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LIFE OF THE PLEISTOCENE 



Sphaerium solidulum (Prime) 

 rhomboideum (Say) 

 fabale (Prime) 

 Pisidium walkeri Sterki 



crucialum Sterki 



Pisidium variabile Prime 



" virginicitm (Gmelin) 

 " adamsi Prime 

 " noveboracense Prime 

 " abdilnm Haldeman 



* GASTROPODA 



HELICrNTDAE 



Helicina occulta Say 



Pleuroceridae 



Pleurocera subulate (Lea) Goniobasis depygis (Say) 



elevatum (Say) lialdemani (Tryon) 



elevatum lewisii (Lea) Anculosa coslata Anthony 



VlVIPARIDAE 



Campeloma decisum (Say) Campeloma subsolidum (Anth.) 



AMNtCOLIDAE 



Amnicola limosa (Say) Somalogyrus depressus Tryon 

 limosa porala (Say) isogonus (Say) 



emarginata (Kiister) Bythinella tenuipes Couper 



Cincinnati ensis (Lea) Pomaliopsis lapidaria (Say) 



Valvatidae 



Valvata bkarinala perdepressa Walker 



Valiata tricar inala Say 

 " sincera Say 



Physa heteroslropha Say: 

 " ancillatia Say 



Ancylus tardus Say? 

 " rivularis Sav 



Physidae 



Aptexa hypnorun (Linne) 



Ancylidae 



Ancytus parallel us Hald. 





Planorbis anlrosus Conrad 

 " trkolvis Say 

 " partus Say 



Planorbidae 



Planorbis defleclus Say 



albus Miiller { = hirsutus Gould) 

 Segmentina armigcra (Say) 



Lymnaeidae 

 Lymnaca stagnalis appressa Say Galba obritssa (Say) 



Galba palustris (Miiller) " humilis modicella (Say) 



" refiexa (Say) " caperata (Say) 



" elodes (Say) 



Auricuudae 

 Carychimn exiguum (Say) Carychium exile H. C. Lea 



Vaixonudae 

 Vallonia perspectiva Sterki Vallonia gracilicosta Reinh. 



" costaia (Muller) " pulchella (Miiller) 



" cyclophorella Ancey 



! 



