lOIO 



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 group includes some of the largest of the Unionidae. Found in all of the Eastern States 

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



Fig. 1512. 



