n 



ridges give it an hexagonal outline. The base is rather deeply 

 excavated for the insertion of the column. The six plates in the 

 second range are of unequal size and the larger ones follow the 

 smaller basal plates so that the symmetry of the body is re- 

 stored, two are pentagonal, two hexagonal and two heptagonal. 

 These plates bear sharfD ridges radiating from the center to each 

 angle. There are eight plates in the third range of unequal size 

 and different in outline. The summit is covered with very convex 

 plates. The mouth is near the margin, slightly elevated and sur- 

 rounded by four convex plates, one of which is much larger than 

 the others. The central plate is heptagonal and surrounded by 

 seven plates. There are several smaller plates on the vault. There 

 are nine arm openings to the vault. 



This species is probably more nearly related to C. iudiKucitnis 

 than to any other described species. It differs, bowevei", in the 

 general form and in the absence of the constriction below the 

 arms. The third range of plates are not alike in the two species 

 and the vaults are different. That species has twenty-one arms 

 disposed in clusters; this one has only nine, and they are not in 

 clusters. The plates of the vault in that species bear pores and 

 pustules, while in this the plates are smooth and convex. There 

 are pores and pustules between the radiating lines in that species 

 and there are none in this. The surface ornamentation will readily 

 distinguish the species as well as the general form. 



The specimen illustrated is from the Niagara Group, at Osgood, 

 Indiana, and is in the collection of S. A. Miller. Four specimens 

 are in the collection of Wm. F. E. Gurley, from the Niagara 

 Group, at St. Paul, Indiana, and they seem to differ only in bear- 

 ing higher and sharper radiating lines. 



CAKYOCRINUS BULBULUS, U. sp. 



Plafp II, Fig. 15, anterior side view showing mouth al ihe sinu- 



mii and arm openings laleraUi/: Fig. 16, posterior 



view; Fig. 17, summit view; Fig. 



18, tiasal view of same. 



Body bulbous, or subovoid, subpyramidal from the column to 

 the middle of the second range of plates, where, by i-eason of the 

 central protuberances on the plates, it is hexagonal; above this, it 

 is less angular, but the mouth is produced above the rest of the 



