CRINOIDEA OF THE WAVEKLY GKOUP. 179 



Arms composed of short, wide, equal sided plates, whicli are angular 

 on the back. The surface of the arm plates is striato-granulose. 



The plates of the body are marked by indistinct radiating ridges, 

 which show a tendency to become nodose. The second radial plates are 

 strongly angular, and sub-carinate along the middle. 



Column near the body composed of thin, unequal plates, and shows a 

 tendency to become sub-angular below. 



This species differs from Z. paternus in the turbinate form of the calyx, 

 the angulated and sculptured surface of the body, and the sub-angular 

 form of the arms. In the anterior ray it differs in having the division 

 of the arms take place on the fourth plate in the radial series, instead of 

 the seventh. In this respect, and in the bifurcation of the antero-lateral 

 and postero-lateral rays, this species corresponds precisely with Z. scopa- 

 rius, but differs in the sub-carinate and carinate character of the plates 

 of the body, which are ornamented by minute nodes, or nodose ridges, 

 while the basal plates are a little more distinctly marked than in that. 



Formation and locality: In shales of the Waverly group, at Richfield, Summit 

 county, Ohio. 



