, with the greatest
width in the middle and about equalling the height, anterior extremity
bluntly pointed, posterior obtuse. — Surface of shell slightly hairy and roughly
sculptured with concentric ridges and sattered tubercles, anterior edge of valves
armed with a row of about 7 denticles, less marked on the left valve; right
valve moreover provided, somewhat below the infero-posteal corner, with a
very conspicuous blunt spine pointing obliquely downwards, quite absent on
the left valve. Anterior antennae with the terminal part a little longer than
the distal*segment of the basal one, middle joint almost twice as long as the
1st. Posterior antennae with the flagellum comparatively feebly developed.
Vibratory plate of mandibular palp small, with only 4 setae.

Colour of shell not yet ascertained.

Length of adult female 0.90 mm.

Remarks. — The reference of this form to the genus Cyprideis would seem
to be somewhat questionable, as it differs conspicuously from the type described
above in the shape and sculpturing of the shell. Yet, I have thought it right
to place it provisionally in the present genus, as I have found otherwise some
evident accordances, thus in the peculiar armature of the right valve with a
very conspicuous toothlike process at the infero-posteal corner. My acquaint-
ance with the species was formerly confined to 2 detached valves only, a left
and a right, and the strongly marked dissimilarity of these valves led me to
the establishment of 2 spurious species, described under the names of Cythe-
ridea dentata and C. inermis. Brady, however, having had the opportunity of
examining a perfect shell, with both valves in situ, could ascertain the per-
plexing asymmetry of the valves in the present species, which he rightly iden-
tified with Cytheridea sorbyana described as early as the year 1856 by Jones
from fossil shells.

158

Occurrence.'-The 2 valves, originally examined by me, were found 1^
my late father in shell-sand from 0xfjord, Finmark, Norman found subsequently
some empty shells at Stoksund in the Hardanger-Fjord, and more recently the
same author met with this species, in fresh and living specimens, in Kloster
Fjord, East Finmark. Some few of these specimens were kindly sent to me,
mounted dry, and by moistening them I found in one of the shells most of
the limbs tolerably preserved to allow a closer examination. On the accom-
panying plate figures of these limbs are given; but the posterior part of the
body was shrunk, and could not of course be compared with that of the
preceding species.

Distribution.— Briiish Isles, Spitsbergen, Franz-Josef Land.

Fossil. — Norway, Scottland.

Gen. 33. Cytheridea, Bosquet, 1852.

Generic Characters. — Shell more or less reniform in shape and rather
solid, with the surface evenly convex, without lateral protuberances, bilt marked
with more or less conspicuous flattened tubercles. Valves only slightly unequal,
with the edges unarmed; marginal zone rather narrow and densely striated;
inner duplicatures broader than' in Cyprideis. Hinge about as in that genus.
Anterior antennae very robust, with the terminal joint comparatively small.
Posterior antennae with the flagellum reduced in female, apical claws 2 in
number. Vibratory plate of mandibular palp small, with the number of seta;
reduced. Palp of maxillae with the distal joint rather prolonged. Legs very
distinctly transformed in male; right 1st leg pronouncedly prehensile, with the
joints of the terminal part more or less confluent; right 2nd leg with the ter-
minal part reduced to a slight rudiment; left 2nd leg much coarser than ■!
female, subprehensile; right 3rd leg with several bunches of hairs on the 1st
joint of the terminal part. Caudal rami and genital lobes about as in Cyprideis.

Remarks. — This genus is here taken in a more restricted sense than
generally admitted, some of the species formerly referred to it being discarded
and transferred to the genus Cyprideis. As the type of the present genus maj'
be considered C. papillosa, Bosquet. The genus is represented in the Norvegian
Fauna by 2 well-defined species, to be described below.

159

69. Cytheridea papillosa, Bosquet.

(PI. LXXIII, PI. LXXIV, fig. 1.)
Cytheridea papillosa. Bosquet, Entom. fossiles des terr. tertiaires de la France, p. 42.

PI. II, fig. 5 a— d.
Syn : Cyprideis Bairdii, G. O. Sars.

Specific Characters. — Female. Shell, seen laterally, oblong oval or some-
what reniform in shape, scarcely higher in front than behind, greatest height
about half the length, dorsal margin almost straight and horizontal, joining the
hind edge by an even curve and sloping slowly in front, ventral margin very
slightly sinuated, anterior extremity broadly rounded off, posterior obliquely
deflexed, terminating below in a somewhat exerted obtuse corner;— seen dor-
sally, regularly oblong ovate in outline, with the greatest width about equal to
the height, anterior extremity pointed, posterior more obtuse. — Surface of shell
smooth and shining, slightly hairy at each extremity, and ornamented with
scattered very conspicuous rounded tubercles or papillae of whitish colour.
Anterior antennae very robust, with the distal segment of the basal part con-
siderably expanded and exceeding in length the terminal part, middle joint of
the latter only slightly longer than the 1st, last joint about half as long. Post-
erior antennae with the spine attached to the end of the penultimate joint
posteriorly, claw-shaped, resembling the apical claws. Vibratory plate of mandi-
bular palp with one long plumose apical setae and 2 much smaller lateral ones.

Male. — Shell more elongate than in female, with the ventral margin more
deeply sinuated and the hind extremity more obliquely produced. 1st right leg
with all the joints of the terminal part coalesced, apical claw very strong and
abruptly curved; 2nd right leg with the terminal part reduced to a small simple
lamella; 2nd left leg much coarser than in female, with the apical claw falci-
form curved and denticulated at the end; 3rd right leg with 4 bunches of hairs
on the 1st joint of the terminal part. Copulative appendages with the basal
part obliquely oval in shape, terminal part rather large, slightly bilobed, anterior
lobe triangular, posterior much broader and somewhat boot-chaped.

Colour of shell light reddish brown clouded in some places with a dark
violet hue; limbs yellow-coloured.

Length of adult female 0.95 mm., of male 1.20 mm.

Remarks.— This form was described as early as the year 1850 by Bosquet
from fossil tertiary shells, and has subsequently been observed in recent state
by several authors. It is easily recognised by its smooth, reddish brown cou-
loured shell and by the very conspicuous opaque whitish papillae on its surface.

160

1

At first I erroneously referred it to tfie genus Cypridels and described is as ne
under the name of Cypridels Balrdll.

■ Occurrence.— This is one of our commonest Cytheridae, being found rattier
abundantly around the whole of the Norwegian coast in moderate depths. It
shares with some other Cytherid« the particularity that, when coming in con-
tact with the air, it remains floating on the surface, and may thus be easily
picked up from the samples examined.

Distribution. — British Isles, Iceland, Greenland, Spitsbergen, Gulf of S
Lawrence, Franz- Josef Land.

Fossil.— France (tertiary), Norway (glacial and postglacial), Scotland, Canada

li

4

70. Cytheridea punctillata, Brady.

(PI. LXXIV, fig. 2.)

Cytheridea punctillata. Brady, Ann. Mag. Nat. Hist. Vol. XVI, p. 189. PI. XXVllI, figs. 17—20.

Syn : Cypridels proxima, G. O. Sars. J||

Specific Characters. — Female. Shell, seen laterally, subovate or somewhat
triangular in shape, much higher in front than behind, greatest height considerably
exceeding half the length, dorsal margin boldly arched in front, with indication
of an angle above the eyes, thence sloping gently behind and joining the hind
edge by an even curve, ventral margin very slightly sinuated, anterior extremity
broadly rounded, posterior much narrower and somewhat obliquely blunted,
with the lower corner scarcely exerted and obtuse;— seen dorsally, regularly
oblong oval in outline, with the greatest width about half the length and both
extremities bluntly pointed. Surface of shell of a dull appearance, being marked
everywhere with closely set small rounded pits, and moreover exhibiting a
number of tubercles or papillae, which however are of smaller size and less
conspicuous than in the preceding species; extremites finely hairy. Anterior
antennae less robust, with the distal segment of the basal part scarcely longSl
than the terminal part, middle joint of the latter more prolonged, last joint
very small. The other appendages of a structure very similar to that in the
preceding species.

Male. — Shell considerably more elongate than in female, with the greatei
height scarcely exceeding half the length. Right 1st leg less powerfully developed
than in C. paplllosa, with the 1st joint of the terminal part well defined and
armed at the end anteriorly with a strong spine, the other 2 joints confluent;
apical claw far less strong. Right 2nd leg exactly of same appearance as in
the said species. Left 2nd leg likewise rather similar, though somewhat less
powerful. Copulative appendages with the basal part rounded quadrangular

11

161

in shape, terminal part comparatively short and produced at each extremity,
anterior lappet obtuse at the end, posterior acuminate.

Colour of shell dull brownish, limbs bright yellow.

Length of adult female 0.75 mm., of male 0.81 mm.

Remarks. — The present species is nearly allied to C. papillosa, but easily
distinguished by the somewhat different shape of the shell, the surface of which
is of a much more dull appearance, with the papillae far less conspicuous. It was
described by me in the year 1865 under the name of Cyprideis proxima; but
both the generic and the specific names are to be changed as above.

Occurrence.— l\\\s species is rather common in the upper part of the
Christiania Fjord, and I have also taken it in several other places on our coast,
up to the Lofoten islands. Norman has recorded it is far North as VadsO,
East Finmark, and the distribution of this form around the whole of the Nor-
wegian coast is thus ascertained. It occurs generally in depths of 6—20 fathoms
on a muddy bottom, often associated with C papillosa. Owing to the more
firm consistency of the shell, it is never found, like the last named species,
floating on the surface of the water.

Distribution. — British Isles, Iceland, Baffins Bay, Spitsbergen, Bay of St.
Lawrence, Franz Josef Land.

Fossil. Norway, British Isles (glacial and postglacial).

Gen. 34. Eucythere, Brady 1866.

Syn : Cytheropsis, G. O. Sars.

Generic Characters. — ShtW more or less triangular in shape, much higher
in front than behind, and rather compressed in its anterior part. Valves thin
and pellucid, with the surface evenly convex and adorned with scattered more
or less conspicuous flattened tubercles or papillae, as in Cytheridea; hinge rather
imperfect; inner duplicatures comparatively broad anteriorly; marginal zone
broad, and crosed by distant pore-channels, edges smooth with scattered hairs.
Eyes coalesced. Anterior antennae less robust than in Cytheridea, with the
terminal joint more prolonged. Posterior antennae with the flagellum well
developed in both sexes. Vibratory plate of mandibular palp very small.
Maxillae with the innermost masticatory lobe much reduced, palp with the
distal joint long and narrow. Legs rather feeble, not transformed in male.
Brush-like male appendages peculiarly developed.

Remarks. — This genus was established in the year 1865 by the present
author; but as the name Cytheropsis proposed had been preoccupied, it was

20 — Crustacea.

162

1

the following year replaced by Brady with that of Eucythere. The genus
presents some characters in common with Cytheridea, yet differing conspicu-
ously in the shape and thin consistency of the shell, as also in some of the
other structural details. The extraordinary development of the brush-like male
appendages is a character quite peculiar to the present genus and scarcely
found in any other of the Cytheridae. Another character by which this genus
differs from the other genera comprised within the present subfamily is the,
want of any transformation of the legs in the male sex. The genus as yef
only comprises the 2 species described below.

71. Eucythere argus, G. O Sars.

(PI. LXXV, fig. 1).
Cytheropsis argus, G. O. Sars, Oversigt af Norges marine Ostracoder, p. 58.

Specific Characters. — Female. Shell, seen laterally, oblong triangular in
shape, greatest height somewhat in front of the middle and not fully attaining
half the length, dorsal margin strongly arched in the middle and sloping
gradually to each extremity, more steeply behind, ventral margin slightly
sinuated, anterior extremity broadly rounded, posterior much narrower and
blunted at the end; — seen dorsally, oblong ovate in outline, greatest width far
behind and about equal to the height, anterior extremity tapering to an acute
point, posterior much broader and obtuse at the end. Surface of shell adorned(|
with a number of very large and conspicuous rounded tubercles or papillae of
an opaque whitish colour, and clothed at each extremity with scattered fin(
hairs. Anterior antennae with the distal segment of the basal part unusualh
prolonged, exceeding in length the terminal part, last joint of the latter about
half the length of the middle one. Posterior antennae with the terminal joinj
comparatively large, apical claws rather unequal, the posterior much shortt
and thinner than the anterior, which is distinctly denticulated at the end ii
front. Vibratory plate of mandibular palp with 2 setae only. Maxillae with th(
innermost masticatory lobe unisetose, distal joint of palp about as long as th(
proximal one. Legs only slightly increasing in length posteriorly, seta on th(
anterior edge of the basal part rather coarse and curving slightly upwards.

yWa/^.— Shell much more elongate than in female, with the dorsal margii
more evenly curved, and the posterior extremity more narrowly produced.
Colour of shell not jet ascertained.

Length of adult female 0.61 mm., of male 0.64 mm.

Remarks. — The present species is easily recognised by the very large an(
conspicuous opaque white papillae adorning the surface of the shell, and indeec

;ii

163

the specific name proposed alludes to this ornament, which somewhat res-
embles that found in Cytheridea papillosa (see above).

Occurrence.— \ have only had an opportunity of examining a single living
specimen of this form, found, many years ago, in the upper part of the Chri-
stiania Fjord; but several empty shells were picked up by my late father from
shell-sand taken at 0xfjord, Finmark.

Distribution.— Bniish Isles, Gulf of St. Lawrence.

Fos^l. — Norway, Scotland, Canada.

72. Eucythere declivis, (Norman).

(PI. LXXV, fig. 2).

Cythere desUvis, Norman, Nat. Hist. Trans. Northumb. & Durham, Vol. 1, p. 16, PI. V,

figs. 9-12.

Syn: Cytheropsis tenuitesta, G. O. Sars.

Specific Characters. — Female. Shell, seen laterally, short triangular in
shape, very high in front and rapidly tapered behind, greatest height almost
attaining ^lo of the length, dorsal margin gibbously arched in front and sloping
rather sleeply behind, ventral margin very slightly sinuated, anterior extremity
broadly rounded, posterior narrowly blunted; — seen dorsally, oblong ovate in
outline, greatest width behind and much less than the height, anterior extre-
mity tapering to an acute point, posterior obtuse. Valves very thin and pel-
lucid, with the surface finely punctate and provided with scattered rather small
papillae. Anterior antennae more slender than in the preceding species, with
the distal segment of the basal part less prolonged, last joint exceeding half
the length of the preceding joint. Posterior antennae less robust, with the
terminal joint smaller, anterior apical claw smooth. Maxillae with the inner-
most masticatory lobe bisetose, distal joint of palp longer than the proximal
one. Legs more slender than in E. argus, and more rapidly increasing in
length posteriorly; apical claw very long.

Male. — Shell considerably more elongate than in female, seen laterally,
narrow clavate in outline, tapering behind to an obtuse corner. Copulative
appendages of comparatively simple structure, terminating in a rounded lobe
with thickened margins. Brush-like appendages very large, flabelliform, each
appendage being expanded at the end to a rounded disc densely edged with
curled bristles.

Colour of shell not yet ascertained.

Length of adult female 0.58 mm., of male 0.62 mm.

164

Remarks. — This form was recorded as early as the year 1864 by Norman
as a species of Cythere, and was described the following year by the present
author under the name of Cytheropsts tenuitesta. It is easily distinguished
from the preceding species, both as to the shape and sculpturing of the shell,
and to the structure of the appendages, and I am indeed perplexed to see,
that Brady and Norman in one of their more recent papers have suggested
these 2 forms to be only varieties of a single species.

Occurrence.— \ have only seen a few specimens of this species, taken,
many years ago, in the upper part of the Christiania Fjord. Norman records
it also from Finmark.

Distribution. — British Isles, Bay of St. Lawrence, Franz Josef Land, Medi-
terranean.

/^055//.— Scotland.

Gen. 35, Krithe, Brady & Robertson, 1874.

Syn: Ilyobates, G. O. Sars.

I

Generic Characters. — Shell thin and pellucid, though rather firm, with the
surface smooth and polished; inner duplicatures of valves very broad in front,
marginal zone crossed by scattered, somewhat irregular pore-channels anc
surrounded in front by a thin hyaline border. Hinge imperfectly developec
Eyes absent. Anterior antennae with the basal segments very coarse an<
expanded, terminal part rather movably articulated with the basal one, and
very short and compact, armed with slender upwards-curving spines. Posterior
antennae with 3 claws on the terminal joint, flagellum well developed in bot^
sexes. Mandibles with 2 of the cutting teeths much larger than the other^
vibratory plate of the palp small, with 2 apical setae and a rudiment of a^
lateral one. Maxillae about as in Cyiheridea. Legs comparatively shoi
terminal part of the 2 anterior pairs only composed of 2 joints, by the coj
lescence of the 2 outer ones; left 2nd leg in male very powerful, subprehensiU
Caudal rami and genital lobes about as in Cyiheridea.

Remarks. — This is a rather anomalous genus, and its reference to th<
present subfamily appears indeed somewhat questionable. Yet, as I do not
find a better place for classifying this genus, and as I am unwilling to estabj|
lish a new subfamily only founded on a single genus, I have preferred to
include it provisionably in the subfamily Cy the ride ince, with which it agre^l
at least in one essential character, viz., the partial transformation of the leg?
in the male sex. The genus was established in the yearJlSeS by the present

165

author; but as the name Ily abates proposed had been preoccupied, it was in
1874 replaced by Brandy & Robertson with that of Krithe. In addition to the
type species described below, a few nearly alHed species have been recorded
by Brady and by G. W. Muller.

73. Krithe bartonensis, (Jones).

(PI. LXXVII).

Cytherideis bartonensis, Jones, Tertiary Entoniostraca, p. 50, PI. V, figs. 2, 3.

Syn: Ilyobates prcetexia, G. O. Sars.

Specific Characters —Female. Shell, seen laterally, oblong oval in shape,
somewhat higher behind than in front, greatest height about equalling half
the length, dorsal margin slightly arched and joining the hind edge by a quite
even curve, ventral margin almost straight, anterior extremity well rounded off,
posterior rather broader and somewhat obliquely blunted, with the lower corner
almost rectangular; — seen dorsally, oblong ovate in outline, tapering in front
to a sharp point, posterior extremity blunted and inflexed in the middle;
greatest width somewhat less than half the length. Surface of valves without
any distinct pittings, but provided with scattered very small tubercles and a
few fine hairs at each extremity; marginal zone well marked both in front
and below, and of somewhat various width; hyaline border of anterior edge
rather .broad, and very conspicuous in fresh specimens. Anterior antennae
with the terminal part scarcely as long as the distal segment of the basal part
and armed with about 7 spines, 3 of them attached to the middle joint, last
joint very short, with 3 spines. Posterior antennae with the apical claws very
slender. Legs whh only a single seta on the anterior border of the basal part.
Posterior extremity of body blunt at the end.

Male. — Shell of rather smaller size than in female and much narrower,
seen laterally, almost cylindrical in shape. Left 2nd leg powerfully developed,
with the 2 joints of the terminal part considerably thickened, and the apical
claw very strong. Copulative appendages with the basal part much expanded,
rounded triangular in shape, and sending of below a long rod-like process
curving backwards; terminal part comparatively short, and acutely produced
both in front and behind.

Colour light yellowish brown, by the translucent body; limbs bright yellow.

Length of adult female 0.82 mm., of male 0.76 mm.

Remarks. — This peculiar form was recorded as early as the year 1856 by
Jones from fossil shells, and referred by him to the genus Cytherideis. It was

166

subsequently observed in the recent state by the present author, and described
in 1865 under the name of Ilyobates prcetexta, both names being however
Habie to drop. The present Ostracod is easily recognised from the other
indigenous Cytheridae, both by the outwards appearance and by the structure
of the appendages.

Occutrence.—\ have taken this form in several places of our coast, from
the Christiania Fjord to the Lofoten islands, and Norman records it also from
Finmark (Vadso). It is generally found in depths of from 20 to 50 fathoms,
on a muddy bottom, and is easily detected by the particularity, that when
coming in contact with the air, et remains floating on the surface, like the
case with Cytheridea papulosa. The movements of the animal are rather slow,
and during its crawling on the bottom, the anterior antennae are stroke up-
wards in a peculiar manner, somewhat like the case with the Cypridce.

Distribution. — British Isles, Iceland, Bay of Biskay.

Fossil. — Norway, British Isles.

Subfam. 3. Cytherinae.

i

Characters of the subfamily. — Shell of very firm consistency, calcareous?
with the surface more or less roughly sculptured, in some cases provided with
variously formed projections or spines. Hinge generally well developed, with
distinct closing teeth in front and behind. Both pairs of antennae strong, sub-
pediform; the anterior ones with the terminal part 3- or 4-articulate, and armed
in front with 2 or 3 clawlike spines intermingled with thin bristles, last joint
more or less produced, and in some cases armed with a claw-like spine in
addition to the setae. Legs normally developed and of same appearence in th^
two sexes. ™

Remarks. — In this subfamily I propose to comprise the more typical
Cytheridae grouping themselves more closely around the genus Cythere (sens,
strict.). The chief characters distinguishing this subfamily are given in the
above short diagnosis. It is by far the most comprehensive of the subfamilies
treated of in the present account, both as to the number of genera and as t
that ot the species.

167

Gen. 35. Cythere, O. Fr. Miiller 1785.

Generic Characters. — Shell slightly compressed and more or less reniform
in shape, with the surface evenly convex, without any projections or spines.
Valves somewhat unequal, with the inner duplicatures rather broad; marginal
zone well marked and crossed by more or less crowded pore-channels, edges
smooth, Hinge with the closing teeth in front and behind well developed.
Eyes widely appart. Antennae robust; the anterior ones with the terminal part
triarticulate, middle joint elongate and armed in front with 2 stout claw-like
spines; the posterior ones with the apical claws rather short and stout, flagellum
well developed in both sexes. Vibratory plate of mandibular palp much reduced.
Maxillae with the masticatory lobes more or less produced, palp comparatively
narrow. Legs rather strong and only slightly increasing in length posteriorly,
anterior border of basal part with 2 unequal setae. Caudal lamellae edged with
3 bristles, 2 apical and 1 lateral. Copulative appendages of male with the
terminal part of various shape in the different species.

Remarks. The limits of this genus, which originally comprised all the
Cytheridae, have in recent time been considerably succincted by the removal
of a number of the forms into distinct genera. But even in the restriction now
generally adopted, this genus comprises a vast number of species, both fossil
and recent. As however these species, almost in every case, have been examined
only from the shell, it is very difficult to decide their true mutual relationship.
Some of them look indeed so very different from the type of the present genus,
that I am much inclined to believe that they are not at all congeneric; but
this cannot properly be settled, except by a careful examination of the limbs.
In the present Account I have felt justified, on the base of a thorough ana-
tomical examination, to establish 4 new genera for comprising some species
hitherto considered as true members of the genus Cythere. In the restriction
here adopted, the present genus is represented in the Fauma of Norway by
only 3 species, to be described below.

73. Cythere lutea, O. Fr. Miiller.

(PI. LXXVil.)

I Cythere lutea, O. Fr. Muller, Entomostracn, p. 65, PI. Vll, figs 3, 4.

Syn: Cythere reniformis, Baird.
, — setosa, Brady.

Specific Characters. — Female. Shell rather compressed, seen laterally,
short reniform in shape, greatest height in the middle and almost attaining ^k

I

168

of 1Ik> Iciij^lli, (lors.'il iii;ii^;iii KC'iilly .'iK'tu-d, U-riiiiiuiliii^ boili in lioiil .iiid bc-liiiid
will) a slij^lit niiis'lr, vi'iilrfil iiiarjs'in (U-cply simuiU'd in llu* middle .ind finviiif^
I'vi'iily upwards behind, nnterior cxlremily soitu'wlinl ohlicincly loundcd, posterior
slij^lilly aiif^Mdale in llie niiddk*; seen dorsnlly, oMmii- ovule in oiilliiie, with
the greatest widlli far behind jnid about ecpud to '^ju ol llie lenj^hl, bolli ex-
livun'lies ()i)tnsely pointed, the .interior much imrrower than the posterior.—
Valves rather une(|nMl the lif^lit one overla|)pinj^', the left eonsjiicuonsly alonj^j
the dorsal laee, smface densely pitted and provided with scattered rounded
tubercles, mar^^jiiial zone rather broad and erossi-d by somewhat distant pou
channels, niilerlor and posterior edj^^es clothed wilh scattered stiff hairs.
Anterior nuteiuJtE wilh the terudnal part mutli Ioniser than the distal sej^ment
of the l)usal part, Inst joint com|)aralivi'ly small, scarcely exceedin^j^ in lenj^th
V.I of the middle one, spines of the latter very strong, <'iiid denticulated on the
outer edj^e. i'osterior anteimie with the flajiellum very coarsely developped.
Le^s comparatively robust. I^osterior extremity of body tipped l)y a hi^jhly
chitiiiised spiuiform process.

Moll'. Shell comparatively less hij^h than in female, with the dorsal
marf.;in nearly strai>.{ht and the ventral more deeply sinuated. (A)pidative appen
dages very lar^e, with the basal part rounded cpiadran^jidar in shape, and
sending: off below a slender process poinlin|.i backwards and slijsditly bilobed
at the extremity, beiiij^ moreover provided inside with a dark-colomed hooked
string curving downwards; terminal pail produced in front and behind to
acute lappet, the posterior narrower than the anterior.

Colour of shell dark reddich-brown, with the marj^inal zone lij^hter, opacple
whitish; liud)s of a brownish yellow hue. h

Length of adult female IK7'1 mm., of male somewhat less. "

Rcniarlis. This form was described and figured as early as the year 1785
by O. b'r. Mdller, and ought to be considered as the type of the present Keiitif
It is easily recognised fioin most of the other (>ytlieridie by the dark leddish
brown colour ot the shell.

Oci'imvncv. — This is one ol oiii (diniiionesl (]yllie!id;e, beiii)^ loiiiid rati
abundantly all round the whole ol the Noiwegiau coast in the littoral /o
among algie, and is often left in tidal pools on the beach.

Distribution, British Isles, Kattegat, Iceland, Cjieenland, Hay of
Lawrence.

FosslL — Norway, British Lsles, C.anada.

:ed

I

169

74. Cythere albomaculata, li.iird.

(PI. LXXVIII.)

C^nirri' alhomanilnla, JJalid, Brltinh KntomoktMca, p, I'i'), I'l, XX, (lj{. 7,

Specific Characters.— Female. Shell seen laterally, oval renlforni in shape,
"icalest height about in the middle and only sliglilly exceeding half the length,
dorsal margin nearly straight in the middle and joining the hind edge withont
;iiiy iiilervending angle, ventral margin deeply sinnated in front of the middle
;iii(| lightly curwed upwards behind, anterior extremity well rounded off and
r i'l( i;d)ly bowed below, posterior scarcely narrower and slightly angular in
the middle;— seen dorsally, oblong fusiform in outline, with the greatest width
in the middle and slightly exeeding */o of the length, both extremities pointed
.'Mid nearly equal. — Surface of valves smooth, width scattered rather small tu-
bercles, marginal zone narrower than in C. lulca, but crossed by nimii*rous
( losely set pore-channels, anterior edge, very densely hairy. Antennae remark-
.ibly short and stout, the anterior ones with the terminal part but little longer
lli.-ti) the distal segment of the basal part, last joint about half the lenght of
the preceding one, and armed with a rather strong spine resembling those on
the nn'ddle joint. Mandibular palp with the inner distal seta of the penul-
timate joint remarkably strong- and falciform curved. Maxilla; with the distal
joint of the palp shorter than in C. lulea.

Male. Shell of rather larger size than in female and much more elongate,

Willi the anterior extremity strongly bowed below and the ventral sinus more

li.irply marked. Copulative appendages very large, with the basal part rounded

oval in shape; terminal part produced in front to a somewhat irregularly curled

l.'ippet, but quite obtuse behind.

(.olour of shell yellowish gray, irregularly clouded with a darker hue, so as
lo leave a number of more or less conspicuous lighter areas; limbs dark yellow.

Length of adult female 0.84 mm., of male 0.96 mm.

Remarks. — The descriptions and figures given l)y Baird and most other
authors of this species refer only to the male sex. In the female the shell is
oi a much shorter and stouter shape, more like that of the preceding species,
- as easily to be confounded with it. On a closer examination, however, it
may readily be distinguished by the closely striated marginal zone of the valves
and the dense clothing of hairs in particular on the anterior edges, as also by
the very different colour of the shell, hi the structural details .some well-marked
differenses from the preceding species are found, as Jioted in the above description.

21 Cruttiiceo.

170

Occurrence. — This species, though very common off the British Isles, is
rather rarely met with on the Norwegian coast. I have only taken a few spe-
cimens at Risor, south coast of Norway, in the laminarian zone, and Norman
has recorded it, likewise quite occasionally, from Lervik in the outer part of
the Hardanger-Fjord.

Distribution. — British Isles, Iceland, Bay of Biscay.

Fossil. — Scotland.

75. Cythere viridis, O. Fr. Miiller.

(PI. LXXVIII, fig. 2.)

Cythere viridis, O. Fr. Miiller, Entomostraca, p. 64, PI. VII, figs. 1, 2.

Syn: Cythere cyamos, Norman.

Specific Characters. — Female. Shell very short and compressed, seen
laterally, rounded quadrangular in shape, somewhat higher in front than behind,
greatest height about equal to ^/s of the length, dorsal margin somewhat gib-
bous in the ocular region and sloping obliquely behind with an almost straight
course, ventral margin distinctly sinuated in the middle and curving evenly
upwards behind, anterior extremity broadly and somewhat obliquely rounded,
posterior a little narrower and obtusely truncated; -seen dorsally, oblong oval
in outline, with the greatest width about equal to Vs of the length, sides nearly
parallels in the middle, anterior extremity more narrowly pointed than the
posterior. Surface of valves closely punctate, with scattered very small tubercles,
marginal zone rather narrow and finely striated, anterior and posterior edges
clothed with short hairs. Anterior antennae with the terminal part twice as
long as the distal segment of the basal one, last joint very narrow and produced,
being fully as long as the middle one. Legs comparatively more slender than
in the 2 preceding species.

Male. Shell less high than in female; with the anterior extremity m
bowed below and the ventral sinus deeper. Copulative appendages co
paratively of smaller size than in the 2 preceding species, with the termi
part evenly rounded off at the end, basal part sending off from its infero-posteal
corner a slender process pointing forwards, and provided inside with a freel
projecting chitinous string curved in the form of a circle.

Colour of shell light brownish, with a more or less distinct olivaceous
tinge; limbs colourless.

Length • of adult female scarcely exceeding 0.50 mm., of male abo
the same.

?lv

li

II

171

Remarks. — The identity of the above-decribed form with that originally
recorded by O. Fr. Miiller seems to me to be indoubitable. Lilljeborg has
however described as Cythere viridls another very different Cytherid, and for
this raison the specific name of the present form was changed by Norman to
that of cyamos. It is a very small species and may easily be taken for young
of C. lutea. On a closer examination it is however found to be well distin-
guished from any of the 2 preceding species, both as to the shell and to the
structure of some of the appendages.

Occurrence. — This small Ostracod is very common in the upper part of
the Christiania Fjord close to the beach among alg£e, and I have also taken
it in many other places, up to the Finmark coast.

Distrlbniion.—Kaiiegai, British Isles.

Fossil. — Norway, Scotland.

Oen. 36. Leptocythera, G. O. Sars, n. ^.

Syn: Cythere auct. (p.irt)

Generic Characters. —Sh^W, as a rule, narrow and elongated, much com-
pressed, with the valves subequal; surface in some cases roughly grooved, but
more frequently smooth and marked with more or less conspicuous pittings;
inner duplicatures moderately broad, marginal zone crossed by somewhat distant
pore-channels. Hinge well developped. Eyes confluent. Anterior antennae
comparatively short and stout, with the terminal part 3-articulate, carrying in
front 3 coarse spines, last joint more or less produced. Posterior antennae
with 2 apical claws; flagellum well developed in both sexes. Mandibular
palp rather narrow, with 3 comparatively short and stout spines on the ter-
minal joint; vibratory plate much reduced. Maxillae with the masticatory lobes
rather short; palp of moderate size. Legs, as a rule, rapidly increasing in
length posteriorly, basal part with only a single seta on the anterior margin.
Caudal lamellae with 2 rather distant bristles. Copulative appendages of male
with 2 backwards-pointing processes below the basal part; terminal part exerted
in front and behind to a projecting lappet.

Remarks. — In this new genus I propose to comprise a number of species
hitherto described as true members of the genus Cythere, but differing from
that genus, as defined above, by the very narrow and elongated shape of the
shell, the wholly confluent eyes, and also by some other particularities in the
structural details noted in the above diagnosis. The type of the genus is
Cythere pelliicida Baird, to whif^h several other species subsequently detected

172

bear a very close affinity, so as to form with it a quite natural group. All the 9
species of Cythere recorded by G. W. Muller from the Gulf of Naples are
unquestionably referable to the present genus. In the following pages will be
described 5 species occurring off the Norwegian coast.

76. Leptocythere pellucida, (Baird).

(PI. LXXIX, fig. 1).

Cythere pellucida, Baird, British Entomostraca, p. 173, Pi. XXI, fig. 7.

Syn: Cythere confusa, Brady & Norman.

Specific Characters. — Female. Shell, seen laterally, elongate subqua-
drangular in shape, almost equally high throughout, greatest height not nearly
attaigning half the length, dorsal margin only very slightly arched, with
indication to an angle above the eye, ventral margin distinctly sinuated in
front of the middle, anterior extremity obliquely rounded, posterior transversely
truncated, with the upper corner somewhat projecting and compressed, lower
corner rounded off; — seen dorsally, narrow ovate in outline, with the greatest
width far behind and about equal to '/s of the length, side-edges almost straight
and parallel in the middle, anterior extremity sharply pointed, posterior more
obtuse. Valves rather thin and pellucid, surface smooth and marked with
somewhat irregular pittings more scattered in the anterior part and assuming
behind a more or less elongate form, edges clothed in front and behind with
line hairs. Anterior antennae with the terminal part about the length of the
distal segment of the basal part, last joint rather produced, exceeding in length
the preceding one. Last pair of legs with the terminal part about twice as
long as that of the 1st pair, and armed at the tip, in front of the apical cla
with 3 small spines.

Male.—ShtW rather more elongate than in female and somewhat hig
in front than behind, with the supero-posteal corner more projecting. Cop
ative appendages with the anterior lappet of the terminal part acutely produced,
posterior shorter and obtuse at the tip.

Colour yellowish brown, from the dark translucent body; limbs brig
yellow.

Length of adult female 0.70 mm., of male 0.73 mm.

Remarks.— Ih^ present species was described as early as the year 1850
by Baird as Cythere pellucida, and has been recorded under this name by
most subsequent authors. In the year 1889, however, Brady and Norman p
posed to change the specific name to confusa, because they had found tha
some specimens in Norman's collection, determined by Baird as C. pellucida,

as

J

f
II

SI

I

173

were more properly referable to the form described below as Leptocythere
castanea. I think however that Baird had confounded these 2 nearly allied
species, and that in reality the specimen originally described by him has
belonged to the present species, the figure given of it in his work on the British
Entomostraca agreeing much better with this than with the other species.

Occurence. — I have taken this species in several places on the Norwegian
coast, from the Christiania Fjord to Finmark. It is not strictly a littoral form,
being only found at some depth, in the laminarian zone.

Distribution. — British Isles, Holland, Bay of Biscay, Mediterranean.

/^05Si7.— Norway, Scotland.

77. Leptocythere, Macallana (Brady & Roberts.).

(PI. LXXIX, fig. 2.)

Cythere Macallana, Brady & Robertson, Ann. Mag. Nat. Hist., ser. IV, Vol. Ill, p. 368,

PI. XIX, figs 5—9.

Specific Characters. — Female. Shell, seen laterally, somewhat irregularly
oblong subreniform in shape, higher in front than behind, greatest height
nearly equal to half the length, dorsal margin well arched in front and sloping
obliquely behind, ventral margin distinctly sinuated in front of the middle and
gently curved behind, anterior extremity broadly rounded, posterior obtusely
truncated, with the upper corner slightly projecting; — seen dorsally, narrow
ovate in outline, with the greatest width behind and about equal to V3 of the length,
anterior extremity more pointed than the posterior. Valves rather thin and
pellucid, with the surface smooth and only indistinctly pitted, but marked with
distant very small tubercles, anterior and posterior edges finely hairy. Anterior
antennae rather robust, with the first 2 joints of the terminal part comparatively
broader than in the preceding species, last joint scarcely longer than the
middle one.

Male. — Shell somewhat more elongated than in female and more tapered
behind, with the dorsal margin more evenly arched and the upper-posteal
corner more projecting. Copulative appendages differing conspicuously from
those of the preceding species in the shape of the terminal part, the anterior
lappet of which is much shorter and obtusely rounded at the end, whereas
the posterior lappet is more produced and pointed.

Colour light yellowish, with a slight brownish tinge.

Lenght of adult female 0.50 m., of male about the same.

Remarks.— This is a rather small species, and might, on a cursory view,
easily be taken for young of the preceding one. It is however a well defined

174

species, differing conspicuously in the shape and sculpturing of the shell, as
also in the structure of the copulative appendages of the male.

Occurrence. — I have only had an opportunity of examining very few
specimens of this form, taken, several years ago, in the laminarian region at Riser.
Norman has recorded it also from Drobak and from Lervik, Hardanger Fjord.

Distribution. — British Isles, Holland, Mediterranean.

Fossil. — Scottland.

78. Leptocythere castanea, G. O. Sars.

(PI. LXXX, fig. 1.)

Cythere castanea, G. O. Sars, Oversigt af Norges marine Ostracoder, p. 32.

Syn: Cythere propinqva, G. O. Sars.
, — pellucida, Brady & Norman (non Baird).

Specific Characters. — Female. Shell, seen laterally, oval quadrangular in
shape, a little higher in front than behind, greatest height about equalling half
the length, dorsal margin only slightly arched, ventral distinctly sinuated in
front of the middle and gently curved behind, anterior extremity broadly rounded,
posterior obtusely truncated, with the upper corner well marked, lower obsolete;
— seen dorsally, oblong ovate in outline, greatest width behind the middle and
exceeding somewhat V^ of the lenght, anterior extremity more pointed than the
posterior. Valves of rather firm consistency and very little pellucid, the surfa
being marked with closely set very sharply defined rounded pits, extremiti
clothed with fine hairs. Anterior antennae robust, resembling in shape tho;
in L. macallana; last joint however more produced, exceeding considerably t
preceding one in length.

yWa/e. — Shell narrower and more compressed than in female, more tapered
behind, with the upper-posteal corner rather projecting. Copulative appendag
with both lappets of the terminal part greatly produced and exerted in ve
slender sharp points.

Colour of shell dark reddish brown, limbs bright yellow.

Length of adult female 0.69 mm., of male about the same.

Remarks.— This species, though nearly allied to the 2 preceding ones,
easily recognised by the comparatively shorter and stouter shape of the sh
and by the very strongly marked pittings of its surface, as also by the mu
darker colour. As mentioned above, Brady and Norman wrongly identified
with Cythere pellucida of Baird. Indeed, the name pellucida would be extremely
impropriate to the present species, which in reality is just distinguished by th^

175

very little transparent opaque shell. The form recorded by me in 1869 under
the name of Cythere propinqva is identical with the present species, and not,
as believed by Brady and Norman, with L. macallana.

Occurrence. — I have taken this form occasionally in the upper part of the
Christiania Fjord, more frequently at Svelvik, entrance of the Drammen Fjord.
In the latter locality it occurred near the beach in slightly brackish water, and
its occurrence under similar conditions has also been stated by other authors.

Distribution.- -British Isles, Holland.

Fossil. — Scotland.

79. Leptocythere ienera (Brady).

(PI. LXXX, fig. 2.)
Cythere tenera. Brady, Monogr. Brit. Ostracoda, p. 399, Pi. XXVIII, figs. 29—32.

Specific Characters. — Female. Shell seen laterally, of a very narrow and
elongate shape, a little higher in front than behind, greatest height not nearly
attaining half the length, dorsal margin slightly arched in front and sloping
gently behind, ventral margin distinctly sinuated in the middle and curving
evenly upwards behind, anterior extremity weli rounded off, posterior narrowly
obtuse, with the upper corner scarcely projecting; — seen dorsally, narrow oblong
in outline, with the greatest width rather less than Va of the length, both ex-
tremities obtusely pointed. Valves very thin and pellucid, almost destitute of
pittings and only marked with a few small tubercles, edg-es minutely hairy.

Male. — Shell only slightly differing in shape from that in the female.
Copulative appendages with the lappets of the terminal part but slightly pro-
duced, the posterior obtuse at the tip, the anterior pointed.

Colour whitish pellucid.

Length of adult female 0.45 mm.

Remarks. — This species may be easily distinguished from the 3 preceding
ones by the narrow and elongated shape of the shell, and by the very thin
and transparent valves. It is also of rather smaller size than any of them.

Occurrence. — A single female specimen of this form, that figured on the
accompanying plate, was taken, some years ago, at Risor, South coast of Nor-
way, in a depth of about 20 fathoms. Norman has recorded it also from
Drobak and from Lervik, Hardanger Fjord. Among some specimens kindly
forwarded to me by that author, mounted dry, I found a single male, and by
moistening this specimen, I succeeded in extracting from the shell the copulative
appendages in a condition perfect ennough to admit a closer examination.

176

As seen from the figure given, they differ conspicuously from those of the
other species in the shape of the terminal part.

Distribution. — British Isles, Holland, Bay of Biscay.

Fossil. — Scotland.

80. Leptocyihere crispata (Brady).

(PI. LXXX, fig. 3.)

Cythere crispata, Brady, Ann. Mag. Nat. Hist., ser. IV, Vol. II, p. 221, Pi. XIV, figs. 14—15.

Syn: Cythere cicatricoia, G. O. Sars (not Reuss).
, — bad/a, Brady (not Norman).

Specific Characters. — Female. Shell, seen laterally, oval subreniform in
shape, higher in front than behind, greatest height exceeding somewhal half
the length, dorsal margin gibbously arched in the ocular region and sloping
gently behind, ventral margin slightly sinuated in the middle, anterior extremity
broadly rounded, posterior much narrower and obtusely truncated, with the
upper corner but little projecting; — seen dorsally, narrow oblong in outline,
with the greatest width behind and rather less than Vs of the length, side-
margins irregula'Iy flexuous, both extremities obtuse at the tip; the anterior
narrower than the posterior. Valves of rather firm consistency, with the sur-
face very uneven, exhibiting irregular depressions or grooves defined by more
or less distinct elevated ridges. Anterior antennae with the terminal part som^B
what longer than the distal segment of the basal one; spine of the proximal
joint much reduced, last joint shorter than the middle one. Legs less rapidly
increasing in length posteriorly than in the other species.

Colour of shell light chestnut brown.

Length of adult female 0.40 mm.

Remarks. — This small Ostracod was described by the present author
the year 1865 under the name of Cythere cicatricosa. As however this namj
had been preoccupied by Reuss for a different species, the specific name w£
replaced by Brady in the year 1868 with that of crispata. The said authoi
had previously identified this form with Cythere badia of Norman, whicl
however is specifically different, though nearly allied. Some of the species
Cythere described by G. W. Muller from the Gulf of Naples look very like thj
present form, and it is not improbable that one or other of them might tur^
out to be identical with the northern species.

Occurrence. — I have taken this form occasionally in the upper part
Christiania Fjord, as also in some other places on our southern and westerl

Cypridas

Ostracoda

Podocopa

PI. LXV

G. O. Sars del.

1. Pionocypris Almi, 6. O. Sars

2. ,, picta (Strauss)

3. Cypridopsis aculeata (Costa)

Cypridas

Ostracoda

Podocopa

PI. LXVI

I

6. 0. Sars del.

Cypridopsella villosa (Jurine)

CypridsB

Ostracoda

Podocopa

PI. LXVII

M

m w ■

|\# ^^ #' £A> 1\

G. O. Sars del.

Darwinula Stevenson! (Br. & Rob.)

Cytheridae

Ostracoda

Podocopa

PI. LXVIII

6. O. Sars del.

Limnicythere sancti-patricii (Br. & Rob.)

Cytheridae

Ostracoda

Podocopa

PI. LXIX

/•V/.t

6. O. Sars del.

1. Limnicythere sancti-patricii (male)

2. „ inopinata (Baird)

Cytheridas

Ostracoda

Podocopa

PI. LXX

6. O. Sars del.

Cytherissa lacustris, G. 0. Sars

1

Cytheridffl

Ostracoda

Podocopa

PI. LXXI

G. O. Sars del.

Cyprideis littoralis (Brady)

Cytherids

Ostracoda

Podocopa

PI. LXXII

^1 1^ T- -V->-^

AV: >

6. O. Sars del.

1. Cyprideis littoralis (Brady), male

2. ,, sorbyana (Jones)

Cylheridae

Ostracoda

Podocopa

PI. LXXIII

^^A^x-,

^ \i#

6. O. Sars del.

Cytheridea papillosa, Bosquet

CytheridaB

Ostracoda

Podocopa

PI. LXXIV

/. cca- -^f/o'.

-^

77

^#. "1/

;2.r^t-

fv

m

u^a

G. O. Sars del.

1. Cytheridea papillosa (Bosquet), male

2. ,, punctillata, Brady

Cytheridae

Ostracoda

Podocopa

PI. LXXV

/■-:'-

t ^ • -at>. '*»-.-

G. O. Sars del.

1. Eucythere argus, 6. O. Sars

2. „ declivis (Norman)

Cytherid®

Ostracoda

Podocopa

PI. LXXVI

e. O. Sars del.

Krithe bartonensis (Jones)

Cytheridae

Ostracoda

Podocopa

PI. LXXVII

l\

^

u.

o.yf.

/m>

\

a.'

M /

/m -'^

oC~

i'\\.>

--^s^

^-^^

^ V' )fri

G. O. Sars del.

Cythere lutea, O. Fr. MiJller

Cytheridae

Ostracoda

Podocopa

PI. LXXVIII

/■^-l

6. O. Sars del.

1. Cythere albomaculata, Baird

2. ,, viridis, 0. Fr. Muller

Cytheridffi

Ostracoda

Podocopa

PI. LXXIX

/.^./,

G. O. Sars del.

1. Leptocythere pellucida (Baird)

2. „ Macallana (Brady & Rob.)

Cytheridae

Ostracoda

Podocopa

PI. LXXX

6. O. Sars del

1. Leptocythere castanea, G. O. Sars

2. ,, tenera (Brady)

3. ,, crispaia (Brady)

177

coast. It is found in the laminarian region at a depth of a few fathoms, but
may easily escape to attention by its small size.

Distribution. — British Isles, ? Mediterranean.

Fossil. — Scotland.

Gen. 37. Cytheromorpha, Hirschmann, 1901.

Generic Characters. — Shell short and stout, of very firm consistency, with
the surface conspicuously pitted. Hinge well developed. Eyes distinctly
separated. Anterior antennae with the terminal part 4-articulate, and armed in
front with 4 strong spines, last joint prolonged, with one of the apical setae
spiniform. Posterior antennae with 2 claw-like spines inside the penultimate
joint, apical claws very slender; flagellum of same appearance in the 2 sexes.
Mandibular palp with the terminal joint very small, vibratory plate rather fully
developed. Maxillae with the masticatory lobes not much prolonged, palp with
the distal joint comparatively short. Legs rapidy increasing in length posteri-
orly, basal part with 2 unequal setae on the anterior border. Caudal lamellae
edged at the tip with 2 bristles. Copulative appendages of male very large,
but with the terminal part imperfectly developed.

Remarks. — This genus was established in the year 1901 by Hirschmann,
to comprise 2 Cytherids found by him in the Gulf of Finland, one of them
being subsequently identified with a Cythere long ago described by Brady.
The genus, which is admitted by Dr. Aim, is nearly allied to Cythere, in the
restriction here adopted, but differs decidedly in the structure of the anterior
antennae, and in the much fuller development of the vibratory plate on the
mandibular palp. In addition to the 2 species observed by Hischmann, the
Cythere rubida Brady is very probably referable to this genus, and perhaps
also some other species described by that author solely from the shell. Only
the type species is represented in the Fauna of Norway.

81. Cytheromorpha fuscata, (Brady).

(PI. LXXXI).

Cythere fuscata. Brady, Ann. Mag. Nat. Hist. Ser. IV, Vol. Ill, p. 47, PI. VII, figs. 5—8.

Syn : Cythere drammensis, G. O. Sars.
„ Cytheromorpha albula, Hirschmann.

Specific Characters. — Female. Shell, seen laterally, short oval or some-
what subtriangular in shape, much higher in front than behind, greatest height
nearly attaining Vs of the length, dorsal margin gibbously arched in the ocular

22 — Crustacea.

178

region and sloping rather steeply behind, ventral margin almost straight,
anterior extremity broadly rounded, posterior much narrower and obtusely
truncated, with the upper corner well marked, the lower rounded off; — seen
dorsally, oblong ovate in outline, with the greatest width behind the middle
and about equal to -/o of the length, anterior extremity pointed, posterior
obtuse. — Valves only slightly transparent, with a slight angular expansion
behind, near the ventral face; surface of a dull appearance, being marked
with closely set somewhat polygonal pits and a few small tubercles; marginal
zone well defined and crossed by somewhat distant pore-channels; edges clothed
with scattered hairs. Anterior antennae with the terminal part much longer than
the distal segment of the basal part, last joint very narrow and nearly as long
as the 2 preceding joints combined. Vibratory plate of mandibular palp edged
with 4 setae of unequal length. Last pair of legs with the terminal part more
than twice as long as that of 1st pair. Genital lobes comparatively large,
reniform in shape.

Male. — Shell considerably more elongate than in female, seen laterally,
oblong subreniform in shape, with the greatest height scarcely attaining half
the length, ventral margin distinctly sinuated in front of the middle, anterior
extremity somewhat deflexed. Copulative appendages with the basal part very
voluminous, oval trigonal in shape, and sending off below 2 blunt processes
curving forwards; terminal part very small and imperfectly defined from the_
basal one, terminating in front in a short pointed lappet.

Colour of shell grayish or pale fuscous.

Length of adult female 0.58 mm., of male 0.70 mm.

Remarks. — This form was recorded as early as the year 1868 by Brad]
and was described the following year by the present author under the nam<
of Cythere drammensis. The identity of this latter form with Cythere fiiscata^
was however not recognised by Brady, who erroneously referred it to anoth(
nearly allied, but evidently different species viz., Cythere rubida Brady. Thij
present species ought to be regarded as the type of the genus Cytheromorphc

Occurrence. — The only place where I have hitherto met with this form
at Svelvik, entrance of the Drammen Fjord. It occurred here rather abundantly
in a short distance from the beach among algae, together with Leptocythere^
castanea and a number of true fresh-water Entomostraca, the surface-water il
the Fjord being almost quite fresh by the afflux of the great Drammen rivei

Distribution.— QnXl of Finland, Sweden, British Isles, Holland.

Fossil. — Scotland.

179

Gen. 38. Xenocythere, G, O. Sars, n.

Generic Characters. — Shell cuiieate in shape, much higher in front than
behind, with the ventral face broad and flattened. Valves subequal, moderately
strong, with the inner duplicatures rather broad in front and crossed by scattered
pore-channels. Hinge with the edges minutely crenulated in the middle, closing
teeth imperfectly developed. Eyes confluent. Antennae comparatively short and
stout, the anterior ones with the terminal part triarticulate and armed in front
with 3 clawlike spines, the posterior ones with only a single apical claw ac-
companied posteriorly by a very small spine. Vibratory plate of mandibular
palp comparatively small, with only 3 setae, the anterior one rudimentary.
Maxillae with the masticatory lobes rather produced, palp comparatively narrow.
Legs moderately slender, basal part with only a single seta of the anterior
margin. Caudal lamellae rounded in shape, with 2 comparatively small bristles.
Copulative appendages of male large, with the basal part remarkably high,
terminal part triangular in shape.

Remarks.— This new genus is only founded on a single species, which
however exibits some rather distinct differences from the other genera here
recorded, both as to the general shape of the shell and to the structure of
some of the appendages.

82 Xenocythere cuneiformis (Brady).

(PI. LXXXII).

Cythere cuneiformis, Brady, Monogr. Brit. Ostnacoda, p. 404, PI. XXXI, figs. 47—54.

Syn : Cythere ventricosa, G. O. Sars (not Speyer).

Specific Characters. — Female. Shell, seen laterally, oblong sublavate in
shape, tapering behind to an obtuse point; greatest height quite in front, and
about equal to half the length, dorsal margin gibbously bent in the ocular
region and sloping rather steeply behind at a nearly straight course, ventral
margin very slightly sinuated, anterior extremity obliquely rounded off, posterior
rather narrow and exerted below to an obsusely conical prominence;— seen
dorsally, broadly ovate in outline, with the greatest width about half the length,
lateral margins slightly concaved in the middle, anterior extremity obtusely
pointed, posterior abruptly contracted to a projecting conical prominence. Sur-
face of valves indistinctly pitted, and more or less conspicuously rugose longi-
tudinally, being clothed at each extremity with scattered fine hairs. Anterior
antennae with the last joint about half the length of the penultimate one.

180

Posterior antennae with the terminal joint rather small, apical claw moderately
slender, lateral spine scarcely exceeding in length Y? o^ the claw.

Male of smaller size than female, and hawing the shell rather narrower,
with the dorsal margin slightly concaved. Copulative appendages with the
basal part oblong quadrangular in shape and narrowly truncated above, terminal
part produced in front to a narrow lappet obtuse at the tip.

Colour of shell light yellowish brown.

Length of adult female 0.75 mm., of male 0.64 mm.

Remarks. — This form was described as early as the year 1865 by the
present author; but as the specific name at that time proposed had been
preoccupied by Speyer for another Cytherid, it was subsequently chanced by
Brady as above. It is an easily recognisable form, distinguished at once from
most, other Cytherids by the peculiar shape of the shell.

Occurrence. — The present Cytherid is of rather rare occurrence. I have
only met with it quite occasionally in some places on the south coast of Nor-
way (Langesund, Risor), at moderate depths. Norman has recorded it also
from the Hardanger Fjord, at Lervik.

Distribution.— Bhi\sh Isles.

Fossil. — Norway, Scotland.

Gen, 39. Kyphocythere, G. O. Sars, n.

Generic Characters. — Shell short, ventricose, angular, with the surfaiP
partly rugose and provided with scattered nodiform protuberances. Valves
subequal, rather thin and fragile, faintly areolate, and everywhere very finely
punctate. Hinge with the closing teeth well developed. Eyes wholly absej
Antennae slender and attenuated, the anterior ones with the terminal p|
3-articulate, last joint much produced; the posterior ones with 3 slender api(
claws, flagellum well developed in both sexes. Mandibular palp comparative
narrow, with 2 plumose setae on the vibratory plate. Maxillae with the mas
catory lobes short and stout, palp not very slender, proximal seta of the vibrate
plate remarkably thickened at the base and clothed at this place with k
deflexed cilia. Legs rather slender, with only a single seta of the anter|
border of the basal part. Caudal lamellae small, bisetose. Copulative appe
dages of male with the basal part of moderate size, terminal part narro\
produced in front.

Remarks. — This is another new genus, which I have found it necessi
to establish, in order to include an anomalous species, hitherto referred to

181

genus Cythere, but in reality differing both from this genus and its alHes by
several well-marked particularities. The generic name proposed alludes to the
peculiar gibbosity of the shell.

83. Kyphocythere limicola (Norman).

(PI. LXXXll.)

Cythere limicola, Norman, Nat. Hist. Trans. Northumb. & Durham, Vol. I, p. 20.

PI. VI, figs. 1-4.

Syn: Cythere nodosa, G. O. Sars.
— areola ta, Brady.

Specific Characters. — Female. Shell, seen laterally, subquadrangular in
shape, a little higher in front than behind, greatest height considerably exceeding
half the length, dorsal margin nearly straight in the middle, but gibbously
produced both in front and behind, ventral margin slightly sinuated in the
middle and curving evenly upwards behind, anterior extremity obliquely rounded
off, posterior obtuse or slightly angular in the middle; — seen dorsally, irregularly
ovate or somewhat hexagonal in outline, with the greatest width behind and
slightly exceeding half the length, lateral edges angularly bent behind, anterior
extremity abruptly contracted, posterior triangular. Surface of shell very uneven,
each valve being provided dorsally, in front of the projecting supero posteal corner,
with 2 successive very conspicuous nodiform protuberances, and more ventrally
with a broad angular expansion continued in front as a well-marked ridge
curving upwards to the ocular region; central part of valves transversally
rugose; edges smooth and clothed in front and behind with scattered very fine
hairs. Anterior antennae with the terminal joint very narrow and fully as long
as the preceding joint. Posterior antennae with the apical claws gradually
increasing in length distally. Posterior extremity of body terminating in 2
juxtaposed setae.

Male of rather smaller size than female, with the shell less high and the
dorsal margin slightly concaved. Copulative appendages of moderate size,
basal part irregularly rounded, terminal part produced in front to a very long
and thin lappet, behind to a short triangular corner.

Colour of shell fuscous grey; limbs colourless.

Length of adult female 0.65 mm.

Remarks. — This remarkable form was first described by Norman from
specimens collected off the eastern coast of England, and was subsequently
recorded by the present author under the name of Cythere nodosa. The peculiar
rugose and tuberculated surface of the shell and the absolute absence of eyes

182

renders this form easily recognisable, from any of the species described in the
preceding pages.

Occurrence. — Some few specimens of this Cytherid have been collecte
many years ago, partly in the Trondhjem Fjord, partly off the Lofoten islands
(Odvaer), from'rather considerable depths ranging to 100 fathoms, muddy bottom^

Distribution. — British Isles.

Fossil. — Scotland.

f

d

Gen. 40. Hemicythere, G. O. Sars, n.

Generic Characters. — Shell of very solid consistency, calcareous, resembling
somewhat in shape that of Cythere. Valves more or less unequal, with the
surface distincly pitted or roughly reticulate, marginal zone closely striated, edges
densely hairy in front. Hinge with the closing teeth well developed. Eyes
distinctly separated. Anterior antennae with the terminal part 3-articulate,
middle joint elongated, with 2 claw-like spines in front, last joint moderately
produced. Posterior antennae with 3 apical claws, the 2 proximal ones much
thinner than the distal; flagellum in male normally developed, in female much
shorter and somewhat thickened in the middle, with the extremity very delicate
and blunted at the tip. Mandibles with the cutting part very coarse, palp
almost straight, with the terminal joint comparatively short, vibratory plate
small, with only a single plumose seta accompanied outside by a rudimentary
hook-like spine. Maxillae with the masticatory lobes comparatively short, palp
of moderate size. Legs moderately strong, the 2 anterior pairs with 2 setae
on the anterior border of the basal part: last pair with only a single such seta.
Caudal lamellae small, with 2 plumose set« on the tip. Copulative appendages
of male with the terminal part well defined, triangular in shape. fl

Remarks.— 1:\\\'$, new genus is proposed to comprise a number of species
generally referred by recent authors to the genus Cythereis, but differing from
this genus, as defined by Jones, in several regards. It holds in reality
intermediate position between this genus and Cythere (in the restriction he]
adopted), approaching in some respects more closely to the latter genus,
the Fauna of Norway 8 species, referable to this genus, are represented.

84. Hemicythere viliosa, G. O. Sars.

(PI. LXXXIV.)
Cythere viliosa, G. O. Sars, Oversigt af Norges marine Ostracoder, p. 42.

Specific Characters.— Female. Shell, seen laterally, subreniform in shaj
greatest height about in the middle and exceeding half the length, dorsal margin

183

gently arched and joining the posterior one without any intervening angle,
ventral margin distinctly sinuated in front of the middle and slightly convex
behind, anterior extremity broadly rounded and somewhat bowed below, posterior
narrower and obliquely truncated, with the lower corner somewhat exerted, but
obtuse at the end; — seen dorsally, oblong ovate in outline, with the greatest
width behind the middle and somewhat less than half the length, anterior
extremity pointed, posterior more obtuse. Surface of valves evenly convex and
of a somewhat dull appearance, being all over conspicuously pitted and clothed
at each extremity with closely set rather coarse hairs. Both pairs of antennae
very robust, the anterior ones with the last joint about half the length of the
preceding one, the posterior ones with the fagellum scarcely extending to the
middle of the terminal part.

Aiale of about same size as the female, but having the shell considerably
narrower and more tapered behind. Copulative appendages with the terminal
part produced in front to an acute triangular lappet, and crossed inside by 2
anteriorly-verging processes issuing from the basal part, the lower one highly
chitinised and sharply pointed at the tip, the upper terminating in a narrow,
slightly upturned lobule, which projects somewhat beyond the edge in front.

Colour of shell dark fuscous, with a distincte violaceous tinge, marginal
zone lighter; limbs bright yellow.

Length of adult female 0.70 mm.

Remarks. — The present form resembles somewhat in the general shape
of the shell Cythere lutea, but is at once distinguished by the very different
sculpture of the valves and, when examined in the fresh state, also by the
rather dissimilar colour. It is a true member of the genus Hemicyihere, as
here defined, agreeing in all structural details with the several species of this
genus described in the sequel.

Occurrence. — The species occurs not unfrequently off the Norwegian coast,
from the Christiania Fjord to Finmark in the laminarian region.

Distribution. — British Isles, Iceland, Bay of Biscay.

/^055//.— Norway, British Isles.

85. Hemicythere emarginata, G. O. Sars.

(PI. LXXXV, fig. 1.)
Cythereis emarginata, G. O. Sars. Oversigt af Norges marine Ostracoder, p. 38.

Specific Characters. — Female. Shell, seen laterally, short subreniform in
shape, somewhat higher in front than behind, greatest height considerably
exceeding half the length, dorsal margin gently arched in the middle and

184

somewhat abruptly bent both in front and behind, ventral margin shghtly
sinuated in front and nearly straight behind, anterior extremity obliquely rounded
off, posterior very distinctly emarginated in the middle, the emargination being
bounded above by a somewhat gibbous corner, below by a projecting lobe
obtusely truncated at the end; — seen dorsally, oblong ovate in outline, greatest
width behind the middle and not nearly attaining hah the length, side-edges
somewhat angular behind, anterior extremity gradually narrowed and sharply
pointed at the end, posterior obtusely triangular. Valves very unequal and
rather dissimilar in shape, the right one having the dorsal margin much more
strongly bowed in the middle than the left, whereas the anterior and posterior
angles are nearly obsolete. Surface of shell somewhat uneven, each valve
exhibiting behind a well-marked vertical ridge and below it a broad rounded
expansion, having moreover in front a few radiating folds; edges smooth and
rather densely hairy in front and behind; sculpture well marked, resembling
that in the preceding species. Antenna comparatively less robust, than in
H. villosa, but of a very similar structure; vesicle leading to the flagellum of
the posterior ones however much larger and slightly bilobed.

Male somewhat smaller than female, but having the shell of a rather
similar shape. Copulative appendages with the terminal part very sharply
defined, and acutely produced both in front and behind.

Colour of shell dark fuscous.

Length of adult female 0.80 mm.

Remarks. — The present species is easily recognised by the very con
spicuous emargination on the posterior extremity of the shell, especially strongly
marked on the right valve, this character having indeed occasioned the specific
name proposed. Otherwise it is rather closely allied to H. villosa. though o
rather larger size.

Occurrence. — This is a true northern species. I have only taken it in th
fresh state off the Lofoten islands and rather sparingly, whereas it occurre
very abundantly in shell-sand from 0xfjord, Finmark.

Distribution. — Arctic Sea, Shetland.

Fossil. — Norway, Scotland.

86. Hemicyihere crenulata, G. O. Sars.

(PI. LXXXV, fig. 2).
Cythereis crenulata, G. O. Sars, Oversigt af Norges marine Ostracoder, p. 39.

Specific Characters. — Female. Shell, seen laterally, oval subreniform ii
shape, somewhat higher in front than behind, greatest height exceeding half

jrply

185 _

the length, dorsal margin gibbously projecting in the ocular region, behind
which it exhibits a distinct concavity, thence gently arched and joining the
hind margin by an abrupt curve, ventral margin nearly straight, anterior
extremity broadly rounded off, posterior obliquely truncated and very slightly
emarginated in the middle, lower corner somewhat projecting, but obtuse at
the end; — ^seen dorsally, oblong ovate in outline, with the greatest width
behind and nearly attaining half the length, side-edges almost straight in the
middle and slightly angular behind, anterior extremity obtusely pointed, posterior
triangular. Valves less unequal than in the preceding species, with the surface
slightly uneven, exhibiting in the posterior part, below', a broad rounded
expansion, above a somewhat angular prominence, anterior edge and lower
part of posterior regularly crenulated and clothed with fine hairs; sculpture less
strongly marked than in the preceding species, the pittings being rather smaller
and more densely set. Eyes rather large and conspicuous, elliptical in shape.
Anterior antennae nearly as in the preceding species, the posterior ones however
with the apical claws comparatively more slender.

Male not yet observed.

Remarks. ~The present species is nearly allied to H, emarglnata, but of
smaller size, and differing somewhat in the shape of the shell, as seen laterally,
h is moreover easily distinguished by the well-marked crenulation of the
anterior edges and the lower part of the posterior ones, this character having
indeed given rise to the specific name proposed.

Occurrence. — I have only had an opportunity of examining a few female
specimens of this form, taken several years ago at Langesund, south coast of
Norway. Norman has however found it also in 2 localities of the western
coast, Lervik and Korsfjord.

Distribution. — British Isles, Dawis Strait, Greenland.

87. Hemicythere finmarchica, G. O. Sars.

(PI. LXXXV, fig. 3).
Cythereis finmarchica, G. O. Sars, Oversigt af Norges marine Ostracoder, p. 41.

Specific Characters.— Female. Shell, seen laterally, elongate subquadran-
gular in shape, slightly higher in front than behind, greatest height scarcely
exceeding half the length, dorsal margin somewhat angularly bent in the
ocular region, thence almost straight and gently sloping behind, ventral margin
very slightly sinuated in front of the middle, anterior extremity broadly rounded,
posterior rather narrower and obliquely truncated, with a very slight emargingtion

23 — Crustacea.

)i me

4

186

in the middle, upper corner obtuse, lower more prominent, but blunt at the
end; — seen dorsally, subovate in outline, with the greatest width nearly equal
to half the length, side-edges straight in the middle and scarcely at all angular
behind, both extremities gradually contracted, the anterior more pointed than
the posterior. Surface of valves rather evenly convex, with a very slight
expansion below the posterior part, anterior edges and lower part of posterior
very slightly and somewhat irregularly crenulated, being moreover clothed with
fine hairs; sculpture well marked and of the usual kind. Anterior antennae
with the terminal joint rather small, scarcely exceeding in length ^'3 of the
preceding joint. Posterior antennae comparatively short and stout.

Male not yet examined in detail.

Colour of shell yellowish brown.

Length of adult female 0.74 mm.

Remarks.— The above-described species is easily distinguished from those
recorded in the preceding pages by the rather narrow and elongated shape of
the shell, and by the more evenly convex surface of the valves. The struc-
ture of the limbs is however not very different.

Occurrence. — This form was originally described from some empty shells
found by my late father in shell-sand from 0xfjord, Finmark. I have sub-
sequently had an opportunity of examining this form in the fresh and living
state, a few female specimens being taken at Korshavn, south coast of Norway

Disttibuiion.—Bniish Isles, Bay of Biscay, Cape Vert.

88. Hemicythere quadrideniata, (Baird).

(PI. LXXXVI, fig. 1).
Cy there quadrideniata, Baird, British Entomostraca, p. 173, PI. XXI, fig. 2.

Specific Characters.— Female. Shell, seen laterally, oblong subquadrangu"
lar or somewhat clavate in shape, rather higher in front than behind, greatest
height only slightly exceeding half the length, dorsal margin somewhat pro-
minent in the ocular region and sloping gently behind at an almost straight
course, ventral margin very slightly sinuated in front and quite straight behind,
anterior extremity broadly rounded, posterior much narrower and obliquely
truncated, upper corner rounded off, lower somewhat produced and blunt at
the end;— seen dorsally, narrow and somewhat irregularly oblong in outline,
greatest width not nearly attaining half the length, side-edges angularly waved,
both extremities somewhat blunt at the end. Surface of shell rather uneven,
each valve exhibiting in the posterior part, above a somewhat projecting

(

187

angular prominence, below a broad rounded expansion, anterior edge densely
fringed with hairs, posterior more sparingly hairy, but divided at the end of
the lower projecting corner into 4 very conspicuous obtuse teeth. Sculpture
well-marked and of the usual appearance. Antennae moderately strong, the
anterior ones with the terminal joint nearly half the length of the preceding
joint, the posterior ones with the apical claws comparatively short, flagellum
more prolonged than in the other species, extending considerably beyond the
middle of the penultimate joint.

Male rather smaller than female, and having the shell comparatively
narrower. Copulative appendages with the terminal part obtusely triangular
in shape.

Colour of shell yellowish brown.

Length of adult female 0.72 mm.

Remarks. —Tht present species was described as early as the year 1850
by Baird, and was chiefly characterised by the lower corner of the posterior
extremity having the edge divided into 4 blunt teeth. The form examined by
me agrees in this character, as also in .the general shape of the shell pretty
well with the specimen originally described and figured by Baird; but Brady
has recorded some apparently more deviating forms adduced to this species.

Occurrence — The species seems to be of rather rare occurrence on the
coasts of Norway. I have only met with it quite occasionally in a single
locality, viz., at Riser, south coast of Norway, and Norman has taken a few
specimens at Lervik, Hardanger Fjord.

Distribution. — British Isles, Bay of Biscay.

Fossil. — Scotland.

89. Hemicythere angulata, G. O. Sars.

(PI. LXXXVI, fig. 2).
Cythereis angulata, G. O. Sars, Oversigt af Norges marine Ostracoder, p. 46.

Specific Characters. — Female. Shell, seen laterally, oblong subreniform
in shape, much higher in front than behind, greatest height about equal to
half the length, dorsal margin angularly bent in the ocular region and gently
arched in the middle, sloping rather steeply behind, ventral margin distinctly
sinuated in front, but nearly straight behind, anterior extremity broadly rounded
and somewhat bowed below, posterior much narrower and obliquely truncated,
without any obvious emargination in the middle, lower corner somewhat pro-
jecting and blunt at the end; — seen dorsally, of a shape rather similar to that

188

in the preceding species, but comparatively broader and more pronouncedly
angular. Surface of shell rather uneven in its posterior part, each valv<H
exhibiting above a distinctly angular prominence, and below a likewise some-
what angular expansion, anterior edge densely fringed with hairs, lower part
of posterior edge more sparingly hairy and without any distinctly marked
teeth; sculpture as in the preceding species. Antennae comparatively shorter
and stouter, terminal joint of the anterior ones not nearly attaining half th^
length of the penultimate one, flagellum of the posterior antennae much shorter
than in the preceding species. ^

Male of rather small size, as compared with the female, with the shel^
much narrower. Copulative appendages differing conspicuously from those of
the preceding species in the shape of the terminal part, the anterior extremity
of which is peculiarly bent in a hamiform manner.

Colour of shell reddish brown.

Length of adult female 0.69 mm.

Remarks.— Tht present species is nearly allied to the preceding one,"
of somewhat smaller size, and slightly differing in the shape of the shell. It
also differs in the want of any distinct teeth on the posterior edges of the valves.

Occurrence.—] have taken this form in several places on the Norwegian
coast, from the Christiania Fjord to Finmark, in the laminarian zone, though
nowhere in any abundance.

Distribution. — British Isles, Baffin's Bay.

Fossil. — Scotland.

90. Hemicyihere latimarginata, (Speyer).

(PI. LXXXVI, fig. 3).

Cythere latimarginata, Speyer, Die Ostracoden der Casseler Tertiaerbildungen, p. 22,

PI. Ill, fig. 3 a-d.

Syn: Cythereis abyssicola, G. O. Sars.

Specific Characters.— Female. Shell, seen laterally, oblong quadrangul
in shape, somewhat higher in front than behind, greatest height quite anteri-
orly and slightly exceeding half the length, dorsal margin projecting in the ocular
region to a very conspicuous gibbous prominence, behind which it appears
distinctly concaved, being only in its posterior part somewhat convex, ventral
margin rather deeply sinuated in the middle, anterior extremity unusually short,
being bluntly rounded off and considerably bowed below, posterior extremity
almost transversly truncated, with the lower corner but slightly produced and
evenly rounded off; — seen dorsally, irregularly oval in outline, with the greatest

189

width about half the length and the side-edges conspicuously angular, anterior
extremity bluntly truncated at the end, posterior sharply deHned in front and
likewise bluntly truncated. Surface of shell rather uneven, each valve exhibiting
posteriorly, as in the 2 preceding species, an angular dorsal prominence and
a likewise somewhat angular subventral expansion, the anterior part being
moreover slightly umbonate laterally; edges smooth and rather densely hairy
at each extremity; sculpture well marked, of the usual kind. Antennae unu-
sually slender, terminal joint of the anterior ones exceeding half the length of
the preceding joint; flagellum of the posterior ones very short.

Male a little smaller than female, with the shell comparatively narrower
and the dorsal margin more pronouncedly concaved in front. Copulative
appendages with the terminal part rather large and acutely produced in front;
basal part sending off below 2 unequal processes, the anterior one somewhat
spoon-shaped and curving forwards inside the terminal part, the other pointing
straight downwards and somewhat pyramidal in shape.

Colour of shell light fuscous.

Length of adult female 0.70 mm.

Remarks. — This form was recorded as early as the year 1863 by Speyer
from some fossil specimens found in tertiary deposits at Cassel, and was sub-
sequently observed by the present author in the living state, being described
under the name of Cythereis abyssicola. It is an easily recognisable species,
differing conspicuously from the other known forms in the shape of the shell.

Occurrence. — I have myself only met with this species in a single locality
of the Norwegian coast, viz., off the Lofoten islands, where it occurred in very
considerable depths, down to 300 fathoms. Norman has however found it
also in some places on the western coast.

Distribution. — British Isles, Da wis strait, Greenland, Spitsbergen.

Fossil. — Germ any.

91. Hemicythere concinna, (Jones).

(PI. LXXXVII, fig. 1).

Cythere concinna, .lones, Monogr. Tert. Entomostraca, p. 29, PI. IV, fig. 7 a— f.

Syn: Cythereis clavata, G. O. Sars.

Specific Characters.— Female. Shell, seen laterally, pronouncedly clavate
in shape, much higher in front than behind, greatest height exceeding some-
what half the length, dorsal margin angularly bent in the ocular region and
sloping gradually behind, ventral margin almost quite straight, anterior extre-

1

i

190

mity broadly and somewhat obliquely rounded, posterior much narrower and
almost transversely truncated, upper corner obtuse, lower a little more pro-
minent and rounded off at the end;— seen dorsally, irregularly oblong in out-
line, with the greatest width about equal to V^ oi the length, side-edges
somewhat bowed in front of the middle and slightly angular behind, both
extremities obtusely truncated, the posterior a little broader than the anterior.
Surface of valves with somewhat irregular and densely set pittings, less con-
spicuous than in the preceding species, and moreover marked with scattered
small tubercles, edges quite smooth and rather densely hairy in front and
behind. Hinge with the closing teeth very strongly developed. Anterior
antennae with the terminal joint somewhat prolonged, exceeding considerably
half the length of the preceding joint. Posterior antennae with the apical claws
rather slender, flagellum short and scarcely thickened in the middle

Male of about same size as female, but having the shell comparativel
narrower, with the dorsal margin perfectly straight. 2nd pair of legs slightly
transformed, the apical claw being abruptly curved and armed with about 8
thin spinules gradually diminishing in length distally. Copulative appendages
with the terminal part remarkably small, obtusely triangular in shape.

Colour of shell dark fuscous brown, with the marginal zone lighter; limbs
bright yellow.

Length of adult female 0.95 mm

Remarks. — This form was recorded as early as the year 1856 by Jones
from fossil tertiary shells. It was subsequently observed by the present author
in the living state, and described under the name of Cythereis cLavata. The
species is easily recognised from the other known forms of the present genus
by the very coarse and pronouncedly club-shaped shell. fl

Occurrence. — I have taken this form very abundantly in the upper part
of the Christiania Fjord at a depth of 7 — 12 fathoms, muddy bottom. It also
occurs in many other places on our coast up to Finmark.

Distribution. — British Isles, Gulf of St. Lawrence, Dawis Strait, Spitzberg^

Fossil. — Norway, Scotland.

92. Hemicythere oblonga, (Brady).

(PI. LXXXVII, fig. 2),
Cythere oblonga, Brady, Trans. Zool. Soc. London, Vol. V, p. 373, PI. 59, fig. 5 a— d.

Specific Characters. — Female.ShoW somewhat tumid, seen laterally, rather
regularly oblong oval in shape, slightly higher in front than behind, greatest

hmbs

191

height scarcely exceeding half the length, dorsal margin with a slight indication
to an angle in the ocular region and gently sloping behind, ventral margin slightly
sinuated, anterior extremity obliquely rounded, posterior a little narrower and
obtusely blunted, with the lower corner not at all produced;— seen dorsally,
broadly oval in outline, with the greatest width in the middle and exceeding
somewhat half ihe length, side-edges quite evenly curved, both extremities
obtusely pointed, the anterior narrower than the posterior. Surface of valves
evenly convex, but coarsely sculptured throughout with very conspicuous and
somewhat irregular pits defined by a network of thickened stripes, anterior
edges and lower part of posterior divided into densely set obtuse denticles and
fringed with scattered very fine hairs, posterior part of ventral margin distinctly
jagged. Anterior antennae with the terminal joint comparatively small, scarcely
attaining half the length of the preceding joint. Posterior antennae with the
apical claws short and stout, flagellum remarkably thickened in the middle.

Male, as usual, having the shell comparatively more elongate than in
female, but otherwise of a very similar appearance. Copulative appendages
rather large, but resembling in shape those of H. concinna, the terminal part
being very poorly developed.

Colour of shell yellowish brown.

Length of adult female 0.96 mm.

Remarks. — In the general shape of the shell this form has a perplexing
similarity to some of the species of the genus Cytheridea, for instance the
above-described C. paptllosa. It is however at once distinguished by the very
different sculpture of the valves, agreeing in this respect, as also in the struc-
ture of the several limbs perfectly with the other species of the present genus.

Occurrence. — The only place, where I have met with this distinct species,
is at Korshavn, south coast of Norway. Several specimens, both males and
females, were taken here, some years ago, in a depth of about 20 fathoms,
muddy bottom.

Distribution. — British Isles, Bay of Biskay, Mediterranean.

Gen. 41. Cythereis, Jones, 1849.

Generic Characters. — Surface of shell more generally rather uneven, with
variously formed projections or spines, anterior and posterior edges always
strongly denticulated; sculpture less coarsely marked than in the preceding
genus, in some cases quite inconspicuous. Hinge with the closing teeth well
developed. Eyes, when present, very conspicuous and adjacent to pellucid

192

tubercles of the valves. Anterior antennae with the terminal part distinctly
4-articulate, last joint more or less prolonged. Posterior antennae with the
apical claws rather slender; flagellum poorly developed in both sexes, with
the distal part of a remarkably weak consistency. Mandibles with the cutting
part less strong than in Hemlcythere, palp having the terminal joint much
prolonged and curved; vibratory plate rather fully developed, being fringed
with 5 setae, 3 apical and 2 lateral, one of the latter rudimentary. Maxillae
about as in Hemicythere. Legs rather slender. Caudal lamellae conical in
shape, with 2 rather unequal apical setae and one lateral. Copulative appendages
of male of somewhat varying shape in the different species.

Remarks.— This genus was established as early as the year 1849 by Jones,
to comprise some of the fossil CytheridcB examined by him, in which the
shell exhibited a particularly rough and spiny surface. The close relationship
of this genus to Cythere was stated by the present author, on examining the
limbs in some recent species, though a few differences were found chiefly
relating to the structure of the flagellum of the posterior antennae. On that
reason the genus was supported by me, as also subsequently by G. W. Muller,
but was taken by both of us in a much wider sense than done by Jones.
Brady however did hot at all admit this genus,, which he combined with
Cythere. In the present account the extent of the genus has been consider-
ably limited by the establishment of the new genus Hemicythere, the species
of which were formerly included in Cytherels. The chief differences between
these 2 genera are found in the structure of the anterior antennae and of the
mandibles. Another characteristic difference has also recently been stated
relative to the flagellum of the posterior antennae, which in the present genus
is very poorly developed not only in the female, but also in the male. 5
species referable to this genus will be described in the sequel.

93. Cytherels tuberculata, G. O. Sars.

(PI. LXXXVIII).
Cytherels tuberculata. G. O. Sars, Oversigt af Norges marine Ostracoder, p. 37.

Specific Characters.— Femaie. Shell, seen laterally, oblong subclavate
shape, gradually tapered behind, greatest height quite in front and only slightly
exceeding half the length, dorsal margin distinctly angular in the ocular region
and sloping behind at nearly a straight course, ventral margin very slightly
sinuated in the middle and curving gently upwards behind, anterior extremity
broadly rounded off, posterior much narrower and obtusely blunted, upper
corner obtuse, lower rounded off; — seen dorsally, somewhat irregularly oblong

193

oval in outline, being slightly constricted in the middle and obtusely angular
in the posterior part, greatest width rather behind and not fully attaining half
the length, both extremities somewhat blunted at the end, the anterior narrower
than the posterior. Surface of valves only slightly uneven, and faintly reticu-
lated, being marked with somewhat irregular pittings and scattered small
tubercles, anterior edges and lower part of posterior armed with a very con-
spicuous and rather regular row of somewhat blunt denticles, but only sparingly
hairy. Eyes well developed. Anterior antennae with the 4 joints of the
terminal part well defined, last joint scarcely as long as the 2 preceding ones
combined. Posterior antennae moderately strong, with the flagellum quite short,
scarcely extending to the middle of the penultimate joint. Legs somewhat
less slender than in the other species.

Male a little larger than female, and having the shell comparatively
narrower. Flagellum of posterior antennae more prolonged than in female, but
with the distal part very thin and fragile. Copulative appendages largely
developed and of a rather unusual shape, the basal part being produced below to
a greatly prominent and complicated lobe, obtuse at the end, and exerted behind
to a thin digitiform lappet, in front to a much stronger hooked process; ter-
minal part remarkably narrow and prolonged, tapering gradually to a thin
somewhat flexuous lash.

Colour of shell dark yellowish brown; limbs bright yellow.

Length of adult female slightly exceeding one millimeter.

Remarks. — In the general appearance of the shell and its sculpture this
form bears a rather close resemblance to the species of the preceding genus,
and might indeed, without a closer examination, easily to adduced to that genus.
Yet, the structure of the antennae and the mandibles is decidedy different and
proves it to be in reality referable to the genus Cythereis, as here defined.

Occurrence. — This form is by no means rare off the Norwegian coast. I
have taken it in many places, from the Christiania Fjord up to Finmark in
depths ranging from 10 to 30 fathoms, muddy bottom.

Distribution.— Bniish Isles, Iceland, Spitzbergen, Gulf of Lawrence, Bay
of Biscay, Mediterranean.

Fossil. — Norway, British Isles.

24 — Crustacea.

194
94. Cytherels echinata, G. O. Sars.

Cythereis echinata, G. O. Sars, Oversigt af Norges marine Ostracoder, p. 44.

Syn : Cythere catenala, Brady.
„ — irpex, Brady.

„ — monacantha, Brady.

Specific Characters. — Female. Shell rather clumsy and tumid, seenj
laterally, broadly oval in shape, slightly higher in front than behind, greatest
height about equal to ^/s of the length, dorsal margin projecting in the ocular
region to a very distinct gibbous prominence, immediately behind which it
appears slightly concaved, thence gently arched and joining the hind edge
without any intervening angle, ventral margin scarcely at all sinuated, being
slightly convex behind, anterior extremity broady rounded, posterior rather
narrower and obtusely blunted, with the lower corner evenly rounded off; —
seen dorsally, broadly ovate in outline, with the greatest width somewhat behind
the middle and exceeding half the length, side-edges evenly curved, anterior
extremity gradually narrowed to an obtuse point, posterior broader and more
blunt at the tip. Surface of valves evenly convex and everywhere armed with
numerous sharply pointed spines, those on the anterior edges pretty regularly
disposed, those on the posterior extremity somewhat unequal, 2 or 3 of them
at the infero-posteal corner being rather stronger than the others; sculpture
rather feeble, in the form of slightly defined areolae arranged somewhat concentri-
cally. Eyes apparently quite absent. Anterior antennae with the terminal joint
much prolonged, being fully as long as the 2 preceding joints combined.
Posterior antennae very slender, with the penultimate joint remarkably long
and narrow, apical claws much elongated; flagellum however rather short. Legs
slender, and rapidly increasing in length posteriorly. m

Male resembling the female in the general appearance, though having"'
the shell comparatively somewhat more elongated, with the dorsal margin more
distinctly concaved in front. Flagellum of posterior antennae still more reduced
than in female, being both shorter and thinner. Copulative appendages with
the basal part rounded triangular in shape and not at all produced below, but
armed in front with a small dentiform projection; terminal part comparatively
large, broadly oval in shape and not obviously produced either in front or behind.

Colour of shell dark fuscous gray.

Length of adult female 1.20 mm., of male 1.25 mm.

Remarks. — This is a very distinct and easily recognisable species, being
well distinguished from the other known members of the present genus by th

I

195

short and clumsy shape of the shell and by its strongly spinous armature. It
is one of the largest forms of known Cytheridae.

Occurrence. — I have taken this form occasionally in the upper part of the
Christiania Fjord in depths of 30 to 50 fathoms, muddy bottom, and also off
the Lofoten islands, where it descends to the considerable depht of 300 fathoms.
Norman records it also from some localities on the western coast of Nor^vay.

Distribution. — Great deeps of the Atlantic (Challenger Expedition).

95. Cythereis dunelmensis (Norman).
(PI. xe.) J -

Cythere dunelmensis, Norman, Nat. Hist. Trans, of Nortliumb. & Durham, Vol. I, pag. 23,

PI. VII, figs. 1—4.

Syn: Cythereis horrida, G. O. Sars.

Specific Characters.— Female. Shell, seen laterally, oblong quadrangular
in shape, rather higher in front than behind, greatest height somewhat exceeding
half the length, dorsal margin strongly prominent in the ocular region and
sloping gently behind at nearly a straight course, ventral margin slightly sinuated
in the middle, anterior extremity broadly rounded, posterior rather narrower and
nearly transversely truncated, upper corner well marked, lower rounded off;—
seen dorsally, rather regularly oblong oval in outline, with the greatest width
about in the middle and somewhat less than half the length, both extremities
obtusely pointed and nearly equal. Surface of valves evenly convex but armed
with numerous clumsy spines of somewhat unequal size and irregular shape,
some of them arranged more regularly in a curved series near the anterior
extremity, edges of the latter fringed with a likewise regular row of somewhat
spatulate denticles' successivelly increasing in size downwards, posterior extremity
with spines of somewhat varying shape, some of them, at the infero-posteal
corner, rather prolonged; hairy coating rather sparse. Sculpture of valves
distinctly reticulate. Eyes very large and conspicuous, with a glittering lustre.
Anterior antennae with the terminal joint rather prolonged, though scarcely
atfaining the length of the 2 preceding joints combined. Posterior antennae
with the penultimate joint less slender than in C. echinata, flagellum very short.
Legs moderately slender, with the 1st joint of the terminal part clothed in front
with fascicles of thin bristles.

Male of about same size as female, but having the shell conspicuously
narrower and more elongate in shape, some of the spines on the hinder part
of the ventral face being arranged on each side in a pretty regular series well

I

I

196

seen in the ventral aspect of the shell, each series containing 6—8 spines
successively increasing in size posteriorly. Flagellum of posterior antennae very,
little longer than in female. Copulative appendages with the basal part slightly
projecting below, terminal part subtriangular in shape, obtusely produced both
in front and behind.

Colour of shell whitish, with a slight yellow tinge, but in most cases
appearing much darker owing to muddy particles adhering to the numerous
spines on the surface of the shell; limbs bright yellow.

Length of adult female amounting to 0.92 mm., of male to 0.95 mm.

Remarks. — This form was first recorded by Norman as a species of th
genus Cythere, and was somewhat later observed by the present author, who
described it under the name of Cythereis horrida, the specific denomination
alluding to the coarse spinous armature of the shell. It is a true member of
the present genus, but easily recognisable from the other species.

Occurrence. — I have taken this form not unfrequently in several places
on the Norwegian coast, from the Christiania Fjord up to Finmark. It is
generally found in depths ranging from 10 to 50 fathoms, muddy bottom

Distribution.— Bn[\sh Isles, Iceland, Baffins Bay, Spitzbergen.

Fossil. — Scotland.

96. Cythereis Jonesi, Baird.
(PI. XCI.)

Cythere Jonesi, Baird, British Entomostraca, p. 175, Pi. XX, fig. 1.
Syn : Cythere fimbriata, Norman.
„ — ceratoptera, Bosquet.

, Cythereis spectabilis, G. O, Sars.

Specific Characters. — Female. Shell, seen laterally, obtusely quadrangular
or auriculate in shape, higher in front than behind, greatest heigt exceeding
somewhat half the length, dorsal margin angularly produced in the ocular
region and nearly straight behind, sloping" gently towards the supero-postea
corner, ventral margin scarcely at all sinuated, being even a little conve
throughout, anterior extremity broadly rounded, posterior rather narrower and
likewise obtusely rounded off; — seen dorsally, somewhat lozenge-shaped or
trapezoid in outline, widening gradually from before backwards to about the
posterior third part of the lenght, whence it abruptly contracts behind, both
extremities somewhat blunt at the end. Valves comparatively thin, semipellucid,
but armed with a somewhat limited number of very conspicuous spines, pretty
regularly arranged; each valve exhibiting laterally, near the ventral face, a well

li

197

marked wing-like expansion terminating in a strong obliquely outward-pointing
spiniform process, and bordered in front of this process with a regular series
of about 8 somewhat flattened spines extending to the anterior extremity;
upper part of each valve with a longitudinal row of 6 lamellar spines, the
foremost one rather broad and conically produced behind, the hindmost occu-
pying the supero-posteal corner of the valve; anterior edge flanked above by
a thin undivided lamella angularly projected just above the eye, lower part of
the edge armed with about 8 somewhat blunt denticles; posterior edge bordered
with 6 spines successively increasing in size downwards, the lowermost being
considerably prolonged; central portion of valves perfectly smooth and without
any obvious sculpture, only exhibiting in its hindmost part a few comparatively
small spines; hairy coating of the valves very scarce. Eyes, as in the preceding
species, very large and conspicuous. Antennae rather slender, resembling in
structure those in C. dunelmensts. Legs with the 1st joint of the terminal part
quite smooth in front.

Male very similar to the female, though having the shell a little more
elongate. Flagellum of posterior antennae scarcely larger. Right 2nd leg con-
spicuously more strongly built than the others. Copulative appendages with
the terminal part much produced in front and exerted behind to a narrow
digitiform process.

Youngs, recently hatched, of a rather peculiar appearance, having the winglike
expansions of the valves strongly prominent and flanked with a quite undivided
thin lamella, anterior edges likewise with all the denticles confluent. In somewhat
older youngs the terminal spine of the wing-like expansions has however become
well defined.

Remarks. — This remarkable form was recorded as early as the year 1850
by Baird from a single empty shell. It was however not recognised by the
subsequent authors, owing to the rather imperfect description and figure given
by Baird, being indeed described as new under 3 different names, as seen from
the above-given synonymes. Brady has however ascertained the identity of
the present species with the form originally examined by Baird and has restored
the specific name given to it by that author.

Occurrence. — I have taken this form occasionally in the upper part of the
Christiania Fjord in depths of from 30 to 50 fathoms, muddy bottom, and I
have also met with it in some other places on the south and west coasts
of Norway.

Distribution. — British Isles, Bay of Biscay, Mediterranean.

/^os5//.— British Isles, Belgium, France.

198

97. Cythereis mucronata, G. O. Sars.

(PI. XCII.)

Cythereis mucronata, G. O. Sars, Oversigt af Norges marine Ostracoder, p. 48.

Syn: Cythere spinosissima, Brady.

J

Specific Characters. — Female. Shell of an appearance rather similar t
that in the preceding species, though comparatively somewhat more elongate;
seen laterally, oblong quadrangular in shape, with the greatest height in front
and but very little exceeding half the length, dorsal margin straight or slightl)^
concaved, sloping gently towards the rather prominent supero-posteal corner,
ventral margin distinctly convex in its anterior part, anterior extremity broadly
rounded, posterior much narrower and obtusely truncated, with the lower corner
rounded off; — seen dorsally, pronouncedly lozenge-shaped, the side-edges being
angularly bent behind the middle, both extremities somewhat blunt at the ends.
Valves of firmer consistency than in C. Jonesi and quite opacous, each exhibiting
laterally, near the ventral face, a well-marked wing-like expansion terminating
in a strong sharply pointed spiniform process, and bordered with a regular
row of somewhat spatulate spines continued for some distance upwards along
the anterior extremity, frontal edges of the valves, as in the preceding species,
provided above with a thin undivided crest terminating just above the eye-
tubercle in i sharp corner, lower part of the edges bordered with a regular
series of densely set strong denticles; posterior edges armed with 6 — 8 somewhat
unequal spines, the lowermost particularly strong and sharply pointed. Lateral
faces of the valves rough from numerous somewhat irregular, more or less
sqamiform prominences, those nearest the dorsal margin of each valve being
however of a more uniform appearance and arranged in a regular longitudina3J|
row. Eye-tubercles well marked, though somewhat smaller than in C. Jonesi.
Structure of the several limbs very similar to that in the said species. Jl

Male slightly larger than female, and having the shell somewhat mor^
elongate in shape. Legs exactly as in female, the 2nd pair not being transj
formed. Copulative appendages only slightly differing from those in th
preceding species, basal part however more triangular in shape, und terminal
part obtusely produced behind. ■

Youngs, recently hatched, as in the preceding species, with the spines
bordering the anterior edges and the lateral expansions of the valves replaced by
undivided thin marginal lamellae, the expansions being however less produce^
than in the youngs of C. Jonesi.

Colour of shell dark fuscous.

Length of adult female 1.10 mm.

11

199

Remarks.— The above-described species is closely allied to C.Jonesi, but
of somewhat larger size and moreover easily distinguished by the numerous
scale-like prominences on the lateral faces of the valves, as also by the muc-
ronated shape of the spine attached to the infero-posteal corner and of that
terminating the lateral expansions of the valves.

Occurrence. — The only place where I have met with this form is at Skraa-
ven, Lofoten islands. It was found here occasionally in the considerable depth
of 200—300 fathoms, muddy bottom. Norman has however taken it also at
Stoksund, west coast of Norway.

Distribution. — Shetland.

Fossil. — Belgium.

Subfam. 4. Cytherurinae.

Remarks. This subfamily has been proposed by G. W. Miiller, but I do
not find that its real extent is clearly defined. As far as I understand, it is
taken by that author in a very wide sense. In the present account this sub-
family is restricted to comprise a number of very small Cytheridse,. chiefly
referable to the genus Cytherura, G. O. Sars. The subfamily is well distinguished
from the 3 preceding ones, both as to the shell and to the structure of the limbs.

Gen. 42. Cytherura, G. O. Sars, 1865.

Generic Characters. — Shell, as a rule, comparatively thin, only slightly
calcareous, terminating behind in a more or less sharply defined obtuse protu-
berance, surface smooth or slightly reticulated, often with longitudinal folds,
which in some cases are elevated to sharp keels. Hinge imperfectly developed.
Eyes distinctly separated. Anterior antennae rather feeble, with the terminal
part gradually attenuated, 4-articulate, and clothed in front with scattered com-
paratively short setae. Posterior antennae with the penultimate joint distinctly
subdivided, apical claws short, flagellum well deweloped in both sexes. Mandibles
very strong, with the cutting teeth blunt and more or less' reduced in number,
palp 4-articulate, with none of the setae particularly prolonged, vibratory plate
very small, with only a single distinctly developed seta. Maxillae with both the
palp and the masticatory lobes narrowly produced, the 2 lowermost of the setae
bordering the vibratory plate quite nacked and turned downwards. Legs not

200

much prolonged, 1st pair with a single seta on the anterior border of the basal
joint, 2nd pair with 2 such setae, last pair with no seta on this border. Caudal
lamellae very small and simply rounded, without any marginal bristles. Copu-
lative appendages of male distinguished by a very conspicuous dark-coloured
string issuing from the lower face of the basal part and more or less spirally
convoluted at the base.

Remarks. — This genus was established in the year 1865 by the present
author, and has been admitted by all subsequent authors in the sense originally
adopted. The generic name alludes to the peculiar protuberance of the hind
extremity of the shell found, more or less distinctly defined, in all the known
species. The genus is very rich in species, most of them being found in
rather shallow water among algae. In the succeeding pages 12 species refer-
able to this genus will be described, and Norman has also recorded from the^
Norwegian coast a few other species not yet observed by me.

98. Cytherura gibba, (O. Fr. Miiller).

(PI. XCIII).

Cythere gibba, O. Fr. Miiller, Entomostraca, p. 66, PI. VII, figs. 7—9.

Syn: Cythere gibbera, O. Fr. Miiller (male).
„ Robertsoni, Brady $ .

Specific Characters. — Female. Shell rather tumid, seen laterally oblong
subreniform in shape, scarcely higher in front than behind, greatest height
about equalling half the length, dorsal margin only slightly bent in the ocular
region and perfectly straight in the middle, joining the hind margin by a quite
gentle curve, ventral margin distinctly sinuated in front and somewhat bowed
behind, anterior extremity broadly rounded, posterior gradually contracted to
an obtuse protuberance located in the longitudinal axis of the shell; — seen
dorsally, broadly ovate in outline, with the greatest width behind the middle
and rather exceeding half the length, side-edges abruptly bowed behind, both
extremities sharply pointed at the end, the anterior somewhat narrower than
the posterior. Valves only slightly unequal, each exhibiting behind the middle
a very conspicuous rounded tuberosity, surface otherwise quite evenly convex,
without any obvious folds, but with indication to a faint reticulate pattern;
edges smooth and clothed with scattered hairs. Eyes comparatively small, but
well observable in fresh specimens. Anterior antennae with the terminal joint
rather prolonged, being fully as long as the preceding joint. Posterior antennae
comparatively slender, with the penultimate joint distinctly subdivided in the
middle by an oblique suture. Legs of moderate length.

i\

201

Male conspicuously differing from the female in tiie shape of the shell,
which, seen laterally, is comparatively narrower, with the dorsal margin slightly
concave and the ventral more deeply sinuated; seen dorsally, rather swollen
behind, but gradually tapered anteriorly, without any trace of the lateral tubero-
sities occuring in female. Sculpture of valves very strongly marked in form
of a rather regular reticulation. Copulative appendages very large and com-
plicate, basal part rounded quadrangular in shape, and sending off at the
junction with the terminal part a slender posteriorly pointing process, some-
what elbowed in the middle and abruptly hooked at the extremity; copulatory
string of quite an extraordinary length, spirally convoluted at the base and
ascending upwards to the dorsale face of the basal part, terminating in a very
thin point; terminal part obtusely rounded off in front, but irregularly indented
behind, the lower corner being produced to a somewhat digitiform narrow
process, above which is a curved spine and 2 rounded lobules.

Colour of shell very dark, almost blach, but with the tips of both extre-
mities and an oblique band across the back whitish.

Length of adult female 0.56 mm.

Remarks. — This form has been recorded as early as the year 1785 by
O. Fr. Muller, and ought thus more properly to be regarded as the type of
the present genus. Another supposed species, named by that author Cythere
gibbera, has turned out to be the male of the present form. It is an easily
recognisable species, being well distinguished from the other known members
of the present genus by the shape and sculpture of the shell, as also by its
peculiar colour.

Occurrence. — In habits the present species ought more properly to be
regarded as a brackish-water form, being found most abundantly in places where
the salinity of the water is much reduced. I have myself only met with it in the
upper part of the Christiania Fjord, near the town, where a few specimens were
taken, many years ago, close to the beach among Zostera. According to
Zencker this form is viviparous^ a particularity not observed in any of the
other known species.

Disiribuiion.— Kaiiegai, Baltic, Finland, Pritish Isles, Holland.

Fossil. — Norway, Scotland.

25 — Crustacea.

202

99. Cytherura nigrescens, (Baird).

(PI. XCIV, fig. 1).

Cy there nigrescens, Baird, British Entomostraca, p. 171, PI. XXI, figs. 4, 4 a.

Specific Characters. — Female. Shell rather compressed, seen laterally,
oval in shape, about equally high in front and behind, greatest height slightly
exceeding half the length, dorsal margin gently arched, joining the anterior
and posterior edges without any intervening angle, but sloping somewhat more
steeply behind than in front, ventral margin slightly sinuated in the middle,
anterior extremity rounded off, posterior exerted to a well defined conical
protuberance somewhat obliquely truncated at the tip and located about in
the longitudinal axis of the shell; — seen dorsally, narrow oblong in outline,
with the greatest width somewhat behind the middle and about equalling ^/s
of the length,' side-edges rather evenly curved, both extremities pointed, the
anterior somewhat narrower than the posterior. Valves slightly unequal and
rather thin, with the surface quite smooth, without any obvious sculpture,
being only marked by scattered small knobs; inner duplicatures remarkably
broad, that in front limited inwards by a somewhat irregularly waved line
sending off to the edge a number of very conspicuous fine pore-channels
partly arranged in bundles, that of the hind extremity strongly bowed inwards;
edges smooth and clothed with scattered very fine hairs. Anterior antennae
very slender, with the terminal joint rather small, not nearly attaining half th
length of the preceding joint. Posterior antennae with the dividing suture oi
the penultimate joint located considerably above the middle. Legs com
paratively small.

Immature specimens conspicuously differing from the adults in the shap
of the shell, which gradually tapers behind to an obtuse point, the dorsal
margin being boldly and evenly arched, whereas the ventral one is nearly straight.

Male very like the female, but of smaller size, and having the shell, seen
laterally, somewhat narrower, with the dorsal margin nearly straight. Copu-
lative appendages rather unlike those of the preceding species, basal part
obliquely oval in shape and without any processes below, copulatory string
comparatively short, bent in a circle, with the extremity deflexed; termin
part rather small, securiform in shape.

Colour of shell in the greater extent very dark, almost black, extremities
however much lighter and semipellucid.

Length of adult female scarcely exceeding 0.43 mm.

Remarks. — This form also has been recorded at a rather early date, viz
in the year 1850, being described by Baird as a species of the genus Cythen

at? "

203^

It is easily distinguished from the preceding species by its much smaller size
and rather different shape of the shell.

Occurrence. — The present species is very common on the Norwegian coast,
being found rather abundantly everywhere in the littoral zone, and often left
in tidal pools. It is one of our smallest Ostracoda, the specimens being only
visible to the naked eye as small dark points moving slowly on the bottom
or along the algae growing on it.

Distribution.— British Isles, Holland, Fosse de Cap Breton, Bay of Biscay.

Fossil. — Norway, British Isles, Canada

100. Cylherura similis, G. O. Sars.

(PI. XCIV, fig. 2).

Cytherura similis, G. O. Sars, Oversigt af Norges marine Ostracoder p. 72.

Syn: Cytherura propinqva, Brady.
,, — Sarsii, Brady.

Specific Characters. — Female. Shell somewhat less compressed than in
C. nigrescens, seen laterally, oval subreniform in shape, greatest height some-
what exceeding half the length and occurring in the middle, dorsal margin
only slightly arched and sloping quite equally to both extremities, ventral
margin distinctly sinuated in the middle and somewhat bowed behind, anterior
extremity broadly rounded, posterior only very slightly exerted, though exhi-
biting in the middle a quite short and obtuse protuberance; — seen dorsally,
oblong oval in outline, with the greatest width behind the middle, posterior
extremity more abruptly contracted than the anterior. Surface of valves nearly
smooth, with only fainte trace of a reticulation behind; inner duplicatures
comparatively less broad than in the preceding species and more regularly
defined inwards. Antennae of a structure very similar to that in the said
species; defining suture of^the penultimate joint of the posterior ones however
occurring exactly in the middle.

Male not yet observed.

Colour of shell much paler than in C. nigrescens.

Length of adult female 0.54 mm.

Remarks. — As indicated by the specific name proposed, this form exhibits
an appearance somewhat similar to that of C. nigrescens. It is however of
much larger size, and differs moreover conspicuously in the shape of the shell,
as seen laterally, being in particular distinguished by the comparatively much
shorter and blunter protuberance of the hind extremity.

204

Occurrence.- Only very few specimen of this form have as yet come
under my notice, all of the female sex. They were taken, many years ago,
in the upper part of the Christiania Fjord in a depth of a few fathoms. Some
empty shells were moreover found by my late father in shell-sand from 0xfjord,
west Finmark.

Distribution. — British Isles, Arctic Sea.

Fossil. — Norway, Scotland.

101. Cytherura sella, G. O. Sars.

(PI. XCV, fig. 1).

Cytherura sella. G. O. Sars, Oversigt af Norges marine Ostracoder, p. 73.

Syn: Cvthernra cuneaia, Brady.
„ „ flavescens, Brady.

Specific Characters. — Female. Shell somewhat compressed, seen laterally,
oval subquadrangular in shape, scarcely higher in front than behind, greatest
height about equal to half the length, dorsal margin quite straight in the
middle joming the hind edge by an even curve, but more abruptly bent in
front, with indication to an angle in the ocular region, ventral margin gently
sinuated in the middle and joining the hind edge by a bold curve, anterior
extremity obtusely rounded, posterior exerted to a well defined and rathe Jl
narrow protuberance located distinctly above the longitudinal axis of the shell; —
seen dorsally, narrow oblong or lanceolate in outline, with the greatest with
behind the middle and about equalling ^/o of the length, anterior extremity
gradually tapered, posterior more abruptly contracted. Surface of valves evenly
convex and marked with faint longitudinal stripes connected by fine transvers
lines, so as to form a somewhat reticulate pattern; inner duplicatures ver
broad, considerably reducing the extent of the central area of the valves, which
is deeply emarginated behind and angularly bent in front. Anterior antenn
with the terminal joint only slightly shorter than the preceding joint. Posterio:
antennae with the dividing suture of the penultimate joint located a little abovi
the middle. Legs of 1st pair with 2 setae on the infero-posteal corner of th
basal joint, apical claw of this and the 2nd pair almost straight. Last pair o
legs with the 1st joint of the terminal part much longer than the other 2 com
bined, apical claw much prolonged and abruptly incurved.

Male of smaller size than female, and having the shell, seen laterally,'
comparatively narrower, with the corsal margin somewhat concaved; posterior
part of the shell considerably swollen. Copulative appendages large, with th

I

205

basal part rounded quadrangular in shape and sending off at the junction
with the terminal part a posteriorly-curving falciform piece, copulatory string
narrowly convoluted at the base, with the extremity pointing backwards; ter-
minal part provided at the base in front with a nose-shaped projection, distal
part rather produced and narrowly rounded at the tip.

Colour of shell in its greater extent whitish, semipellucid, but marked in
the centre by a very conspicuous sharply defined blackish patch of a saddle-
like shape, extending down the sides of the valves.

Length of adult female 0.44 mm.

Remarks. — The present species is easily distinguished from the preceding
ones by the almost quadrangular shape of the shell, and by the protuberance
of the hind extremity being located distinctly above the longitudinal axis.
When examined in the fresh state, it is moreover easily recognisable by the
sharply defined dark saddle-like patch occupying the centre of each valve, a
character which indeed has given rise to the specific name proposed.

Occurrence. — I have only met with this form in the upper part of the
Christiania Fjord, where some few specimens were taken, many years ago,
from a depth of 6 — 10 fathoms. Norman has however found it also in 2
localities on the western coast of Norway.

Distribution. — British Isles, Holland, Fosse de Cap Breton, Bay of Biscay.

Fossil. — Scotland.

102. Cytherura atra, G. O. Sars.

(PI. XCV, fig. 2).
Cytherura atra, G. O. Sars, Oversigt af Norges marine Ostracoder, p. 75.

Specific Characters.— Female. Shell, seen laterally, oblong subreniform
in shape, equally high in front and behind, greatest height scarcely exceeding
half the length, dorsal margin gently arched behind, more abruptly bent in
front, with a slight indication to an angle in the ocular region, ventral margin
slightly sinuated in the middle and terminating behind in a well-marked
angular corner, anterior extremity obliquely rounded, posterior only slightly
produced, the terminal protuberance being rather short and blunt, located in
the longitudinal axis of the shell; — seen dorsally, oblong lanceolate in outline,
with the greatest width behind the middle and somewhat exceeding Vs of the
length, both extremities pointed, the posterior more abruptly contracted at the
end than the anterior. Surface of valves evenly convex, exhibiting a faint
reticulate pattern, edges smooth and very sparingly hairy. Anterior antennae

_206

with the terminal joint very small, not even attaining half the length of the
preceding joint. Posterior antennae with the dividing suture of penultimate
joint occurring nearly in the middle.

Male unknown.

Colour uniformly dark blackish extending over the whole of the shell.

Length of adult female 0.59 mm.

Remarks. — In its general appearance this form bears some resemblance
to the above-described species C. similis. It is however of rather larger size,
and has the shell comparatively more elongate, with the infero-posteal corner
distinctly angular. When observed in the living state, it is moreover at once
distinguished by the uniform blackish colour of the shell, which character haSj
indeed given rise to the specific name proposed. \

Occurrence. — The only place where I have hitherto met with this species
is at Skraaven, one of the Lofoten islands, where a few female specimens
were taken in a depth of about 3 fathoms, sandy bottom.

Distribution . — Sh etl a n d .

Fossil. — Norway, Scotland.

103. Cytherura intumescens, G. O. Sars, n. sp.
(PI. XCVI. fig. 1).

specific Characters. — Female. Shell much inflated, seen laterally, oval
subquadrangular in shape, equally high in front and behind, greatest height
slightly exceeding half the length, dorsal margin nearly straight in the middle,
and sloping behind with an even curve to the posterior protuberance, ventral
margin slightly sinuated in the middle and rather strongly bowed behind, but
without any trace of a projection or distinct angle, anterior extremity broadly
and somewhat obtusely rounded, posterior produced to a well defined protu-
berance located distinctly above the longitudinal axis of the shell; — seen dor-
sally, very broad and somewhat lozenge-shaped, with the greatest width in
front of the middle and considerably exceeding half the length, anterior
extremity tapered to an obtuse point, posterior abruptly contracted to a conica
prominence. Surface of valves evenly convex throughout and exhibiting a
well-marked reticulate pattern. Anterior antennae with the terminal part rather
slender, 2nd joint the largest, last joint only slightly shorter than the preceding
one. Posterior antennae with the dividing suture of the penultimate joint
occurring considerably above the middle.

II

207

Male of somewhat iarger size than female and sHghtly differing in the
shape of the shell, the posterior part of which is greatly swollen. Copulative
appendages very large, with the basal part rounded quadrangular in shape
and sending off below, at the junction with the terminal part, a slender pos-
teriorly-curving piece sligtly sigmoid at the end, copulatory string comparatively
short; terminal part somewhat securiform in shape, being exerted at the
posterior corner to a narrowly rounded lobule.

Colour of shell not yet ascertained.

Length of adult female 0.57 mm., of male 0.61 mm.

Remarks. — The male specimen figured by Brady & Norman in 1889
under the name of C. cornuta Brady seems to agree pretty well with the
male of the present species, as here described. I think however that its identifi-
cation with the form originally described by Brady under that name is wrong.
In any case the specific name cornuta is quite unapplicable to the present
species, as there is no trace of any corniform lateral projectfon, either in the
female or in the male. The form recorded by Brady in his Monograph as
C. Gibba O. Fr. Miiller is unquestionably the female of the present species.

Occurrence. — Two specimens only (a male and a female) of this form
have as yet come under my notice. They were found among some Ostracoda
collected, some years ago, at Riser, south coast of Norway, from depths ranging
from 10 to 30 fathoms.

Distribution. - British Isles.

104. Cytherura affinis, G. O. Sars.

(PI. XCVI. fig. 2).

Cytherura affinis, G. O. Sars, Oversigt af Norges marine Ostracoder, p. 77.

Specific Characters. — Female. Shell rather tumid, seen laterally, oblong
oval in shape, somewhat higher in front than behind, greatest height not
nearly attaining half the length, dorsal margin forming a quite even and gentle
curve throughout, without any indication of angle in the oculgr region, ventral
margin almost straight in the middle and gently bowed behind, anterior
extremity broadly rounded, posterior produced to a rather prominent pro-
tuberance located slightly above the longitudinal axis of the shell; — seen
dorsally, of a shape somewhat resembling that of the preceding species, but com-
paratively less broad, the greatest width scarcely exceeding half the length.
Valves with the central thickened area considerably reduced in extent, surface
conspicuously reticulated. Both pairs of antennae very slender and narrow,

208

terminal part of the anterior ones wiih the 1st joint the longest, the last 2
joints subequal in length and combined about as long as the preceding joint.
Posterior antennae with the dividing suture of the penultimate joint located
far above the middle. Mandibles very strong but with the palp rather poorly
developed. Maxillae with the palp and the masticatory lobes extremely narrow,
the 2 innermost lobes confluent at the base.

Male unknown.

Colour not yet ascertained.

Length of adult female 0.62 mm.

Remarks. — This form was originally described by the present author from
a single empty shell only, and of course solely the external characters could
be determined at that time. More recently however a few complete specimens
have come under my notice, whereby I have been enabled also to examine the
limbs, which exhibit some well-marked particularities in their structure, as shown
by the above diagnosis. It is one of the largest known species of the present
genus.

Occurrence.— The specimen at first examined was found by my late father
in shell-sand from 0xfjord, west Finmark, and another specimen was also
obtained by him from postglacial deposits. The complete specimens sub-
sequently found were taken off the west coast of Norway, the exact locality
not being noted.

Distribution. — Not yet observed out of Norway.

Fossil. — Norway.

105. Cytherura striata, G. O. Sars.

(PI. XCVll, fig. 1).

Cytherura striata, G. O. Sars, Oversigt af Norges marine Ostracoder, p. 74.

Syn: Cytherura qvadrata, Norman.

Specific Characters. — Female. Shell somewhat compressed, seen laterally,'
oblong subquadxangular in shape, almost equally high in front and behind,
greatest height nearly attaining half the length, dorsal margin straight andfl
horizontal in the .middle, sloping evenly in front, more steeply behind, ventral
margin slightly sinuated in front of the middle and somewhat angular behind,
anterior extremity obtusely rounded, posterior drawn out to a rather prominent
protuberance located below the longitudinal axis of the shell; — seen dorsally,
narrow oblong in outline, with the greatest width scarcely exceeding Vs of th(
length, side-edges nearly straight and parallel in the middle, anterior extremity

Cytheridae

Ostracoda

Podocopa

PI. LXXXI

6. O. Sars del

Cytheromorpha fuscata, (Brady)

Cytheridae

Ostracoda

Podocopa

PI. LXXXII

G. O. Sars del.

Xenocythere cuneiformis, (Brady)

Cytheridee

Ostracoda

Podocopa

PI. LXXXIII

6. O. Sars del.

Kyphocythere limicola, (Norman)

Cytheridae

Ostracoda

Podocopa

PI. LXXXIV

6. O. Sars del.

Hemicythere villosa, 6. O. Sars

J^ j^ri

i^i

Cytheridae

Ostracoda

Podocopa

PI. LXXXV

G. O. Sars del.

1. Hemicythere emarginata, 6. 0. Sars

2. ,, crenulata, 6. 0. Sars

3. ,, finmarchica, 6. O. Sars

Cytheridae

Ostracoda

Podocopa

PI. LXXXVI

G. O. Sars del

1. Hemicythere qvadridentata, (Baird)

2. „ angulata, 6. O. Sars

3. „ latimarginata (Speyer)

•*.<**
'^:^^\

Cytheridae

Ostracoda

Podocopa

PI. LXXXVII

/.?/

'If

/i^

n I

6. O. Sars del.

1. Hemicythere concinna, (Jones)

2. „ oblonga, (Brady)

^1

Cytheridae

Ostracoda

Podocopa

PI. LXXXVIII

6. O. Sars del.

Cythereis tuberculata, 6. O. Sars

Cytheridae

Ostracoda

Podocopa

PI. LXXXIX

6. O. Sars del.

Cythereis dunelmensis, (Norman)

i' \

Cytheridae

Ostracoda

Podocopa

PI. xc

G. O. Sars del

Cythereis echinata, 6. 0. Sars

CytheridaB

Ostracoda

Podocopa

PI. xci

^ L\,.^-'^-

6. O. Sars del.

Cythereis Jonesi, (Baird)

CytheridaB

Ostracoda

Podocopa

PI. XCII

G. O. Sars del

Cythereis mucronata, 6. 0. Sars

CytherJdas

Ostracoda

Podocopa

PI. XCIII

6. O. Sars del.

Cytherura gibba, (O. Fr. Miiller)

CytheridgB

Ostracoda

Podocopa

PI. xciv

G. O. Sars del.

1. Cytherura nigrescens, (Baird)

2. ,, similis, 6. 0. Sars

1

Cytheridae

Ostracoda

Podocopa

PI. xcv

6. O. Sars del.

1. Cytherura sella, 6. O. Sars

2. „ atra. 6. O. Sars

'<^

Cytheridae

Ostracoda

Podocopa

PI. xcvi

6. O. Sars del.

1. Cytherura intumescens, G. O. Sars

2. „ affinis, 6. O. Sars

%

209

pointed, posterior abruptly contracted to a narrow conical prominence. Valves
of rather firm consistency and marked with distinct longitudinal striae or folds
partly connected with transverse lines, to form a somewhat irregular reticulation,
exhibiting moreover a well-marked punctation of the shell. Anterior antennas
with the joints of the terminal part not much differing in size, the last being
fully as long as the preceding one. Posterior antennae with the dividing suture
of the penultimate joint located a little above the middle. Legs rather slender,
the last pair with the 1st joint of the terminal part somewhat exceeding in
length the other 2 combined.

Male of about same size as the female, but having the shell conspicu-
ously narrower, with the dorsal margin slightly concaved and the ventral more
deeply sinuated. Copulative appendages with the basal part obliquely oval
in shape and sending off below, at the junction with the terminal part, a
slender recurved piece somewhat elbowed in the middle, and more posteriorly
another much smaller deflexed process; copulatory string excessively prolonged,
forming and ample turn and thence ascending to the very dorsal face; terminal
part irregularly triangular in shape, projecting at the end anteriorly in a beak-
like deflexed corner, behind which are 2 successive rounded lobules.

Colour of shell light orange, somewhat darker in front,

Length of adult female 0.49 mm.

Remarks. — The present species is easily recognised from those described
in the preceding pages by the comparatively large size of the protuberance
terminating the shell behind and by the situation of this protuberance below
the longitudinal axis of the shell. The specific name alludes to another parti-
cularity, viz., to the rather strongly marked longitudinal striae or folds adorning
the surface of the valves. When examined in the fresh state it is also well
disitnguished by the light orange colour of the shell.

Occurrence. — I have taken this ^orm occasionally in the upper part of the
Christiania Fiord in depths of 10 to 20 fathoms, and have also met with it in
several other places, both of the south and west coasts of Norway.

Distribution. — British Isles, Holland, Mediterranean.

Fossil. — Norway, Scotland.

106. Cytherura producta, Brady.

(PI. XCVII, fig. 2).

Cytherura producta, Brady, Mon. recent British Ostracoda, p. 443, Pi. XXXII, figs. 60, 61.

Specific Characters. — Female. Shell rather tumid, seen laterally, narrow
oblong oval in shape, somewhat higher in front than behind, greatest height

26 — Crustacea.

210

not nearly attaining half the length, dorsal margin evenly arched throughout,
without any angular bend either in front or behind, ventral margin very slightly
sinuated in front of the middle and only little bowed behind, anterior extremity
somewhat irregularly rounded, being obtusely produced in the middle, posterior
gradually narrowed to a very prominent protuberance located slightly below
the longitudinal axis of the shell;— seen dorsally, broadly oval in outline, with
the greatest width a little behind the middle and exceeding somewhat half
the length, lateral faces flanked by an evenly curved pellucid border, both
extremities conically produced at the end, the posterior somewhat more ab-
ruptly contracted than the anterior. — Valves rather thin and pellucid, each pro-
vided near the ventral face wiih an elevated thin longitudinal rib, very con-
spicuous in the dorsal or ventral aspects of the shell; surface perfectly smooth,
without any obvious sculpture; central area of valves much reduced in extent.
Anterior antennae with the joints of the terminal part successively diminishing
in size, the last very small, scarcely attaining half the length of the preceding
joint. Posterior antennae with the dividing suture of penultimate joint located
nearly in the middle.

Male not observed.

Colour of shell not yet ascertained.

Length of adult female 0.50 mm.

Remarks.— The above-described form is easily recognisable by the greatly
produced protuberance of the hind extremity, as also by the very conspicuous
lateral crests. The shape of the shell differs also somewhat from that in the
other species, both as seen laterally and dorsally.

Occurrence.— A few female specimens of this form were found among
some Ostracoda collected at Korshavn, south coast of Norway, from depths
ranging from 20 to 40 fathoms, muddy sand. Norman has also recorded the
species from 2 localities on the west coast.

Distribution.— British Isles, Holland.

107. Cyiherura acuticostaia, G. O. Sars.

(PI. XCVIII, fig. 1).
Cytherura acuticostaia, G. O. Sars, Oversigt over Norges marine Ostracoder, p. 76.

Specific Characters.— Female. Shell rather tumid, seen laterally, s
subquadrangular in shape, equally high in front and behind, greatest height
exceeding half the length, dorsal margin nearly straight in the middle and
gently curved behind, joining the anterior edge without any obvious angle in

i

211

the ocular region, ventral margin very sligthly sinuated and terminating behind
in a somewhat projecting blunt corner, anterior extremity obtusely rounded
and slightly bowed below, posterior produced above the middle to a well
defined beak-like protuberance;— seen dorsally, broadly oval in outline, with
the greatest width attaining ^1% of the length, side-edges in their greater extent
evenly curved, but distinctly angular behind, anterior extremity obtusely pointed,
posterior abruptly contracted to a narrow conical prominence. Valves of rather
firm consistency, with the surface very uneven, each valve being provided with
6 — 8 somewhat irregular and partly interrupted sharp longitudinal folds or ribs,
2 of which, located near the ventral face, are particularly strong and terminate
behind in dentiform projections; a faint reticulation moreover present, especially
visible in the posterior part of the shell. Anterior antennae very slender, with
the 2nd joint of the terminal part the longest, last joint a little shorter than
the preceding one. Posterior antennae with the dividing suture of the penulti-
mate joint located rather above the middle. Legs comparatively slender, last
pair with the 1st joint of the terminal part about the lengt of the other 2
combined,

Male of nearly same size as female, but having the shell somewhat
narrower, with the posterior extremity more obliquely truncated bebw. Copu-
lative appendages with the basal part oval in shape and sending off below a
knife-schaped recurved piece, copulatory string not much prolonged, but con-
siderably thickened at the base; terminal part produced at the end to a beak-
shaped projection and having the anterior edge bowed in the middle.

Colour of shell light brownish or violaceous.

Length of adult female 0.52 mm.

Remarks. — The present species is easily recognised from the other indi-
genous forms by the short and tumid shell and by the sharp longitudinal ribs
adorning the valves and partly terminating behind in dentiform projections.
Some of the forms recorded by G. W. Miiller from the Gulf of Naples come
very near to this species, though none of them are apparently strictly identical
with the northern form.

Occurrence. — 1 have taken this form not unfrequently in several places of
our south and west coasts, from the Christiania Fjord to Trondhjem, at depths
ranging from 6 to 20 fathoms, sandy bottom.

Distribution. — British Isles, ? Mediterranean.

Fossil. — Norway, British Isles.

212

108. Cyiherura lineata, Brady.

(PI. XCVIII, fig. 2).
Cytherura lineata, Brady, Mon. rec. Brit. Ostracoda. p. 441, PI. XXXII, figs. 30— 3i,

Specific Characters. — Female. Shell, seen laterally, oblong oval in shape,
somewhat higher in front than behind, greatest height about equal to half the
length, dorsal margin gently arched throughout and sloping quite evenly to
the tip of the hind protuberance, ventral margin scarcely at all sinuated and
only slightly bovi^ed behind, anterior extremity broadly rounded, posterior pro-
duced to a well-marked protuberance somewhat obliquely truncated at the tip
and located a little above the longitudinal axis of the shell; — seen dorsally,
regularly oblong oval in outline, with the greatest width in the middle and
equal to half the length, side-edges evenly bowed, both extremities pointed,
the posterior somewhat more abruptly contracted than the anterior. — Valves
rather thin and pellucid, surface marked with fainte longitudinal striae, which
are connected by transverse lines, thus forming a very distinct reticulate pattern
extending over the whole of the shell. There is however no trace of any
punctation, such as found in C. striata, its nearest ally. Both pairs of antennae
unusually short and stout, the anterior ones with the first 3 joints of the
terminal part of uniform length, last joint somewhat shorter. Posterior antennae
with the dividing suture of penultimate joint located exactly in the middle.

Male not observed.

Colour of the shell not yet ascertained.

Length of adult female 0.45 mm.

Remarks. — I think I am right in identifying the above-described form with
that originally recorded by Brady, as it on the whole agrees pretty well with
the figures given in his Monograph. The author has however subsequently
(in 1889) withdrawn this species, supposing it to be founded only on young
specimens of his C. cornuta, a view which I am by no means prepared to
assent. It seems to me to be a well defined species, nearest allied to the
above described C. striata, from which it is however at once distinguished by
the very different shape of the shell, as seen dorsally.

Occurrence. — A solitary female specimen only of this form has as yet come
under my notice. It was found among some Ostracoda collected at Riser,
south coast of Norway, from depths of 10 — 20 fathoms.

Distribution. — British Isles.

lUUlC.

4

213
109. Cytherura undata, G. O. Sars.

(PI. XCIX, fig. 1).

Cytherura undata, G. O. Sars, Oversigt af Norges marine Ostracoder, p. 75.
Syn: Cytherura humilis, Brady.
„ — pumila, Norman.

Specific Characters. — Female. Shell somewhat compressed, seen laterally,
oval subrhomboid in shape, a little higher in front than behind, greatest height
exceeding somewhat half the length, dorsal margin quite evenly arched throug-
hout, ventral margin nearly straight and terminating behind in an angular
corner, anterior extremity rather obliquely rounded, posterior obliquely trun-
cated below and forming about in the middle a very short and blunt protu-
berance;— seen dorsally, oblong oval in outline, with the greatest width not
nearly attaining half the length, side-edges scarcely at all curved and somewhat
waved, anterior extremity tapering to a blunt point, posterior abruptly con-
tracted to a short conical prominence. Valves of rather firm consistency and
very little pellucid, surface much uneven, exhibiting a peculiar undulate or
wrinkled appearance, the wrinkles being only few in number and rather irregu-
larly arranged, forming in the posterior part of the shell more or less elevated
rounded protuberances. Anterior antennae with the terminal part rather coarse,
last joint however very small. Posterior antennae with the dividing suture of
penultimate joint located somewhat above the middle. Legs not much pro-
longed, last pair with the 1st joint of the terminal part shorter than the other
2 combined.

Male of rather smaller size than female and having the shell much nar-
rower, with the dorsal margin quite straight in the middle. Copulative appen-
dages with the basal part obliquely oval in shape and sending off below 2
unequal processes, the anterior one the larger and drawn out to a narrow
slightly recurved lappet, copulatory string very coarse and curled up in a dense
spiral; terminal part oblong quadrangular in form, being almost transversely
truncated at the end.

Colour of shell opaquous bluish gray.

Length of adult female 0.52 mm.

Remarks.— This is an easily recognisable species, being in particular
distinguished by the peculiarly undulated or wrinkled surface of the valves, to
which character indeed the specific name proposed alludes.

Occurrence. — I have taken this form occasionally in several places on the
Norwegian coast, from the Christiania Fjord up to the Lofoten islands. All
the specimens were found in the laminarian zone on a sandy bottom.

214

Distribution. — British Isles, Holland, Spitzbergen, Dawis Strait, Gulf of
St. Lawrence.

Fossil: — Norway, British Isles, Canada.

110. Cytherura fuiva, Brady & Robertson.
(PI. XCIX, fig. 1).

Cytherura fulva, Brady & Robertson, Ann. Mag. Nat. Hist., ser. IV, Vol. XIII, p. 116,

Pi. IV, figs. 1—5.

Specific Characters.— Female. Shell very tumid, seen laterally, suboval in
shape, equally high in front and behind, greatest height about half the length,
dorsal margin nearly straight in the middle and evenly bent both in front and
behind, ventral margin very slightly sinuated and gently boved behind, anterior
extremity well rounded, posterior produced in the middle to a rather short and
blunt protuberance; — seen dorsally, broadly and regularly ovoid in outline, with
the greatest width somewhat behind the middle and considerably exceeding
half the length, side-edges quite evenly curved throughout, posterior extremity
more sharply pointed than the anterior. — Valves nearly equal and rather
opacous, surface evenly convex and marked with scattered rounded tubercles,
exhibiting moreover a very delicate regular reticulation; inner duplicatures
much narrower than in the other known species and quite simple, being evenly
emarginated both in front and behind. — Anterior antennae very slender, with
the last joint of the terminal part much prolonged, being almost twice as long
as the preceding joint. Posterior antennae with the penultimate joint extremely
narrow and wanting the usual dividing suture, the 2 lateral setiferous ledges
quite opposite. Mandibles with the outermost outting tooth remarkably strong
and prominent, the others short and blunt. Maxillae with the distal joint of
the palp unusually prolonged. Legs of moderate length, last pair with the
1st joint of the terminal part about as long as the other 2 combined.

Male of smaller size than female, but resembling it in the general shape
of the shell. 1st pair of legs comparatively more strongly built than in female.
Copulative appendages very large and compact, with numerous irregular
chitinous thickenings partly projecting anteriorly, copulatory string of very
delicate structure; terminal part not clearly defined from the basal one, and
ending in a thin triangular lamella.

Colour of shell, according to Brady yellowish.

Length of adult female 0.50 mm.

I

215

Remarks.— This is a somewhat anomalous species, differing from the other
known forms notably, both in the structure of the shell and in that of some
of the appendages, though apparently referable to the present genus.

Occurrence. — Some few specimens of this remarkable form were obtained at
Korshavn, south coast of Norway, from a depth of 20 — 30 fathoms, muddy sand.

Distribution.— Bniish Isles, Holland, Fosse de Cape Breton, Bay of Biscay.

HI. Cytherura clathrata, G. O. Sars.

(PI. C, fig. 5).

Cytherura clathrata, G. O. Sars, Oversigt af Norges marine Ostracoder, pag. 77.

Specific Characters. — Female. — Shell somewhat compressed, seen laterally,
rounded subtrigonal i shape, greatest height in the middle and almost attaining
^3 of the length, dorsal margin boldly arched, and sloping rather steeply both
in front and behind, ventral margin not at all sinuated, being distinctly convex
throghout, anterior extremity rather oblique and narrowly rounded below, with
the edge divided into 3 — 4 short and broad tooth-like projections, posterior
extremity produced about in the middle to a comparatively short protuberance,
well defined below by a distinct sinus;— seen dorsally, oblong oval or
somewhat lanceolate in outline, with the greatest width behind the middle
and about equal to half the length, anterior extremity gradually tapered to a
sharp point, posterior abruptly contracted at the end, to form a narrow conical
prominence. — Valves of rather firm consistency and remarkably unequal, the
right one considerably overlapping the left along the dorsal face, and having
the hind protuberance conspicuously narrower, each valve provided near the
ventral face with a well-marked longitudinal crest appearing, in the dorsal aspect
of the shell, as a thin border flanking the sides, posterior part of the shell
with 2 superposed rounded protuberances on each side; surface roughly reti-
culated, the meshes being defined by distinctly elevated ribs, one of these
ribs, running along the middle of each valve being particularly strong, inner
duplicatures quite simple, emarginated both in front and behind.— Anterior
antennae comparatively slender, with the 2 middle joints of the terminal part
nearly equal in length, last joint about half as long as the preceding one.
Posterior antennae much coarser, with a well marked oblique suture of the
penultimate joint a little above the middle, apical claws more slender than in
the other species. Legs of moderate length, last pair with the 1st joint of the
terminal part about as long as the other 2 combined.

216

Male somewhat smaller than female, but scarcely differing from it in
general shape of the shell. Copulative appendages of comparatively small
size and simple structure, basal part rounded quadrangular in shape, with only
a few chitinous thickenings and a small pointed process below; terminal part^
abruptly recurved, having the form of a thin falcate lamella.

Colour of shell dark violaceous brown.

Length of adult female 0.62 mm.

Remarks. — The present form differs notably from those described in
preceding pages in the shape and structure of the shell, and should perhaps
more properly be included in a particular genus together with the succeeding
species to which it is evidently closely allied. _

Occurrence. — I have only met with this form in a single locality, viz., inB
the 0stnaes Fjord, at the Lofoten islands, where a few specimens were taken
in a depth of 6 — 12 fathoms, sandy bottom.

Distribution. — British Isles, Arctic Sea; Spitzbergen, Baffins Bay.

Fossil: — Norway, British Isles.

112. Cytherura cellulosa, (Norman).
(PI. C, fig. 2).

Cythere cellulosa, Norman. Nat. Hist. Trans. Northumb. & Durham, Vol. I, p. 22,
Pi. V, figs. 17—20, Pi. VI, fig. 17.

Syn: Cytherura nana. G. O. Sars.

Specific Characters. — Female. Shell much compressed, seen laterally, oval
subrhomboid in shape, greatest height in the middle and about equal to V«M
of the length, dorsal margin well arched throughout, ventral nearly straight
and terminating behind in a blunt corner, anterior extremity obliquely rounded,
with the edge divided below into 5 blunt tooth-like projections, posterior
extremity obliquely truncated below and produced somewhat above the middle
to a blunt protuberance; — seen dorsally, narrow oblong in outline, the greatest
width scarcely exceeding V3 of the length, side-edges straight and parallel in
the middle, both extremities pointed, the posterior somewhat more abruptly
contracted than the anterior.— Valves, as in the preceding species, very unequal
and dissimilar in shape, surface however quite evenly convex, without any
projecting ribs, but marked with a number of irregular rounded areolae of
of unequal size, each containing in the middle a little knob-shaped tubercle; inner
duplicatures, as in the preceding species, simply emarginate. — Anterior antennae
somewhat less slender than in the said species, with the terminal joint rathei

217

smaller. Posterior antennae very like those in C. clathrata, but with the apical
claws comparatively shorter. Legs likewise shorter; last pair with the 1st joint
of the terminal part not attaining the length of the other 2 combined.

Male of smaller size than female and having the shell comparatively less
high. Copulative appendages of almost exactly same structure as in the pre-
ceding species.

Colour of shell dark reddish brown, with the marginal parts lighter.

Length of adult female scarcely exceeding 0.35 mm.

Remarks. — The present species agrees in almost all the structual details
closely with C. clathrata. It is however of very much smaller size, being in
reality one of the smallest Ostracoda known, and differs moreover conspicuously
in the sculpture of the shell.

Occurrence.— \ have taken this form not infrequently in several places of
the south and west coasts of Norway among algae of the littoral zone. Owing
to its extremely small size it may however easily escape to attention.

Distribution.— Bniish Isles, Holland, Fosse de Cape Breton, Bay of Biscay,
Mediterranean.

Fossil: — Norway, British Isles.

Subfam. 5. Loxoconchinae.

Remarks.— In this subfamily I propose to include the 2 genera Loxoconcha
and Cytheropieron, which seem to me to present some characters in common,
thus forming a natural group distinguishing itself from the other subfamilies
here recorded. Both genera are well represented in the Fauna of Norway.

Gen. 43. Loxoconcha, G. O. Sars, 1865.

Syn: Normania. Brady.

Generic character s.—S\\&\\ more or less pronouncedly rhomboid in shape,
with the posterior part rather bowed and compressed below. Surface of valves
evenly convex, without any traces of lateral expansions. Hinge with the
closing teeth distinct, though rather small. Eyes well developed, in some cases
confluent. Anterior antennae with the terminal part, as a rule, composed of 4
joints clothed with scattered simple setae, the last one rather prolonged. Posterior
antenna without any dividing suture of the penultimate joint, anterior setiferous

27 - Crustacea,

218

ledge of this joint placed at a higher level than the posterior, apical claws com-
paratively slender. Mandibles of normal structure, with the palp rather large
but imperfectly jointed, vibratory plate well developed, being provided with 3
plumose setae and a rudiment of a 4th. Maxillae with the terminal joint of
the palp rather prolonged, narrow cylindrical in shape, vibratory plate with only
one of the setae at the base deflexed. Legs comparatively slender, rapidly
increasing in length posteriorly. Caudal lamellae provided behind with a knob-
like prominence carrying 2 divergent setae. Copulative appendages of male
with the terminal part somewhat imperfectly defined and more or less boot-
shaped.

Remarks. — This genus is chiefly characterised by the short rhomboid
shape of the shell, and by the want of any lateral expansions of the valves.
In the structural details some well marked differences are found between
this and the succeeding genus. It comprises several species both from the
northern Ocean and from more southern latitudes. 4 species, belonging to the
Fauna of Norway, will be described in the sequel.

113. Loxoconcha impressa, (Baird).

(PI. C).

Cy there impressa, Baird, British Entomostraca, p. 175, pi. XXI, fig. 9.

Syn: Cythere viridis, Lilljeborg (not O. Fr. Miiller).
, , flavida, Zencker.

, , rhomboidea, Fisher.

, elliptica, Brady.

, Loxoconcha rhomboidea, G. O. Sars.

Specific Characters.— Female.— SheW rather tumid, seen laterally, short
rhomboid in shape, greatest height in the middle and about equal to ^/s of^l
the length, dorsal margin boldly arched and sloping somewhat more steeply
in front than behind, ventral margin slightly sinuated anteriorly and evenly
bowed behind, anterior extremity obliquely rounded, posterior bluntly prominent
above and oblique below;— seen dorsally, broadly fusiform in outline, with the
greatest width in the middle and exceeding half the length, side-edges boldly
curved, both extremities narrowly contracted and sharply pointed at the end.— Jj
Surface of valves marked with densely set small impressed pits, and moreover
provided with a limited number of somewhat more conspicuous knob-like
tubercles; inner duplicatures rather broad and crossed by distant fine pore-
channels, edges thin and clothed with scattered delicate hairs. Eyes very
conspicuous and widely apart. Anterior antennae exceedingly slender, with thej

1

219

2 middle joints of the terminal part imperfectly separated, last joint very
narrow and prolonged, with the apical setae unusually long and delicate.
Posterior antennas likewise comparatively slender, with the penultimate joint
verry narrow and having the anterior setiferous ledge placed near the base.
Legs moderately prolonged, last pair with the 1st joint of the terminal part
about the length of the other 2 combined.

Male of somewhat larger size, than female an differing conspicuously in
the shape of the shell, which is comparatively less tumid and, seen laterally,
more oblique, with the dorsal margin nearly straight and angularly bent both
in front and behind. Copulative appendages with the basal part oblong oval
in shape and wanting any freely projecting string insides, terminal part pro-
duced in front to an obtuse point and almost rectangular behind.

Colour of shell light yellowish, with very conspicuous dark specks.

Length of adult female 0.64 mm., of male 0.68 mm.

Remarks. — The present form was recorded as early as the year 1850 by
Baird as a species of Cythere. It was however not recognised by the sub-
sequent authors, who described it under several other specific names, as seen
from the above-given list of synonyms. Indeed, I cannot doubt, that both the
form described by Lilljeborg as Cythere viridi's and that recorded by Zencker
as C. flavida are in reality identical with the present species. Brady and
Norman have however referred these forms to a separate species named
Loxoconcha viridis, and quote as a synonym Loxoconcha elliptica Brady. In
my opinion the 3 said forms are quite undistinguishable from the above
described species. Being that recorded at the earliest date, it ought of course
to be regarded as the type of the present genus.

Occurrence. — This is one of our commonest Cytherids, being found rather
abundantly along the whole of our coast in the littoral zone among algae, on
the leafs of which the animals are seen to climb with great dexterity by the
aid of their slender posterior antennae and legs.

Distribution.— British Isles, Kattegat, Baltic, coast of France, Mediterranean.

Fossil. — Norway, British Isles, Calabria.

114. Loxoconcha granulata, G. O. Sars.

(PI. CII, fig. 1).

Loxoconcha granulata, G. O. Sars, Oversigt af Norges marine Ostracoder, p.

Specific Characters. — Female. Shell moderately tumid, seen laterally, more
angular in shape than in the preceding species, greatest height a little behind
the middle and scarcely attaining 73 of the length, dorsal margiu nearly straight

220

and angularly bent both in front and behind, ventral margin slightly sinuated
anteriorly and considerably bowed behind, anterior extremity obliquely rounded,
posterior produced about in the middle .to an obtuse prominence; — seen
dorsally, oblong ovate or somewhat lanceolate in outline, with the greatest
width behind the middle and scarcely exceeding half the length, anterior
extremity gradually tapered to a sharp point, posterior abruptly contracted and
conically produced at the end.— Surface of valves of a dull appearance, being
marked with densely set small, but very distinct impresed pittings. Antennae
far less slender than in the preceding species, the anterior ones with the 2
middle joints of the terminal part distinctly defined, penultimate joint almost
as long as the 2 preceding ones combined, last joint much narrower, but
scarcely shorter, setae on this part remarkably strong, almost spiniform. Posterior
antennae with the setiferous ledges of the penultimate joint located much
farther down than in L impressa. Legs very narrow and prolonged, last pair
with the 1st joint of the terminal part much longer than the other 2 combined,
and having the seta on the end considerably produced.

Male somewhat smaller than female, and having the shell less high,
resembling in shape that in the female of the next species. Copulative
appendages rather compact, subtriangular in shape, and provided insides with
a distinct circularly curved string; terminal part not clearly defined from the
basal one, and produced in front to a very thin somewhat upturned point.

Colour of shell uniformly dark fouscous.

Length of adult female 0.63 mm.

Remarks. — The present species is easily recognised by the rough granula
surface of the valves, to which character indeed the specific name proposed
alludes, and differs also conspicuously from the preceding species in the shape
and colour of the shell. Moreover the structure of the antennae is essentially
different. The Cy there guttata of Norman is scarcely, as opined by Brady &
Norman in 1889, identical with the present species, as the sculpture of the
shell is apparently rather different.

Occurrence. — I have taken this form occasionally in several places of our
coast, from the Christiania Fjord to Finmark, at depths ranging from 10 to
30 fathoms, muddy bottom.

Distribution. — British Isles.

Fossil. — Norway, Scotland.

II

e

J

221

115. Loxoconcha tamarindus (Jones).

(PI. CII, fig. 2).
Cythere tamarindus, Jones, Tertiary Entomostraca, p. 49, PI. Ill, figs 4, a— b.
Syn: Cythere Icevata, Norman.
„ Loxoconcha longipes. G. O Sars.

Specific Characters. — Female. Shell somewhat compressed, seen laterally,
obliquely oval in shape, greatest height only slightly exceeding half the length,
dorsal margin nearly straight, somewhat bent in front and slightly angular
behind, ventral margin a little sinuated in front and evenly bowed behind,
anterior extremity obliquely rounded, posterior slightly prominent above the
middle;— seen dorsally, narrow ovate in outline, with the greatest width behind
the middle and about equal to Vs of the length, anterior extremity gradually
tapered to a sharp point, posterior likewise pointed, but more abruptly con-
tracted at the end. — Valves rather thin, with the surface quite smooth, being
only marked with scattered small knobs. Anterior antennae resembling in
structure those in L. granulata, though the mutual length of the joints of the
terminal part is somewhat different, the last joint being considerably longer
than the preceding one, which does not attains the length of the first 2 joints
combined. Posterior antennae almost exactly as in the said species. Legs
rather prolonged, though scarcely as narrow as in that species.

Male resembling the female in its general appearance, but of somewhat
smaller size and having the shell comparatively narrower. Copulative append-
ages with the basal part oval in shape, and exhibiting inside a very distinct
freely projecting string curved in a circle and bent downwards; terminal part com-
paratively large and rather prominent in front, ending in a very sharp point,
being well defined at the base anteriorly, but behind confluent with the basal part.

Colour of shell light reddish brown, with the marginal parts lighter.

Lenght of adult female 0.60 mm^

Remarks. — This form was recorded as early as the year 1856 by Jones from
fossil shells, and was subsequently observed in the living state by the present
author, who described it under the name of Loxoconcha longipes. It is easily
recognised from the 2 preceding species by the much narrower shape of the
shell, as also by its colour.

Occurrence. — I have met with this form occasionally in several places on
our coast, from the Christiania Fjord to Lofoten, in depths ranging from 10
to 30 fathoms.

Distribution.— Bniish Isles, Iceland, Cap Breton, Mediterranean.

Fossil. — Norway, British Isles, Calabria.

222

■Si

116. Loxoconcha fragilis, G. O. Sars.

(PI. CII, fig. 3).
Loxoconcha fragilis, G. O. Sars, Oversigt af Norges marine Ostracoder, p. 65.

Specific Characters.— Female. Shell much compressed, seen laterally,
oval subrhomboid in shape, greatest height considerably exceeding half the
length, dorsal margin somewhat bowed in the ocular region, but sloping other-
wise with a quite even and gentle curve until the tip of theJiind prominence,
ventral margin slightly sinuated in front and rather bowed behind, anterior
extremity well rounded, posterior produced above to a blunt prominence and
evenly rounded off below; — seen dorsally, narrow oblong in outline, with the
greatest width in the middle and scarcely exceeding Vs of the length, both
extremities evenly contracted and sharply pointed at the end.— Valves very
thin and pellucid, with the posterior part much compressed below, surface
perfectly smooth and polished, without any obvious sculpture, inner duplicatures
remarkably broad posteriorly, marginal zone well defined and crossed by very
distinctly marked pore-channels. Eyes confluent. Anterior antennae very slender,
with all the joints of the terminal part well defined, the last about half the
length of the preceding one. Legs likewise comparatively slender und pro-
longed, last pair with the 1st joint of the terminal part about the length of
the other 2 combined.

Male, as usual, smaller than female, with the shell comparatively narrower.
Copulative appendages rather compact and sending off below 2 or 3 irregular
processes, but without any distinctly defined string insides; terminal part very
small and not clearly defined from the basal one, projecting in front to a
obtuse lobule.

Colour of shell whitish pellucid, with a dark patch behind the ocular region
curving somewhat upwards at the end.

Length of adult female 0.49 mm.

Remarks. — This is a somewhat aberrant species, differing rather con-
spicuously from the other known members of the present genus in the very
thin and fragil shell and in the wholly coalescence of the eyes. The form
recorded by G. W. Miiller from the Gulf of Naples under the name of L. pellu-
eida seems to be nearly allied to the present species, though apparently distinct.

Occurrence. — Although nowhere occurring in any abundance, this form
has been taken in several places of the Norwegian coast, from the Christiania
Fjord to Lofoten, in the sublittoral region among algas.

Distribution. — British Isles.

Fossil. — Scotland.

*

11

region

I

223

Gen. 44. Cytheropteron, G. O. Sars, 1865.

Generic Characters. —ShoW of somewhat varying shape, generally thin and
pellucid, with no sharply marked sculpture. Valves slightly unequal, each
provided with a well defined, more or less prominent alaeform lateral expansion
occurring near the ventral face. Hinge imperfectly developed. Eyes wholly
absent. Anterior antennae with the terminal part, as a rule, only composed of
3 joints clothed with scattered simple setae, last joint very small. Posterior
antennae with a well marked dividing suture of the penultimate joint, and with
the anterior setiierous ledge of this joint located far below. Mandibles strongly
dentate at the end, palp of moderate size, but with the vibratory plate con-
siderably reduced, being only provided with a single seta. Maxillae with the
masticatory lobes rather produced, palp very narrow, with the distal joint small,
vibratory plate, as in Cytherura, provided at the base with 2 thin abruptly
deflexed setae issuing from a well defined lobule. Legs more or less slender
and prolonged. Posterior end of body drawn out to a much prolonged conical
point. Caudal lamellae short, with 3 small bristles, one apical and 2 lateral.
Copulative appendages of male without any freely projecting string insides, but
provided below with 3 peculiar corniform processes, the foremost more or less
ramified at the end; terminal part simple, lamellar.

Remarks. — The present genus is chiefly characterised by the peculiar alae-
form lateral expansions of the valves, to which indeed the generic name pro-
posed alludes. It differs moreover from the preceding genus in the wholly
absence of eyes, as also somewhat in the structure of the antennae. G. W.
Miiller considers it to be nearly allied to Cytherura, but I think that its relation-
ship to Loxoconcha is rather closer. Several species of this genus have been
recorded, all of them being true deep-water forms. In the following pages 10
species will be described as members of the Norwegian Fauna.

117. Cytheropteron latissimum, (Norman).
(PI. CIII).

Cy there latissima, Norman, Nat. Hist. Trans. Northumb. & Durham, Vol. I, p. 19,

PI. VI, figs. 5-8.

Syn: Cytheropteron convexum, G. O. Sars.

Specific Characters. — Female. Shell very tumid, but with the alaform
expansions only slightly prominent, seen laterally, oval subtriangular in shape,
somewhat higher in front than behind, greatest height about equal to ^k of

224

the length, dorsal margin rather bowed in the ocular region, but sloping
evenly behind, ventral margin slightly sinuated in front of the middle, anterior
extremity obliquely rounded and somewhat bowed below, posterior produced
in the middle to an obtuse prominence not clearly defined below; — seen dor-
sally, broadly ovate in outline, with the greatest width behind the middle and
about equal to the height, side-edges iregularly bent posteriorly, anterior
extremity evenly tapered, posterior somewhat abruptly contracted at the end
to a conical prominence. Valves with the alasform expansions well marked,
but not much prominent, terminating behind in an obtuse angle, surface marked
with slight pittings arranged in more or less vertical rows. Antennae moderately
slender, the anterior ones with the penultimate joint about twice as long as
the preceding one. Legs gradually increasing in length posteriorly, last pair
with the 1st joint of the terminal part considerably longer than the other
2 combined. fli

Male a little smaller than female, but only slightly differing in the shape
of the shell. Copulative appendages of moderate size, with the basal part
rounded triangular in shape, foremost corniform proces tripartite at the ex-
tremity; terminal part rather narrow and transversely truncated at the end.

Colour of shell whitish gray, semipellucid.

Length of adult female 0.65 mm.

Remarks. — This form was recorded in the year 1865 by Norman as
species of Cytherej and was in the same year observed by the present author,"
but erroneously identified with Cyihere convexa Baird, which is a true member
of the genus Hemicythere, as defined above. In the general outward appear-
ance it is not unlike some of the species of the genus Loxoconcha, and may
easily, at the first sight, be mistaken as such. On a closer examination it is
however found to differ essentially in the absolute want of eyes and in the
presence of distinct, though rather small alaeform lateral expansions of the
valves. The structure of the limbs and of the copulative appendages in th(
male moreover proves it to be a genuine membre of the present genus.

Occurrence.— \ have taken this form not unfrequently in the upper part of
the Christiania Fjord, as also in several other places on our coast up to
Finmark, at depths ranging from 10 to 30 fathoms muddy bottom.

Distribution.— Bniish Isles, Holland, Iceland, Spitzbergen, Baffins Bay.

Fossil.— Norway, Scotland, Canada.

1i

225

118. Cyiheropieron alaium, G. O. Sars.

(PI. CIV, fig. 1).
Cytheropleron alatum, G. O. Sars, Oversigt af Norges marine Ostracoder, p. 81.

Specific Characters. — Female. Shell exhibiting a very peculiar appearance
on account of the excessive development of the alaeform expansions, seen
laterally, narrow oblong in shape, greatest height in the middle and scarcely
exceeding half the length, dorsal margin gently arched throughout, ventral
very slightly sinuated, anterior extremity obtusely rounded off, posterior pro-
duced in the middle to a well-defined protuberance somewhat obliquely trun-
cated at the end;— seen dorsally, very broad, square-shaped, with the width
between the tips of the alaeform expansions fully attaining the length, both
extremities narrowly produced. — Valves thin and pellucid, without any obvious
sculpture, alaeform expansions remarkably large and prominent, extending
somewhat downwards, and triangular in shape, each exerted at the end to a
sharp spiniform process, posterior edge of the expansion provided with a row
of peculiar appendages, the 2 proximal ones somewhat remote from the others
and lamelliform, being divided at the end into fine points; inner duplicatures
of the valves rather broad and crossed by scattered fine pore-channels. — An-
tennae of a structure very similar to that in the preceding species. Legs
extremely slender and narrow, with the apical claw much prolonged. Posterior
end of body produced in a remarkably long conical process.

Male of rather smaller size than female, but resembhng it in the general
shape of the shell. Copulative appendages built on the same type as in C.
latisslmum, but with the basal part comparatively smaller and the corniform
processes somewhat differing in shape; terminal part rather large, subtriangular.

Colour of shell whitish pellucid.

Length of adult female 0.70 mm.

Remarks.— Ih^ present form is at once recognised from any of the other
known species by the enormous development of the alaeform expansions of
the valves, giving the animal a quite particular appearance, and rendering it
rather difficult to get a lateral view of the shell.

Occurrence. — The species was first observed in the upper part of the
Christiania Fjord, where a few specimens were taken in a depth of about 30
fathoms, and I have subsequently met with it occasionally also in some other
places on the south coast of Norway (Riser, Korshavn) at about the same depth.

Distribution.— Bniish Isles, Shetland.

28 — Crustacea.

226

119. Cytheropieron hamatum, G. O. Sars.

(PI. CIV, fig. 2).
Cytheropteron hamatum, G. O. Sars, Chr. Vid. Selsk. Forhandl. 1869, p. 172.

Specific Characters. — Female. Shell much shorter and stouter than in the
preceding species, with the alaeform expansions far less developed, seen later-
ally, irregularly oval in shape, g eatest height in the middle and about equal
to % of the length, dorsal margin considerably arched, ventral slightly sinuated
in front and evenly convex behind, anterior extremity rather obliquely rounded,
posterior produced in the middle to a well defined protuberane, narrowly
truncated at the end; — seen dorsally, somewhat lozenge-shaped, with the greatest
width (between the tips of the alaeform expansions) not nearly attaining the
length, both extremities sharply pointed, the posterior more abruptly contracted
than the anterior. — Valves somewhat coarser than in the preceding species,
with the alaeform expansions short rectangular in shape and issuing rather
behind the middle, each produced at the end to a sharp spiniform process
more or less distinctly curved forwards in a hamiform manner; surface marked
with slight pittings arranged partly in concentric rows. Antennae comparatively
less slender than in C. alatum, but of a very similar structure. Legs likewise
less narrow and prolonged than in that species. J I

Male resembling the female in the shape of the shell, butt of somewhat
smaller size. Copulative appendages rather like those in the preceding species,
differing however somewhat in the shape of the corniform processes, as also,
in that of the terminal part, which is narrowly rounded at the end.

Colour of shell whitish grey.

Length of adult female 0.62 mm.

Remarks. — Though rather closely allied to C. alatum, this species
once d'stinguished by the more compact appearance of the shell and by the
far less prominent alaeform expansions, wh ch do not exhibit any appendages
posteriorly and have the terminal spine somewhat hamiform curved, hence the
specific name proposed. ' m\

Occurrence. — The only locality where 1 have as yet met with this species,
is at Skraaven, one of the Lofoten islands. It was found here occasionally at
the considerable depth of 120—300 fathoms, muddy bottom. Norman has,
however taken it at Stoksund, west coast of Norway.

DLslribution.S^'xizhtxgtn, Dawis Strait,

Fossil. — Scotland.

^1

227

120. Cyiheropteron punctatum, Brady.

(PI. CV, fig. 1).
Cyiheropteron punctatum, Brady, Mon. Brit. rec. Ostracoda, p. 449, PI. XXXIV, figs. 45—48.

Specific Characters. — Female. Shell comparatively short and stout, with
the alaeform expansions well defined, but quite simple, seen laterally, suboval
in shape, greatest height in the middle and about equal to 7^ ol the length,
dorsal margin considerably arched, ventral scarcely at all sinuated, anterior
extremity somewhat produced and obtusely rounded off at the end, posterior
drawn out in the middle to a distinct obtusely conical protuberance defined
above by a well-marked sinus; — seen dorsally, square-shaped in outline, with
the greatest width (between the tips of the alaeform expansions) somewhat
exceeding V.t of the length, anterior extremity gradually tapered to a sharp
point, posterior abruptly contracted and terminating in a conical prominence.
— Valves with the alaeform expansions somewhat prominent, triangular in shape,
terminating behind in an obtuse-angular corner; surface of shell closely punc-
tate. Limbs scarely exhibiting any noticeable particularity in their structure.

Male not observed.

Colour of shell whitish, semipellucid.

Length of adult female 0.45 mm.

Remarks. — This is a very small species and may, at the first sight, easily
be mistaken to be only the young of C. latissimum. It is however quite cer-
tainly distinct, differing conspicuously by the much more prominent alaeform
expansions, as also by the very distinct punctation of the valves.

Occurrence.— Two female specimens only of this form have as yet come
under my notice. They were found at Korshavn, south coast of Norway, at
a depth of about 30 fathoms, muddy sand. Norman has taken it also at
Sartoro, near Bergen.

Distribution. — British Isles, Fosse de Cap Breton, Bay of Biscay.

12L Cytheropteron crassipinnatum, Brady & Norman,
(PI. CV, fig. 2).

Cytheropteron crassipinnatum, Brady & Norman, Mon. recent marine & freshwater
Ostracoda 1889, p. 212, PI. XX, figs. 16-18.

Specific Characters. — Female. Shell with the alaeform expansions con-
siderably produced, but without any apical or lateral spines, seen laterally,
oblong oval in shape, a little higher in front than behind, greatest height
somewhat exceeding half the length, dorsal margin rather arched in front and

228

sloping gently behind, ventral margin slightly sinuated, anterior extremity
obtusely rounded, posterior produced to a blunt prominence located somewhat
above the longitudinal axis of the shell; — seen dorsally, square-shaped, with
the width, between the tips of the alasform expansions, somewhat less than
the length, both extremities narrowly produced. — Valves rather thin and pellucid,
with scattered small pits on the surface, alaeform expansions rather prominent,
triangular in shape, and projected about in the middle, each terminating in a
somewhat swollen blunt corner. — Anterior antennae with the terminal part rathelH
thin and scarcely longer than the distal joint of the basal part, being distinctly
quadriarticulate. Posterior antennae of the usual structure. Legs rather slender
and produced, last pair with the 1st joint of the terminal part considerablj
longer than the other 2 combined.

Colour of shell whitish.

Length of adult female 0.44 mm.

Male unknown.

Remarks- -This is also a very small species, and apparently nearly alliec
to tl e preceding one, though easily distinguished by the considerably more
prominent alaeform expansions and their rather different form. The shape of_.
the shell is also somewhat dissimilar. ™

Occurrence. — A single female specimen of this form was found among
some Osiracoda collected at Riser, south coast of Norway, at depths ranging
from 10 to 30 fathoms.

Distribution.— W^si of Ireland.

122. Cytheropteron angulatum, Brady.
(PI. CV, fig. 3).

Cytheropteron angulatum, Brady & Robertson, Ann. Mag. Nat. Hist., ser. IV, Vol. IX, p. 62?

PI. 2, figs. 7, 8.

Specific Characters.— Female. Shell of a peculiar angular appearance, with
the alaeform expansions rather slight, seen laterally, irregularly oblon-^ oval in
shape, somewhat higher in front than behind, greatest height slightly exceeding
half the length, dorsal margin well arched in front of the middle, but sloping
gently behind, ventral margin slightly sinuated anteriorly and curving evenly
upwards behind, anterior extremity obtusely rounded, posterior somewhat
obliquely truncated, with the upper corner distinctly projecting, lower obsolete; —
seen dorsally, rather irregular in outline, with the greatest width in front of
the middle and about equal to ^jh of the length, side-edges evenly bowed in

229

front, but irregularly wawed behind, anterior extremity gradually tapered to an
obtuse point, posterior abruptly truncated at the end. Valves rather uneven
in their posterior part, each valve being produced at the supero-posteal corner
to a rather prominent obtuse protuberance and having laterally 2 or 3 nodi-
form prominences; alaeform expansiors located somewhat in front of the middle
and quite simple, arcuate; surface of valves marked with rather slight scattered
pittings.— Anterior antennae with the terminal part 3-articulate and about twice
as long as the distale joint of the basal part. Posterior antennae of quite
normal structure. Legs moderately slender, last pair with the 1st joint of the
terminal part about the length of the other 2 combined.

Colour of shell not yet ascertained.

Length of adult female 0.52 mm.

Male, unknown.

Remarks. — In the outward appearance of the shell this form differs con-
spicuously from any of the other known species: but the structure of the several
appendages proves it in reality to be a true membre of the present genus.

Occurrence. — A single female specimen only of this peculiar form has as
yet come under my notice. It was found among some Ostracoda collected,
some years ago, at Ris0r, south coast of Norway, in depths ranging from 10
to 20 fathoms.

Distribution. — British Isles.

Fossil. — Scotland, Canada.

123. Cytheropieron subcircinatum, G. O. Sars.

(PI. CV, fig. 4).
Cytheropieron subcircinatum, G. O. Sars, Oversigt af Norges marine Ostracoder, p. 81.

Specific Characters. — Female. Shell rather tumid, but with the alasform
expansions poorly developed, seen laterally, short oval in shape, greatest height
in the middle and about equal to Vs of the length, dorsal margin evenly
arched and sloping somewhat more steeply behind than in front, ventral margin
very slightly sinuated anteriorly and gently convex behind, anterior extremity
narrowly rounded, posterior produced in the middle to a blunt prominence; —
seen dorsally, almost circular in outline, though having the extremities some-
what produced, greatest width a little behind the middle and about equal to
^3 of the length, side-edges evenly curved. — Valves rather thin, semipellucid,
with the surface smooth and only marked with small scattered puncta; alae-
form expansions very little prominent, in the form of slight borders flanking

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230

the shell near the ventral face. Anterior antennae of the usual structure.
Posterior antennae with the dividing suture of penultimate joint imperfectly
defined. Legs moderately slender, last pair with the 1st joint of the terminal
part about the length of the other 2 combined.

Colour of shell whitish.

Length of adult female 0.58 mm.

Male unknown.

Remarks.— The present species is easily recognised from those described
in the preceding pages by the almost circular shape of the shell, as seen
dorsally, a character which indeed has given rise to the specific name
proposed.

Occurrence. — I have taken this form occasionally in the upper part of the
Oslo Fjord, as also at Riser, south coast of Norway. Norman records it more-
over from Lervik, Hardanger Fjord.

Distribution. — British Isles.

124. Cytheropteron testudo, G. O. Sars.

(PI. CVI. fig. 1).

Cytheropteron testudo, G. O. Sars, Chr. Vid. Selsk. Forh. 1869, p. 29.

Specific Characters. — Female. Shell moderately tumid, seen laterally, short
oval or somewhat pyriform in shape, greatest height a little in front of the
middle and about equal to ^5 of the length, dorsal margin boldly arched and
sloping rather steeply both in front and behind, ventral margin scarcely at all
sinuated, being gently convex thoughout, anterior extremity obliquely rounded,
posterior drawn out to a very narrow and prominent caudiform projection
located somewhat below the longitudinal axis of the shell:— seen dorsally,
suboval in outline, with the greatest width nearly equal to the height, side-
edges evenly curved, anterior extremity only slightly contracted and remark-
ably blunt at the end, posterior tapered to a narrow conical prominence. —
Valves of rather firm consistency and but little pellucid, with the surface evenly
convex and closely punctate, being moreover marked with scattered small
tubercles; alaeform expansions rather slight, in the form of evenly curvedaj
borders flanking the shell near its ventral face. Limbs on the whole quite
normal in structure.

Colour of shell opacous white.

Length of adult female 0.50 mm.

Male unknown.

idi

231

Remarks.— The present species is nearly allied to C. subcircinatum, but
easily distinguished by the greatly projecting caudiform prominene of the shell
behind, giving it a quite particular appearance. The shell differs moreover
conspicuously in its sculpture, as also in the remarkably blunt anterior extre-
mity, as seen dorsally.

Occurrence. — I have only met with this species at the Lofoten islands,
where a few female specimens were taken, many years ago, from the con-
siderable depth of 120 fathoms. Norman has recorded the species also from
great deeps of the Hardanger Fjord.

Distribution, — Not yet observed out of Norway.

125. Cytheropteron inflatum, Brady.

(PI. CVI, fig. 2).
Cytheropteron inflatum, Brady, Ann. M.ig. Nat. Hist., ser. IV, Vol. II, p 33. figs. 8 — 10.

Specific Characters. — Female. Shell moderately tumid, seen laterally, oval
subtrigonal in shape, greatest height in the middle and about equal to ^k of
the length, dorsal margin very strongly, almost gibbuusly arched in the middle
and sloping steeply, with a slight concavity, to each extremity, ventral margin
slightly sinuated and curving gently upwards behind, anterior extremity some-
what obliquely rounded, posterior obtusely produced et the end; — seen dorsally,
regularly fusiform in outline, with the greatest width in the middle and about
equal to the height, side-edges quite evenly curved, both extremities gradually
contracted and nearly equal. — Valves rather thin, with the surface smooth'
only marked with slight scattered pits; alaeform expansions simple rounded off.
Limbs of a structure very similar to that in C. subcircinatum.

Colour of shell whitish semipellusid.

Length of adult female 0.55 mm.

Male unknown.

Remarks.— Iht above described species agrees with the 2 preceding ones
in the quite simple rounded alaeform expansions of the valves, but is easily
distinguished from either of them by the general shape of the shell. The
specitic name is somewhat unappropriate, as the shell in reality is less tumid
than in most of the other species.

Occurrence. — A single female specimen only of this form has as yet come
under my notice. It was taken at Korshavn, south coast of Norway from a
depth of about 30 fathoms, muddy sand.

Distribution. — British Isles.

232
126. Cytheropteron nodosum, Brady.

(PI. CVl, fig. 3).
Cytheropteron nodosum, Brady, Mon. Brit. Ostracoda, p. 448, PI. XXXIV, figs. 31—34.

Specific Characters. — Female. Shell comparatively more tumid than in
the preceding species, seen laterally, suboval in shape, greatest height in the
middle and about equal to 7^ of the length, dorsal margin quite evenly arched
throughout, ventral slightly sinuated in front of the middle, anterior extremity
obliquely rounded, posterior bluntly produced at the end; — seen dorsally,
broadly ovate in outline, with the greatest width somewhat behind the middle
and rather exceeding 7^ of the length, side-edges evenly curved, both extre-
mities pointed and nearly equal.— Valves rather thin, semipellucid, each exhibiting
dorsally 2 rounded nodiform protuberances, the one at some distance from the
anterior extremity, the other quite posteriorly; alaeform expansions rather slight
and quite evenly rounded off; surface of valves faintly punctate. Antennae
almost exactly as in the preceding species. Legs however comparatively more
slender, last pair with the 1st joint of the terminal part exceeding somewhat
in length the other 2 combined.

Colour of shell whitish, semipellucid.

Length of adult female 0.58 mm.

Male unknown.

Remarks.— This species is closely allied to the preceding one, and may
indeed, at the first sight, easily be confounded with it. On a closer exami-
nation it is however found to differs somewhat in the shape of the shell, and
more particularly in the presence of the characteristic nodiform protuberances
on the dorsal face of the valves, to which the name of the species alludes

Occurrence.— Of this form likewise only a single female specimen has as
yet come under my notice. It was found in the same locality as the preceding
species. Norman has taken it also in 2 localities of our western coast.

Distribution — British Isles, Fosse de Cap Breton, Bay of Biscay, Gulf o
St. Lawrence.

Fossil. — British Isles, Canada.

I

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II

Subfam. 6. Bythocytherinae.

Remarks. — The type of this subfamily is the genus Bythocythere G. O.
Sars, with which the somewhat anomalous genus Pseudocythere G. O. Sars^
apparently ought to be associated. Moreover I have felt justified to considei

233

the form previously recorded as Bythocyihere simplex Norman, as the type of
a particular genus likewise included within the present subfamily.

Gen. 45. Bythocythere, G. O. Sars, 1865.

Generic Characters. — Shell of somewhat varying shape, but as a rule rather
tumid, with more or less conspicuous lateral expansions and with the posterior
extremity obtusely produced. Valves comparatively thin, with the surface
smooth or faintly punctate; hinge imperfectly developed. Eyes in most cases
wanting. Anterior antennae with the segments of the basal part rather dilated,
the distal one obpyriform in shape and provided with 3 bristles, one on each
side and one rather smaller at the end; terminal part very narrow and flexible,
4-articulate, with the joints nearly equal in length and clothed with scattered
simple setae. Posterior antennae with the 1st joint of the terminal part rather
large, middle joint not subdivided and having the anterior setiferous ledge
close to the end, last joint armed with 3 claws successively increasing in length
posteriorly; flagellum with the knee above the middle. Mandibular palp with
the vibratory plate well developed, fringed with 6 — 8 plumose setae. Maxillae
with both the masticatory lobes and the palp short and stout, vibratory plate
comparatively large and provided at the base with 4 densely crowded deflexed
bristles. Legs slender and prolonged, seta at the base of the 1st pair replaced
by a small lamella divided at the end into 2 finely ciliated setiform lashes
and having moreover 2 simple bristles laterally; each of the 2 proximal joiiits
of the terminal part in all the pairs provided at the end anteriorly with a well
defined seta. Caudal lamellae somewhat deflexed and conically produced, with
one apical and 2 lateral bristles. Copulative appendages of male comparatively
small, with the terminal part well defined and abruptly deflexed.

Remarks. — This genus was established in the year 1865 by the present
author and has been admitted by all subsequent authors. It is here taken in
a somewhat more restricted sense than at first adopted, one of the species,
B. simplex Norman being, as mentioned above, discarded to form the type
of a particular genus, Macrocythere. 5 species referable to the present genus
will be described in the sequel.

127. Bythocythere turgida, G. O. Sars.

(PI. CVII).

Bythocythere turgida, G. O. Sars, Oversigt af Norges marine Ostracoder, p. 84.

Specific Characters. — Female. Shell very tumid, with the ventral face
flattened, seen laterally, short subrhomboid in shape, nearly equally high in

29 — Crustacea.

234

front and behind, greatest height about equal to 7^ of the length, dorsal margin
very slightly arched and somewhat angularly bent in the ocular region, ventral
margin indistinctly sinuated in front and rather bowed hehind, anterior extremity
obliquely rounded, posterior produced above the middle to a blunt prominence
defined dorsally by a slight sinus; — seen dorsally, broadly ovate or cordiform
in outline, with the greatest width behind and almost attaining ^3 of the length,
side-edges gradually expanding backwards and abruptly bent near the posterior
part of the shell, anterior extremity obtusely pointed, posterior abruptly con-
tracted to a conical prominence;— end-view short pyramidal. — Valves of some-
what firmer consistency than in most of the other species, though rather
pellucid, each exhibiting a well marked obtuse expansion flanking the side
below and terminating behind in a rounded corner; surface otherwise smooth
and marked with small rounded pits more conspicuous in the lower part of
the shell, posterior edge of each valve fringed below with a regular row of f |
small denticles. Eyes distinctly visible in the living animal, though rather
poorly developed, with light pigment.— Anterior antennae with the terminal
part considerably exceeding in length the basal one, last joint very narrow
and carrying on the tip a bunch of rather long and thin bristles. Posterior
antennae with the 1st joint of the terminal part fully twice as long as broad,
middle joint much narrower, last joint very small. Legs moderately slender,
last pair with the 1st joint of the terminal part shorter than the other 2
combined.

Male very like the female both in size and in the general shape of the
shell. Copulative appendages with the terminal part considerably produced,
lanceolate in form.

Colour of shell light yellowish white, variagated with a few small reddish
specks dorsally.

Length of adult female 0.90 mm.

Remarks. — The above-described form ought to be regarded as the type
of the present genus, being that first named of the species originally recorded.
It is easily recognised from the other known species by the short and com-
pact shape of the shell and by the presence of distinct, though rather poorly ,
developed eyes. f I

Occurrence.— \ first met with this form in the Hallandspol near Drobak,
where some few specimens were found at a depth of about 10 fathoms, muddy
bottom, and I have subsequently also taken it in several other places, both
on the south and west coasts of Norway in moderate depths.

Distribution. — British Isles, Spitzbergen, Gulf of St. Lawrence.

1

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235

128. Bythocythere constricta, G. O. Sars.

(PI. CVIII, fig. 1).
Bythocythere constricta, G. O. Sars, Oversigt af Norges marine Ostracoder, p. 85.

Specific Characters. — Female. Shell much less compact than in the pre-
ceding species, seen laterally, oblong subquadrangular in shape, somewhat
higher behind than in front, greatest height scarcely exceeding half the length,
dorsal margin perfectly straight and horizontal, being somewhat angularly bent
hoth in front and behind, ventral margin slightly sinuated anteriorly and con-
siderably bowed behind, anterior extremity obtusely rounded off, posterior pro-
duced, considerably above the middle, to a well-marked rather broad protuber-
ance obliquely truncated at the end; — seen dorsally, irregularly fusiform in
outline, exhibiting, somewhat in front of the middle, a very conspicuous deep
constriction, side-edges both in front and behind the constriction abruptly
bowed, greatest width somewhat less than the height, anterior extremity
obtusely pointed, posterior gradually tapered to a narrow conical prominence.
Valves very thin and pellucid, with the lateral expansions rather slight, surface
slightly rugulose and faintly marked with small scattered pits, edges of valves
quite smooth. Eyes wholly absent. Antennae of a structure very similar to
that in the preceding species. Legs however comparatively more slender and
prolonged, last pair with the 1st joint of the terminal part about the length
of the other 2 combined.

Male of smaller size than female, but resembling it in the general shape
of the shell, though having the posterior part somewhat broader, as seen
laterally. Copulative appendages of a structure very similar to that in the
preceding species.

Colour of shell uniformly whitish pellucid.

Length of adult female 0.80 mm.

Remarks. — Though closely agreeing with the preceeding species in the
structure of the several appendages, the present form is at once distinguished
by the rather different appearance of the shell, and more particularly by its
very conspicuous mediate constriction, as seen dorsally, a character which
indeed has given rise to the specific name proposed.

Occurrence. — This form was originally described from a single female
specimen taken af the islands Bollaerene in the lower part of the Oslo Fjord
at a depth of 30 — 40 fathoms, soft clayish bottom. I have subsequently also
met with it occasionally in some other places on the Norwegian coast, at
similar depths.

236

Distribution.— Bniish Isles, Fosse de Cap Breton, Bay of Biscay, Spitz-
bergen.

/^055//.— Holland, Skotland.

129. Bythocythere Bradyi, G. O. Sars, n. sp.
(PI. CVIII, fig. 2).

Specific Characters.— Female. —SheW moderately tumid, seen laterally, oblong
oval in shape, about equally high in front and behind, greatest height not
fully attaining Vs of the length, dorsal margin almost straight and scarcely
angularly bent either in front or behind, ventral margin slightly sinuated in
front and evenly convex behind, anterior extremity obtusely rounded, posterior
produced a little above the middle to a blunt protuberance;— seen dorsally,
rather regularly fusiform in outline, without any distinctly marked mediate
constriction, greatest width in the middle and nearly equal to half the length,
anterior extremity obtusely pointed, posterior abruptly contracted to a short
conical prominence. — Valves of somewhat firmer consistency than in the pre-
ceding species and less pellucid, with the lateral expansions rather slight and
conspicuously oblique behind, surface quite smooth and marked with some-
what distant small pits, edges unarmed. Eyes absent. Structure of the several
limbs very little different from that in the preceding species.

Colour of shell not yet ascertained.

Length of adult female 0.73 mm.

Male unknown.

Remarks. — This form has been erroneously described and figured by
Brady as the male of B. constricia. It is however quite certainly a distinct
species, and may properly bear the name of its discoverer.

Occurrence. — Several specimens of this form, all of the female sex were
found among some Ostracoda collected, several years ago, at Bukken, outside
the Stavanger Fjord, from a depth of about 40 fathoms. I have not met with
it in any other place of the Norwegian coast.

Distribution — British Isles.

130. Bythocythere dromedaria, G. O. Sars.

(PI. CVIII, fig. 3).
Bythocythere dromedaria, G. O. Sars, Oversigt af Norges marine Ostracoder, p. 86.

Specific Characters. — Female. Shell rather tumid, seen laterally, of a|
somewhat irregular shape, being gibbously vaulted in front and abruptly con-|

I

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II

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237

tracted behind, greatest height about equal to Vs of the length, dorsal margin
forming anteriorly a bold and quite even curve, with no trace of angle in the
ocular region, and followed by a slight concavity defined behind by a distinct
angular corner, ventral margin slightly sinuated in front and evenly bowed
behind, anterior extremity somewhat obliquely rounded, posterior produced in
the middle to a well-defined blunt protuberance; — seen dorsally, broadly fusi-
form in outline, with the greatest width about equal to half the length, side-
edges quite evenly curved, both extremities abruptly contracted and acuminate,
the posterior somewhat more produced than the anterior. Valves thin and
pellucid, with the surface smooth and only marked with small distant pits,
edges unarmed, lateral expansions but slightly prominent and obtusely rounded.
Eyes absent. Antennae of a similar structure to that in B. constricta. Legs
very slender and narrow, last pair with the 1st joint of the terminal part about
the length of the other 2 combined.

Male resembling the female in the general shape of the shell. Copulative
appendages distinguished from those in the other species by the short cordi-
form shape of the terminal part.

Colour of shell whitish pellucid.

Length of adult female 0.78 mm.

Remarks.— Ihxs, species is easily recognised from those described in the
preceding pages, by the peculiar shape of the shell, as seen laterally, the
gibbously arched dorsal face being particularly very characteristic, and having
indeed given rise to the specific name proposed.

Occurrence. — Some few specimens of this form were taken, many years
ago, in the upper part of the Oslo Fjord, from a depth of about 50 fathoms,
muddy bottom, and I have subsequently also met with it occasionally in some
other places on the Norwegian coast.

Distribution.— ks yet not recorded out of Norway.

131. Bythocythere insignis, G. O. Sars.

(PI. CIX, fig. 1).
Bythocythere insignis, G. O. Sars, Chr. Vid. Selsk. Forhandl. 1869, p. 173,

Specific Characters.— Female. Shell remarkably expanded laterally, seen
from the side, oval subrhomboid in shape, about equally high in front and
behind, greatest height about equal to half the length, dorsal margin nearly
straigth, though exhibiting in front a slight convexity defined from the anterior
edge by a short sinus, ventral margin faintly sinuated anteriorly and rather

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238

obliquely ascending behind, anterior extremity bluntly rounded off, posterior
drawn out quite above to a rather prominent obtuse protuberance;— seen
dorsally, very broad, square-shaped, with the greatest width, between the tips
of the lateral expansions, about equal to Vs of the length, side-edges angularly
bent behind the middle, anterior extremity obtusely pointed, posterior abruptly
contiacted to a narrow conical prominence.— Valves rather thin, with the sur-
face slightly rugulose and marked with distant small pits, posterior edges finely
denticulate, lateral expansions very prominent, alaeform, and almost rectangular
in shape, each terminating in an obtusely rounded corner and having moreover
traces of 2 or 3 blunt prominences of the hind margin. Eyes absent. Struc-
ture of the limbs quite normal.

Male somewhat smaller than female, and having the shell comparatively
narrower, as seen laterally. Copulative appendages with the terminal part oval
in shape, and having attached to its base in front a peculiar somewhat twisted
deflexed lobule.

Colour of shell whitish pellucid.

Length of adult female 0.70 mm.

Remarks. — In the outward appearance this form looks rather different
the other known species, and bears a perplexing similarity to some of the
species of the genus Cytheropteron. The structure of the several limbs proves
it however to be a true member of the present genus, being apparently nearly
allied to B. dromedarla. fl

Occurrence. — I have hitherto only met with this species off the Lofoten
islands, where 2 specimens, male and female, were taken in the considerable
depth of 120 fathoms, soft clay.

Distribution. — As yet not recorded out of Norway.

Gen. 46. Pseudocythere, G. O. Sars, 1865.

Generic Characters. — Shell much compressed, without any lateral ex-
pansions; posterior extremity produced above to a caudiform prominence.
Surface of valves quite smooth, without any obvious sculpture, inner duplicatures
rather broad, marginal zone well marked and crossed by distant pore-channels;
hinge imperfect. Eyes wholly absent. Anterior antennae with the terminal
part distincly 5-articulate, the 4 proximal joints rather short and stout, last
joint abruptly much narrower and greatly prolonged, setae of this part unusu-
ally long and slender, forming together a dense apical fascicle. Posterior

239

antennae with the middle joint of the terminal part very narrow and prolonged,
without any setiferous ledge anteriorly, but distinctly subdivided above the
middle. Mandibles with the cutting teeth narrow unguiform, palp of moderate
size, with the vibratory plate well developed. Maxillae with the masticatory
lobes narrowly produced and the 2 joints of the palp nearly equal in length,
vibratory plate with only 3 deflexed setae at the base. Legs slender and of a
similar structure to that in Bythocythere. Caudal lamellae extremely small,
bisetose. Copulative appendages of male comparatively poorly developed.

Remarks. — This genus is evidently somewhat related to Bythocythere, so
as properly to be associated with it in the same subfamily, differing however
very conspicuously in the general appearance of the shell, as also in the
structure of some of the appendages, especially that of the antennae. In ad-
dition to the form described below, 3 other species referable to the present
genus have been recorded from more southern latitudes.

132. Pseudocyihere caudaia, G. O. Sars,

(PI. CIX, f g. 2).
Pseudocyihere caudata, G. O. Sars, Oversigt af Norges marine Ostracoder, p. 88.

Specific Characters.— Female. Shell, seen laterally, oval subquadrangular
in shape, greatest height quite in front and about equal to half the length,
dorsal margin nearly straight and continuous with the anterior edge, sloping
gently behind, ventral margin slightly sinuated in the middle and terminating
behind in a well-defined corner tipped with a small dentiform projection,
anterior extremity broadly rounded off, posterior somewhat obliquely truncated
and produced above to a rather prominent protuberance continuous with the
dorsal margin, but well defined below;— seen dorsally, narrow lancet-shaped,
with the greatest width somewhath in front of the middle and not even
attaining Va of the length, both extremities narrowly produced and acuminate.
Valves of rather firm consistency, but highly pellucid, with the surface smooth
and polished and almost bare of hears. — Anterior antennae with the distal
segment of the basal part scarcely thickened proximally and provided with 2
slender setae, one in the middle of the anterior edge, the other at the end
behind, the 4 proximal joints of the terminal part successively diminishing in
size, last joint almost as long as these joints combined, and extremely narrow,
linear in shape. Posterior antennae with the dividing suture of the penultimate
joint located at about the end of the upper Vs of the joint, distal part extremely
narrow, apical claws of moderate length and nearly equal. Legs very narrow

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240

and prolonged, basal lamella of 1st pair very small and provided with 4 delicate
setae, last pair with the 1st joint of the terminal part shorter than the other
2 combined.

Male a little smaller than female and having the shell comparatively
narrower, with the dorsal margin slightly concav. Copulative appendages very
small, with the basal part only slightly dilated, terminal part well defined, in
the form of an oval deflexed lamella somewhat angularly produced behind.

Colour of shell whitish, transparent.

Length of adult female scarcely exceeding 0.55 mm. f

Remarks. — The above-described form is easily recognisable from any of
our other Cytherids, both as to the general appearance of the shell and to
the somewhat anomalous structure of the antennae. It is the type of the
present genus.

Occurrence. — 1 first found this form in the upper part of the Oslo Fjord
at a depth of about 40 fathoms, soft clayish bottom, and have subsequently
met with it also in some other places on the Norwegian coast up to the
Trondhjem Fjord in similar depths. In spite of its small size, it is easily
detected in any sample taken up by the dredge, owing to a particularity which
it shares with some other Cytherids, viz., that the animals, when coming in
contact with the air, remain floating on the surface of the water.

Distribution. — Britisch Isles, Fosse de Cap Breton, Bay of Biscay, Mediter-
ranean, Kerguelen.

Fossil. — Scotland, Ireland.

Gen. 47. Macrocythere, G. O. Sars, n.

Generic Characters. — Shell elongate, compressed, sharply pointed behind,
without any lateral expansions. Hinge imperfectly developed. Eyes absent.
Anterior antennae with the segments of the basal part considerably dilated,
terminal part comparatively shorter than in Bythocyihere, but, as in that genus,
composed of 4 joints only slightly differing in length. Posterior antennae
without any dividing suture of the penultimate joint. Mandibles and maxillae
of a structure nearly agreeing with that in Bythocythere. Legs of female
likewise rather similar, last pair in male however conspicuously transformed,
subprehensile. Caudal lamellae conical in shape, with one rather long apical
seta and 2 much shorter lateral bristles. Copulative appendages of male com-
paratively large and attached to a fleshy stalk, terminal part well developed
and somewhat bent in the middle.

i

{

Cytheridae

Ostracoda

Podocopa

PI. XCVII

6. O. Sars del.

1. Cytherura striata, 6. O. Sars

2. — producta, Brady

Cytheridae

Ostracoda

Podocopa

PI. XCVIII

^

U^

6. O. Sars del

1. Cytherura acuticostata, S. O. Sars

2. — lineata, Brady

Cytheridae

Ostracoda

Podocopa

PI. xcix

r-U

6. O. Sars del.

1. Cytherura undata, 6. O. Sars

2. — fulva, Brady

Cytheridae

Ostracoda

Podocopa

PI. c

6. O. Sars del.

1. Cyiherurffi dathrata, 6. O. Sars

2. — cellulosa, Norman

Cytheridae

Ostracoda

Podocopa

PI. CI

6. O. Sars del.

Loxoconcha impressa, Baird

Cytheridae

Ostracoda

Podocopa

PI. Cll

6. O. Sars del.

1. Loxoconcha granulata, 6. O. Sars

2. — tamarindus, Jones

3. — fragilis, 6. O. Sars

Cytheridae

Ostracoda

Podocopa

PI. cm

G. O. Sars del.

Cytheropteron latissimum, Norman

Cytheridae

Ostracoda

Podocopa

PI. CIV

6. O. Sars del.

1. Cytheropteron alatum, 6. O. Sars

2. — hamatum, 6. O. Sars

Cytheridae

Ostracoda

Podocopa

PI. cv

G. O. Sars del.

1. Cytheropteron punctatum, Brady

2. — crassipinnatum, Brady & Norm.

3. — angulatum, Brady

4. — subcircinatum, 6. O. Sars

Cytheridae

Ostracoda

Podocopa

PI. cvi

2. a.''

G. O. Sars del.

1. Cytheropteron testudo, 6. O. Sars

2. — inflatum, Brady

3. — nodosum, Brady

Cytheridae

Ostracoda

Podocopa

PI. evil

6. O. Sars del.

Bythocythere turgida, 6. 0. Sars

Cytheridae

Ostracoda

Podocopa

PI. CVIII

6. O. Sars del.

1. Bythocythere constricta, 6. O. Sars

2. — Bradyi, 6. 0. Sars

3. — dromedaria, 6. 0. Sars

Cytheridffi

Ostracoda

Podocopa

PI. cix

6. O. Sars del

1. Bythocythere insignis, G. O. Sars

2. Pseudocythere caudata, 6. O. Sars

Cytheridae

Ostracoda

Podocopa

PI. ex

6. O. $ars del.

Macrocythere simplex, Norman

CytheriHae

Ostracoda

Podocopa

PI. CXI

G. O. Sars del.

1. Xestoleberis auraniia, Baird

2. — depressa, 6. O. Sars

Cytheridae

Ostracoda

Podocopa

PI. CXII

G. O. Sars del.

Sclerochilus contortus, Norman

• 241

Remarks. --This new genus is proposed, to include the large Cytherid
originally recorded by Norman under the name of Cy there simplex and sub-
sequently described by the present author as a new species of his genus
Bythocythere. True, this form agrees in most of the structural details rather
closely with that genus; but the shell is of a very dissimilar appearance, and
I have also found some well-marked differences in the structure of the appen-
dages, making it convenient to discard it as the type of a particular genus.
Among these differences it is whorthy to name the very conspicuous transfor-
mation of the last pair of legs in the male, not found in any other Cytherid
known to me.

133. Macrocythere simplex, (Norman).

(PI. CX).

Cythere simplex, Norman, Nat. Hist. Trans. Northumb. & Durham, Vol. 1, p. 17, PI. V, figs. 1—4.

Syn: Bythocythere acuminata, G. O. Sars.

Specific Characters.— Female. Shell, seen laterally, elongate oval in shape,
a little higher behind than in front, greatest height not nearly attaining half
the length, dorsal margin only very slightly arched and joining the anterior
and posterior edges without any intervening angle, ventral margin distinctly
sinuated in front of the middle and gently bowed behind, anterior extremity
evenly rounded off, posterior gradually contracted to a sharp point located
about in the longitudinal axis of the shell;— seen dorsally, narrow oblong in
outline, with the greatest width about in the middle and scarcely exceeding
\3 of the length, side-edges evenly curved, anterior extremity obtusely pointed,
posterior gradually tapered to a narrow conical prominence. Valves of rather
fine consistency, but very pellucid, with the surface perfectly smooth and polished,
not exhibiting any obvious sculpture, inner duplicature well defined and rather
broad, marginal zone highly chitinised and crossed by numerous fine pore-
channels, edges smooth and almost bare of hairs. — Anterior antennae with the
terminal part scarcely longer than the basal one, and clothed with scattered
thin setae. Posterior antennae with the 1st joint of the terminal part nearly
twice as long as broad, middle joint of equal width throughout and provided
anteriorly near the end with a well-marked setiferous ledge, apical claws rather
slender and successively increasing in length posteriorly. Legs slender, and
scarcely differing in structure from those in Bythocythere.

Male of about same size as female, but differing somewhat in the shape
of the shell, which is conspicuously more expanded behind, with the dorsal
margin straight or even a little concave in the middle. Last pair of legs very

30 — Crustacea.

242

strongly built, with the joints of the terminal part considerably dilated
provided with powerful muscles, apical claw strong, falciform, and shorter than
the preceding joint. Copulative appendages with a distinctly projecting chitinou
string inside the basal part, terminal part somewhat nose-shaped, with tli
posterior edge deeply sinuated and the extremity narrowly rounded.

Colour of shell whitish, semipellucid, and variegated with a few irre
gularly arborescent pigmentary patches of a light reddish hue.

Length of adult female amounting to 1.33 mm.

Remarks.— Th\s is an easily recognisable form, being well distinguished
both by the characteristic shape of the shell and by its comparatively large
size. It is indeed apparently the largest of all hitherto known Cytheridae

Occurrence.— \ have taken this magnificent Ostracod in many places o
the Norwegian coast, from the Oslo Fjord to Lofoten in depths ranging
from 20 to 50 fathoms. It is easily detected in the samples examined, both
by its large size and by its particularity of remaining floating on the surface
of the water, when coming in contact with the air.

Distribution. — British Isles, Hunde Islands, Baffin Bay.

Fossil. — Scotland, Ireland.

J

Subfam. 7. Xestoleberinae.

Remarks. — This subfamily is proposed to include the genus Xestoleberis
G. O. Sars, which cannot properly find its place within any of the other sub-
families here recorded. Another genus, unquestionably referable to this sub-
family, has recently been established by G. W. Miiller under the name of
Microxestoleberis, and I am also of opinion that the peculiar fresh-water genus
Metacypris Brady ought to be adduced to the same subfamily. In the struc-
ture of the several limbs some accordance may be found with the Cytherince,
as above defined; but the shell is of a very dissimilar appearance and in
particular distinguished by its encompassing behind a roomy breading cavity
for the reception of the mature ova during their further development. Only^
the typical genus is represented in the Fauna of Norway.

Gen. 48. Xestoleberis, G. O. Sars, 1865.

Generic Characters. —Sh^W tumid, narrowed in front, with the ventral face
distincly flattened behind. Valves slightly unequal, with the surface smooth

243

and polished, inner duplicatures moderately broad and very sharply defined
behind; hinge line somewhat flexuose. Eyes well developed. Antennae not
much prolonged, the anterior ones with the terminal part 4-articulate and
clothed with scattered comparatively short setae, some of them more or less
spiniform. Posterior antennae without any dividing suture of the penultimate
joint, apical claws rather stout and 2 in number, flagellum very coarse with
the knee far below. Mandibles coarsely dentate at the end, palp of moderate
size, with the vibratory plate comparatively small, bisetose. Maxillae with the
masticatory lobes narrowly produced, palp likewise rather slender, with the
distal joint narrow cylindrical in shape, vibratory plate without any deflexed
setae at the base. Legs comparatively short and stout. Caudal lamellae with
2 short bristles on the tip. Copulative appendages of male well developed,
with the terminal part rather narrow, deflexed.

Remarks.— This genus was originally founded by the present author on
2 species occurring on the Norwegian coast, one of them having been long
ago known and described as a species of the genus Cythere. In recent times
a great number of species referable to the present genus have been recorded
from different parts of the oceans, all of them rather closely allied to the two
at first described.

134. Xestoleberis aurantia, (Baird).

(PI. CXI, fig. 1).
Cythere aurantia, Baird, Britisti Entomostraca, p. 171, PI. XXI, fig. 8.

Syn: Cythere nitida, Lilljeborg.
,, — viridis, Zencker (not O. Fr. Miiller).

Xestoleberis nitida, G. O. Sars.

Specific Characters.- Female. Shell, seen laterally, subtriangular in shape,
greatest height somewhat behind the middle and almost attaining -/a of the
length, dorsal margin considerably arched, forming in the middle an abrupt
almost angular bend and sloping rather steeply in front, somewhat less so
behind, ventral margin almost straight, anterior extremity narrowly rounded,
posterior much broader and somewhat obliquely truncated, with the lower
corner slightly produced, but obtusely rounded off at the end; — seen dorsally,
rather regularly ovate in outline, with the greatest width behind the middle
and almost attaining ^ .-, of the length, anterior extremity gradually contracted
to an obtuse point, posterior rounded off at the end. — Valves moderately firm
and semipellucid, with the surface smooth and shining, being only marked by
scattered very small knobs, marginal zone narrow and crossed by distinctly

244

marked porechannels, edges clothed with fine hairs. Eyes well separated;
immediately in front of them a rather conspicuous dark pigmentary spot.—
Anterior antennae with the distal segment of the basal part oblong in shape,
gradually tapered towards the end and provided with a short seta at the infero-
posteal corner; terminal part only slightly attenuated, with the last joint rather
small, each of the 3 preceding joints with a rather stout spiniform seta
anteriorly. Posterior antennae comparatively strongly built, with the anterior
setiferous ledge of the penultimate joint placed opposite to the posterior ledge
at about the middle of the joint; vesicle leading to the flagellum unusually
large, club-shaped. Legs not much differing in size, last pair with the 1st
joint of the terminal part about the length of the other 2 combined.

Male a little smaller than female, and having the shell comparatively
less tumid, with the infero-posteal corner somewhat more projecting. Copulative
appendages with a well-defined spirally curled string inside the basal part,
terminal part narrow linguiform in shape.

Colour of shell more or less dark brownish orange.

Length of adult female but little exceeding half a millimeter.

Remarks.— This form was recorded as early as the year 1858 by Bai
as a species of the genus Cyihere and was subsequently described under 2
other specific names, viz., by Lilljeborg as C. nitida and by Zencker as C. vlrldls,
being erroneously identified with the so named species of O. Fr. Muller. It
is the type of the present genus.

Occurrence.— Iht present Ostracod is a strictly littoral form, being found
rather frequently along our whole coast close to the beach among algas, and
often left in tidal pools together with other littoral animals.

Distribution.— Bni'ish Isles, Kattegat, Baltic, Holland, Franklin Pierce Bay.

Fossil. — Norway, Scotland, Ireland.

135. Xestoleberis depressa, G. O. Sars.

(PI. CXI, fig. 2).
Xestoleberis depressa, G. O. Sars, Oversigt af Norges marine Ostracoder, p. 68.

Specific Characters. — Female. — Shell exceedingly tumid, with the posterior
part distinctly depressed, seen laterally almost semilunar in shape, greatest
height but little exceeding half the length, dorsal margin forming a rather even j
arch quite continuous with both the anterior and posterior edges, ventral
margin slightly sinuated in front of the middle, anterior extremity considerably
tapered and distinctly deflexed, almost beak-shaped, though rounded at the

li^

245

end, posterior more obtuse and somewhat obliquely deflexed; — seen dorsally,
broadly ovate in outline, with the greatest width quite behind and considerably
exceeding the height, anterior extremity gradually tapered to an obtuse point,
posterior broadly rounded off and somewhat emarginate in the middle. Valves
rather transparent, with the surface smooth and of a pearly lustre, but marked
with scattered small knobs. Eyes well developed; but no pigmentary spot in
front of them observable. Anterior antennae with the terminal part com-
paratively narrower than in the preceding species, none of the setae spiniform.
Posterior antennae differing from those in the said species except by the apical
claws being somewhat more slender; vesicle leading to the flagellum much
smaller. Last pair of legs with the 1st joint of the terminal part somewhat
longer than the other 2 combined.

Male of somewhat smaller size than female and having the shell much
less tumid, seen dorsally, regularly oval in outline, with the greatest width in
the middle and the extremities almost equally contracted. Copulative appen-
dages with the terminal part triangular in shape.

Colour of shell pearly white, transparent, with a somewhat ramified
reddish brown patch dorsally behind the ocular region; breading cavity of
female generally filled with numerous developing ova and embryos distinctly
traced through the pellucid shell.

Length of adult female 0.64 mm.

Remarks.— The above-described form is easily recognised from the pre-
ceding one by the much more tumid shell, the posterior part of which is
distinctly depressed behind in the female; hence the specific name proposed.
It is also of rather larger size and much more transparent.

Occurrence. — I have taken this form not unfrequently in several places
on the Norwegian coast, from the Oslo Fjord to Lofoten, but only in some-
what greater deeps, in the Laminarian region.

Distribution.— Bx'xWsh Isles, Spitzbergen, Greenland, Davis Strait, Gulf of
St. Lawrence, Bay of Biscay, Mediterranean, Kerguelen.

Fossil. — Norway, Scotland, Ireland, Holland, Canada, Calabria.

Subfam. 8. Paradoxostominae.

Remarks. — This subfamily is here taken in a somewhat wider sense than
generally admitted, the genus Sclerochilus G. O. Sars, being included within
it, because I have found that this genus in some regards presents an evident

II

246

approach to the other members referred to that subfamily. True, the oral cone
is not terminated in a sucking disk, like that found in the typical genus Para-
doxostoma; but in another genus, Paracytherois, recently established by G. W.
Muller and unquestionably belonging to the present subfamily, there is likewise
no trace of any sucking disk on the oral cone; and the presence of such a
disk cannot of course be regarded as an exclusive character of the subfamily
Paradoxes to mince. 4 genera referable to the present subfamily will be treated
of in the sequel. A 5th apparently distinct genus, Machairina (^Iphochlliis) m
Brady, may be here named; but this genus is as yet only known, as regards
the shell.

Gen. 49. Sclerochilus, G. O. Sars, 1865.

Generic Characters. — Shell compressed, more or less elongate in shape,
and of rather firm consistency, with the marginal zone highly chitinised. Sur-
face of valves smooth, without any obvious sculpture. Hinge imperfect. Eyes
coalesced. Anterior antennae with the terminal part 5-articulate and clothed
with long and slender setae, forming a dense apical fascicle. Posterior antennae
robust, with the penultimate joint distinctly subdivided, but without any seti-
ferous ledge in front, apical claws 3 in number, one of them reduced in male;
flagellum slender, with the knee about in the middle, vesicle leading to it large,
bifurcate. Oral cone projected obliquely forwards and obtuse at the tip, with
the 2 lips well defined. Mandibles with the masticatory part narrowly produced
and scarcely at all incurved, cutting edge very oblique and finely denticulated,
palp slender and imperfectly jointed, with the vibratory plate narrow, trisetose.
Maxillae with the basal part rather prolonged and apparently composed of 2
distinct segments, the distal one conically tapered, terminal part rather defective,
only exhibiting a single narrow, unisetose masticatory lobe inside the palp,
the latter indistinctly jointed, with 2 curved apical setae; vibratory plate narrow
lanceolate in shape, with 2 or 3 thin deflexed setae at the base. Legs com-
paratively short and stout, with each of the tirst 2 joints of the terminal part
provided with a short spine at the end anteriorly. Caudal lamellae divided
into 2 rounded lobes, the anterior one trisetose, the posterior bisetose. Copu-
lative appendages of male with the terminal part rather small, lamelliform.

Remarks.— l\\'\s genus is considered by G. W. Muller to be a very
primitive type, and it is on that reason treated of at the very head of the
Cytheridce. I am not prepared to assent in this view. In my opinion it is
on the contrary considerably diverging from the usual Cytherid type, especially

I

I

I

■ _ 2 47_

as regards the structure of the oral parts, and it is therefore included here
within the last and most anomalous of the 8 subfamilies in which the Cythe-
ridae have been subdivided in the present Account. In addition to the typical
form described below, 6 other species, referable to this genus, have been
recorded by G. W. Muller, 3 of them from the Antarctic Ocean, the other 3
from the Gulf of Naples.

136. Sclerochilus contortus, (Norman).

(PI. CXII).

Cy there contorta, Norman, Ann. Mag. Nat. Hist. Vol. IX, p. 48, PI. II, fig. 15.

Specific Characters.— Female. Shell, seen laterally, oblong bean-shaped
somewhat higher behind than in front, greatest height not nearly attaining
half the length, dorsal margin forming a gentle and quite even arch continuous
with both the anterior and posterior edges, ventral margin deeply sinuated in
front of the middle and gently convex behind, anterior extremity evenly
rounded off at the end, posterior obtuse, with no trace of a corner below;—
seen dorsally, very "narrow oblong, with the greatest width not even attaining
Vs of the length, both extremities pointed and nearly equal. Valves semi-
pellucid, with the surface glabrous, inner duplicatures rather broad in front
and also well marked along the ventral face, marginal zone however com-
paratively narrow throughout and crossed by numerous short pore-channels,
edges clothed with fine hairs. Eye easily observable in the living animal, but
very soon vanishing in preserved specimens. Anterior antennae with the distal
segment of the basal part only slightly dilated, and provided with 2 slender
setae, one in the middle of the anterior edge, the other at the infero-posteal
corner, terminal part scarcely as long as the basal one, with the 1st joint much
larger than the other 3, which i^apidly diminish in size, the last carrying on
the tip several extremely thin and slender setae partly connected at the base,
so as to present the appearance of a spurious apical joint. Posterior antennae
very robust, with the dividing suture of the penultimate joint located somewhat
below the middle, vesicle leading to the flagellum with each of the lappets
slightly bilobular at the end. 1st pair of legs with only a single curved spine
at the end of the basal joint, but with 3 juxtaposed delicate setae at the infero-
posteal corner.

Male of rather smaller size than female, but only slightly differing in the
general shape of the shell. Copulative appendages with the basal part obli-
quely oval in shape, terminal part defined from the basal one in front by a

lind

4

nan m\

248 •

deep incision and somewhat widening distaliy, with the extremity rounded off
and sHghtly angular behind. Caudal lamellae well observable immediately below
the copulative appendages, and notably differing from those in female by the
great size of the anterior lobe.

Colour of shell whitish, semipellucid, with a dark patch dorsally behind
the ocular region.

Length of adult female 0.80 mm.

Remarks. —This form was recorded as early as the year 1862 by Norm
as a species of Cythere, and was subsequently described by the present author
as the type of his genus Sclerochilus. The form recorded by G. W. Miiller
under that name from the Gulf of Naples is a different species, viz., 5. abbre-
viatus, Brady.

Occurrence.— \ have taken this form not unfrequently in several places
on the Norwegian coast, from the Oslo Fjord to Finmark, in depths ranging
from 10 to 30 fathoms.

Distribution.— Bniish Isles, Arctic Ocean: Greenland, Spitzbergen, Franz
Joseph Land.

Fossil.— Noiv/ay, Scotland, Ireland, Canada.

Gen. 50. Paracytherois, G. W. Muller, 1894.

Generic Characters.— ShtW thin and fragile, much compressed, and of
more or less elongate shape, with the marginal zone of the valves com-
paratively broad and crossed by distant somewhat irregular pore-channels.
Hinge-line of right valve with traces of closing teeth in front and behind.
Eyes wholly absent. Anterior antennae very narrow, with the segments of the
basal part not at all dilated, terminal part only composed of 3 joints clothed
with scattered comparatively short setse. Posterior antennae with the penul-
timate joint distinctly subdivided and provided with a small setiferous ledge,
anteriorly, last joint with a single apical claw accompanied by a small bristle.
Oral cone projected almost straight forwards and terminating in an acute
beak-like point, lips partly coalesced. Mandibles simple styliform, in some
cases projecting long beyond the oral aperture, palp rudimentary. Maxillae
with 2 very narrow masticatory lobes, palp shorter than these lobes, vibratory
plate with 2 thin deflexed setae at the base. Legs rather narrow, with the
last joint considerably prolonged. Caudal lamellae very small, with only a
single bristle at the base. Copulative appendages of male with the terminal
part more or less imperfect.

249

Remarks.— This genus has been established by G. W. Muller, to include
5 species found by him in the Gulf of Naples, and was chiefly characterised
by the peculiar beak-like appearance of the oral cone and by the great
reduction of the mandibles. On the closer examination of the forms of the
present subfamily found off the Norwegian coast, I have been enabled to
state, that some northern species hitherto recorded by Brady as members
of the genus Paradoxostoma. in reality are referable to the present genus.
3 such species will be described in the sequel.

137. Paracytherois arcuata, (Brady).

(PI. CXIII, fig. 1).

Paradoxostoma arcuatum, Brady, Mon. Brit. Ostracoda, p. 461, PI. XXXV, figs. 37, 38.

Syii: Paracytherois rara, G. W. Miiller.

Specific Characters. — Female. Shell, seen laterally, oblong bean-shaped,
not unlike that of Sclerochilus contortiis, greatest height somewhat behind the
middle and not nearly attaining half the length, dorsal margin forming a rather
even arch sloping somewhat more steeply behind than in front, ventral margin
rather deeply sinuated in front of the middle and gently convex behind,
anterior extremity somewhat deflexed and evenly rounded off at the end,
posterior terminating below in an obtuse corner;— seen dorsally, very narrow,
lancet-shaped, with the greatest width not even attaining ^U of the length;
both extremities sharply pointed, the anterior somewhat narrower than the
posterior. — Valves thin and pellucid, with the surface smooth and polished,
marginal zone well marked and rather broad along the ventral face, pore-
channels very few in number, but easily observable. — Anterior antennae with
the distal segment of the basal part long and narrow, almost cylindrical in
shape, and without any setae; terminal part scarcely longer than this segment,
with the joints very unequal in^ size. Posterior antennae with the dividing
suture of the penultimate joint located about in the middle. Legs not much
prolonged, last pair with the 1st joint of the terminal part considerably shorter
than the. other 2 combined.

Male resembling the female both in size and in the general shape of
the shell. Copulative appendages with the basal part obpyriform in outline,
terminal part consisting of 2 subequal curved spines.

Colour of shell whitish, pellucid.

Length of adult female 0.55 mm.

Remarks. — The above-described form agrees pretty well with the descrip-
tion and figures given by Brady of his Paradoxostoma arcuatum, and I am

31 — Crustacea.

also of opinion, that the form recorded by G. W. Miiller from the Gulf of
Naples under the name of Paracytherois rara is the very same species. It
ought to be considered as the type of the present genus.

Occurrence. — Several specimens of this form have been taken, long ago,
off the west coast of Norway, from deep water among Hydroidae, but were
only quite recently identified.

Distribution.— Brliish Isles, Mediterranean.

/^055//.— Scotland.

138. Paracytherois fiexuosa, (Brady).

(PI. CXllI, fig. 2).

Paradoxostoma flexiioTiim, Brndy, Mon. Brit. Ostracoda, p. 461, Pi. XXXV, figs. 30-34,

Syn: Paracytherois striata, G. W. Miiller.

Specific Characters. — Female. Shell, seen laterally, of a very narrow and
peculiar flexous shape, distinctly attenuated both behind and in front, greatest
height about in the middle and scarcely exceeding \';i of the length, dorsal
margin forming a strong and quite even arch sloping rather steeply towards
the anterior extremity, ventral margin distinctly sinuated in front of the middle
and gently bowed behind, anterior extremity narrowly produced below, almost
beak-shaped, though rounded off at the end, posterior somewhat exerted and
narrow obtuse;— seen dorsally, lancet-shaped, with the greatest width not nearly
attaining V4 of the length, both extremities sharply pointed and nearly equal.
Valves very thin and transparent, with the surface smooth and polished, though
on a closer examination exhibiting traces of an extremely fine longitudinal
striation, marginal area rather narrow in front, but considerably widening along
the ventral face.— Structure of the several appendages only very little differrent
from that in the preceding species.

Colour of shell whitish pellucid.

Length of adult female 0.60 mm.

Male not observed.

Remarks.— The present species is nearly allied to the preceding one, but
is easily distinguished by the characteristic shape of the shell, as seen laterally.
It seems to me evident, that the form recorded by G. W. Miiller from the
Gulf of Naples under the name of P. striata is the same species.

Occurrence. — A few female specimens of this form were found together
with the preceding species, the exact locality not being ascertained.

Distribution.— Bniish Isles, Holland, Fosse de Cap Breton, Bay of Biscay,
Mediterranean.

I

251

139. Paracyiherois producta, (Brady & Norm.).

(PI. CXIII, fig. 3).
Paradoxostoma prodiictiim, Brady & Norman, Mon. recent Ostracoda 1889, p. 236,

PI. XXI, figs. 9. 10.
Syn: Paracyiherois oblonga. G. W. Miiller.

Specific Characters.— Male. Shell, seen laterally, very narrow oblong in
shape, greatest height scarcely exceeding Va of the length, dorsal margin only
slightly arched and sloping somewhat more steeply behind than in front, ventral
margin distinctly sinuated in front of the middle and gently convex behind,
anterior extremity rather broad and remarkably bowed below, being obliquely
blunted at the end, posterior gradually tapered to a narrowly obtuse corner
located below the longitudinal axis of the shell; — seen dorsally, narrow fusi-
form or lancet-shaped, with the greatest width about equal to \i of the length,
both extremities sharply pointed and nearly equal. — Valves very thin and pel-
lucid, with the marginal zone comparatively broad and crossed by very distinctly
marked pore-channels rather irregularly arranged in front. — Anterior antennae
comparatively more strongly built than in the 2 preceding species, but of a
very similar structure. Posterior antennae, on the other hand, rather more slender,
with the penultimate joint very narrow and having the dividing suture located
above the middle. Oral cone very sharply pointed at the extremity and some-
what deflexed. Copulative appendages comparatively small, with the terminal
part undivided in the form of a curved beak-like lamella.

Female of somewhat smaller size than male, and having the shell com-
paratively shorter, with the dorsal face more vaulted.

Colour of shell not yet ascertained.

Length of adult male 0.45 mm.

Remarks. — This is a very small species, and is moreover easily recognised
from the 2 preceding ones by the rather different shape of the shell. The
form recorded by G. W. Miiller from the Gulf of Naples under the name of
P. oblonga is unquestionably identical with the present species.

Occurrence. — I have not myself taken this form ; but Norman sent me
some specimens taken by him recently in the Bergen Fjord and mounted dry
on a slide. By moistening the shells, I succeeded in finding in one of them
tiie limbs tolerably well preserved, to allow of a detailed examination, and I
have therefore thought it right to describe the species here along with the
other 2 found by myself.

Distribution. As yet only found off the west coast of Norway.

252

Gen. 51. Cytherois, G. W. Miiller, 1884.

Generic Characters. —SheW, as a rule, less compressed than in the pre-
ceding genus, but rather thin and fragile, of more or less elongate shape, with
the inner duplicatures rather broad, marginal zone however very narrow through-
out. A single well-developed eye always present. Anterior antennae with the
distal segment of the basal part narrow cylindrical in shape, terminal part
longer than this segment and composed of 3 joints. Posterior antennae com-
paratively robust with the penultimate joint distinctly subdivided, but without
any setiferous ledge in front, last joint with a single apical claw accompanied
behind by a very small bristle. Oral cone rather massive and directed down-
wards, terminating in a somewhat imperfect sucking disk. Mandibles very
strongly built and highly chitinised, with the masticatory part not at all
incurved and gradually tapered to a blunt point exhibiting inside slight traces
of cutting teeth; palp slender and of rather feeble consistency, with the proxi-
mal joints wholly coalesced, terminal joint falciform curved and densely seti-
ferous, vibratory plate rudimentary. Maxillae provided at the end with 4 densely
crowded narrow digitiform lobes, the outermost one representing the palp;
vibratory plate comparatively short, with 2 deflexed setae at the base. Legs
rather thin and of moderate length. Caudal lamellae very small, with one or
2 short bristles. Copulative appendages of male with the basal part large and
expanded, terminal part however comparatively poorly developed, lamelliform.

Remarks. This gtuus, established in the year 1884 by G. W. Muller,
is nearly allied to Paradoxostoma, to which its species had indeed formerly
been referred, but differs very notably in the powerful development of the
mandibles and in the somewhat incomplete sucking disk on the extremity of
the oral cone. 3 species referable to this genus will be described in the sequel.

140. Cytherois Fischeri, G. O. Sars.

(PI. CXIV).

Paradoxostoma Fischeri, G. O. Sars, Oversigt af Norges marine Ostracoder, p. 96.

Syii: Cytherois virens, G. W. Muller.

Specific Characters. — Female. Shell, seen laterally, oblong subtriangular
in shape, scarcely higher behind than in front, greatest height in the middle
and nearly equal to half the length, dorsal margin boldly arched, almost
angularly bent in the middle, and sloping rather steeply both in front and

253

behind, ventral margin almost straight or very faintly sinuated in front of the
middle, both extremities narrowly rounded off at the end; — seen dorsally, oblong
oval in outline, with the greatest width in the middle and about equal to Vo
of the length, both extremities obtusely pointed. Surface of valves smooth and
glabrous, only marked with scattered small puncta, edges very finely hairy.
Eye well observable in the living animal, but, as usual, vanishing in preserved
specimens. Anterior antennae moderately slender, with the middle joint of the
terminal part scarcely longer then the 1st, last joint very narrow and prolonged.
Posterior antennas comparatively short and stout, with the dividing suture of
penultimate joint located near the end, apical claw rather slender. 1st pair of legs
considerably smaller than the other 2, which are nearly of equal length. Caudal
lamellae much reduced, with only a single small bristle at the posterior corner.

Male of rather larger size than female, and having the shell comparati-
vely more elongate. Copulative appendages with the basal part broadly sub-
quadrangular in shape, terminal part projected forwards, and pronouncedly
boot-shaped, being considerably constricted at the base and expanded distally.

Colour of shell light yellowish, with a broad band of a dark olivaceous
hue across the middle, each extremity more or less distinctly tinged with the
same colour.

Length of adult female 0.50 mm., of male 0.58 mm.

Remarks.— This form was first described by the present author as a
species of the genus Paradoxostoma, and was subsequently recorded by
G. W. Miiller as the type of his genus Cytherois, though under a different
specific name (virens). It is readily distinguished from the other 2 species
here described by the shape and colour of the shell.

Occurrence. — I have taken this form rather abundantly in the upper part
of the Oslo Fjord, as also in several other places on the Norwegian coast.
It is a strictly littoral form, being found close to the beach among algae, and
not seldom left in tidal pools together with other littoral animals.

Distribution. — British Isles, Pommerania, Mediterranean.

Fo55//.— Scotland, Ireland.

141. Cytherois vitrea, G. O. Sars.

(PI. CXV. fig. 1).
Paradoxostoma vitreum, G. O. Sars, Oversigt af Norges marine Ostracoder, p. 95.

Specific Characters.-- Female. Shell, seen laterally, oblong in shape, more
tapered in front than behind, greatest height rather behind the middle and
not nearly attaining half the length, dorsal margin well arched behind and

254

sloping gradually anteriorly, ventral margin almost straight, or very slightly
concave in front of the middle, anterior extremity rather narrow and some-
what angular, at the end, posterior much broader and obtusely truncated; —
seen dorsally, narrow oblong in outline, with the greatest width about equal
to V4 of the length, anterior extremity more pointed than the posterior. Valves
thin and highly transparent, with the surface smooth and shining. Eye large
and very conspicuous in the living animal. — Anterior antennae exceedingly thin
and slender, with the middle joint of the terminal part more than twice as
long as the 1st, last joint however very small. Posterior antennae much more
robust, with the distal segment of the basal part rather prolonged, dividing
suture of penultimate joint located about in the middle, apical claw com-
paratively short. Mandibles of a similar coarse structure to that in the type
species, palp however rather thinner and more prolonged. Maxillae with the
terminal digitiform lobes very narrow and prolonged. Legs about as in the
preceding species. Caudal lamellae with 2 distant bristles on the edge.

Male of considerably larger size than female, and having the shell con-
spicuously more elongate in shape. Copulative appendages with the basal
part rather expanded and irregularly rounded in outline; terminal part securi-
form in shape, with the posterior corner narrowly produced.

Shell nearly colourless and highly transparent.

Length of adult female 0.52 mm., of male 0.60 mm.

Remarks. — The present species is easily recognised from the preceding
one by the somewhat different shape of the shell, as also by the wholly absence
of any pigmentary patches on the valves, which are so highly transparent that
the enclosed body appears rather clearly through their walls; hence the specific
name proposed. Some well-marked differences are also found in the structure
of the appendages, as shown by the above given diagnosis.

Occurrence. — I have met with this species in several places on the Nor-
wegian coast, from the Oslo Fjord to Lofoten. It is only found in greater
depths ranging from 20 to 50 fathoms, never, as the typical species, in the
littoral zone.

Distribution. — Shetland, Faroe Islands.

142. Cytherois pusilla, G. O. Sars, n. sp.

(PI. CXV, fig. 2).

Specific Characters.— Female. Shell, seen laterally of a shape somewhat
similar to that in C. vitrea, though comparatively rather narrower, with the
greatest height scarcely exceeding -k of the length, dorsal margin rather evenly

255

arched throughout, ventral ahnost straight, anterior extremity narrowly pro-
duced, posterior somewhat broader and obliquely rounded off; — seen dorsally,
very narrow, oblong in outline, with the side-edges almost straight in the
middle and both extremities obtusely pointed. —Valves less transparent than in
C. vitrea, but with the surface perfectly smooth and polished. Eye well
observable in the living animal. Anterior antennae comparatively less slender
than in the said species, but of a rather similar structure, though the mutual
relation of the joints is a little different. Posterior antennae with the dividing
suture of penultimate joint located near the extremity, apical claw rather slender.
Legs rapidly increasing in length posteriorly, last pair considerably more strongly
built than the other 2, with the joints of the terminal part distinctly ciliated
along the anterior edge.

Male, unlike the case with the 2 preceding species, of smaller size than
female, and very little differing in the shape of the shell. Copulative appen-
dages with a rather conspicuous thickish curved prominence in front; terminal
part very small, irregularly oval in shape, and pointing straight downwards.

Remarks. — In the general shape of the shell this form bears some
resemblance to C. vitrea; but the structure of the several appendages seems
to be more in accordance with that in C. Fischeri. It is however of much
smaller size than either of these 2 species, and differs also conspicuously
in colour.

Occurrence ~Sq\!QX^[ specimens of this small species were collected, many
years ago, at Skutesnses, southwest coast of Norway, in rather shallow water
among algae, and 1 have also met with it occasionally in some other places
on our coast.

Distribution. --ks yet only known from Norway.

Gen. 52. Paradoxostoma, Fischer, 1855.

Generic Characters. — Shell thin and fragile, of somewhat different shape
in the several species, but, as a rule, higher behind than in front, inner
duplicatures of valves less broad than in the preceding genera, marginal zone
very narrow, with only slight traces of pore-channels. A single well-developed
eye present. Anterior antennae slender and narrow, but with the distal segment
of the basal part less prolonged than in the 2 preceding genera ; terminal part
composed of 4 well defined joints clothed with scattered rather short setae, the
last 2 joints much smaller than the preceding ones. Posterior antennae with
the penultimate joint distinctly subdivided and provided in front with a small

256

setiferous ledge, last joint with 2 unequal claws, flagellum very coarse. Oral
cone of a similar appearence to that in Cyt/ierois, but with the sucking disk
completely closed. Mandibles thin, styliform, terminating in a sharp point,
palp very narrow and imperfectly jointed. Maxillae provided at the extremity
with 3 masticatory lobes, the innermost much smaller than the other 2, palp
rudimentary or quite wanting, vibratory plate with 2 partly connected thin fl
deflexed setae at the base. Legs narrow and rapidly increasing in length
posteriorly, with the terminal joint, as a rule, very slender and in the last pair
distinctly ciliated along the anterior edge, apical claws comparatively short and
stout. Caudal lamellae very small, with' a recurved bristle in front. Ripe ova
received in the cavity of the shell for further development. Copulative appen-
dages of male with the basal part large and expanded, sending off below a
thin lamella, terminal part poorly developed and more or less spiniform in shape.
Remarks.— This genus was established in the year 1855 by Fischer, to
include a Cytherid (P. dlspar) observed by him at Madeira, and was chiefly
characterised by the suctorial nature of the mouth. Many other forms,
apparently agreeing in this respect with Fischer's species, were subsequently
detected and referred to the same genus. Yet, as above mentioned, G. W.
Miiller has pointed out certain well-marked differences of the mouth-organs in
some of these species, inducing him to the establishment of the 2 new genera
Cytherois and Pamcyiherois treated of in the preceding pages. There still
remains however a rather considerable number of forms unquestionably referable
to the present genus in the restriction here adopted, both from the northern
Ocean and from more southern latitudes. In the following pages 7 species,
as yet observed off the Norwegian coast, will be described.

143. Paradoxostoma variabile, (Baird).

(PI. CXVl).

Cvthere variabilis, Baird, British Entomostraca, p. 170, PI. XXI, figs. 10, 11.

Specific Characters. —Female. Shell, seen laterally, oval subcuneiform in
shape, rather high behind and gradually narrowed in front, greatest height
nearly equal to half the length, dorsal margin well arched behind and sloping
slowly anteriorly, ventral margin scarcely at all sinuated, being conspicuously
bowed in its posterior part, anterior extremity narrowly produced, posterior
much broader and obliquely rounded, with a slight indication to an angle
above;— seen dorsally, oblong oval in outline, with the greatest width in the
middle and somewhat exceeding ^Ih of the length, both extremities obtusely

257_

pointed. Valves semipellucid, with the surface very smooth and polished,
wanting any obvious sculpture, edges almost bare of hairs, but bordered with
a narrow hyaline rim. Eye rather large and well conspicuous in fresh speci-
mens. Anterior antennae moderately slender, with the 2nd joint of the terminal
part slightly longer than the 1st, the last 2 joints combined exceeding half the
length of this Joint. Posterior antennae with the dividing suture of penultimate
joint located about in the middle, apical claws very short; vesicle leading to
the flagellum rather large, clavate in shape. Mandibular palp not much pro-
longed, with the terminal joint comparatively short. Maxillae without any trace
of a palp. Legs rather slender, but with the apical claw comparatively short
and stout.

Male of rather larger size than the female, with the shell comparatively
more elongate in shape. Copulative appendages coarsely developed, with the
basal part very large and expanded; terminal part represented by 2 diverging
pieces, the anterior one spiniform and slightly tortuous, the posterior somewhat
larger and lamelliform, terminating behind in an acute corner.

Colour of shell somewhat variable, but more frequently light yellowish
or whitish, with 2 sharply defined patches of a dark violaceous or almost black
hue on each side, the one about in the middle, the other near the posterior
extremity, a 3rd less sharply defined patch being moreover generally present
in the oral region of the shell.

Length of adult female amounting to 0.60 mm., of male to 0.68 mm.

f^emarks.— The present species, being that recorded at the earliest date,
ought of course to be regarded as the type of the genus Paradoxostoma. It
is easily recognised from the other known species by the characteristic cunei-
form shape of the shell, as seen laterally, and also partly by the colour.

Occurrence. — This is one of our commonest Cytheridae, occurring very
abundantly along the whole of the Norwegian coast in the littoral zone among
algae, and often left in tidal pools together with other littoral animals.

Distribution. — British Isles, Holland, Arctic Ocean: Baffin Bay, Hunde
Island, Spitzbergen.

Fossil.— Norway, Scotland, Ireland, Canada.

32 — Crustacea.

258

144. Paradoxostoma ensiforme, Brady.
(PI. cxvn, fig. 1).

Paradoxostoma ensiforme, Brady, Mon. British Ostracoda, p. 460, PI. XXXV, figs. 8—11.
Syn: Paradoxostoma angusttim, O. W, Miiller.

Specific Characters.— Female. Shell rather elongate, seen laterally almost
ensiform in shape, with the greatest height not nearly attaining half the length,
dorsal margin somewhat abruptly arched behind the middle and sloping at a
nearly straight course to the tip of the hind extremity, ventral margin slightly
sinuated in front of the middle and evenly bowed behind, anterior extremity
narrowly produced, posterior terminating in a well-marked obtuse corner
located about in the longitudinal axis of the shell;— seen dorsally, narrow
oblong in outline, with the greatest width in the middle and about equal to
V3 of the length, side-edges somewhat irregularly curved, anterior extremity
more contracted than the posterior. Valves rather thin and pellucid, with the
surface very smooth and polished, inner duplicatures comparatively narrower
than in the type species. — Anterior antennae considerably prolonged, with the
1st joint of the terminal part fully as long as the distal segment of the basal
one and somewhat exceeding the length of the 2nd joint, last 2 joints however
rather small and combined not nearly attaining half the length of the preceding
one. Posterior antennae comparatively slender, with the dividing suture of the
penultimate joint located somewhat above the middle, principal apical claw
much more prolonged than in the type species. Legs resembling in structure
those in that species, though having the apical claw more slender.

Male slightly smaller than female, but very little differing in the shape
of the shell. Copulative appendages far less strongly built than in the pre-
ceding species and rather dissimilar in shape, basal part subtriangular in shape
and provided at the end in front with a small slightly bilobular prominence
and below with a rather large somewhat curved lamella; terminal part narrow
spiniform and doubled upon the said lamella so as forming together with it
a sort of pincers.

Colour of shell not yet ascertained.

Length of adult female 0.74 mm.

Remarks.—The. present species bears some resemblance in its general
appearance to P. varlabile, but is, on a closer comparison, easily distinguished
by the much more elongate shell, which seen laterally, exhibits a somewhat
ensiform shape; hence the specific name proposed by Brady, The form

I

_259

recorded by G. W. Miiller from the Gulf of Naples under the name of P.
angustiim is unquestionably the same species.

Occurrence. ' Some few specimens of this form were found in the material
of P. variabile collected in various places of the Norwegian coast. Norman
has recorded it from Lervik, in the outer part of the Hardanger Fjord.

Distribution. — British Isles.

145. Paradoxostoma obliqvum, G. O. Sars.

(PI. CXVII, fig. 2).
Parodoxostoma obliqvum, G. O. Sars, Oversigt af Norges marine Ostracoder, p. 97.

Specific Characters. — Female. Shell, seen laterally, irregularly oval or
somewhat rhomboid in shape, greatest height in the middle and about equaling
half the length, dorsal margin forming a rather bold and quite even arch,
ventral very slightly sinuated in front of the middle and gently bowed behind,
joining the hind edge without any intervening angle, anterior extremity narrowly
rounded, posterior obliquely blunted, with the upper corner considerably pro-
duced in the form of an obtuse protuberance well defined above by a distinct
sinus of the dorsal margin; seen dorsally oblong oval in outline, with the
greatest width somewhat in front of the middle and about equal to Vs of the
length, both extremities gradually contracted and nearly equal. — Valves rather
thin and fragile, with the surface smooth, but clothed everywhere with scattered
rather long hairs; marginal zone comparatively broader than in the other known
species and crossed by well-marked distant pore-channels. Anterior antennae
rather slender, with the 1st joint of the terminal part nearly as long as the
distal segment of the basal one, but somewhat shorter than the next joint,
last 2 joints combined exceeding half the length of the preceding one. Posterior
antennae with the dividing suture of penultimate joint located about in the
middle, apical claws very short. Legs of a similar structure to that in the
preceding species.

Male rather smaller than female and having the shell less vaulted above
Copulative appendages resembling in structure those in P. ensiforme, but with
the basal part comparatively broader, and the terminal part exerted to a very
thin and sharp point.

Colour of shell not yet ascertained.

Length of adult female amounting to 0.90 mm.

Remarks.— 0\ this form at first only 2 empty shells were known to me;
but subsequently I have had the opportunity of examining some perfect speci-

260

mens, and have thereby convinced myself, that this form is in reality a true
member of the present genus, in spite of the somewhat anomalous appearance
of the shell. It is much the largest of the species known to me. The form
recorded by Brady under the above name is not this species, but unquestion-
ably that next described.

Occurrence. — The 2 empty shells originally examined were found by my
late father in shell-sand from 0xfjord, West Finmark; those subsequently
obtained were, as far as I remember it, taken off the Lofoten islands in a few
fathoms' depth.

Distribution. — Apparently not yet known out of Norway.

146. Paradoxostoma Bradyi, G. O. Sars (new name).
(PI. cxvm, fig. 1).

Paradoxostoma obliqvum, Brady, Mon. Brit. Ostracoda, p. 459, PI. XXXV, figs. 18

(not G. O. Sars).

Specific Characters. — Female. Shell more tumid than in the other known
species, seen laterally, short oval in shape, greatest height a little behind the
middle and considerably exceeding half the length, dorsal margin evenly arched
throughout, ventral very slightly sinuated in front of the middle and gently
bowed behind, anterior extremity obtusely rounded off at the end, posterior
produced a little above the middle to a short protuberance well defined both
above and below;— seen dorsally, regularly oblong oval in outline, with the M
greatest width nearly equal to half the length, both extremities obtusely pointed.
— Valves of rather firmer consistency than in P. obliqvum and only slightly
pellucid, surface perfectly smooth and almost bare from hairs, marginal zone
narrow, with no sharply-marked pore-channels.— Anterior antennae rather pro-
longed, with the 2nd joint of the terminal part fully twice as long as the 1st. |
Posterior antennae resembling in structure those in P. obliqvum, except that
the dividing suture of penultimate joint is located somewhat above the middle.
Maxillae with a distinct rudiment of palp in the form of a simple curved seta
issuing from a somewhat thickened base, innermost masticatory lobe compara-
tively more fully developed than in the type species, with 3 apical setae. Legs
of the usual structure.

Colour of shell in the living animal not yet ascertained; but in the
preserved specimens examined by me there are distinct traces of 3 transverse
dark bands, one in the middle and one at each extremity.

Length of adult female 0.68 mm.

Male unknown.

II

I

261

Remarks.— The present form has been erroneously identified by Brady
with P. obliqvum, and must of course have a new specific name. 1 propose
to name it as above. It may be easily recognized both from P. obliqvum and
most other species by the rather short and clumsy shape of the shell.

Occurrence. A have had an opportunity of examining 3 well-preserved
female specimens of this form. They were found in my material of Para-
doxostoma collected at different times and in different places of the Norwegian
coast, the exact locality were they occurred not being ascertained.

Distribution. —British Isles.

147. Paradoxostoma hibernicum, Brady.

(PI. CXVIII, fig. 2).
Paradoxostoma hibernicum, Brady, Mon. Brit. Ostracoda, p. 460, PI. XXXV, figs. 35—38.
Syii: Paradoxostoma sarnlense, Brady.
„ — rotiindatum, G. W. Miiller.

Specific Characters. — Female. Shell, seen laterally suboval or elliptical
in shape, greatest height in the middle and scarcely exceeding half the length,
dorsal margin gently arched and sloping nearly at a straight course to the
hind end of the shell, ventral margin very slightly sinuated in front and evenly
bowed behind, anterior extremity obtusely rounded off, posterior gradually
contracted to an obtuse corner not sharply defined either above or below;—
seen dorsally oblong oval in outline, with the greatest width in the middle
and about equal to ^/o of the length, both extremities obtusely pointed and
nearly equal. Valves thinner and more pellucid than in the preceding species
and almost bare from hairs. — Anterior antennae comparatively less prolonged,
with the 2nd joint of the terminal part not nearly twice as long as the 1st.
Posterior antennae likewise somewhat stouter than in P. Bradyi, but otherwise
of a rather similar structure. Legs comparatively short and stout, with the last
joint less prolonged than in the other known species.

Colour of shell not yet ascertained.

Length of adult female 0.58 mm.

Male not observed.

Remarks.— \ think I am right in identifying the above-described form with
Brady's species, though the figures given by that author in his Monograph do
not fully agree with those here reproduced. Yet, in a subsequent memoir,
edited by Brady and Norman in common, new figures of the shell have been
given, and these figures are in better accordance with the form examined by
me. The species seems to be nearest allied to P. Bradyi, but is of much

2G2

smaller size and differs moreover conspicuously in the general shape of
the shell. The form recorded by G. W. Muller fiom the Gulf of Naples
under the name of P. rotiindatum I am unable to distinguish from the
present species.

Occurrence.— ^omt few specimens of this form, all of the female sex, were
found in my material of Paradoxosioma, the exact locality not being noted.

Distribution.— Biiiish Isles, Mediterranean.

148. Paradoxostoma pulchellum, G. O. Sars.

(PI. CXVIII, fig. 3).
Paradoxostoma pulchellum, G. O. Sars, Oversigt af Norges marine Ostracoder, p. 95.

Specific Characters. — Female. Shell much compressed, seen laterally,
oval or more properly semilunar in shape, greatest height in the middle and
about equal to half the length, dorsal margin forming a bold and quite even
curve throughout sloping somewhat more steeply behind than in front, ventral
margin almost straight, both extremities somewhat deflexed and in quite the«
same manner obliquely rounded off at the end;— seen dorsally, very narrow"
lancet-shaped, with the greatest width a little in front of the middle and not
even attaining V4 of the length, extremities narrowly contracted and pointed, J|
in particular the anterior one. Valves rather thin, with the surface perfectly
smooth and shining; inner duplicatures comparatively broad.— Anterior antennaeil
moderately slender, with the 1st joint of the terminal part somewhat longer
than the 2nd. Posterior antennas with the distal part very narrow and pro-
longed, dividing suture of penultimate joint located somewhat below the middle,
apical claw of moderate length. Mandibular palp exceedingly slender and
distinctly 3-articulate. Maxillae, as in the type species, without any trace of a
palp. Legs thin, resembling in structure those in P. variabile.

Colour of shell rather characteristic, a broad transverse band of a dark
violaceous hue occupying the greater part of its extent, extremities pellucid
and tinged with golden yellow.

Length of adult female scarcely exceeding half a millimeter.

Male unknown.

Remarks.—The present form is easily recognisable from any of the other'
species here described, being well distinguished both by the general shape of
the shell and by its beautiful colour. It is one of the smallest species known.

Occurrence. -~\ first found this form at Valle, lower part of the Oslo Fjord,
among algae near the beach, and have more recently also met with it

I

263

Skutesiiaes, south west coast of Norway. Norman has moreover taken it at
Lervik, Hardanger Fjord. All the specimens examined by me were of the
female sex.

Distribution.— Bniish Isles.

149. Paradoxostoma abbreviatum, G. O. Sars.

(PI. CXIX, fig. 1).

Paradoxostoma abbreviatum, G. O. Sars, Oversigt af Norges marine Ostracoder, p. 94.

Syii: Paradoxostoma coeciim, G. W. Miiller.

Specific Characters. — Female. Shell rather compressed, seen laterally,
sort oval in shape, much broader behind than in front, greatest height about
equal to ^5 of the length, dorsal margin gently arched, sloping rather steeply
behind, ventral margin very slightly sinuated in front and considerably bowed
behind, anterior extremity narrowly rounded and somewhat oblique below,
posterior much broader and terminating in a blunt corner;— seen dorsally,
rather narrow, lancet-shaped, with the greatest width in the middle and not
nearly attaining ^iz of the length, anterior extremity more sharply pointed
than the posterior. Valves thin and pellucid, with the surface smooth and
polished. Eye well observable in the living animal, but, as usual, soon
vanishing in preserved specimens.— Anterior antennae moderately slender, with
the 2nd joint of the terminal part very narrow and fully twice as long as the
1st. Posterior antennae with the 1st joint of the terminal part rather dilated,
dividing suture of penultimate joint located a little above the middle, vesicle
leading to the flagellum deeply cleft into 2 diverging rami. Legs compara-
tively thin, and of the usual structure.

Alale a little smaller than female and having the shell comparatively less
vaulted dorsally. Vesicle leading to the flagellum of the posterior antennae
much larger than in female, with the rami club-shaped. Copulative appendages
distinguished by the peculiar development of the terminal part, which is pro-
duced in the form of a very long falciform curved spine, basal lamella of
moderate size and securiform in shape.

Colour of shell clear yellowish, tinged at the extremities with orange, and
exhibiting in the centre a rounded patch of a dark brownish hue.

Length of adult female 0.58 mm.

Remarks. —This is a well recognizable species, and I am perplexed to
see that Brady at first (in his Monograph) has uttered some doubt about its
distinctness from P. variabile, to which species is does not in reality present

264

I

any closer resemblance, either in the shape of the shell or in its colour. It
is moreover of much smaller size. The form recorded by G. W. Muller from
the Gulf of Naples under the name of P. coecum is unquestionably the same
species. The specimens examined by him were taken from preserved material,
and the inadequate specific name given to this form on the wrong supposition,
that the eye was wanting, may thereby most likely find its explanation.

Occurrence. — I have taken this form not unfrequently in the upper part
of the Oslo Fjord, as also in several other places, both on the south and
west coasts of Norway. It is a strictly littoral species, occurring near the
beach among algae.

Distribution. Bniish Isles, Fosse de Cap Breton, Bay of Biscay, Holland,
Mediterranean, Kerguelen.

Fossil. — Scotland, South Wales.

150. Paradoxostoma Normani, Brady.

(PI. CXIX, fig. 2).

Paradoxostoma Normani, Brady, Mon. Brit. Ostracoda, p. 458, Pi. XXXV, figs. 39, 40.

Syn: Sclerochilns contortiis var. abbreviata, Brady & Robertson.

Specific Characters.— Female. Shell less compressed than in the pre-
ceding species, seen laterally, oval subreniform in shape, rather broad behind
and much narrowed in front, greatest height only slightly exceeding half the
length, dorsal margin forming a bold and quite even curve throughout, ventral
margin deeply sinuated in front and considerably bowed behind, anterior
extremity distinctly deflexed and narrowly rounded at the end, posterior much
broader and terminating in a blunt corner; — seen dorsally, regularly oblong
oval in outline, with the greatest width about equal to -/o of the length, both
extremities pointed. Valves, as in the preceding species, very thin and highly
transparent. Anterior antennae comparatively less slender, with the 2nd joint
of the terminal part not nearly attaining twice the length of the 1st. Posterior
antennae rather like those in P. abbreviatum, vesicle leading to the flagellum
however comparatively smaller, though distinctly cleft. Legs of the usual structure.

Male somewhat resembling that of the preceding species, but with the
shell, seen laterally, narrower and more distinctly sinuated below. Copulative
appendages rather dissimilar, with the basal part rounded triangular in outline
and produced at the end in front to a beak-like deflexed prominence; terminal
part only slightly prolonged, resembling the said prominence both in size and
shape; basal lamella very small.

265

Colour of shell whitish pellucid, tinged with pale yellow.

Length of adult female scarcely exceeding half a millimeter.

Remarks. — Owing to a certain resemblance in the shape of the shell with
Sclerochiliis contortus, the present form was at first by Brady and Robertson
erroneously regarded as merely or peculiar variety of that Cytherid. It is
however in reality very different and unquestionably a true member of the
genus Paradoxostoma, being apparently nearly allied to P. abbfevlatum, though
well distinguished by the less compressed shell and by the deep sinus of the
ventral margin, as also by its much inferior size.

Occurrence.— \ have taken this form occasionally in some places on the
south coast of Norway, Risor, Korshavn, in the littoral zone among algae.

Distribution. — British Isles, Fosse de Cap Breton, Bay of Biscay.

151. Paradoxostoma (?) rosiratum, G. O. Sars.

(PI. CXIX, fig. 3).
Para^ioxosioma rostra ftim, G. O. Sars, Oversigt af Norges marine Ostracoder, p. 97.

Remarks. — I do not find it appropriate here to give any detailed description
of this rather doubtful species, of which as yet only 2 detached valves (both
left) have come under my notice. Yet, for the sake of completeness, copies
of my original drawings are added on the accompanying Plate fig. 3.

As to the systematic position of this form, I am by rjo means assured
that it in reality is referable to the present genus. The shape of the shell is
indeed rather dissimilar to that in the other known species, and bears some
resemblance to the shell in the genus Cytherideis ; but the inner duplicatures
are distinctly different, and in particular is their peculiar flexure at the interior
extremity very remarkable and unlike the case in any other Ostracod known
to me. Indeed, the true systematic i elation of the present form can only be
settled by an anatomical investigation of fresh specimens.

Occurrence. — The 2 detached valves originally examined by me were
found by my late .father in shell-sand from 0xfjord, West Finmark. In his
most recent publication 1896 Norman notes the finding of 3 specimens of
this peculiar form between tide marks at Vads0, without however giving any
further information about the species.

Distribution. — As yet only known from the Finmark coast.

33 — Crustacea.

LIST OF PLATES.

The following are tlie chief markings of the iigures Avith their significations:
$: Female,— </: Male,—/., v., d., c, fr.: left, right, dorsal, ventral, frontal views of
shell,— !''./., /•..• left or right valve,—//-, ni.: frontal margin of xdlve.—muscl. sp.: muscular
spots,— sc/^/. .• sculpture,— i^.; rostre,— //..- hinge,— A'.; eye,— oc; ocellus,-/..- tentacle,—
«'; anterior antenna, — a'; posterior antenna,— ;-. /..- inner ramus. — L.: anterior lip,— il/.:
mandible,— //*..- maxilla,— //t/^..- maxilliped, — j;;. .- legs, — urs.: urosome. — C'..- caudal lamella or
ramus. — CO/), apji.: copulative appendages of male,— p/'. /..- ejaculatory tube, — Y'.; testicle, —
Sp.: Spermatozoids, — or..- ovarial tube.

PI. I.

Cypridina norvegica, Baird.

PI. II.

Cypridina norvegica (continued).

PI. III.

Cypridina norvegicra, female and male.

PI. IV.
Cypridina megalops, G. O. 8ars.

PI. V.

Pliilnmedes globosus, (Lilljeborg).

PI. VI.

Pliiloinedes globosus (continuedj.

PL VII.

I'hiloniedes globosus, male.

PI. VIII.

Pliiloinedes Lilljeboi'gi, 0. O. Sars.

PI. IX.

Asterope Marife, (Baird).

PI. X.

i. Asterope Maria? (continuedj.
2. Asteroj)e abyssicola. (J. O. Sars.

PI. XI.

Conclioecia elegans, G. O. ISars.

PL XII.
Conchoecia elegans (continued).

PL XIIL

1. Conchoecia borealis, G. 0. Sars.

2. Conclioecia obtusata, G. O. Sars.

PL XIV.

Polycope orbicuUiris, G. O. Sars.

PI. XV.

1. Polycope orbicularis, male.

2. Polycope punctata, G. O. Sai-s.

PL XVI.

1. Polycope areolata, G. O. Sars.

2. Polycope clathrata, G. O. Sars.

3. Polycope pustulata, Ci. O. Sars.

PL XVII.

1. Polycope subkevis, G. 0. Sars.

2. Polj'copsis compressa, (Brady & Robertson).

PL XVIII.

Cytherella abyssorum, G. O. Sars.

PL XIX.
Cytherella abyssorum (continued).

PL XX.
Pontocypris trigonella, G. O. Sars.

PL XXI.
Erythrocypris mytiloides, (Brady).

268

PI. XXII.

Erythrocypris mytiloides, male.

PI. XXIII.

1. Erytlu-ocypris liispida, G. 0. Sars.

2. Erythrocypris pallida, G. W. Miiller.

PI. XXIV.

Argilloecia cylindrica, Cf. (). Sars.

PI. XXV.

Argilloecia conoidea, G. 0. Sars.

PI. XXVI.

Macrocypris miuiia, (Baird).

PI. XXVII.
Macrocypris minna (continued).

PI. XXVIII.

Maci'ocypria angusta, G. O. Sar.s.

PL XXIX.

Bythocypris bosquetiana, Brady.

PI. XXX.

1. Bythocypris obtusata, G. O. Sars.

2. Bairdia inflata, Norman.

PL XXXI.

Paracypris polita, G. O. Sars:

PL XXXII.

Candona caudida, (O. Pr. Miiller).

PL XXXIII.

(^aiidona Candida (continued).

PL XXXIV.

1. Candona neglecta, G. O. Sars.

2. Candona lapponica, Ekman.

PL XXXV.

Candona caudata, Kaufmann.

PL XXXVI.

Candona Sarsi, Hartwig.

PL XXXVII.

Candona rostrata, Brady & Norman.

PL XXXVIII.

1. Candona marchica, Hartwig.

2. Candona stagnalis, G. O. Sars.

PL XXXIX. •

1. Candona albicans, Brady.

2. Candona compressa, Koch.

PL XL.

1. Cryptocandona Vavrai, Kaufmann.

2. Cryptocandona leducta. Aim.

PL XLI.

Candnnopsis Kingsleyi, (Brady & Robertson).

PL XLII.
Cyclocypris globosa, G. O. Sars.

PL XLIIL

1. Cyclocypris. ovum, (Jurine).

2. Cj'clocypris Isevis, (0. Pr. Miiller).

3. Cj^clocypris serena, (Koch).

PL XLIV.
Cypria exsculpta, (Fischer).

PL XLV.

1. Cypria ophthalmica, (Jurine).

2. Cypria lacustris, G. O. Sars.

PL XLVI.

Notodronias monachus, (O. Er. Miiller).

PL XLVII.

1. Notodromas monachus (continued).

2. Cyprois marginata, (Strauss).

PL XLVIII.
Cyprois marginata (continued).

PL XLIX.
Ilyocypris biplicata, (Koch).

PL L.

1. Ilyocj'pris gibba, (Ramdohr).

2. Iliocyprella Bradyi, G. 0. Sars.

PL LI.
Cypris pubera, 0. Fr. Miiller.

PL LII.
Eucypris virens, (Jurine).

PL LIII.

1. Eucypris crassa, (0. Fr. Miiller).

2. Eucypris elliptica, (Baird).

PL LIV.

Cypricercus fuscatus, (Jurine).

269

PI. IX.

1. C'ypricercus affiuis, (Fischer).

2. Cypricereus hii'sutus, (Fischer).

3. Cypricereus obliqvns. (Brady).

PL LVI.

1. Cyprinotus salinu.s, (Brady).

2. Cyprinotus fretensis, (Brady).

PI. LVIT.

Heterocypris incongruens, (Ramdohr).

PI. LVIII.

Dolerocypris fasciata, (O. Fr. Miiller).

PI. LIX.

Herpetocypris reptans, (Baird).

PI. LX.

Prionocypris liitaria, (lioch).

PI. LXI.

1. Prionocypris glacialis, (1. O. Surs.

2. Prionocypris pigra, (Fischer).

PI. LXII.

Prionocypris olivacea, (Brady & Norman).

PI. LXIII.

Pionocypris vidua, (O. Fr. Miiller).

PI. LXIV.

1. Pionocypris helvetica, (Kavifmanii).

2. Pionocypris obesa, (Brady & Robertson)
.•5. Pionocypris elongata, (Kaiifmann).

PI. LXV.

1. Pionocj-pris Almi, Gr. 0. Sars.

2. Pionocypris picta, (Strauss).
;!. Cypridopsis acnleata, (Costa).

PI. LXVI.

Cypridopsella villosa, (Jurine).

PI. LXVII.

J)ar\vimila Stevensoni, (Brady & Robertson).

PI. LXVIII.

Tjimn icy there Sancti Patricii, Brady &
Robertson.

PI. LXIX.

1. Limnicythere Sancti Patricii (continued).

2. Limnicythere inopinata, (Baird).

PI. LXX.

Cjtherissa lacnstris, G. O. Sars.

PI. LXXI.

Cyprideis littoralis, (Brady).

PI. LXXII.

1. Cyprideis littoralis (continued).

2. Cyprideis sorbyana, (Jones).

PI. LXXIII.

Cytheridea papillosa, Bosquet.

PL LXXIV.

1. Cythei'idea papillosa (continued).

2. Cytheridea punctillata, Brady.

PL LXXV.

1. Eiicythere argus, Gr. O. Sars.

2. Eucytliere declivis, (Norman).

PL LXXVI.
Krithe bartonensis, (Jones).

PL LXXVII.
Cy there lutea, 0. Fr. Miiller.

PL LXXVIII.

1. Cythere albomacnlata, Baird.

2. Cythere viridis, O. Fr. Miiller.

PL LXXIX.

1. Leptocythere pellucida, (Baird).

2. IjeptocythereMacallana, (Bradj'ifc Roberts.).

PL LXXX.

1. Leptocythere castanea, G. O. Sars.

2. Leptocythere tenera, (Bradj^.

3. Leptocythere crispata, (Brady).

PL LXX XL

Cytheromorpha fuscata, (Bradj).

PL LXXXIL

Xenocythere cuneiformis, (Bradj')-

PL LXXXIH.

Kyphocythere limicola, (Norman).

PL LXXXIV.
Hemicythere villosa, G-. 0. Sars.
PL LXXXV.

1. Hemicythere emarginata, G-. O. Sars.

2. Hemicythere creniilata, (r. O. Sars.

;3. Hemicythere finmarchica, G-. 0. Sars.

270

PI. LXXXVI.

1. Hemicy there qvatlridentata, (Baird).

2. Hemicythere anjrulata, G. O. Sars.
.'5. Hemicythei-p latimarg'inata, (Speyer).

PI. LXXXVII.

1. Hemicythere eoncinna, (Jones).

2. Hemicythere oblonga, (Brady).

PI. LXXXVIII.
Cythereis tnherciilata, G. O. Sars.

PL LXXXIX.

Cythereis dunelmensis, (Nomnan).

PI. XC.
Cythereis echinata, G. O. Sars.

PI. XCI.
Cythereis Jonesi, (Baird).

PI. XCII.
(lythereis mucroiiata, G. O. Sars.

PI. XCIIT.

Cytheriira gil)l)a, (O. Fr. Miiller).

PI. XCIV.

1. Cytherura nigrescens, (Baird).

2. Cytherura similis, G. O. Sars.

PI. XCV.

1. Cj'theriira sella, G. O. Sars.

2. (Cytherura atra, G. 0. Sars.

PI. xcvr.

1. Cytherura intumescens, G. O. Sars.

2. Cytherura affinis, G. O. Sars.

PI. XCVII.

1. Cytherura striata, G. O. Sars.

2. Cytherura produeta, Brady.

PI. XCVIII.

1. Cythei'ura acuticostata, G. O. Sars.

2. Cj'therura lineata, Brady.

PI. XCIX.

1. Cytherura undata, G. O. Sars.

2. Cytherura fulva, Brady «t Robertson.

PI. C.

1. Cytherura dathrata, G. O. Sars.

2. Cythenn-a cellulosa, (Norman).

PI. CI.

Loxoconclia impressa, (Baird).

PI. CI I.

1. Loxoconcha granulata, G. O. Sars.

2. Loxoconcha tamarindus, (Jones).

3. Loxoconcha frao-jlis, (i. O. Sars.

PI. cm.

Cytheropteron latissimum, (Norman).

PI. CIV.

1. Cytheropteron alatum, G. O. Sars.

2. Cytheropteron hamatum, G^. O. Sars.

PI. CV.

1. Cytheropteron jmnctatum. Brady.

2. Cytlieropteron crassipinnatum, Brady Si

Norman.

3. Cytheropteron an<.>'ulatum. Brady.

4. Cytheropteron subcircinatum. (r. O. Sars.

PI. CVI.

1. Cj^theropteron testudo, G. O. Sars.

2. Cytheropteron inflatum, Bi"ady.
;-5. Cytheropteron nodosum, Brady.

PI. cvn.

Bythocythere tur<iida, (\. 0. Sars.

PI. CVIII.

1. Bythocythere constricta, G. O. Sars.

2. Bythocythere Bradyi, G. O. Sars.
ii. Bythocythere dromedaria, G. O. Sarf.

PI. CTX.

1. Bythocythere insignis, G. 0. Sars.

2. Pseudocythei'e caudata, G. O. Sars.

PI. ex.

Macrocythere simplex. (Norman).

PI. CXI.

1. Xestoleberis aurantia, (Baird).

2. Xestoleberis depressa, G. O. Sars.

Pi. CXII.

Sclerochihxs contortus, (Norman).
PI. CXIH.

1. Paracytherois arcuata, (Brady).

2. Paracytherois flexuosa, (Brady).

3. Paracytherois produeta,' (Brady).

PI. CXIV.
Cytherois Fischei-i, G. O. Sars.

271

PI. cxv.

1. Cytherois vitrea, G. O. Sais.

2. Cytherois pusilla, (i. O. Sar.s.

PL CXVI.

I'aradoxostoma variabile, (Baird).

PL CXVII.

1. Paradoxostoma ensiforme, Brad.y.

2. Paradoxostoma obliqvum, (t. O. Sars.

PL CXVIII.

1. Paradoxostoma Bradyi, (1. O. Sars.

2. Paradoxostoma hibernicum. Brady.

3. Paradoxostoma pulcliellum, G. O. Sars.

PL CXIX.

1. Paradoxostoma abbreviatum, (r. O. Sars.

2. Paradoxostoma Normani, Brady.

:^. Paradoxostoma rostratum. (r. O. Sars.

n

INDEX.

Page

Acanthopus . 153

resistans 153

Aglaia .68, 69

Argilloecia 53

aurea 145

caudata 55

conoidea 56

cylindrica 54

Asterope 15

abyssicola 19

Grimaldi 18

granlandica 12

marice 17

norvegica 17

oblonga 17

Asteropinae 16

Bairdia 66

angusta 61

bosquetiana 64

complanata 64, 65

inflata 67

minna 59

obliquata 67

obtusata 65

subdeltoidea 67

Bairdiidae 62

Bairdiinoe 62

Beyrichia 2

Bradycinetus 10

globosus 12

brenda 12

Lilljeborgi 14

Bythocypris 63

bosquetiana 64

obtusata 65

reniformis 64

By thocy there.. 232, 233, 239
240

34 — Crustacea.

Page

acuminata 241

Brady i 236

constricia . . . 235, 236, 237

dromedaria 236. 238

insignis 237

simplex 233

turgida 233

By thocy therinop 232

Candocyprinae 89

Candona 71

acuminata 76

albicans 82

anceps 87

Candida 72, 73, 74

caudata 76

compressa 83

dentata 77

detecta 77

elongata 76

fabaeformis 73, 88

fallax 83, 84

Kingsleyi 88

lappcmica 75

limbata 79, 80

lucens 71, 72

tnarchica 79, 80

neglecta 73

parallela 82, 83

pubescens 77, 78, 83

qvadrata 81, 82

rara 81, 82

reducta 86

reptans 128

rostrata 79, 80, 81

Sarsi 77

stagnalis 81

Zenkeri 81, 82

Candonides . . 69, 71, 89, 95

Page

Candoninae 89

Candonopsis 85 87

Kingsleyi 88

Cladocera 1

Cladocopa 2, 28

Conchoecia 21

antipodarum 25

borealis 24

elegans 22, 26

maxima 25

obtusata 26

— var. antarctica 27

quadranguiaris .... 22, 24

Conchoeciidce ... 2, 3, 4, 19

Conchostraca 1

Copechaete 15, 16

elongata 18

Copepoda 1

Cryptocandona 85

Vdvrai 85

reducta 86

Cyclocyprides 89

Cyclocypris 90. 95, 96

dispersa 90, 91

globosa 90

loBvis 93

ovum 92, 93, 95

— Serena 94, 95

Serena 93, 94

Cylindroleberis 15, 16

mariae 17

oblonga 17

Cypretta 134, 135

Cypria 95

exsculpta 96

lacustris 98

ophthalmica 97, 98

Cypricercus 116, 117

274

Page

affinis 116, 119

cuneatus 117

fuscatus 118

hirsutus 120

obliqvus 121

Cyprideis 153, 154, 158

Bairdii 159, 160

littoralis 155

proxima 160, 161

sorbyana 157

torosa".. 153, 154, 155, 156

Cypridina . . 5, 5, 7, 1 0, 11

brenda 13

globosa 11, 12

mariae 17

megalops 9

norvegica 7, 9, 10

oblonga 17

Reynaudi 7

Cypridinidce 2, 4, 5

Cypridopsella . 138, 141, 142

elongata 138, 139

tumida 137, 138

villosa 143

Cypridopsides 134

Cypridopsis ... 135, 141. 143

aculeate 141, 156

elongata 139

globulus 135

helvetica 136

obesa 137

picta 140

smaragdiiia 143

vidua 135, 136, 141

villosa 141, 143

Cypridce 2, 45

Cyprinotus 122. 124

dngalensis 122

dentato-marginatus 122, 123

fretensis 123

incongruens 125

salinus 122, 124

Cyprince 68

Cypris 110, 113

aculeata 141

adusta 118

affinis 119

bimuricata 100

biplicata 106

bispinosa Ill

Candida 72

cinerea 90, 91

Page

compressa 83, 97

crassa 115

cuneata Ill

dispar 103

dromedaria 115

elegantula 96, 97

elliptica 116, 120

ephippiata 127

exsculpta 96

fasciata 126, 127

flava 103

fretensis 123

fusca 118, 125

fuscata minor 119

gi'bba 106, 108

globosa 90

hirsuta 119, 120

hispida 118

incongruens 125

Jurini 130, 131

lucida 130, 131

lutaria 130, 131

laevis 92, 93, 94

marginata 103

minuta 92, 93

monacha 100

obliqvus 121

ornata 113

pantherina 93

picta 140

pigra 132, 133

prasina 122

pubera ///

pubescens 78

punctata 97

— var. striata ... 96

punctillata Ill

pygmaea 92

reptans 128

reticulata 119

salina 122

serena 94

striata Ill

strigata 122, 131

striolata 96

tesselata 114, 119

tristriata 113

tumefacta ....130, 132, 133

vidua 135

virescens 128

Westwoodi 143

Cyprois 102

Page

dispar 103

flava TT • 103

marginata 103

monacha 100

Cyproniscus 8

cypridinae 9

Cy there.. 167, 171, 177, 182
192, 243

albomaculata 169

•areolata 181

aurantia 243

avena 50

badia 1 76

catenata, 194

celhilosa 216

ceratoptera 196

cicatricosa 176

concinna 189

confusa 172

contorta . . : 247

convexa 224

crispata 176

cuneiformis 179

cyamos 170

decHvis 163

drammensis 177, 178

dunelmensis 195

elliptica 218

fimbriata 196

flavida 218, 219

fuscata 177

gibba 200

gibbera 200. 201

guttata 220

inflata 67

inopinata 151

irpex 194

Jonesi 196

lacustris 153

latimarginata 188

latissima 223

limicola 181

lutea 167. 171, 183

laevata 221

Macallana 173, 175

minna 58, 59

monacantha 194

nigrescens 202

nitida 243, 214

nodosa 181

oblonga 190

pellucida ... 171, 172, 174

275

Page

propinqva 174, 175

quadridentata 186

reniformis 167

rhomboidea 218

Robertsoni 200

rubida 177, 178

setosa 167

simplex 241

spinosissima 198

tamarindus 221

tenera 175

variabilis 256

ventricosa 179

villosa 182

viridis.. 170. 218, 219, 243 \
244

Cytliereis 182, 191

abyssicoia 188, 189

angulata 187

clavata 189, 190

crenulata 184

dunelmensis 195

echinata 194, 195

emarginata 183

finmarchica 185

horrida 195. 196

Jonesi 196. 198, 199

macronata 198

spectabilis 196

tiiberculata 192

Cytherella 1, 39

abyssonim 41

Beyrichi 41, 42

scotica 41, 42

serrulata 40

sordida 40

Cytherellid(e 2, 39

Cythereliiformes 39

Cytheridea . . . . 152, 153, 154

158, 161

dentata 157

inermis 157

lacustris 153

littoralis 156

papulosa ... 158, 159. 161

163, 191

punctilata 160

sorbyana 157

torosa 155

— var. teres 155

Cytherideince 152

Cytiierideis 265

bartonensis 165

Cytheridce 2, 146. 246

Cytherinoe .... 152, 166. 242

Cytherissa 152, 154

lacustris 153

Cytherois 252, 253, 256

Fischen 252. 255

pusilla 254

virens 252, 253

vitrea 253, 254, 255

Cytheromorpha 777

albula 177

fuscata 177

Cytlieropsis 161

argus 162

tenuitesta 163, 164

Cytheropteron 217, 223, 238

alatum 225. 226

angulatum 228

convexuni 223

crassipinnatntn 227

hamatiim 226

inflatum 231

lotissimiim . 223. 225, 227

nodosum 232

punctatum 227

subcircinatum . . . 229, 231

testudo 230

Cythenira 199. 223

acuticostata 210

af finis 207

atra 205

cellulosa 216

clathrata 215. 217

cornuta 207, 212

cuneata 204

flavescens 204

fulva 214

gibba 200. 207

liiitnilis 213

intumescetis 206

lineata 212

nana 216

nigrescens 202, 203

producta 209

propinqva 203

pumila 213

qvadrata 208

Sarsii 203

sella 204

similis 203, 206

striata 208, 212

Page

undata 213

Cytherurino' 148, 199

Darwinella 144, 145

Stevensoni 145

Darwinula 144. 145

aurea 145

improvisa 145, 146

Stevensoni 145

Dolerocypris 126

fasciato 127

Doloria 7

Erythrocypris ... 48, 50, 70

hispida 52

my til hides 50

pallida 53

serrata 50, 51

Eucvprides 110

Eucypris 113, 117, 131

affinis hirsuta 116, 119, 120

clavata 113

crassa 115

elliptica 116

fasciata 127

fuscata 'affinis 119

— major 118

glaciaiis 131

incongruens 125

Lilljeborgi 113

lutaria 130

ornata 113

palaermitana 122

pigra 132

virens 113, 119

virens acuminata 114

— rnedia 114

~ obtusa 114

Eucythere 161

argus 162. 163

declivis 163

Eurycypris 110

pubera HI

Gigantocypris 2

Gomphocytliere 148, 149

Halocypridae 3, 19

Halocypriformes 3

Halocypris 22

Clausi 27

Hemicy there . . . 182. 192, 224

angulata 187

concinna 189, 191

crenulata 184

emarginata 183. 185

276

Page

Jininarchica 185

latimarginata 188

oblonga 190

qnadridentata 186

villosa 182. 184

Herpetocypris. ni, 128. 130

Chevreuxi 129

fasciata 127

glacialis 131

Jurini 130

olivacea 133

peregrina 128. 130

reptans 128

strigata 130

tiimefacta 132

Heterocypris 124

aiirea 126

capensis 126

incongruens -. . . 125

Hungarocypris 99

lliocyprella • . 109

Bradyi 109

repens 109 ,

llyobates 164

pratexta 165, 166

Ilyodromus 134

olivaceus 133 ;

llyocyprides 105 '

Ilyocyprinae 105

llyocypris.. 47, 105, 109, 110

bipUcata 106, 110

Bradyi 109

gibba 106, 107, 108

gibba var. bicornis.... 108

„ var. repens. 109, 110

inermis 109 i

iners 109 |

Krithe 164 '

bartonensis 165

Kyphocythere 180

limicola 181 \

Leperditia 2 !

Leptocythere 171 \

castanea ... 173, 174, 178 '

crispata 176

Macallana 173 \

pellucida 172 \

tenera 175

Leucocythere 148

Limnicythere 148, 149

incisa 151, 152

inopinata 151 1

Page

sancti-patricii 149

Limnicytherince 148, 152

Loxoconcha . . . 217, 223, 294

elliptica 219

fragilis 222

graniilata 21U, 221

impressa 218

longipes 221

pellucida 222

rhomboidea 218

tamarindns 221

viridis 219

Loxoconchince 217

Machairina 246

Macrocypria 00

angusta (H

Macrocypridina 7

Macrocyprina" 47, 57

Macrocypris 58, 60

angusta 61

minna 59

succinea 57

Macrocythere 233, 240

simplex 241

Megalocypris 2

Metacypris 242

Microconchoecia 27

Microxestoleberis 242

Monoculus

aurantius 125

candidus 72

fasciatus .' 127

fuscatus 118

monachus 100

ovatus Ill

ovum 92

vidua 135

villosus 143

virens 113, 114

Myodocopa 2, 4

Neocypris 117

Nesidea 66

Newnhamia 99-, 100

Normania 217

Notodromas 99, 102, 103, 104

monachus 100

Notodromides 99

Paraconchoecia

gracilis 22, 24

Paracypretta 134

Paracypria 69

Paracyprides 69

Page

Paracypridopsis 144

Paracypris 68, 69

polita 70

Paracytherois . 246, 248, 256

arciiata 249

flexiiosa 250

oblonga 251

prodiicta 251

rara 249, 250

striata 250

Paradoxostoma 147, 148, 246
249, 252, 255, 257

abbreviatum 263, 265

angustum 258, 259

arcuatum. 249

Bradyi mO, 261

coecum 263, 264

dispar 256

ensiforme 258, 259

Fischeri 252

flexuosum 250

hiberniciim 261

Normani 264

obHqviim . . . 259. 260, 261

productum 251

piilchellum 262

(?) rostatum 265

rotundatum 261, 262

snrnlense 261

variabile 256 258, 259, 262
263

Paradoxostoinatidae 148

Paradoxosiomino' . . 245, 246

Philomedes 10, 15

brenda . ... 12

globosiis 12, 1 4

Lilljeborgi 14

longicornis 11, 12

Philomedinas 11, 13

Piilyctenophora 69

Phyllopoda 1

Pionocypris . . . 1H5, 141. 143

Almi 139

elongata 138

helvetica 136

obesa 137

picta 140

vidua 135, 136, 138

Platycopo 2, 38

Podocopa 2, 44

Polycheles 144, 145

Stevenson! 145

277

Page

Polycope 1, 29

areolata 33

clathrata 34

compressa 36, 37

orbicularis 31, 36

punctata 3^

pustulata 35

serrata 38

subloevis 35

Polycopidce 2, 29

Polycopiformes 28

Polycopsis 36

compressa 37

Pontocypria 47

Pontocyprince 46

Pontocypris 47, 50

hispida 52

Page

mediterraiiea 49

serrulata 50

trigonella 48

Potamocypris . . 142, 143, 144

maculata 143

villosa 143

Primitia 2

Prionocypris 130

glacialis 131

lutaria 130

oLivacea 133

pigra 132

serrata 130

Pseudocandona 78

Pseudocy there 238

caudata 239

Sclerochilus . . 245, 246, 248

Page

abbreviatum 248, 264

contortus 247, 265

contortus var. abbrevia-
tum 264

Siphonocostraca 7

Stenocypris 127

fasciata 127

Strandesia 117

Vargula 7, 8

Xenocythere 179

cuneiformis 179

Xestoleberince 242

Xestoleberis 242

aurantia 243

depressa 244

nitida 243

Xiphochilus 246

Ostracoda

Cytheridae

Podocopa

PI. CXIII

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G. O. Sars del.

1. Paracytherois arcuata, (Brady)

2. '— flexuosa, (Brady)

3. — producta, (Brady)

Cytherids

Ostracoda

Podocopa

PI. cxiv

G. O. Sars del.

Cytherois Fischeri, 6. O. Sars

Cytheridae

Ostracoda

Podocopa

PI. cxv

I'tI

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CI- 60.

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'■■^>(r£y>^:

2.a.'

G. O. Sars del.

1. Cytherois vitrea, 6. O. Sars

2. — pusilla, 6. O. Sars

Cytheridae

Ostracoda

Podocopa

PI. cxvi

G. O. Sars del.

Paradoxostoma variabile, (Baird)

CytheridaB

Ostracoda

Podocopa

PI. CXVII

6. O. Sars del.

1. Paradoxostoma ensiforme, Brady

2. — obliqvum, 6. O. Sars

Cytheridae

Ostracoda

Podocopa

PI. CXVIII

G. O. Sars del.

1. Paradoxostoma Bradyi, 6. 0. Sars

2. — hibernicum, Brady

3. — pulchellum, 6. O. Sars

Cytheridae

Ostracoda

Podocopa

PI. cxix

6. O Sars del

1. Paradoxostoma abbreviatum, 6. O. Sars

2. — Normani, Brady

3. — rostratum, 6. O. Sars

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