776 THE CRINOIDEA CAMERATA OF NORTH AMERICA. 



width, widest at two thirds their height; slightly contracted at the top and 

 twice as long as their width at the bottom ; the outer surface a little convex, 

 and somewhat angular along the median line ; facets deeply excavated to 

 almost the full width of the plate, leaving a slight truncation at each side. 

 Costals and distichals two each, united by syzygy, their combined length about 

 equal to the width ; both costals and the lower distichal completely resting 

 within the radial facet. Lines of union between the hypozygal and epizygal 

 joints straight, but those between the costals and distichals, and between the 

 distichals and palmars, decidedly waving and much more distinct. The upper 

 faces of the epizygal joints provided with tongue-lil^e processes, which enter 

 corresponding recesses upon the lower faces of the plates of the succeeding 

 order. First palmar deeply excavated along the upper face, and constituting 

 a part of the calyx ; the succeeding ones are free arm plates, and bend ab- 

 ruptly outward. Arms twenty, strong, simple, biserial and pendent, resting 

 by their dorsal surfaces upon the radials and anal plate, which are slightly 

 impressed thereby. Pinnules stout and long; their ambulacral furrows wide, 

 and roofed over by small covering plates. Ventral disk slightly convex, 

 almost flat, the ambulacra exposed to view. Four of the interradii have but 

 one plate in contact with the radials, while the anal plate supports three, the 

 former as well as the latter abutting against the second distichal.?, but not 

 against the iirst, nor against the costals, which rest within the I'adial facet. 

 Anal opening subcentral, passing through the flat surface of the disk. Column 

 round and small. 



Horizon and LocaUtij. — Kaskaskia group ; Grayson Springs, Grayson Co., 

 Ky., and Sloans Valley, Pulaski Co., Ky. 



Tt/2-)es in the Major Lyon collection, Jeffersonville, Ind. 



Remarks. — A strict enforcement of the rules of nomenclature would, 

 according to some opinions, require the above specific name to be rejected 

 on account of erroneous composition. After being so long recognized in 

 scientific literature we prefer not to change it, — at least not until greater 

 necessity appears for doing so. 



