314 PALAEONTOLOGY OF ILLINOIS. 



Zeacrinus? crassus, M. and W. 



PL 26, fig. 2 a, 2 6. 



Cyathocrinua? crassus, Meek and Worthen, September, 1860. Proceed. Acad. Nat. Sci., 

 Philad., p. 392. 



Body below the summit of the first radial plates, depressed 

 basin-shaped, about twice as wide as high, rounded below, and 

 composed of thick, smooth, somewhat convex plates, which are 

 joined by well defined, subpunctate sutures. Base very small, 

 or about one-fourth the breadth of the body, pentagonal, deeply 

 concave, and apparently nearly hidden by the column. Sub- 

 radial pieces wider than high, extending at first nearly hori- 

 zontally outwards from the base, after which they curve up- 

 wards; four of them are hexagonal, and one, on the anal side, 

 heptagonal; the angle at the middle of the base of each being 

 very slightly salient. First radial plates larger than the sub- 

 radials" nearly twice as wide as high, horizontally truncated 

 above, and nearly or quite straight on the upper side, which is 

 longer than the inferior sloping edges; four of them penta- 

 gonal, and one, on the left of the anal pieces, hexagonal. First 

 anal piece nearly as large as one of the subradials, pentagonal 

 in form, and resting between the superior sloping sides of two 

 of the subradial plates, while its lateral margins connect with 

 two of the first radial pieces. Second anal piece, about one- 

 third as large as the first, upon the upper, short, truncated side 

 of which it is supported ; longer than wide, pentagonal or hex- 

 agonal in form, and extending near half its length above the 

 margins of the two first radials, with which it connects on 

 each side. Remaining parts unknown. Height, from base to 

 summit of first radials, 0.45 inch ; breadth, 0.92 inch ; breadth 

 of base, 0.24 inch. 



