﻿246 



Cincinnati Society of Natural Hisiory. 



2. C. FAKER I, 11. Sp. 



(Plate IV. Figs. 303 b.) 



Shell strongly curved and gradually tapering; septa wide, ten in the space 

 of two inches, measuring on the outer curve ; section elliptical, with the 

 the lateral diameter the greater ; siphuncle small, dorsal ; body chamber 

 and surface unknown. Length on outer curve of ten septa, two inches ; 

 on inner curve, one inch. 



Locality: Waynesville, Ohio; upper part of group. 



This species differs from all the others heretofore described from this 

 group in the great width of the septa in connection with the rapid curva- 

 ture of the shell. From C. vatiandigkami it is separated by the gradual 

 tapering and the wide septa. 



3. C. ventricosum, S. A. Miller. 1875. 



(Cin. Quar. Jour. Sci., II, p. 131, fig. 16.) 



Shell ventricose, gently curved and rapidly enlarging toward the aper- 

 ture ; section circular, or nearly so ; septa slightly concave, curving 

 forward on dorsal side : siphuncle nearly marginal on dorsal side, abruptly 

 expanded within the chambers. Diameter of the ends in a specimen 2.30 

 inches long, .44 and 1.20 inches. 



Locality: Columbia Avenue, Cincinnati, 150 feet above low water. 



The ventricose shell, larger size and abruptly expanding siphuncle in 

 the chambers, will distinguish 'this species from the preceding ones. 



4. C. irregulare, ■ YVetherby. 1881. 

 (Jour. Cin. Soc. Nat. Hist., IV, p. 79. PI. 2, fig. 3.) 



Shell moderately curved ; septa ne?My equal in anterior third, shorter 

 and smaller in posterior third of length: section elliptical; siphuncle compar- 

 atively large, and dorsal. 



Localities: Freeport and Waynesville, Warren Co., Ohio, and 

 Versailles, Indiana ; upper part of group. 



The irregularity in size of the septa, and the elliptical section are the 

 main features which distinguish this species from the others. 



5. C. magister, S. A. Miller. 1875. 

 (Cin. Quar. Jour. Sci., II, p. 284.) 



C. obscurum, S. A. M. Ibid, II, p. 132, fig. 17. 



Shell moderately curved, enlarging toward aperture; section sub- 

 elliptical, with transverse diameter the greater ; septa slightly concave ; 

 chambers thin ; siphuncle dorsal. Length of fifteen septa, 3.40 inches, on 



