OF THE UNITED STATES. 157 



is oblique and placed near the middle, and the other 

 less elongated placed near the base; umbilicus none. 



Breadth more than 1-4 of an inch. 



Inhabits Ohio and Pennsylvania. 



In general form it resembles H. ligera, but may 

 be distinguished by the absence of umbilicus, and 

 upon particular examination, by the teeth which are 

 situated far within the aperture. In the collection of 

 the Academy. 



ttt Umbilicated ; labrum simple. 



11. H. *ligera Shell subglobose, pale yellow 

 horn colour, polished ; body whorl, pellucid, yellow- 

 ish- white, opake beneath near the aperture ; volu- 

 tions rather more than six, all excepting the apicial 

 one wrinkled across ; spire convex, a little elevated; 

 umbilicus very small ; suture not deeply impressed ; 

 labrum not reflected. 



Inhabits Missouri. 



Greatest length 3-10. Oblique length less than 

 9-20. Transverse diameter less than 11-20. 



Approaches nearest to H. glaphyra, but is readily 

 distinguished by the greater convexity of the spire, 

 and the smaller umbilicus. Rather common. In 

 Lister's conch, on pi. 81, fig. 82, a shell is represent- 

 ed which may be intended for this species. 



12. H. *solitaria. Shell subglobose, with two or 

 three revolving, rufous hnesj spire conico-convex ; 



