﻿236 CKIS'IARIA 



Subgenus Ckassitksta v^inipson, i()oo. 



Crassitesta Simi'Son, v^yn.. kjoo, p. 586. 



Shell rather solid. ellii)tic-rhon-ill3oid, with a rounded pos- 

 terior ridge, scarcely winged ; beaks full, sculpture not seen ; 

 cpidemiis bright, strongly rayed, with two conspicuous light 

 and three dark rays on the posterior slope ; hinge line curved ; 

 pseudocardinals and laterals reduced to the merest vestiges ; 

 dorsal scars only one or two in the cavity of the beaks ; ad- 

 ductor scars faint ; nacre lurid. 



Type. Cristan'a radiata Simpson. 



Cristaria radiata Simpson. 



Shell elliptic rhomiboid, rather solid, somewhat inflated, 

 with a full, rounded posterior ridge; anterior wing wanting; 

 posterior wing but slightly developed ; beaks full, elevated 

 above the dorsal line, much eroded in the specimens seen, but 

 apparently having somewhat doubly-looped sculpture ; surface 

 shining, greenish-yellow with narrow and wide green rays ; 

 on the posterior slope there are two distinct, yellowish rays ; 

 hinge line evenly curved ; only the faintest vestiges of pseudo- 

 cardinals and laterals are developed ; beak cavities shallow, 

 with one or two pits ; muscle scars shallow ; nacre bluish-white, 

 dull, often blotched, not thickened in front. 



Length yT,, height 45. diam. 28 mm. 



Kien-te sud, (Ngan-houe), China. 

 Dipsas pan'ulus IIkude (part). Conch. Fluv. Nank., \'II, 1881, 



pi. LIT, fig. 96. 

 Cristaria radiata Simpson, Syn., igoo, p. 586. 



I do not know where to place this species, which is so dif- 

 ferent from the other Cristarias that it may not belong to that 

 genus at all. Ileude applied the name Dipsas panmlus to two 

 entirelv distinct forms, figuring the first on plate xxxii of the 

 Conchyliologie Fluviatile Nanking and the present species on 

 plate i.ii. hence T have given the last figured form a new name. 

 T do not think it can be an Anodonta and it may be the type 

 of a distinct genus. 



