CYPRIS. 151 



mud becomes very dry and hard, they perish ; but the 

 eggs do not perish along with the parents, for they can be 

 hatched in four or five days after being placed in water. 



These little creatures seem to be very lively in their 

 native element, being almost constantly in motion, either 

 swimming about rapidly by the action of their antennae, 

 or walking upon the plants and other solid bodies floating 

 in the water. Instead of being fixed to one place, and 

 condenmed to live amidst eternal darkness, Jike the mol- 

 luscous animals to which they bear such resemblance in 

 external covering, "they" to use the words of Midler, 

 " by opening their valves, enjoy light, and move at their 

 will, sometimes burying themselves in the mud, some- 

 times darting through the water, the humid air of their 

 sphere. If they meet any unforeseen object, they conceal 

 themselves all at once in their shells and shut the valves, 

 so that force and address seek in vain to open them." 



This family contains two Genera. 



1. Cypris. — Inferior or pediform antennse provided 

 with a pencil of long hau's or filaments. Animal swim- 

 ming freely in the water. 



2. Candona. — Inferior or pediform antennae destitute 

 of the pencil of long hau's or filaments. Animal creeping 

 on the ground or upon plants. 



Genus 1 — Cypris. 



Cypkis, Miiller, Latreille, M. Edwards, Dana, Sfc. 

 MoNOCULUS, Limiceus, Manuel, cfc. 

 Monocles A coauiLLE bivalve, Jurine. 



Character. — One eye. Two pairs of feet ; one pair 

 always inclosed within the shell. Abdomen terminated 

 by a long, slender, bifid tail. Posterior or pediform an- 

 tennae furnished with a bundle of long setae, generally 

 plumose. Animal swims freely in the water. 



