24 PHYSA HETEROSTROPHA. 



ochre-yellow, which cover the exposed parts. 

 The mantle within the shell is dark brown, fre- 

 quently spotted with light sienna, or golden- 

 yellow, but in one variety it is black.* 



Shell oval, ovate, or elongated, generally 

 translucent, composed of four or five slightly 

 convex whirls: suture well marked: apex point- 

 ed: aperture narrow, longer than the spire, with 

 the labium expanded far upon the body whirl: 

 columella thickened. 



Color. Various shades, from light translu- 

 cent yellowish-brown, to opaque chesnut; the 

 outside and inside seldom presenting different 

 shades. 



Monstrosities. The end of the right ten- 

 tacle furcated, and ending in two distinct points. 

 — Dr. Reinhardt. The posterior extremity of 

 the foot divided into two unequal parts; the one 

 on the left being the smaller, and situated late- 

 rally. 



Geographical Distribution. From latitude 

 31° to the St. Lawrence and the great lakes; 

 and from the North- w^est Territory and "Canada, 



* The shell of this variety cannot be distinguished from 

 those containing light colored animals, either in shape or 

 color. 



