16 
single angle upon it. In Lister’s Conch, pi. 93, fig. 93, is the 
representation of a shell, which is most probably intended for this 
species. Lister’s figure is quoted in the books for II. punctata^ 
but as the figure of a different species, (Born. Mus. pi. 14, fig. I'l 
and 18,) is also referred to as the same, I conclude that two dis- 
tinct species have been confounded together under the common 
name of punctata ; certainly the character from which this name 
was taken is never present on our shell. Specimens have been sub- 
sequently found by Dr. Thomas McEuen near the Falls of 
Niagara. 
H. PALLiATA.-— Shell depressed, with elevated lines, forming 
grooves between them ; epidermis fuscous, rugose with very 
numerous minute tuberculous acute prominences ; volutions five? 
depressed above, beneath rounded, forming an obtuse angle ex- 
teriorly, which is more acute near the termination of the labrum ; 
umbilicus covered with a white callus ; aperture contracted by the 
labrum ; labrum widely reflected, white, two profound, obtuse 
sinuses on the inner side above the middle, forming a prominent 
distinct tooth between them, and a projecting angle near the mid- 
dle of the lip ; labium with a large, prominent, white tooth, 
placed perpendicularly to the whorl, and obliquely to the axis of 
the shell, and nearly attaining the umbilical callus. 
Inhabits Illinois. Length of the column seven- twentieths of an 
inch. Greatest breadth, four-fifths of an inch. 
Var. a. — A very prominent acute carina; destitute of minute 
prominences. Inhabits Ohio. ^ Breadth nearly one inch. 
This shell is found on the banks of the Mississippi in moist 
places. It very much resembles M. iridentatm^ but is destitute of 
umbilicus, has a rugose epidermis, and is much larger. It is still 
more closely allied to appressa, but its superior magnitude, teeth 
and epidermal vesture distinguish it from that species. Specimens 
have subsequently been found by Dr. Thomas McEuen near the 
Falls of Niagara. 
H. iNFLECTA. — -Spire convex ; volutions five, wrinkled across ; 
suture not profoundly impressed ; aperture straight ; labrum re- 
flected, bidentate, teeth separated by a profound sinus, the supe- 
rior tooth inflected ; behind the lip a profound groove, which 
abruptly contracts the aperture in that part, so that although the 
lip is reflected, yet its edge is not more prominent than the general 
