afsnit som hos Branchinecta, skjondt deres indbyr- 
des Leengdeforhold er temmelig forskjelligt. 
Hovedet er forholdsvis af ringe Storrelse og 
stumpt afrundet fortil. Det afgrendser sig skarpt 
fra Nakkesegmentet, der til hver Side viser Skal- 
kjertelen meget tydeligt. Truncus er sterkt for- 
lenget, regelmessigt cylindrisk, og delt i ikke min- 
dre end 19 vel begrendsede Segmenter, hvert bee- 
rende et Par Branchialfodder. 
Bagkroppen udmerker sig i hoi Grad ved sin 
korte og plumpe Form, idet den neppe indtager 
mere end '/s af Kropslengden. Kjonsringene er 
fuldsteendig sammensmeltede saavel indbyrdes som 
med den bagenfor liggende Del af Halen, paa hvil- 
ken alene det bagerste Segment er tydeligt be- 
grendset. Hele dette Parti har, seet ovenfra (Fig. 
2), en nesten peredannet Form, idet det fortil er 
sterkt fortykket og ligesom opblest, med en afrun- 
det knudeformig Protuberans til hver Side, medens 
det bagtil gradvis afsmalnes. Breden over den for- 
reste Del af dette Afsnit er mere end dobbelt saa 
stor som Breden over selve Truncus. Sees Dyret 
fra Siden (Fig. 1), viser sig Storsteparten af den 
ventrale Side af dette Parti optaget af den volumi- 
nose gbeholder, hvis forreste Del er serdeles 
steerkt hvelvet, medens den bagtil kun rager ube- 
tydeligt frem i Form af et kort koniskt Frem- 
spring. Paa Enden af dette Fremspring findes den 
ydre Aabning for Aigbeholderen, som hos Branchi- 
necta, begreendset af 2 vertikale mod hinanden be- 
vegelige Leber, hvoraf den overste er den storste 
og ender i en tilspidset Knude (se Tab. X, Fig. 12). 
Halepladerne (se Tab. IX, Fig. 6) er forholdsvis 
korte, neppe mere end dobbelt saa lange som de er 
brede ved Basis, og viser en bredt lancetdannet 
Form, med Spidsen smalt afrundet. De er hver 
kantede med omtrent 19 cilierede Borster der suc- 
cessivt tiltager i Lengde mod Spidsen. 
Minene (Tab. X, Fig. 1, 0) er forholdsvis korte 
og tykke, neppe lengere end Hovedets halve Brede, 
og af den seedvanlige peredannede Form, med @ie- 
globen jevnt afrundet. Qiepigmentet er morkt, dog 
hos det levende Dyr med et tydeligt purpurredt 
Skjer, og de enkelte Synselementer vel udviklede. 
Det enkle Gie sees som en tydelig mork Plet i Mid- 
ten af Hovedets Pandedel. 
Forste Par Folere (Fig. 1, a1, Fig. 3) er for- 
holdsvis betydelig kortere end hos Branchinecta, 
neppe halvt saa lange som Yinene, men viser for- 
ovrigt en meget lignende Bygning, og berer paa 
Spidsen de seedvanlige Lugtepapiller og Foleborster. 
Andet Par Folere (Fig. 1, a) er ligeledes min- 
dre end hos Branchinecta, og har Formen af 2, som 
det synes, fuldkommen ubeveegelige trekantede Flige, 
60 
same body-divisions can be distinguished as in Bran- 
chinecta, although their mutual relations as to length 
are rather different. 
The head is comparatively small and bluntly 
rounded in front. It is sharply defined from the 
cervical segment, which shows tlie shell-gland on 
each side very distinctly. The trunk is greatly 
elongated, regularly cylindrical, and divided into no 
less than 19 well-defined segments, each bearing a 
pair of branchial legs. 
The posterior part of the body is highly remar- 
kable for its short and stout form, constituting, as 
it does, scarcely 1/s of the length of the body. The 
genital segments are completely coalesced, both 
mutually and with that part of the tail posterior 
to them, in which only the hindmost segment is 
distinctly defined. The whole of this part, seen 
from above (fig. 2), is almost pyriform, being very 
much thickened in front, and as it were inflated, 
with a rounded, nodiform protuberance on each side, 
while posteriorly it tapers gradually. The breadth 
of the front part of this section is more than double 
as great as that of the trunk itself. When the 
animal is seen from the side (fig. 1), the greater 
part of the ventral side of this region appears to be 
occupied by the voluminous marsupium, the anterior 
part of which is boldly convex, while the posterior 
end projects only slightly in the form of a short, 
conical prominence. At the end of this prominence 
is seen the external opening of the marsupium, 
bounded, as in Branchinecta, by 2 movable lips, the 
upper of which is the larger, and ends in a pointed 
nodule (see Pl. X, fig. 12). The caudal lamelle 
(see Pl. IX, fig. 6) are comparatively short, being 
searcely more than double as long as they are broad 
at the base. They exhibit a broadly lanceolate shape 
with the point narrowly rounded, and are each 
fringed with about 19 ciliated bristles, which suc- 
cessively increase in length towards the point. 
The eyes (Pl. X, fig. 1, 0) are comparatively 
short and thick, scarcely longer than half the 
breadth of the head, and of the usual pyriform 
shape, with the eye-ball evenly rounded. The pig- 
ment is dark, though with a distinct tinge of crim- 
son in the living animal: the visual elements are 
well-developed. The ocellus is observable as a dis- 
tinct dark spot in the centre of the frontal part of 
the head. 
The first pair of antenne (figs. 1, a* and 3) are. 
comparatively much shorter than in Branchinecta, 
being scarcely half as long as the eyes, but in 
other ways exhibit a very similar structure, and 
carry at the extremity the usual olfactory papille 
and sensory bristles. ) 
The second pair of antenne (fig. 1, a*) are also 
smaller than in Branchinecta, and have the form of 
2 apparently perfectly immovable triangular lappets 
