THE MOLLUSC A 



Toil 



149 (148) Shell oval to oblong; beak sculpture consisting of fine, doubly 

 looped ridges Section Eurynia Rafinesque. 



This group has many species and is of general distribution from Manitoba to Texas and 

 eastward. Type, Lampsilis recta Lam. (Fig. 151,^; X 2). 



Fig. 1513. 



150 (147) Shell small, inflated, oval to obovate; male usually more or less 

 pointed posteriorly; female truncated obliquely on the post- 

 base; beak sculpture consisting of rather strong concentric 

 ridges Subgenus CarimciiUna Simpson. 



A well-marked group of small, dark-colored species easily distinguished by the pecuHar beak 

 sculpture. Most of the species are confined to the Southern States from Georgia to Texa.s, but 

 two or three range north to Illinois and southern Michigan. Type, Lampsilis tcxasensis Lea 

 (Fig. i5i4;Xl). 



Fig. 15 14. 



