172 LAND AND FRESn-AVATER SHELLS OF N. A. [pART IV. 



Description. — Shell conical, with four flat whorls, which are crossed 



Fig. 330. rig.331. Fig. 332. Fig. 333. ^^ ^^^^^'^^^^ ''^' ^"^^ '^'''^^ ^^'^^^ ' '"P«^ 



truncated ; suture indistinct ; aperture 



elliptic, two-thirds the length of the 



shell. Color olivaceous, sometimes 



banded with black. 



Length, ^ of an inch. 



JIahitat. — Tennessee. — Haldeman. 



The following are synon^'mes. 



Goniobasis Christyi. — Shell folded, striate or granulate, fusiform, 

 rather thick, inflated, yellowish-olive, banded; spire obtusely conical; 

 sutures impressed ; whorls five, slightly convex ; aperture very large, 

 ovately rhomboidal, banded within; outer lip sharp, scarcely sinuous; 

 columella thickened, slightly twisted. 



Operculum ovate, thin, brown, witli the polar point well removed 

 from the left margin and the base. 



Ilahitat.—V aWcy River, Cherokee City, N. C. ; Prof. David Christy. 



Diameter, -37; length, -07 of an inch. 



Observations. — I have about a dozen of this species from Mr. Clark, 

 collected by Prof. Christy in North Carolina. All the specimens are 

 nearly of the same size and outline, and have the same 



•' Fig. 334. 



bands, usually four, but they difl"er much in the exterior. 



Some have no striae, but those which have cut the irregular 

 folds and form granules. Usually, there are four bands in- 

 distinct on the outside, but well marked within, the two 

 middle ones being approximate. The upper band is the 

 largest, and the callus above is often purple. Some specimens have 

 five or six bands. It reminds one of Melania (Goniobasis) basalis 

 (nobis), but that shell is not so much inflated, nor has it folds, striae 

 or granules like this. The aperture is more than half the length of 

 the shell. I name this after Prof. David Christy, who collected it, 

 with many interesting shells, while in the northwestern part of 

 North Carolina. — Lea. 



This and instabilis are adult forms. 



Goniobasis instabilis. — Shell folded or smooth, fusiform, thick, 

 somewhat inflated, banded or not banded, olivaceous; spire conical; 

 sutures impressed; whorls about five, slightly convex; aperture 

 large, ovately rhomboidal, banded wi'Jiiu ; outer lip acuic, scarcely 

 sinuous; columella thickened, somewhat bent in and twisted. 



