PLATYCEINID^. 667 



Platycrinus contritus Hall and Whitf. 

 Plate LXXI. Fig. 8. 



1863. Hall and Whitfield; 17th Eep. N. Y. State Cab. Nat. Hist., p. 54; and 1875, Geol. Surv. of 

 Olio, Vol. I., Part II., p. 166, Plate 11, Fig. 4. 



This species we only know from the description and figure. Dorsal cup 

 broad, short, concave at the base for the reception of a large column. Plates 

 without ornamentation. Base one third the length of the dorsal cup, form- 

 ing a sharp angle at the lower edge, and slightly projecting outward. 

 Eadials wider than high, somewhat spreading. Costals subpentangular, 

 with short lateral faces. The distichals longer than the costals. Arms four 

 to five to the ray, short, strong, and biserial.* All other parts unknown. 



Horizon and Locality. — Shales of the Waverly group at Richfield, Summit 

 Co., Ohio. 



Type in the New York State Cabinet at Albany. 



Platycrinus oUicula S. A. MiLLEK.f 



1891. S. A. Miller; Geol. Rep. Missouri, Ball. 4, p. 19, Plate 2, Figs. 7, 8. 



From medium size to larger. Dorsal cup tub-shaped, having a wide, flat 

 bottom, slightly constricted at the top of the basals, whence it expands very 

 gradually upwards. Plates thick and convex ; sutures beveled ; surface 

 finely granular. Basals stretched out horizontally, forming a disk of which 

 the edges project beyond the lower ends of the radials in the form of a rim, 

 the latter being the only part of the base seen in a side view. Radials a 

 little longer than wide, slightly sj^reading, their greatest convexity below 

 the facets, the lower face forming a straight line, the upper faces not notched 

 at all, or very little. Facets shallow but wide, occupying more than two 

 thirds the width of the plates, and facing upwards. All other parts 

 imknown. 



Horizon and Locality. — Chouteau group, at Pin Hook bridge, and at 

 Leucke's quarry, near Sadalia, Mo. 



Type in the collection of Mr. Sampson. 



* The description says four arms in the three anterior rays, and five in the two posterior ones ; but if tlie 

 position of the small basal is correctly figured, the five arms do not occur in the posterior, but in the anterior 

 rays. 



f We are unable to give a figure of this species, and the description is made after Miller's. 



