EXPLANATION OF TLATE XXII. 



Fig's 70 A and B. — Symphynota complanata (Barnes) 9, Big Mud 

 Lake, Kenmoor. 



Fig's 71 A and B. — Syniphy}iola costata (Raf.) 9, Black R., 

 Williamsville. 



Fig's 71 C and D. — 5. costata (Raf.) cf, Gasconade R., Gascondy. 



Fig's 71 E and F. — S. costata (Raf.) 9, Miss. R., Hannibal. 



Fig's 72 A and B. — Arcidens conjragosa (Say) 9> Marais des Cygnes 

 R., Papinsville. 



