29 



radials and first interradials, it resembles G. decadwdtylus, but is 

 quite different in all other parts, beside having only ten arms. It 

 can not be mistaken for any other described species. 



Found in the Trenton Group, in Mercer county, Kentucky, and 

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



Family CALCEOCRINID^. 



CALCEOCRINUS KENTUCKIENSIS, n. sp. 



Plate II, Fig. 2^ (interior side view; Fig. 25, posterior side, 

 showing place of attachment of the column of 

 same specimen. 



From the cicatrix for the attachment of the column, we infer, 

 that the body hung close to the column; the column is small and 

 round. We have two specimens, about equally well preserved, 

 both are silicified, but show the sutures correctly, unless it may 

 be in the basal plate. The basal plate is triangular and, as shown 

 by the sutures, composed of four anchylosed plates, though the 

 sutures are obscure. The columnar facet is at the posterior angle. 

 There is a wide gaping suture between the basals and the radials 

 on the anterior side, that is somewhat denticulated on the anterior 

 margin. Following this gaping suture on the anterior side there 

 are three radials, in the first transverse series; the middle one is 

 twice as long as wide, quadrangular, and constricted in the mid- 

 dle; the outer ones are hexagonal, about twice as wide and about 

 twice as large as the middle one. The second transverse series 

 commences in the middle part with a short wide plate that rests 

 upon the superior side of the middle plate in the first series, and 

 upon the inner sloping sides of the two lateral plates, in the first 

 series. It is about three times as wide as long and is succeeded 

 by a plate, that contracts rapidly upward, somewhat in the form 

 of -the frustum of a cone. It has a length about equal to the 

 shorter width. This last plate bears a free single arm composed 

 of rather long round joints. The superior lateral side of each of 

 the lateral plates in the first series bears two brachial plates, the 

 second one of which is axillary and bears free arms. Every sec- 

 ond or third plate in the free arms is axillary, though one of the 

 rays thrown off from each axillary plate is smaller than the main 

 arm and does not bifurcate again. 



