ANCULOSA. 403 



four; aperture rounded, nearly as broad as long; within more or less 

 tinged with dull red ; labium a little flattened. 



Length, three-fifths ; greatest breadth, eleven-twentieths of an inch. 



Observations. — Professor Vanuxem found this curious shell in 

 the north fork of the Holston River, Virginia, 

 where they are extremely abundant. In the old 

 shells the surface, and particularly that of the 

 spire, is considerably corroded, presenting the 

 appearance of having received a fortuitous depo- 

 sition of calcareous matter. This corrosion, however, does not 

 extend to the destruction of any of the whorls, as is the case with 

 many shells, but its effects seem to be confined to the exterior. It 

 is a second species of my proposed genus Anculotus. All the striae 

 of the operculum are concentric to the superior angle. — Say. 



This species, which inhabits an extensive range in Virginia, 

 Tennessee, Ahibama and north Georgia, is somewhat variable 

 in outline and ornamentation. Tlie southwest Virginia speci- 

 mens, which are unicolored, may retain the name of suhglo- 

 bosa, as the typical shells, and the young of these = globula^ 

 Lea, a description of which species follows : — 



Melania (jlobiila. — Shell smooth, subglobose, dark brown, banded; 

 spire short ; sutures impressed ; whorls four, rather convex ; aper- 

 ture large, nearly round, within bluish. 



Habitat. — Tennessee; Dr. Troost. 



Diameter, -22; length, -25 of an inch. 



Observations. — This is a small, globose species, with two very 

 broad bands, one immediately over and the other below the middle 

 Fig. 801. of the body-whorl. The columella is white, inclined to a 



^k rusty hue. The interior of the base is reddish. Some of 



^^ the specimens are small, and present a variety in which the 

 columella is rodder, and the epidermis more j'ellow, with the same 

 distinctive bands. The aperture is nearly two-thirds the length of 

 the shell. — Lea. 



The following is the description of 



Anculo-m rjibbosa. — Shell subglobose, gibbous, thick, nearly black, 

 thickly striate; spire short; sutures impressed; whorls rather flat- 

 tened ; aperture subquadrangular, flesh-colored or whitish. 



Habitat. — Tennessee. 



