502 PALAEONTOLOGY OF ILLINOIS. 



anal plates more abruptly spreading, and proportionally wider than in 

 the typical form, while its nodes are more coalescent, so as more gen- 

 erally to run into continuous ribs. On the base, for instance, each of 

 the two plates has three somewhat nodulous, vertical ridges, with inter- 

 vening rows of the little nodes, while the three rows of nodes on the 

 first radial and anal pieces often run together so as to form mere nodu- 

 lous ridges. It is possible this would be found to be a distinct species, 

 if we could examine a specimen showing the arms. If so, it may be 

 called I). stelli/ormiSj in allusion to the star-like appearance produced 

 by its spreading first radial pieces, with their little ridges running out- 

 ward and converging to the outer extremity of each. 



In another individual the nodes and ridges are all nearly obsolete, 

 excepting a few of the former, which are very prominent at the middle 

 of the outer ends of the first radials ; while another has a single prom- 

 inent node near the small facet in each first radial, for the reception of 

 the second, with a few irregularly scattering nodes on other parts, and 

 slender, obscure, nodular ridges near the lateral margins. From the 

 general appearance of these specimens, we are rather inclined to the 

 opinion that they are all varieties of one variable species. 



'Locality and position Keokuk division of Lower Carboniferous series ; 

 Crawfordsville, Indiana. 



DICHOCEINUS FICUS, 0. and L. 



PI. 14, Fig. 5. 

 Dwhocrinus ficus, CASSEDAY and LYON, 1860. Proceed. Am. Acad. Arts and Sci., Vol. V, p. 24. 



Locality and position Keokuk group ; Crawfordsville, Indiana. 



GENUS CALCEOCKLN T US, Hall. 

 CALCEOCmmis ? BE ABLE TI, Meek and Worthen. 



PL 14, Fig. 9. 

 Calceocrinus Bradleyi, MEEK and WORTHEN. Proceed. Acad. Xat. Soi., Phila., 1&69, p. 73. 



BODY, exclusive of the base, subqnadrangular, with the 

 upper lateral angles obliquely truncated, and the sides 

 rather deeply sinuous, or constricted above the middle; 

 compressed antero-posterioiiy, and rather distinctly con- 

 cave in the central region of the dorsal side below the 

 middle. Lower dorsal plate triangular, and more than 



