OF THE UNITED STATES. 245 



BULLA. 



Species. 



B. *solitaria. Shell remarkably thin and fragile, 

 pellucid, oval, narrowed at base, with numerous im- 

 pressed revolving lines, and transverse very obtuse 

 wrinkles ; aperture surpassing the tip of the shell ; 

 spire none, substituted by an umbilicus ; umbilicus 

 of the base uoue. 



Less than half an inch. 



Inhabits the southern coast of the United States. 



I found a specimen of this species of Bulla on the 

 coast of Maryland, but have not seen another. It is 

 probable that it is rare. It approximates to the de- 

 scription of B. hydatis, but it cau hardly be the same, 

 as it is more oblong than the species B. naucum, 

 agreeably to the figure in the Encyc. Meth., which 

 species is referred to by Dillwyn, as being of the 

 same form with hydatis. 



MELAMPUS, Montf. 



Species. 



M. *bidentatus. Shell thin, fragile, dirty-brown- 

 ish; very little elevated, obtuse; body whirl with 

 minute transverse wrinkles, and revolving impressed 

 striae; labium bidentate, the superior tooth trans- 

 verse, prominent, placed below the middle, the other 

 oblique, less prominent, terminating at the exterior 

 edge of the columella ; labrum with four or five ele- 



