492 PALEONTOLOGY OF ILLINOIS. 



part of the longer side of each arm piece, alternately on 

 each side, and rather closely approximated to each other. 

 Surface in well preserved specimens, finely and obscurely 

 granular, the granules showing on the arms (as seen under 

 a magnifier) a tendency to arrange themselves in longi- 

 tudinal rows, or to assume vermicular forms. Sutures be- 

 tween all the pieces merely linear. 



Entire length of arms and body, 2.80 inches; hight of 

 body to the top of first radials, 0.27 inch; breadth, about 

 0.43 inch ; thickness of column at its connection with the 

 base, 0.17 inch. 



This species seems to combine, to some extent, the characters of Po- 

 tcnocrinus and Zeacrinus. In general, especially in the somewat flat- 

 tened and closely contiguous characters of all the divisions of its arms 

 all around when folded together, as well as, to some extent, in their 

 mode of division, it reminds one of many species of Zeacrinus. In the 

 form of its body, however, and particularly in having three primary 

 radials instead of only two in each of the anterior and posterior lateral 

 rays, and about .eight below the first bifurcation in the anterior ray, as 

 well as in the general form of its body, it agrees more nearly with the 

 typical forms of Poteriocrinus. We know of no species liable to be con- 

 founded with this, when specimens can be seen with its arms well 

 preserved. 



Locality and position Keokuk division of the Lower Carboniferous 

 series ; Crawfordsville, Indiana. 



SUBGENUS SOAPHIOCRI^US. 

 SCAPHIOCKLNTJS DEPRESSUS, M. and W. 



PI. 14, Fig. 8. 

 Scaphiocrinus depressus, MEKK and WORTHEN, 1870. Proceed. Acad Nat. Sci., Phila., p. 27. 



BODY small, somewhat basin-shaped, about twice as wide 

 as high to the top of the first radials, broadly truncated, 

 and concave below, with but slightly expanded or nearly 

 vertical sides. Base occupying the concavity of the under 

 side, and apparently flat or concave. Subradial pieces 

 about as high as wide, a little convex, rising vertically, 



