SCHIZOSTOMA. 377 



Schizostoma robustum. — Shell fusiform, robust, thick, of a dark 

 olive-color ; spire obtuse, consisting of one perfect whorl remaining, 

 with marks of two or three more, lost by truncation ; body-whorl 

 broad, curved, not deep, closed behind by a cord-like cincture, very 

 prominent, beneath which and close to it is a narrow depression 

 or furrow ; aperture narrow, ovate, banded inside ; columella well 

 rounded and covered by callus; lines of growth very distinct and 

 much curved, rendering the shell rough by their prominence. 



Habitat. — Coosa River, Alabama. 



My cabinet. 



Length of shell, seven-eighths; breadth of shell, nine-sixteenths 

 of an inch. Length of aperture, ten-sixteenths ; breadth of aper- 

 ture, five-sixths of an inch. 



Observations. — This is a large, robust species, somewhat resem- 

 bling Melania ampla (nobis) in form, and not unlike 

 it in coloring; it is about the largest species I have seen 

 in this genus, and certainly not the least beautiful; com- 

 pared with G. salebrosa (nobis) herein described, it is 

 larger, smoother, more inflated and has not the rib-like 

 prominences so characteristic of that species; the lower 

 part of the columella is somewhat flattened and thick- 

 ened, and another thickening takes place at the aperture, leaving a 

 thinner space between the two points. — Anthony. 



25. S. glandiila, Lea. 



Schizostoma glandula, LEA, Proc. Acad. Nat. Sci., p. 187, 18G0. Jour. Acad. Nat. 



Sci., V, pt. .'J, t. 35, f. 53, March, 18(53. Obs., ix, p. 71. 

 Gyrotoma glandula, Lea, Binney, Check List, No. 319. Brot, List, p. 27. 



Description. — Shell smooth, short, much inflated, rather thick, yel- 

 lowish horn-color, minutely striate, imperforate; spire short; sutures 

 much impressed; whorls six, banded, the last large and swollen; 

 lip-cut oblique and short; aperture rather large, elliptical, white 

 within ; columella whitish and thickened above ; outer lip sharp and 

 somewhat sinuous. 



Operculum ovate, brown, with the polar point very close to the 

 inner lower edge. 



Habitat. — Coosa River, Alabama ; E. R. Showalter, M.D. 



Diameter, 36; length, -57 of an inch. 



Observations. — A single specimen only was received from Dr. 



