North American Fresh-water Ostracoda. 467 



1868. Cypris comprefisa, Brady (6, p. 372, PI. XXIV., Fig. 1-5; 



XXXVI., Fig. 6). 

 1868. CyiJris ovum, Fric & Nekut (27, p. 48, Fig. 30). 

 1872. Cyprisovum, Fric. (26, p. 228, Fig. 28). 

 1874. Cypris compressa, Brady, Crosskey, & Robertson (14:, p. 



123 ; PI. I., Fig. 5, 6). 

 1885. Cypris punctata, Nordqvist (50, p. 150). 

 1888. Cypris punctata, Schwarz (59 p. 18). 



1888. Cypris compressa, Sostaric (60, p. 47). 



1889. Cypria ophthalmica, Brady & Norman (9, p. 69, PI. XI. ^ 



Fig. 5-9). 

 1891. Cypria ophthalmica, Vavra (68, p. 63, Fig. 19i-19«, 

 201-20*). 



Length .56 mm., height .37 mm., width .32 mm. The 

 American representative seems to be smaller than the 

 European form, if one may judge from the descriptions 

 of Vavra (68, p. 63) and of Brady (6, p. 372). 



Shell much compressed, reniform, clear brown, except 

 at the anterior and posterior ends and just back of the 

 eye-spot where there are dark brown bands or patches, 

 these three bands being perhaps a ready means of dis- 

 tinguishing the species. 



Seen from the side, the dorsal margin is much arched, 

 but hardly as much as in Vavra's specimens. 



Seen from above, the shell is widest at the posterior 

 third, narrow, somewhat acutely pointed anteriorly and 

 rounded posteriorly. 



Natatory setae very long, reaching beyond the tips 

 of the terminal claws by more than the total length 

 of the antennae, or three times as long as the distance 

 between their point of insertion and the tips of the ter- 

 minal claws. 



Terminal segment of second foot somewhat longer 

 than broad, a third as long as the preceding segment, 

 and sinuate at its inner margin. The two terminal short 

 setae are about the same length and as long as the ter- 

 minal segment. 



Caudal rami (Fig. 5) short, rather stout, bent, and 

 fullv ei<2:ht times as long as wide. Terminal claw simple, 



