OSTEACODA 355 



2. CYPRIDOPSIS Brady. Eye single, median; second antennae 

 5-jointed, the natatory bristles extending beyond the terminal bristles; 

 caudal furca rudimentary; males unknown: 11 species, 3 American. 



C. vidua 0. F. Miiller (Fig. 558). Length .6 mm.; height .34 mm.; 

 width .4 mm. ; color yellowish-green with 3 transverse bands on the back 

 and sides: common everywhere in fresh water; a scavenger. 



3. CYPRIA Zenker. Body compressed; eye single, median; second 

 antennae 5-jointed, the 5 natatory bristles very long, extending far 

 beyond the terminal bristles; furca normal, stout: 11 species, 7 

 American. 



C. exsculpta Fischer (Fig. 559). Length .58 mm.; height .38 mm.; 

 width .26 mm.; shell thin, somewhat transparent and covered with a 

 meshwork of longitudinal lines; furca bent: common in shallow ponds 

 and slowly flowing, shallow streams; Europe. 



4. CANDONA Baird. Second antennae of female 

 5-jointed and lacking the natatory bristles; furca 

 strong: on the bottom, in the mud and sand, not 



being able to swim ; 25 species, 9 American. Fig. 



C. acuminata Fischer (Fig. 560). Length 1 mm.; c $l?. 

 height .44 mm.; width .36 mm.; shell pointed 

 behind, white or brown in color; the shorter bristle of the last seg- 

 ment of second foot 3 or 4 times as long as the last segment: often 

 common; Europe. 



5. PONTOCYFRIS Sars. First antennae 7-jointed 

 with bristles longest on the last joint and decreasing 

 in length proximally; second antennae with 4 slender 



Fig. sei ponto- claws on last joint and a group of 5 bristles on the 



cypris edwardsi T,- -, 



(Cushman). antepenultimate: several species; marine. 



P. edwardsi Cushman (Fig. 561). Shell somewhat 



triangular with rounded ends, hirsute; first antennae with 4 bristles from 

 basal joint; length .85 mm.; height .47 mm.: Eel Pond, Woods Hole, in 

 August. 



FAMILY 2. CYTHEEIDAE. 



Shell usually calcareous and hard ; eyes paired but more or less con- 

 fluent, sometimes wanting; first antennae 5 to 7-jointed, with bristles; 

 second antennae leg-like, 4 or 5-jointed, with 2 terminal claws; with a 

 basal segment bearing a long flagellum which contains a duct from a 

 poison gland; mandible with palp; first maxilla normal, second maxilla 

 leg-like and similar to the 2 pairs of legs; furca rudimentary; animals 

 cannot swim: about 700 species and 30 genera, almost exclusively in 

 salt water; 8 American marine and 2 fresh-water genera. 



