172 PALEONTOLOGY OF OHIO. 



from below upwards. The secondary radial series consists of five in each 

 division between the firs'" and second bifurcations, while there are from 

 six to eight plates in each division between the second and third bifur- 

 cations. The antero-lateral interradial areas have one somewhat prom- 

 inent plate of medium size, which rests upon two adjacent first radiais, 

 and lies between the second radial plates. The postero-lateral interra- 

 dial spaces have a single smaller plate situated as in other spaces. The 

 first anal plate is about as large as the larger interradial plate. No other 

 plates have been determined above. 



The branches of the ray divide twice above the first bifurcation, and 

 each bifurcating plate is strongly nodiferous, the node angular and 

 transverse. The surface of the ray, as far as the first division, is regu- 

 larly convex, and the divisions become successively more angular upon 

 the back. The surface of the plates is strongl}'' striato-granulose. 



Column strong, composed near the body of very thin plates, and rap- 

 idly, tapering below. 



In the structure of the body this species is most nearh^ allied to 

 F. communis, differing in the nodose bifurcating plates and in the angu- 

 lar divisions of the ray. ' 



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

 Summit county, Ohio. 



Genus POTERIOCRINUS, Miller. 



POTEEIOCRINUS CRINEUS. 



Plate 12, figs. 6, 7. 



Poteriocrinus crineus; 17th Kept, on N. Y. State Cab. of Nat. Hist., p. 56, 1SG4. Extr. 

 published in 186.3. 



Body turbinate, of medium size. Sub-radial plates of moderate size. 

 First radiais wider than high ; second radiais shorter than the first, 

 stongly wedge-form above, supporting an arm on each upper sloping 

 side, making two arms to each ray. 



The anal area has apparently three plates attached to the calyx, while 

 the upper part of the area is not visible in the specimens examined. 



Arms dividing on the tenth or tAvelfth plate from their origin, composed 

 of a single series of plates, which are alternately longer and shorter on 

 their opposite sides, bearing strong tentacula on the upper part of their 

 longer side. 



