lo University of Michigan 



Zonitoides minnscula (Binn.). 

 Zonitoides nummus Van. 

 Vitrea indentata (Say). 

 Helicodiscus paralleliis (Say). 

 Piipoides marginata (Say). 

 Bijidaria armifera (Say). 

 Bifidaria contracta (Say). 

 Bifidaria cristata P. & V. 

 Bifidaria pentodon (Say). 

 Bifidaria procera (Gld.). 

 Bifidaria tappaniana (C. B. Ads.). 

 Pliysa forshcyi Lea. 



23. Blue Creek Canyon, Wichita ]\Tountains, Oklahoma. 

 Land species identified by Clapp ; Pisidiiun by Sterki. 



Polygyra te.vasiana (Moric). 

 Zonitoides ininiiscida (Binn.). 

 Zonitoides singleyana Pils. 

 Zonitoides nummus Van. 

 Buconuliis trochulus Reinh.? 

 Helicodiscus paralleliis (Say). 

 Pnpoides marginata (Say). 

 Bifidaria contracta (Say). 

 Bifidaria hordcacella Pils. 

 Bifidaria procera (Old.). 

 Bifidaria tappaniana (C. B. Ads.). 

 Physa forshcyi Lea 



Pisidium sp.? "One example, probably not full grown, 

 appears to be friersoni St." (Sterki), 



24. Santa Fe Lake, one and one-half miles south of Tecum- 



seh, Oklahoma. 

 Land species identified by Clapp. 

 Zonitoides minnscula (Binn.). 



