178 PALAEONTOLOGY OF ILLINOIS. 



includes E. 2>cntahbux = (Cyathocrinus ? pcntalobus, Hall), and possibly, also, 

 ScopMoarinus orbicularis, Hall, as well as our Poteriocrinus (Scaphiocrinus) sub- 

 tumidus. 



Cyathocrinus sculptilis, Hall. 



PI. 15, Pig. 2a, 2b. 



Cyathocrinus sculptilis, Hall, 1860. Supplement to Iowa Eeport, vol. i, part ii, p. 59. 

 Cyathocrinus scitulus, Meek and Worthen, Sept., 1860. Proceedings Acad. Nat. Sci., 



Pbilad., p. 393. 

 Cyathocrinus sculptilis (Hall), Meek and Worthen, June, 1861. Ibid, p. 148. 



Body, below the summit of the first radial plates, basin-shaped, 

 about twice as wide as high, truncated at the base, from which 

 the sides expand rapidly upwards; composed of thick, strong, 

 somewhat rugose plates, which are very convex in the middle 

 and deeply excavated at the corners ; sutures distinct. Base 

 small, flat, or truncated on a plane with the under side of the 

 subradials, so as not to be seen in a side view; columnar facet 

 slightly concave, occupying apparently about two-thirds the 

 area of the base, and perforated by a central opening equal to 

 one-third its own diameter. Subradial pieces about as wide as 

 long, directed obliquely outward and upward from the base; 

 four of them pentagonal and one hexagonal, there being no 

 visible angle at the middle of the under side in any of them. 

 First radials much larger than the subradial pieces, about twice 

 as wide as high, unequal, the two on the anal side being shorter 

 than the others; all pentagonal, distinctly truncated and a little 

 concave above, the upper side being much longer than either 

 of the others; some of the superior lateral angles apparently a 

 little truncated, as if for the reception of small interradial pieces. 

 Anal piece about the size of the subradials, subquadrangular, 

 widening from the base upwards. Height to summit of first 

 radials, 0.36 inch; breadth, 0.71 inch; breadth of base, 0.23 

 inch; length of subradials, 0.21 inch; length of longest first 

 radial,. 0.23 inch; breadth of ditto, 0.33 inch. 



