EXPLANATION OF PLATE XVIL 



Fig's 40 A and B. — Adult Megalonaias heros (vSay) 9 , Platte R. 

 Garretsburg. 



Fig's 40 C and D. — Juvenile heros, Osage R., Monegaw Springs. 



Fig's 40 E and F. — Young heros, Osage R., Warsaw. 



Fig's 41 A and B. — Quadrida pustulosa (Lea) 9, Miss. R., Hannibal. 



Fig's 42 A and B. — Adult Q. pustulosa schoolcraftensis (Lea) 9, Platte 

 R., Claire. 



Fig's 42 C and D. — Young schoolcraftensis. — Same locality as adult. 



Fig's 43 A and B. — Q. pustulosa asperala (Lea) cf , Osage R., Bagnell. 



Fig's 44 A and B. — (). nodulata (Raf.) cf. Miss. R., Hannibal. 



