FRESH-WATER MUSSELS. 



147 



Fig. II. — Glochidia of commoa fresh-water mussels. (After Surber. 1912 and 1915-) 



a and 6, Proptera alata. 



c, ProPtera caPax. 



d, ProPUralaevissima. 

 e and /, ProPtera Purpuraia. 



g, Quadrula coccinea. 

 k, Quadrula cbenus. 



i, Quadrula ffrani/era. 

 j, Quadrula keros. 

 k, Qucdrulalachrytnosa. 

 I, Quadrula Tnetanevra. 

 m, Quadrula obligua. 



n, Quadrula plicata. 

 o, Quadrula pustulata. 

 P. Quadrula pusiulosa. 

 q, Quadrula solida. 

 r, Quadrula undata. 



