288 PALEONTOLOGY OF ILLINOIS. 



pearance to the outer surface of the body. Eadials pentagonal, 

 about twice as wide as long, depressed at their lower angles to cor- 

 respond with the depressions of the subradial plates. 



Brachials two, the first quadrangular, and the second pentangular, 

 supporting on their upper sloping sides the first divisions of the 

 rays. All the plates to the top of the second brachials possess the 

 rugged character mentioned above. Anal series unknown. Arms 

 not preserved on the anterior ray, but from the partial preservation 

 of those on the posterior side there seems to be not more than two 

 to each ray. Column round and rather delicate, composed, near 

 the body, of joints of unequal size. 



Geological position and locality: Warsaw beds of the St. Louis 

 group, Warsaw, 111. 



No. 2,463, Illinois State collection. 



PCTEKIOCRINUS CLAYTONENSIS, Worthen. 



Poteriocrinus Claytonensis, WOKTHEN, February, 1882. 



Bulletin No. 1, of the Illinois State Museum of Natural History, p. 18. 



Body of medium size, basin-shaped, about once and a half as 

 wide as high to the top of the radial series. 



Basals small and entirely concealed in the basal concavity by the 

 first columnar joints. Subradials nearly or quite as long as wide, 

 their lower angles curving into the basal concavity. 



Eadials once and a half as wide as long, pentagonal, and trun- 

 cated squarely across the upper margins for the reception of the 

 brachial series. 



Brachials on three of the rays about the same size and form as 

 the radials, and give support on their upper sloping sides to the 

 first divisions of the rays. 



The arrangement and number of the arms cannot be determined 

 from the specimen in hand, but in the right antero-lateral ray a 

 bifurcation takes place on the sixth plate above the brachial, be- 

 yond which the divisions are unknown. The arms are composed of 

 wide, short quadrangular plates, as in Zeacrinus, and would be 

 closely joined when folded as in that genus. Three anal plates are 

 preserved in the specimen under examination, the first one pentag- 

 onal, resting between two of the subradials, and partly under the 



