lOlO FRESH-WATER BIOLOGY 



147 (150) Beak sculpture consisting of coarse parallel ridges, scarcely looped 

 or fine and doubly looped. 



Subgenus Lampsilis s.s. 148 



148 (149) Shell often very large, usually rather thin, inflated, shining, fre- 

 quently rayed. Beak sculpture consisting of coarse parallel 

 ridges, scarcely looped. . - Section Lampsilis s.s. 



This Rroup includes some of the largest of the Unioaidae. Found in all of the Eastern States 

 from New England to Georgia and west to Arkansas. Type, L. ovala Say (Fig. 1512; X I). 



Fiu. 1512. 



