THE CRUSTACEA OF NEW JERSEY. 69 



These characters, chiefly indicated by the simple second an- 

 tennas, clearly distingaiish the present tribe from the others. The 

 Podocopa are mostly fresh-water, while the other tril)es are 

 marine. These latter show the second antennas biramous, one 

 immobile branch rudimentary and the other flexibly elongate 

 with long- natatory setae as the Myodocopa, both movable nata- 

 tory branches well developed in the Cladocopa, and both Ijranclies 

 flattened as in the Platycopa. 



Family CYPRIDID^. 



Last pair of legs bent backwards within shell and not used 

 for locomotion. 



This character at once separates the members of this family 

 from the others found in the Middle States region. In all of 

 them the last pair of leg's are directed downwards and used for 

 locomotion. 



Key to the sub-faimlies. 



a. Natatory setae entirely lacking or little developed ; second antennae of 

 female five-segmented, and of male mostly six-segmented, and with two 

 sense clubs ; terminal segment of second foot with three unlike setae, two 

 of which backwardly directed. candonin^ 



aa. Natatory setae reaching beyond end claws, or approximately to tips of end 

 claws ; second foot with beak-like end-segment and a claw. cypridin.^ 

 aaa. Natatory setae very long, usually twice as long as distance from their 

 origin to tips of end claws ; second feet with three setae, one long, other 

 two short and backwardly directed ; furca usually normal. 



CYCLOCYPRIDIN.S 



Stih-faui'ily C.\ndonin/!^. 



Natatory set?e entirely lacking or little developed. Second 

 anteimcT of female five-segmented, in male mostly six-segmented, 

 and with two sense clubs. Terminal segment of second foot 

 with three unlike setse, two of which are l)ackwardly directed. 



