152 LAND AND FRESH-WATER SHELLS OF N. A. [PART IV. 



whorls five, slopiugly convex, then keeled, longitudinally faintly pli- 



^. „ - ^. - ^. cated, transversely nodulosely 



Fig. 287. rig.287a. Fig. 288. •' "^Fig. 290. Fig.289. 



ridged ; aperture ovate, rather 

 large, slightly effused at the 

 base. 

 ^j Habitat.— 'EloTida. 



Observations. — Distinguished 

 by a papillose sculpture though being crossed with transverse ridges, 

 passing over oblique longitudinal folds. — liceve. 



The following is a copy of the description of 



Goniobasis Doicnieana. — Shell tuberculate, subturreted, clathrate 

 and subcarinate above, transversely striate below, thin, pale brown ; 

 spire conical, clathrate ; sutures irregularly impressed ; whorls seven, 

 subcarinate ; compressed tuberculate on and above the periphery ; 

 aperture rather large, ovately rhomboidal, whitish within; outer lip 

 crenulate, sinuous; columella bent in and twisted. 



Habitat. — Etowah Eiver; J. Postell. 



Diameter, -33; length, -71 inch. 



Observations. — Two specimens only of this beautiful species are 



before me, neither of them being entirely perfect. These two are 



without bands, but one has in the interior slight lines of color, 



' " Fig. 291. 



which indicate that other individuals may be well banded. 



The striae below the periphery are six, and they are thick 

 enough to cause corresponding white lines in the interior 

 The three lines above the periphery are cut b}' close folds on 

 ribs and these make the upper parts beautifully clathrate. 

 This species is closely allied to Canhyi 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, 

 Downieana — form a distinct group among American species, which 

 one would hai'dly 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 de- 

 velop the natural history of Georgia. — Lea. 



