74 



Bryant. Wai,ker 

 Subgenus OBOVARIA s. s. 



Fig. 204 



Shell retrorse to short oval ; beaks high, central ; pseudo-cardinals rarely 

 parallel with the laterals ; cavity of the beaks deep, subcompressed ; nacre 

 bluish-white or purple. Marsupium as in the genus. 



Type: Unio retusa Lam., fig. 203. Animal, fig. 204. 



Subgenus PSEUDOON Simpson, 1900. 



Shell elliptical, inflated, solid; that of the male slightly pointed at the 

 upper posterior part ; epidermis brownish or blackish, rayless or very feebly 



Fig. 205 



