Descriptions of New Fluviatile Shells. 



4-5, gradatis, vix elevatis, ultimo perrnagno, fusco-bilineato ; apertura 

 magna, elongato-ovata ; columella incurva, in sinum tenuem producta. 



Shell short-ovate, smooth, rather thick, light horn-colored; 

 body whorl large, occupying nearly the entire volume of the 

 shell ; spire nearly flat, consisting of 4-5 perfectly plane whorls, 

 scarcely elevated above the body whorl ; aperture long, nar- 

 row ovate ; columella rounded, ending in a slight sinus. 



Length 0.50 inch (13 millim.). Diam. 0.32 inch (8 millirn.). 



Length of aperture 0.36 inch (9 millim.). 



Breadth of do. 0.18 inch (44 millim.). 



Habitat. Tennessee. 



My cabinet. Cab. Lye. Nat. Hist., K Y. 



Obs. Cannot be confounded with any other species ; its 

 remarkably flat whorls rising like steps, but little above each 

 other, with a distinct and slightly raised rim around the peri- 

 phery, will alone be sufficient to characterize the species. It 

 seems more like an Anculosa in form, but is nevertheless a true 

 Melania. Two bands are visible on the body whorl and also 

 within the aperture. 



45. Ulelaiiia undosa. 



Plate III. Fig. 25. 



T, ovata, glabra, subcrassa, stramineo-virente ; spira brevi, conica ; 

 anfr. 6-7, convexis, rapide crescentibus ; ultimo amplo, valde bumeroso, 

 interdum obscure fasciato ; suturis impressis ; apertura irregulariter 

 ovata, intus albido-rubescente, ssepe purpureo-fa?ciata ; labro subsinuoso; 

 columella incurva, in sinum latum producta. 



Shell ovate, smooth, olivaceous, moderately thick ; whorls 

 6-7, rapidly converging to the apex, convex ; body whorl 

 ample, with a distinct, but somewhat rounded shoulder ; sutures 



