CLASSIFICATION OP THE OSTRACODA. 



Ill 



OSTRACODA— CHARACTERS OE CARAPACE. 





SHATE AS SEEN LATERALLY. 



TEXTCRE AND MARKINGS OF 

 SHELL. 



HINGEMENT. 



Cyprid^ — 









Cvpris ... 



Usually reniform or subreniform, 

 valves equal or subequal 



Fragile, usually more or less 

 translucent, smooth, or hispid, 



Consisting of feebly overlapping flanges. 



Jr" 







often slightly punctate, rarely 



■ 







toothed at the lower angles 





Cypridopsis 



Like Cypris, but higber in pro- 

 portion to length, and smaller 



Like Cypris, but commonly hispid 



Like Cypris. 



Potamocypris ... 



Like Cypridopsis, but with right 



Like Cypridopsis, but with a 



Simple. 





valve much larger than left 



more robust and calcareous 

 shell 





Paracypris 



Much elongated, compressed, 



Moderately robust, smooth and 



Simple. 





highest in front 



polished, destitute of sculpture 



- 



Aglaia 



Oblong, subreniform, compressed, 

 nearly equal in height through- 

 out 



As in Paracypris 



Simple. 



Notodromas . . . 



Subquadrangular, very high in 



Like Cypris 



Simple, contact-margins (ventral), over- 





proportion to length, male and 





lapping, that of the (female) left 





female very different in shape 





valve having a conspicuous flattened 

 tooth-like plate at the posterior ex- 

 tremity, articulating with a fossa in 

 the opposite valve. 



Candona 



Elongated, subreniform 



Like Cypris 



Simple, rarely with a prominent curved 

 process near posterior termination of 

 left valve. 



Pontocypris 



Subtriangular or subreniform, 



Thin and fragile, with little or no 



Simple. 





usually higher in front than 



sculpture, more or less hispid 







behind 







ArgillcEcia 



Compressed, oblong, suboval 



Moderately robust, smooth 



Simple. 



Bairdia 



Subtriangular or subrhomboidal, 

 highest near the middle, height 



Moderately robust, smooth or 

 only moderately pitted, some- 



Flexuous, formed by the strongly over- 

 lapping border of the left valve. 







great in proportion to length. 



times toothed on anterior and 



■ 





left valve larger than right and 



posterior margins 







overlapping 







