52 Cincinnati Socirti/ of Natural Ilistorij 



ison, Indiana, is a closely related species, and therefore should 

 be referred to Zitteloceras. 



Zitteloceras clarkeanum, sp. no v. 



1897. Cyitoceras hallianus, Clarke, Geol. Minnesota, 3, pt. 2, p. 805, pi. 60, 

 figs. 11, 12. 



The specimen figured by Clarke from the Platteville 

 member of the Black River group, at Janesville, Wisconsin, 

 differs from the type of Zitteloceras hallianum in its ovate 

 cross-section, more rapid attenuation toward the apical end, 

 and larger size. The regularly spaced squamose growth-lamellae 

 of Zitteloceras hallianiim are replaced by numerous lunate 

 markings with the convex side turned toward the larger end 

 of the specimen, apparently similar to the ornamentation 

 presented by Cyrtoceras (Glyptodendron) eatonense, Claypole, 

 as figured in the Geology of Ohio, volume VII, on page 536, 

 in 1893. 



The specimen figured by Clarke is regarded as sufficiently 

 distinct to receive a separate designation, and hence the name 

 Zitteloceras clarkeamis is proposed, in honor of the distinguished 

 paleontologist. John M. Clarke, who first described it. 



PLATE I 



Fig. 1. Conularia miseneri. A, natural size of cast of speci- 

 men; B, outline of cross-section of same; C, same 

 specimen, enlarged 5 diameters, and illuminated so 

 as to show the vertical striations. Whitewater mem- 

 ber of Richmond group, at Richmond, Indiana. 



Fig. 2. Amphilichas sp. Lower side of pygidium and of parts 

 of several segments; the two anterior lobes and the 

 middle lobe on the right side of the pygidium are 

 missing. Whitewater member of Richmond group, 

 at Richmond, Indiana. 



