71 



Length, about 4-5 inch. InliabitvS Ohio River. 



Found in plenty at the falls of the Ohio. The spire is remarkably 

 carious in the older shells, and the penultimate whirl, between the 

 aperture and the spire, is also remarkably eroded in many older 

 shells. The spire in the young shell is entire, and but little promi- 

 nent, though acute, and the bands are distinct on the exterior of 

 the shell. This shell does not seem to correspond with the genus 

 to which I have, for the present, referred it; and owing to the 

 configuration of the base of the columella, if it is not a Melanopsis, 

 it is probable its station will be between the genera Melania and 

 Acathina. I propose for it the generic name of Anculosa. 



Melania armiqera. — Shell tapering, brownish-horn color; 

 volutions about six, slightly wrinkled ; spire near the apex eroded, 

 whitish ; body whirl with a revolving series of about five or six dis- 

 tant, prominent tubercles, which become obsolete on the spire, and 

 are concealed by the revolution of the succeeding whirls, in conse- 

 quence of which arrangement there is the appearance of a second, 

 smaller, and more obtuse subsutural series of tubercles on the body 

 whirl ; two or three obsolete, revolving, reddish-brown lines ; aper_ 

 ture bluish-white within ; a distinct sinus at the base of the colu- 

 mella. 



Inhabits Ohio River. Length about one inch. 



Distinguished from other N. American species, by the armature 

 of tubercles. 



Bulla fluviatilis. — Shell suboval, pellucid, pale yellowish 

 white, finely wrinkled ; volutions three ; body whirl large, with a. 

 prominently capinated shoulder bounding the spire ; spire perfectly 

 flat or slightly concave, giving to the shell a perfectly truncated 

 appearance in that part ; aperture longer than the columella, ob- 

 long-ovate, extending beyond the tip of the spire ; umbilicus pro- 

 found, edged by a slight carina. 



Length of the aperture one-fifth of an inch. Greatest breadth 

 somewhat less. Inhabits the River Delaware. 



This species seems to be rather rare ; ij; was discovered by Mr. 

 Aaron Stone, deeply imbedded in the mud ; Mr. William Hyde, of 

 this city, has since found specimens of it amongst some dead shells 

 of other genera assembled in a small inlet of the river. 



