a 
inhabiting the United States. 433 
DESCRIPTION’ 
Animal. Not hitherto observed. 
Shell. Depressed-convex, thin ; epidermis light 
horn-color; whorls less than four, with numerous, 
delicate, oblique strie; suture distinct, not much 
impressed ; umbilicus large, showing all the volu- 
tions; aperture rounded, transverse ; lip thin, acute. 
Greatest transverse diameter less than one fourth 
of an inch. 
GEOGRAPHICAL Osten Inhabits the West- 
ern States, is common in Ohio, and particularly 
abundant near Cincinnati, “in low Dottor M 
near the margins of running streams." It is also 
abundant in Massachusetts, near own, and in Ver 
mont. bid I 
REMARKS. - This species —— a very uen re- 
semblance in general aspect to Heux perspectiva, 
Sax, with the immature shells of which it is very 
commonly ; confounded. It needs some attention to ` 
separate the two; but, when the present species. is 
once noticed, it sioe fail to be considered very dis-4* 
tinct. Its discriminative characters, as compared with 
the preceding species, are as follows. 'The mature 
shell is smaller, and has generally rather less, and 
never more, than four whorls, and in shells of the 
same size the number of volutions is less. It is 
thinner and more delicate; its color is light p: its 
 Strie of increase are more numerous, more 
much finer, and less prominent; its suture is dos 
-deeply impressed ; its spire is more convex; and its 
umbilicus less expanded. The character of the 
* 
