33 



lary and supports upon its outer sloping sides the free arms. 

 There are, therefore, ten arms in this species. The arms are 

 small and the first plates are directed horizontally. 



Interradials large, convex and each one bears a central node. 

 Vault slightly convex and covered with rather large, polygonal, 

 convex plates, each one of which bears a central node. The 

 azygous orifice is submarginal, surrounded by seven plates, the 

 larger one of which stands nearly upright on the edge of the 

 azygous interradial. 



This species is distinguished by the surface ornamentation, large, 

 convex, nodose iuter-radials, and position and character of the 

 azygous orifice, and small, horizontally directed second radials, and 

 ten arms. 



Found by Prof. A. G. Wetherby, in the Keokuk Group, in 

 Tennessee, and now in the collection of Wm. F. E. Gurley. 



MACROSTYLOCRINUS INDIANENSIS, n. sp. 



Plate III., Fig. 33, side vicir. 



Calyx semi-elliptical in outline. Sutures beveled. Surface sculp- 

 tured in longitudinal and transverse lines, depending on the shape 

 of the plate, but not radiately sculptured from a central point on 

 any of the plates. 



Basals three, one about half the size of either of the others, 

 and together forming a little cup, that bears a very small cicatrix 

 at the base for the attachment of a very small column. First 

 radials large, about as wide as high, three heptagonal and two 

 hexagonal. Second radials very small, short, quadrangular, about 

 three times as wide as high. Second and third radials together 

 about half as large as the first. Third radials about the same 

 size as the second, pentagonal, axillary, and bearing upon each 

 upper sloping side a single secondary radial. We have three 

 specimens belonging to this species and none of them have more 

 than a single secondary radial and that appears to have supported 

 an arm, though no part of an arm is preserved on either of the 

 specimens, neither is any part of the vault. The species evidently 

 possessed only ten arms. 



The first inter-radial is a narrow, elongated plate, resting be- 

 tween the lateral sides of the first radials and extending as high 



—5 



