har Formen af et ovalt Blad, rundt om besat med 
en Rad af Fjerborster. I nogen Afstand fra Exo- 
poditen, omtrent ved Midten af Stammens Yder- 
kant, er Epipoditen (ep) festet. Den represente- 
res af et forholdsvis ikke meget stort, simpelt, 
aflangt, seekdannet Vedheng, der er rettet skraat 
nedad og bagud. I sin finere Structur skiller den 
sig noget fra de ovrige Vedheng, idet den er af 
mere spongios Beskaffenhed, og antager paa Spiri- 
tusexemplarer meget snart et temmelig opakt Ud- 
seende. Fornden de neynte Hoveddele, som alle 
ogsaa er tilstede hos Nebalia, kommer her endnu til 
et seregent Vedheng, der er specielt eiendomme- 
ligt for Gruppen Anostraca, og som jeg ovenfor 
har benzevnt «Dekpladen», for at antyde dets 
Bestemmelse, der nermest synes at vere den, til 
en vis Grad at erstatte det manglende Rygskjold 
ved at dekke over Roden af Branchialfodderne. 
Dette Vedheng (b) udgaar ligeledes fra Ydersiden 
af Stammen, men lige ved dennes Rod, og har For- 
men af en meget tynd og gjennemsigtig oval Plade, 
regelmessigt sagtakket i Kanterne. — Undersoger 
man ngiere de 11 Par Branchialfodder og sammen- 
ligner dem med hverandre, vil man finde enkelte 
mindre Differentser i deres Bygning. Hvad for det 
forste Storrelsen angaar, saa tiltager de gradvis 
noget i Lengde fra iste til omtrent 5te Par, for 
saa jevnt at aftage i Storrelse bagtil, saa at sidste 
Par neppe er halvt saa stort som 5te og noget min- 
dre end Iste. Det forreste Par (Fig. 9) skiller sig 
fra de folgeude ved en noget ringere Udvikling af 
Exopoditen, medens Endopoditen er forholdsvis ster- 
kere fremspringende, mindre indadrettet, og kun for- 
synet med en enkelt Torn i Inderkanten. Sidste 
Par (Fig. 12) udmerker sig fra de ovrige derved, at 
Epipoditen har antaget Characteren af en tynd 
Plade, besat i Kanterne med cilierede Borster, og 
derved at Dekpladen ganske mangler. Endopoditen 
er paa dette Par meget kort og af afrundet Form, 
medens Exopoditen er vel udviklet.— Hos Hannen 
skiller Branchialfodderne (Fig. 13) sig kjendeligt fra 
samme hos Hunnen ved Endopoditens betydelig ster- 
kere Udvikling. Den er navnlig paa de midterste 
Par sterkt fremspringende indad, nesten af le- 
dannet Form, og forsynet med et stort Antal af 
Randtorner. Rimeligvis har denne Modification af 
Endopoditen hos Hannen et vist Hensyn til Copula- 
tionen, idet Branchialfodderne derved delvis kan fun- 
gere som et Slags Griberedskaber og derved under- 
stotte 2det Par Antenner i deres Function at fast- 
holde Hunnen under Parringen. 
48 
o 
movably articulated to a separate ledge of the stem 
at the outer side of the’ endopodite, has the form of 
an oval lamella, beset all round with a row of plu- 
mose sete. At some distance from the exopodite, 
about in the middle of the outer edge of- the stem, 
the epipodite (ep) issecured. It is represented by a, 
comparatively, not very large, simple, oblong vesicu- 
lar appendage, which turns obliquely downwards and 
backwards. In its microscopical structure it differs 
somewhat from the other appendages, exhibiting a 
more spongious character, and in alcoholic specimens 
it very soon assumes a rather opaque appearance. 
Besides the above nained chief parts, which are all 
also present in Nebalia, another peculiar appendage 
is here added, which particularly distinguishes the 
group Anostraca, and which I have named above 
«the covering plate», in order to indicate its most 
probable purpose, viz, to replace to a certain 
extent the absent carapace in covering over the 
base of the branchial feet. This appendage (b) issues 
likewise from the outer side of the stem, but close 
to the base of the latter, and has the form of a very 
thin and pellucid plate, regularly serrated on the 
edges. — On a closer examination and comparison of 
the 11 pairs of branchial feet, some minor differences 
in their structure will be found to exist. Firstly, as . 
regards the size, they increase successively somewhat 
in length from the Ist to about the 5th pair, after 
which they again gradually decrease in size, in such 
a manner that the last pair are scarcely half as 
large as the Sth and also somewhat smaller than 
the Ist. The foremost pair (fig. 9) differ from the 
succeeding ones by a somewhat slighter development 
of the exopodite, whereas the endopodite is com- 
paratively more strongly produced, less incurvate, 
and only provided with a single spine on the inner 
edge. The last pair (fig. 12) distinguish themselves 
from the others by the epipodite having assumed 
the character of a thin plate edged with ciliated 
bristles, and by the complete want of any covering 
plate. The endopodite is, on this pair, very short 
and of rounded shape, whereas the exopodite is well 
developed. In the male the branchial feet (fig. 13) 
distinguish themselves very markedly from the same 
in the female, by the much stronger development of 
the endopodite. The latter is, especially on the 
middle pairs, strongly produced’ inwards, almost 
falciform in shape, and provided with a great num- 
ber of marginal spines. In all probability this mo- 
dification of the endopodite in the male has a cer- 
tain relation to the act of copulation, since the 
branchial feet thereby become, to a certain extent, 
enabled to act as a kind of prehensile organs, thus 
assisting the 2nd pair of antenne in their function 
to retain hold of the female during copulation. 
