38 University Geological Survey of Kansas. 



reception of the costals, the line of articulation with which is 

 gaping, raised portions of the facet milled. Costals five, mas- 

 sive, stoutly spine-like, pentagonal in outline, lower inner sur- 

 face faceted to meet the radials, upper surface faceted, except 

 the portion protruding in the form of a stout spine to support 

 the large arms. Distichals either one or two to each arm, more 

 commonly two in our specimen, the lowermost quadrangular in 

 outline, massive, a little more than twice as wide as high ; the 

 second distichals are very variable, from four to six times as 

 broad as high. There are ten arms which are very broad and 

 stout, each made up of two series of wedge-shaped, interlock- 

 ing plates which are twice as long as high in the lower portion 

 of the arms and each supporting a single pinnule. The pin- 

 nulse are not well preserved, but are stout, composed of rather 

 large, square plates near their junction with the arms, while 

 farther away they assume a cylindrical form. Where not worn 

 the entire specimen is covered with coarse granulations which 

 are usually a little prolonged. 



Height. 



Basals 11 mm. 



Radials 8 " 



Costals 5 " 



1. Distichals 1-2 " 



2. Distichals 2 " 



Average lower arm plate 2 " 



Calyx 10 " 



Range and distribution : Upper Coal Measures ; Topeka, from 

 the horizon of the Osage coal. 



This species agrees in many respects with Ceriocrinus craigi 

 (Worthen) W. and S. and C. hemisphericus ( Shumard ) W. and 

 S., but each of these possesses an anal plate ; the specimen in 

 hand, though preserved in very perfect condition, shows no in- 

 dication of such a plate. It is also very much like Erisocrinus 

 typus as figured and described by White (Contributions to In- 

 vertebrate Palaeontology No. 6, p. 126, p. 33, f. 5), but the 

 arms of our species are flatter, plates much less convex later- 

 ally, and granulated on the surface instead of smooth. The 

 brachials also are more spine-like in our specimen, and the 

 basals are not nearly so sharply convex as in that species, and 

 v 



Width. 



Length. 



10 mm. 

 16 " 

 15 " 



8 " 

 4 " 

 4 " 



27 " 







9 mm. 









