﻿Cephalopoda of the Cincinnati Group. 



dorsal, 2.18 inches on ventral side. Transverse diameter at the ends 2.90 

 inches and 2.54 inches. 



Locality: 1st ward, Cincinnati, 130 feet above low water. 



5. C. amcenum, S. A. Miller. 1878. 

 (J. C. S. N. EL, I, 105. PI. 3, fig. 8. 

 Shell two to three inches long, gently arched and gradually tapering; 

 section slightly elliptical; body chamber slightly contracted toward front, 

 followed by five or six thin chambers ; septa moderately arched ; siphuncle 

 small, close to dorsal margin. 



Localities: Richmond, Indiana ; Cincinnati. 



The two preceeding species are too closely allied, and it seems likely 

 they may be the same. The differences are so slight that they are easily 

 accounted for by the difference in locality, the first having been 

 found here and the second coming from Richmond. 



Genus 6. LTTUITES, Breynius. 1732. 

 (Tryon, 1883, Struct, and Syst. Concho., II, p. 56.) 

 Trocholites, Conrad, 1838. Sec. Ann. Rep. Geol. Sur. N. Y.,p. 118. 

 Emended Jour. Phil. Acad. Nat. Sci., VIII, p. 274. 



" Shell planorbiform, the whorls close or separate; the last chamber 

 produced in a straight, or outwardly curved line ; lateral margins of the 

 aperture extended and curved toward the interior of the shell, contracting 

 the aperture into two distinct orifices." (Tryon.) "Siphuncle central 

 or sub-central." (Woodward, Man. Mol., 1880, p. 189.) 



1. 'L. planorbiform is, Conrad. 



Trocholites planorbiformis, Conrad. 1842. Jour. Phil. Acad. Nat. 

 Sci., VIII, p. 274. PI. 17, fig. 2. 



Trocholites planoi'biformis, Con. Hall. Pal. of N. Y., I, 310. PI. 84, 

 figs. $ a to f. 



li Volutions higher than wide, longitudinally striated, and with oblique, 

 obtuse, transverse lines, approaching at an angle, but rounded on the centre 

 of the back ; apex profoundly depressed ; back of large volution flattened ; 

 aperture much longer than wide." 



Locality. — (Type) " Grimsby, upper Canada." 



A specimen of what appears to be this species, is represented in the 

 cabinet of this Society by a plaster cast. The label attached bears the 

 name of '■'■Trocholites cincinnatiensis , Clark." No such species has ever 

 been described. It is, from the name, from this locality. 



