114 THE NAUTILUS. 



Zonites minusculus Binn. 

 Zonites suppressus Say. 



Helicid.e. 



Pat)da striatella Auth. 



Patula lineata Say. 



Panctum pygmaeum minutissimum Lea. 



Helix thyroides Say. 



Helix albolabris Say. 



PUPID.E. 



papa contracta Say. 

 Vertigo sp. (juv.) 



SUCCINEID.E. 



Succinea avara Say. 

 Succinea obliqua Say. 

 Succinea ovalis Gould. 



LiMNAEID.i:. 



Limncea catascopiiim Say. 

 Limncea humilis Say. 

 Planorbis trivolvus Say. 

 Planorbis bicarinatus Say. 

 Planorbis parvus Say. 

 Planorbula armigera Say. 

 Ancylus rivularis Say. 

 Physid.e. 



Physa ancillaria Say. 



AURICULIDyE. 



Carychium exiguum Say. 



ViVIPARID.E. 



Campeloma decisum Say. 

 Lioplax subcarinata Say. 



Amnicolid.e. 



Amnicola limosa Say. 

 Amnieola grana Say. 

 Pomatiopsis lapidaria Say. 

 Somatogyrus altilis Lea. 



Valvatid.i:. 



Valvata bicarinata Lea. 



