220 



NI::W YUUK STATE MUSEUM 



from tlio mariiiii of the shell, and fine, regular, uniform, con- 

 centric striae, together with the hinge structure characteristic 

 of t lie genus ; C y p r i c a r d e 1 1 a t e n u i s t r i a t a [fig. 1G9] , 

 a shell of subrectangular outline with a pronounced unibonal 



Fig. 178 P li a c o p s r a n a 



Fiy. 177 Ilomalonotus dekayi 



angulation and extremely fine, tenuous, concentric striae; 

 A c t i II () j» 1 (' 1- i a b o y d i [fig. 170], an oblique winged shell 

 with the wing not strongly defined, a marked anterior ear and 

 etrong surface markings with concentric striae, which however 

 do ii()( inici iiijtl llic i-adii; Nyassa a r gut a [fig. 171], a 

 modioloid shell with numerous small teeth beneath the beak, arcu- 



