44 



HYDREIONOCRINUS GRANCLIFERUS, 11. Sp. 



Plate VI, Fig. 20, azygous side view of calyx and one second 

 radial; Fig. 21, basal view of same specimen. 



Calyx bowl-shaped, about twice as wide as high, concave at 

 the azygous area, columnar cavity abruptly depressed, sutures 

 distinct; surface very granular; column round. 



Basals sunken and nearly covered by the column. Subradials 

 curved abruptly into the columnar depression and almost as 

 rapidly up toward the acute angles, that extend high between 

 the first radials; three hexagonal, the other two heptagonal; all 

 the angles are depressed, as in Barycrinus. First radials tw^ce 

 as wide as high, truncated the entire width above, much thick- 

 ened within, and separated from the second radials, on the 

 outer face, by a gaping suture, but immediately within, a 

 straight ridge extends, -from one outer angle to the other, hav- 

 ing a furrow on each side, so as to form a hinge, on which the 

 second radials articulate; behind the inner furrow, in the mid- 

 dle part of each plate, there is a notch for the arm furrow, and 

 immediately in front of the notch there is a node that seems to 

 have been for a socket in the succeeding plate. Second radials 

 nearly twice as wide as high, concave in the middle, pentagonal, 

 axillary and supporting on the upper sloping sides the free 

 arms. 



First azygous plate twice as long as wide, pentagonal, abut- 

 ting below against a subradial, and resting obliquely between 

 another subradial and the under side of the first radial on the 

 right. Second azygous plate twice as long as wide, truncates 

 a subradial and abuts upon the superior lateral side of the first 

 radial on the left, and the first and third azygous plates on 

 the right. Third azygous plate about as long as wide, trun- 

 cates the first azygous plate and abuts upon the short superior, 

 lateral side of the first radial on the right. 



The arms and proboscis are not preserved, but there is little 

 doubt about the generic reference, and the species is so marked, 

 that it is unnecessary to compare it with an^- other for the 

 purpose of distinguishing it. 



Found in the Dpper Coal Measures, at Kansas City, Missouri, 

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



