28 



ones form part of the arm bases. There are no intersecondary 

 radials. There is no azygous area. 



The vault is quite convex and much depressed in the interradial 

 areas, which is made more conspicuous by the prominence of the 

 ambulacral areas, at the base of the arms. There is a long sub- 

 central proboscis. The vault is covered with large polygonal 

 plates; the smaller plates over the arm furrows near the openings 

 in the vault are not shown in the illustrations, because the sutures 

 are not distinct in our specimens. It is rare that they are cor- 

 rectly exhibited in illustrations of other species, for the same 

 reason. QThe plates are covered with tubercles, those near the 

 base of the proboscis being somewhat spinous. The two inter- 

 radial plates, in each area, that abut upon the three plates in the 

 third range of interradials belonging to the calyx, are elongated 

 and the larger plates of the vault. There are no pores or passages 

 that penetrate the vault between the arms. 



This species is distinguished by its general form, surface ornamen- 

 tation and by having fourteen arms. It is probably as nearly related 

 to D. venusius as to any other species. 



Found in the Hamilton Group, at Charleston, Indiana, and now 

 in the collection of Wm. F. E. Gurley. 



DOLATOCKINUB GREENEI, n. sp. 



Plate III, Fig. 10, basal view; Fig. 11, side view; Fig. 12, 



summit view. 



Calyx hemispherical, very slightly constricted below the arm 

 bases. Surface sculptured in a variety of ways; there are promi- 

 nent nodes in the central part of the larger plates from which 

 there are radiating ridges and there are shorter radiating ridges 

 that do not arise from the central nodes, beside scattering tuber- 

 cles. The radiating ridges are interrupted at the sutures and 

 ventricose in the middle part of the plates with a node at the 

 center of each. Column round, medium size. 



Basal plates expose a pentagonal rim around the column. First 

 primary radials wider than long and of unequal size, two of them, 

 on the azygous side, being much larger than the others, as shown 

 in the upper part of Figure 10. Second primary radials only 

 slightly wider than long, quadrangular, sides nearly parallel. Third 



