16 



single angle upon it. In Lister's Concli. 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 H. punctata, 

 but as the figure of a different species, (Born. Mus. pi. 14, fig. 17 

 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. p^y:.LiATA. — Shell depressed, with elevated lines, forming 

 grooves betweeen 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 acu.te 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 H. tridentata, but is destitute of 

 umbilicus, has a rugose epidermis, and is much larger. It is still 

 more closely allied to npp?-essa, 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 



