98 



LIFE OF THE PLEISTOCENE 





Post- 

 Glacial 64 



Recent 





Lake 

 Michigan 



Small 

 lakes 



Rivers 



Sloughs; 

 swamps 





X 

 X 



X 

 X 



X 











X 

 X 























" neglectum corpulentum 







X 





" noveborocense 



X 





X 





" noiieboracense elevata 





X 

 X 

 X 





" peralta 





X 



X 





" politum 



X 

 X 

 X 





" politum decorum 









" pauperculum 











" punctatum 







X 

 X 



X 





" punctatum simplex 











" roperi 













X 

 X 

 X 

 X 

 X 

 X 

 X 

 X 





X 

 X 

 X 





" scutellatum 



X 



X 

 X 





" s plendidulum 





" superius 











X 



X 

 X 









X 

 X 



X 



X 

 X 





" virginicum 





" ivalkeri 









X 

 X 

 X 

 X 

 X 

 X 





Campeloma decisum 







X 

 X 

 X 

 X 

 X 

 X 

 X 





integrum 



X 

 X 







" integrum obesum 







rufum 







" subsolidum 



X 







" subsolidum exilis 







Valvala tricarinata 



X 

 X 

 X 

 X 



X 



X 





" tricarinata, simplex 





" tricarinata confusa . . 



X 









" tricarinata unicarinata 









" bicarinata 



X 

 X 

 X 



X 



X 

 X 









" bicarinata perdepressa 



X 









" bicarinata normalis 





X 





" lewisii 









Bytkinia tentaculata 











Amnicola limosa 



X 



X 

 X 

 X 

 X 



X 





" limosa parva 





" limosa porata 



X 

 X 

 X 



X 

 X 

 X 



X 



X 

 X 





" lustrica 





" emarginata 











