70 
labrum sliglitly nnd'akted by tbe groove, and with a distinct sinus 
at the base of the columella. 
Inhabits Ohio River. 
Length, one inch and one tenth. Breadth, 3-5 of an inch. 
G-reatest transverse diameter more than 2-5. 
Very common at the Falls of the Ohio River. It is probably 
the largest species of this genus in the United States, and may be 
readily distinguished from its congeners by its broad groove. 
Melania elevata. — Shell gradually attenuating to the apex, 
slightly and irregularly wrinkled, olivaceous ; suture not deepily 
impressed } volutions nine or ten, with several more or less elevated 
revolving lines, of which one being more conspicuous gives the 
shell a carinated appearance ; aperture oblique, equalling the length 
of the second, third, and fourth volutions conjunctly. 
Length, one inch. Breadth two-fifths. Inhabits Ohio River. 
Distinct from our other species, by the elevated revolving lines. 
Melania CONICA. — Shell conic, rapidly attenuating to an acute 
apex, very slightly wrinkled, olivaceous ; suture not deeply im- 
pressed y volutions seven or eight ; aperture oblique, equalling the 
length of the second, third, and fourth whirls conjunctly. 
Var. a. With from one to three, revolving, rufus or blackish 
lines. 
Length, nearly 3-5 inch. Of the aperture, I inch. Inhabits 
Ohio River. 
May be readily distinguished from M. virginica by the much 
more rapid attenuation of the spire, and in the proportional differ- 
ence in the length of the aperture, which in the virginica is not 
more than equal to the length of the second and third whirls. 
Melania pr^rosa. — Shell subglobular, oval, horn color; volu- 
tions three or four, wrinkled across ; spire very short, much eroded 
in the old shell, so much so as to be sometimes not prominent 
above the body whirl ; body whirl large, ventricose, with a very 
obtuse, slightly impressed revolving band; aperture suboval, above 
acute and effuse ; within on the side of the exterior lip about four 
revolving purplish lines, sometimes dotted, sometimes obsolete or 
wanting ; labium thickened, particularly at the superior termina- 
tion near the angle, and tinged with purplish ; base of the colum- 
ella somewhat elongated and incurved, meeting the exterior Bp at 
an angle. 
