1 I 



II 



III 1 IV 



V 



VI 



Circinaria concava (Say) Pils. 



4 













Zonitoides minusculus (Binn. ) Pils. 



.3 













Zonitoides arboreus (Say) Pils. 



2 













* Zonitoides nitidus (Muell.) Pils. 



4 



3 









4 



Vitrea hammonis (Strom.) Pils. 



2 











3 



Euconulus fulvus (Drap.) 



2 













Pyramidula alternata (Say) Pils. 



1 













Pyramidula striatella (Anth.) Pils. 



2 













Helicodiscus parallelus (Say) 



2 













Punctum pygmseum (Drap.) Binn. 



2 













* Suecinea retusa Lea 



3 



1 









2 



Suceinea avara Say 



2 











3 



* Suceinea witteri Shim. 



4 



4 











Agriolimax campestris (Say) 



3 













Phylomycus carolinensis (Bosc.) Per. 



4 













* Carychium exiguum (Say) Gld. 



3 



3 











Lymnaea megasoma Say 













5 



Lymngea stagnalis iugularis (Sav) Walk. 





3 









3 



Lymnaea emarginata angulata (Sower.) 







3 









Lymnaea palustris (Muell.) Sower. 





3 









2 



Lymngea elodes Say 





3 









2 



Lymnaea reflexa Say 





4 









3 



Lymnaea exilis Say 





3 









3 



Lymnaea caperata Say 





2 









2 



Lymnaea obrussa Say 





3 











Lymnaea modicella (Say) Jay 





2 











Lymnaea parva Lea 





3 











Physa Integra Hald. 











2 





Physa sayi Tapp. 





2 









2 



Physa sryrina Say 





1 









2 



Aplexa hypnorum (L. ) Chem. 





2 









2 



Planorbis campanulatus Say 







1 







2 



Planorbis bicarinatus Say 





2 



2 







2 



Planorbis truncatus Miles 







3 







3 



Planorbis trivolvis Say 





1 









2 



Planorbis exacutus Say 





2 









o 



Planorbis albus Muell. 





2 



3 







3 



Planorbis deflectus Say 





3 









2 



Planorbis parvus Say 





1 









2 



Planorbis dilatatus Gld. 





3 











Segmentina armigera (Say) H. & S. Ad. 





3 









o 



o 



Ancylus parallelus Hald. 













5 



Ancylus rivularis Say 









3 



2 





Ancylus diaphanus Hald. 





4 











Valvata tricarinata Say 





3 



1 







1 



Valvata bicarinata Lea 







4 









73 



