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On 
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ZOOLOGY 
Appendages of Cypris. 
1. Ist pair of antennae (antennules). 5. 2nd pair of maxillae. 
Aa ends 55 “ 6. Ist ,, thoracic limbs. 
3. Mandibles. Us Pail 35 ». 
4, Ist pair of maxillae. 
The antennae are usually adapted for walking or swim- 
ming, and in some of the marine forms the shell is notched, so 
Fic. 155.—Lateral view of Cypris can- 
dida. After Zenker. 
. Antennules. 
Antennae. 
. Mandibles. 
. Ist maxillae. 
2nd maxillae. 
1st pair of legs. 
. 2nd pair of legs. 
Tail. 
Eye. 
SOND oO-F CoN er 
that the antennae can be protruded even when the shell is 
closed. In Cypridina the anterior pair bear olfactory hairs, 
and in Cypris the second pair end in hooked bristles, by means 
of which the animal can anchor itself. 
The mandibles are strong and toothed; they bear a palp, 
which is usually elongated and leg-like. The second maxilla 
functions sometimes as a maxilla, sometimes as a leg; there 
are usually two, rarely three, thoracic legs; the abdomen is 
devoid of appendages, and is rudimentary; it may end in a 
caudal fork, as in Cypris, or in a plate beset with setae. 
The oesophagus expands into a crop, which lies in front of 
the true stomach. The last-named region of the alimentary 
canal gives off a hepatic diverticulum on each side, which is 
prolonged into the cavity of the shell. The anus opens at the 
base of the abdomen. These animals are entirely carnivorous. 
A heart is often absent; when it exists, as in Cypridina, it lies 
on the dorsal surface, in the region where the body and shell 
are in continuity. There are as a rule no special respiratory 
organs, respiration probably taking place through the general 
surface of the body. A shell gland is present, and opens in 
the region of the second maxilla. 
There is a cerebral ganglion and a short ventral chain of 
ganglia, which, however, often fuse together to form a com- 
plex ventral nervous mass. The single eye of the Nauplius 
