Descriptions of New Fluviatile Shells. 



it has not the shouldered whorls and tubercular armature which 

 distinguish that beautiful species. 



The bands within the aperture do not reach its outer edge, 

 but a broad, plain area is left between. 



13. IHelania ambus! a. 



Plate II. Fig. 13. 



T. ovata, glabra, subtenui, castanea ; spira obtuse elevata, anfr. 6 

 subconvexis, ultimo magno, substriato; suturis iinpressis; apertura 

 magna, elongato-ovata, intus rubescente ; columella subfoveata, sinurn 

 vix forrnante. 



Shell ovate, rather thin ; smooth, chocolate-colored ; spire 

 obtusely elevated ; whorls about 6, sub-convex ; body whorl . 

 large, substriate ; sutures moderately impressed ; aperture large, 

 narrow ovate, reddish within ; columella indented, with a 

 broad, not very remarkable sinus at base. 



Length 1 inch (26 millim.). Diam. 0.48 inch (12 inillim.). 



Length of aperture 0.48 inch (12 millim.). 



Breadth of do. 0.23 inch (6 millim.). 



Habitat. Alabama. 



My cab. Cab. Lye. Nat. Hist,, K Y. B. W. Budd, M.D. 



Obs. In form not unlike J/i olivula Con., but its very pecu- 

 liar plain, dark, chocolate-colored epidermis and sombre interior 

 will at once distinguish it from all other species. A few irre- 

 gular stria? are visible on the body whorl, and a very obscure 

 narrow band may be observed near the sutures ; in all of the 

 three specimens before me the columella is slightly reflected 

 over a narrow umbilical opening near the base, which appears 

 almost disconnected from the outer lip as in Achatina. The 

 burnt appearance of the shell has suggested its specific name. ' 



