66 



GrRANATOCEINUS WINSLOWI, n. Sp. 



Plate VI, Fig. 34, side view; Fig. 35, basal view. 



Body medium size, subspherical, depressed convex in the in- 

 terradial areas, evenly rounded in the middle part, longer than 

 wide, truncated very slightly at either end ; columnar facet small ; 

 surface sculptured and tubercular. 



Basal plates form a large pentagon notched by the distal 

 ends of the ambulacra. Radials extend less than half the length 

 of the body and have strongly defined sutures. Regular inter- 

 radials more than half the length of the body and incurved at 

 the summit. A longitudinal line of tubercles ornaments the 

 middle of each interradial to its lower extension, which is con- 

 tinued as a double row, or row on each side of the radial 

 suture, to the basal plates, and on each side of these mesial 

 tubercles, there are one or two shorter rows of tubercles. 

 Pseudambulacra rather rapidly expand from the base to the 

 summit and are depressed in their upward extension below the 

 thickened and tubercular margins of the radial and interradial 

 plates, though, at the lower end, their convexity rises higher 

 than the margins of the radials. Pore pieces between fifty and 

 sixty on each side of a mesial furrow, alonsc which their inner 

 ends are crenate, and from which, they are directed obliquely 

 outward and downward. The summit and azygous interradial 

 are so injured, in our specimen, that but little can be ascer- 

 tained of their characters, the ovarian openings, however, are 

 quite small, and we are not sure that there is any more than 

 one to each interradial plate. 



The specific name is given in honor of the late Dr. J. C. 

 Winslow of Danville, Illinois, a personal friend of one of the 

 authors and one of the "old time'' collectors, to whose patience 

 and zeal science has been very greatly indebted. 



The specimen from which this description is drawn was found 

 in the drift at Danville, Illinois, and is in the collection of Wm. 

 F. E. Gurley. The supposition is that it came from rocks of the 

 age of the Burlington Group, a short distance north of Dan- 

 ville, which are now deeply covered with the drift. 



