New Species of Crinoidea and other Fossils. 215 



Interradial areas distinct, tlie posterior one quite large, and com- 

 posed of numerous very small plates. Ovarian aperture situated 

 subcentrally in the largest interradial area. 



This species, in specimens flattened from above, might readily be 

 mistaken for A. Cincinnatiensis Rcemer ; but on comparison, it will 

 be found to have a proportionally larger posterior interradial area 

 composed of smaller plates ; and in the other areas, the plates bor- 

 dering the arm-groove& are proportionally longer and of a different 

 form. When the specimens have been crushed or flattened verti- 

 cally, the body is found to overlap the basal margin of the disc. 



In its normal condition, the specimen has been about half an inch 

 in diameter. 



Formation and locality. In shales of the Hudson-river group, at 

 Cincinnati, Ohio. 



♦Agelacrinus vokticellatus n. sjp. 

 Plate 6, figs. 11-13. 



I Body discoid, depressed-convex on the upper surface ; attached by 



the under surface to foreign bodies. 



Marginal portion of the disc composed of several ranges of minute 

 i squamiform plates : inner portion of the disc occupied by five ele- 

 vated, sinistrally curved and closely coiled rays or arm-grooves, the 

 I curvature of each ray making about one-fourth of a volution. Rays 

 j composed of a double row of lanceolate-spatulate plates, which inter- 

 ! lock at their upper ends to cover the arm-grooves. The plates form- 

 ing the outer curvature of the ray are longest, and inclined at a lower 

 angle than those of the inner side. The inner ends of the rays ter- 

 minate in a solid pyramid formed by the union of the two bifurcating 

 or V-shaped plates and one shield-shaped plate. 



Interradial areas very small, hardly perceptible. Ovarian aperture 

 ! minute, situated near the bases of the postero-lateral rays. 



This species is easily distinguished from the others of this forma- 

 ' tion by having the arms all curved in one direction, and by being 

 almost destitute of interradial areas. 



The specimen described is less than half an inch in diameter. 



Formation and locality. In shales of the Hudson-river group, 

 Cincinnati, Ohio. 



Agelacrinus (Hemicystites) stellatus n. sjp. 

 Plate 6, figs. 5, 6. 

 Body small, subdiscoid, sides of the disc rising nearly vertically 

 from the place of attachment ; composed of verj^ minute squamiform 



