276 PALAEONTOLOGY OF ILLINOIS. 



Granatocrinus cornutus (sp.), M. and W. 



PL 20, fig. 1. 



Pcnlremitcs cornutus, Meek and Wortuen, October, 1860. Proceedings Acad. Nat. Sci., 



Philad., p. 141. 

 Granatocrinus cornutus, Shumard, Oct., 1865. Cat. Palasozoic Fossils, part 1, p. 375. 



Body under medium size, subglobose, broader than high, the 

 widest part being at the middle ; upper and lower extremities 

 truncated. Base deeply concave; basal pieces entirely within 

 the concavity of the under side. Radial pieces long, or extend- 

 ing from the base of the body to near the summit ; narrow, 

 somewhat contracted above and below, and divided by the 

 pseudo-ambulacral areas nearly four-fifths their entire length; 

 all very thick, and rising into prominent carinse on each side 

 of the pseudo-ambulacral fields. Interradial pieces, small for a 

 species of this group, and each projecting out in the form of a 

 very prominent, compressed, horn-like process. Pseudo-ambu- 

 lacral areas very narrow or lance-linear, and deeply impressed 

 between the very prominent, carinated forks of the radial 

 plates. (Summit unknown.) Height, 0.45 inch; breadth, 0.54 

 inch; greatest breadth of radial pieces, 0.20 inch; breadth of 

 pseudo-ambulacral areas, 0.04 inch. 



This species will be readily distinguished from all the others of this group, 

 yet known, by its prominent, horn-like interradial pieces and its strongly cari- 

 nated radial plates. These carinse are so prominent and regular, as to give the 

 whole body the appearance of being divided into ten sharply angular ridges or 

 lobes, extending from near the summit to the base — the intervening depressions 

 at the sutures, and those containing the pseudo-ambulacral areas, being about 

 equal. 



Locality and position : Near Mt. Sterling, Erown county, Illinois; St. Louis 

 division of Lower Carboniferous series. 



