318 PALAEONTOLOGY OF ILLINOIS. 



the second primary radials, which are of very nearly the same 

 size and form as the first, but Fig. 34. 



have their sloping sides above, 

 instead of below, while the su- 

 perior edae of each supports on 

 its upper sloping side the first VJL J 

 brachials, or a series of second- Erisocrims ^ M ,_ (Nat ^ 



ary radials, yet unknown. Sur- < a > Side view8 : (i) Z iew of . ??- d f side v $ vi , e T of 



•/ 'J upper side ; snowing the great thickness of the plates, 



face smooth. The foregoing ^MSS™" 8 surface3 for the recepti0D of the 

 cuts of this species represent it natural size. 



Farther comparisons with some additional specimens, lead us to believe the 

 form from Bellevue, Nebraska, described by us under the name E. nebrascensis, is 

 as we at first suspected, but a variety of this species, with a deeper cup, pro- 

 duced by having its subradials proportionally larger. 



Locality and position : Coal Measures, near Springfield, Sangamon county, 

 Illinois. 



Erisocrinus conoideus, M. and W. 



Erisocrinus conoideus, Meek and Worthen, Aug., 1865. Proceed. Acad. Nat. Sci., 

 Phiiad., p. 150. 



' a Body small, below the summit of the first 



radials truncate-obconic, nearly twice as wide 

 as high; basal pieces a little wider than long, 

 pentagonal as seen projecting beyond the col- 

 umn, and forming together a small low cup, 

 \J^^C/ with diverging sides; subradials near three 

 \\ // times as large as the basal pieces, a little wider 

 than long, and all hexagonal; first radial pieces 



alia 



Erisocrinus conoideus. 



(a) Nat. size, side view of half as long as wide, about twice as large as 



body. (6) Diagram of plates o 7 o 



ofbody, enlarged two diam- fa % subradials, and all broadly truncated on 

 the same horizontal plane above, for the reception of the second 

 radial pieces. Surface smooth; sutures linear, not impressed ; 

 plates not convex. Column, and all the parts above the first 



