ZONITES. 197 



II. DEMISSA, Binncy. PL GO, figs. 10-12. 



Perforated, yellowish horn-color, shining; whorls 6, with 

 minute growth-lines, suture impressed, body-whorl expanding 

 slightly towards the aperture, aperture thickened within. 



Diam. 11*5 mill. 



Western Pennsylvania to Arkansas, So. to Ala. and Texas. 



Vrir. ACERRA, Lewis. PI. 60, fig. 13. 



Shell large, robust, with strong striae. Diam. 20 mill. 



Mts. of E. Tennessee and W. No. Carolina. 



II. CERTNOIDEA, Anthony. PL 60, fig. 14. 



Narrowly perforated, shining, light horn-color, scarcely 

 wrinkled by growth-lines; whorls 7, flattened, narrow, the 

 last slightly inflated below. Diam. 7 mill. 



Jacksonville, Fla.; Charleston, S. C.; 



Neuoberne, N. C.; Norfolk, Va. 



H. PTYCHORAPHE, Wcinland and Martens. (Unfigured). Haiti. 



Subgenus GASTRODONTA, Albers, 1850. 



Section GASTRODONTA (typical). 

 G. LASMODON, Phillips. PL 60, figs. 15, 16. 



Rather widelj r umbilicated, flattened above, more convex on 

 the base, thin, corneous, shining ; whorls 7, narrow, very slowly 

 increasing, minutely striate above, smoother below, suture 

 moderate ; upon the basal part of the aperture are two prominent 

 white, nearly parallel lamina?, extending far into the cavity. 

 Diam. 6 mill. 



Mts. of E. Tennessee and N. Alabama. 



H. MACILENTA, Shuttlcw. PL 60, figs. 18, 19. 



Widely, perspectively umbilicated, depressed above, reddish 

 horn-colored, diaphanous, striated and scarcely shining above, 

 smoother and shining below; whorls 8, narrow, very slowly 

 increasing ; aperture with one or two parallel basal laminae. 



Diam. 8 mill. 



Mts. of E. Tennessee and Western N. Carolina. 



Formerly confounded with //. lasmodon, and I still doubt the 

 propriety of separating it. 



