88 PALAEONTOLOGY OF ILLINOIS. 



about twice as long as wide, strongly constricted in the middle 

 and sharply angular above. 



Arms two to each of the posterior rays, the only ones pre- 

 served in the specimen in hand, composed of long rounded 

 joints, arranged in a somewhat zigzag position, and decreasing 

 in length towards their extremities. Pinnules strong. 



Anal plates arranged as usual in this genus, and united above 

 to form a slender ventral tube, only the lower portion of which 

 is visible. 



Column round, composed of short pieces that decrease in 

 diameter as the distance from the base increases. 



Position and locality: Keokuk limestone", Keokuk, Iowa. 



No. 337 of Mr. L. A. Cox's collection. 



I take pleasure in dedicating this pretty species to my friend 

 Mr. E. O. Ulrich of Newport, Ky. 



ELSAHENS1S. (sp. 11OV.) 

 PI. XIV, Fig. 5. 



Calyx obconical, with straight gradually expanding sides. 

 Base truncated, the under basals forming a shallow cup about 

 three times as wide as high. 



Basals large, the two on the anal side heptagoual, the others 

 a little smaller and pentagonal or hexagonal. 



First radials rather smaller than the basals, pentagonal, and 

 excavated on their upper borders for the reception of the second- 

 ary radials. 



Anal plates three, the first nearly as large as both the others, 

 and situated as is usual in this genus, the first resting between 

 the basals, the second resting on the summit of the left pos- 

 terior radial, and the third on the summit of the first. 



Secondary radials, arms and column unknown. 



Position and locality: Kinderhook group near Elsah, Jersey 

 county, Illinois. 



Collector, A. H. Worthen. 



No. 2560 of the Illinois State Museum. 



