342 



PHYLUM ARTHROPODA 



themselves rapidly by means of their thoracic legs, or swim more 

 gently by means of their second antennae. The mandibular palps, 



Fig. 1 86. — Cypns. 



M., Marks of adductor muscle ; E., eye seen through the shell {SH.) 

 A.I, first antennae; A. 2, second antennae; F., thoracic legs. 



Fig. 187. — Cypris, side view, after removal of one valve. — 



After Zenker. 



e., Eye ; A.r, first antennae ; A. 2, second antennae ; MN., mandibles ; 

 mx.i, first maxilla ; mx.2, second maxilla ; /./, f.2, thoracic legs ; 

 Ab., rudimentary abdomen. 



first and second maxilla3, and maxillipedes together form a pump 

 and a fine sieve, on which the food is caught. Many are ecto- 

 parasitic» especially on fishes ("fish-lice"), and are often very 



