THE NAUTILUS. 31 



scutellatum Sterki. Chautauqua Lake. 



Limnaea catascopium, Say. Cayuga, Canandaigua, Chautau- 

 qua Lakes. 



Limnaea catascopium white variety. Chautauqua Lake. 



Limnaea columella Say. Cayuga, Conesus, Cayuta, Silver 

 Lakes. 



Limnaea elodes Say. Fall Creek and Cayuga Lake (Say's type 

 locality). 



Limnaea elodes var. umbrosa, Say. Conesus Lake. 



Limnaea emarginata Say. Cayuga, Chautauqua Lakes. 



Limnaea humilis Say. Dwyer's Pond, Ithaca. 



Limnaea stagnates Linn. var. appressa, Say. Fall Creek at 

 Ithaca and Canandaigua Lake. 



Planorbis bicarinatus Say. Cayuga, Cayuta, Canandaigua, 

 Chatauqua Lakes. 



Planorbis bicarinatus var. major. Fall Creek, Ithaca. 



Planorbis campanulatus Say. Silver, Cayuta, Chautauqua, 

 Conesus Lakes. 



Planorbis deflectus Say. Fall Creek, Ithaca, Cayuga, Cayuta, 

 Hemlock, Chautauqua Lakes. 



Planorbis exacutus Say. Cayuga, Chautauqua Lakes. 



Planorbis hirsutus Gould. Chautauqua Lake. 



Planorbis lentus Say. Fair Grounds, Ithaca and Cayuga Lake. 



Planorbis parvus Say. Cayuga, Chautauqua Lakes. 



Planorbis trivolvis Say. Chautauqua, Canandaigua, Conesus 

 Lakes and Glacial Kettle near Ithaca. 



Planorbis trivolvis var. corpulentus Say. 



Segmentina armigera Say. Cayuga Lake. 



Ancylus diaphanus Hald. Cayuta Lake. 



Ancylus parallelus Hald. Fall Creek, Ithaca and Cayuga 

 Lakes. 



Ancylus rivularis Say. Cayuga, Chautauqua Lakes. 



Physa ancillaria Say. Owasco, Chautauqua Lakes. 



Physa gyrina Say. Fall Creek, Ithaca. 



Physa, heterostropha Say. Chautauqua Lake, Fall Creek at 

 Ithaca, Courtland Pond. 



Pleurocera subidare Lea. Cayuga Lake. 



Elimia virginica Say. Cayuga, Conesus Lakes. 



