.410 PALEONTOLOGY OF ILLINOIS. 



SCAPHIOCRIKUS NOTABILIS, M. and W. 



PI. 1, Fig. 9. 

 faaphiocrinus notabilis, MEBK and WORTHEN. Proceed. Acad Nat. Sci., Phila., 1869, p.148, 



BODY large, obconic, or expanding gradually from the 

 column to the middle of the first radials, at which point 

 these pieces are protuberant, so as to give the general out- 

 line (as seen in a side view) a tendency towards an inverted 

 bell-shape. Base of a deep cup-form, less than twice as 

 wide at the top as the hight, or about one-third as high as 

 the body to the top of the first radials. Basal pieces higher 

 than wide, and pentagonal in form, the lateral margins 

 being longest. Subradial pieces nearly twice as long as 

 the basal, hexagonal in form, excepting the two on the anal 

 side, which are heptagoiial. First radials somewhat larger 

 than the subradial pieces, slightly wider than long, pen- 

 tagonal in form, and each provided with a very profound 

 sinus for the reception of the second radials, more than 

 one-third as wide as its upper edge, and extending about 

 half way down its outer side. Second radial pieces com- 

 paratively very small, or about one-third as large as the 

 first; pentagonal in form, about as wide as long, rounded 

 on the outer side, and so deeply inserted in the sinus of 

 the first radials on a kind of shoulder-like projection, that 

 their mesial angle above scarcely rises beyond the upper 

 margins of the first radials, each supporting two arms on 

 its superior sloping sides, and separated from that of the 

 next ray on each side, by an interradial space of about once 

 and a half its own breadth. Anal plates two and about 

 half of the third, included as a part of the walls of the 

 body, hexagonal in form, and having the usual arrange- 

 ment of those Poterwcrinites, in a double, vertical, alternat- 

 ing series. 



Arms very long, slender and rounded ; one of them seen 

 to bifurcate first on the sixth, two others on the eighth, 

 and another on the tenth piece, above the second radials. 



