342 NEW MELANID^E OF THE UNITED STATES. 



Hal,, — Etowah River, J. Postell. 



My cabinet and cabinet of Mr. Postell. 

 Diam. -33.. Length -71 inch. 



Remarhs — -Two specimens of this beautiful species only are before me, neither 

 of them being entirely perfect. These two are without bands, but one has in the 

 interior slight lines of color, which indicate that other individuals may be well 

 banded. The strige below the periphery are .six, and they are thick enough to 

 cause corresponding white lines in the interior. The three lines above the peri- 

 phery are cut by close folds on ribs, and these make the upper parts beautifully 

 clathrate. This species is closely allied to Canbyi, herein described, but it is 

 shorter and wider, and the tubercles are more numerous and smaller, having about 

 twenty on the periphery, while Canbyi has about thirteen. These three ornamented 

 little species, — Canbyi, Couperii and Downieana, — form a distinct group among Ame- 

 rican species, which one would hardly expect to find existing here. The aperture 

 is rather more than one-third the length of the shell. I name this species after 

 T. C. Downie, Esq., civil engineer, who has done much to develope the natural 

 history of Georgia. 



Goniobasis Tryoniana. PI. 38, fig. 207. 



Testa granulosa vel striata, subfusiformi, luteo-fusca vel tenebroso-fusca, crassa, robusta, vittata, raid 

 evittata, spira obtuse conoidea ; suturis irregulariter irnpressis ; anfractibus instar seuis, ultimo 

 pergrandi; apertura pergrandi, ovato-rhomboidea, intus valde vittata; labro subcrenulato, vix 

 sinuoso ; columella parum incurva et vix contorta. 



Shell granulose or striate, subfusiform, yellowish brown or dark brown, thick, 

 robust, banded, rarely not banded ; spire obtusely conical ; sutures irregularly 

 impressed ; whorls about six, the last very large ; aperture very large, ovately 

 rhomboidal, much banded within; outer lip subcrenulate, scarcely sinuous; colu- 

 mella slightly bent in and scarcely twisted. 



Operculum ovate, rather thick, dark brown, with the polar point near the left 

 margin, above the base. 



Proc. Acad. Nat. Sci., 1862, p. 272. 

 Sab. — Oostenaula, near Rome, Bishop Elliott ; Etowah River, Georgia, J. Postell ; 

 and Ocoee River and Tennessee River, Rev. G. White. 



My cabinet and cabinets of Bishop Elliott, Mr. Postell, Mr. White, Mr. G. W. 

 Tryon, Jr., and Dr. Hartman. 



Diam. '52, Length 1-01 inch. 



Remarks. — I have a number of specimens from the above various habitats, and 

 they vary very much. Some are more obtuse than others, and some are tuberculate, 

 while others are only transversely striate, close stria; often covering the whole sur- 

 face. Usually the bands do not show on the outside, often giving the surface a 



