INDIANA PALEONTOLOGY. 106. 



The central radial ridge is low and rounded, but becomes more prominent 

 above, forking on the axillary plates till it reaches the bases of the free arms. 



Two of the first.radials are heptagonal and three are hexagonal, all a little 

 wider than long. All of the second radials are hexagonal and a little wider 

 than long, hardly smaller than the first radials. The third radials are pen- 

 tagonal, axillary, a little wider than long and smaller than the second radial 

 plates. The first and only plate of the secondary radial series is axillary while 

 the inner one only of the third radial series is bifurcating, giving rise to six 

 arm bases to each brachial lobe or thirty free arms to the specimen, the char- 

 ■acteristic number, apparently, of the genus. 



The first anal interradial plate is in the ring of the first radial plates and 

 heptagonal in outline, supporting above three hardly smaller hexagonal plates, 

 the latter in turn, supporting upon their upper edges five smaller plates. 



The plates above can not be made out. 



The first or lower plate in the four regular interradial areas is heptagonal 

 and little less in size than the second radial but is of equal length and breadth. 



This plate supports above, three smaller plates and above the latter are 

 three still smaller plates. 



Each interradial plate has a hardly perceptible central node frojn which 

 radiate low ridg^ in groups of threes and twos, terminating on the radials near 

 the central radial ridge. Parallel with the radial ridge and on either side of it 

 is a low rounded supplementary ridge. 



The column occupies about one half of the width of the basal cup and has 

 ■an apparently rounded central perforation. 



The arm lobes are constricted where they leave the body and have a broad 

 paddle-like expression. 



The thirty arm openings are directed slightly upward and, on each lobe, 

 are separated into two groups, by a cleft, of three openings each, a slighter 

 cleft separating the outer one from the inner tsvo bases. 



The ambulacral ridges are not very strong from the base of the arm lobes 

 to the center, having at the fork a low, inconspicuous node. The ventral plates 

 in general are hardly convex. 



The anal opening is small and located about half way from the central 

 spine to the periphery. 



This species differs from Gennseocrinus kentuckiensis in having a less in- 

 flated dorsal cup, very much stronger first radial nodes, less defined radiating 

 lines of ornamentation, stronger arm-base lobes, smooth ventral plates against 

 acutely nodose plates in the former, and in the possession of a central spine, 

 apparently absent in the former. 



From Q. facetus it differs in its larger size, stronger ventral convexity. 



