31 



Secondary radials two. the tirst quadrangular and the second pen- 

 tangular, supporting above the two divisions of the arms, giving four 

 arms to each ray. 



The two first arm-plates are nearly quadrangular, and longer than 

 those above. The third and fourth are nearly triangular, and are 

 succeeded by a double series of slightly interlocking plates 

 that spread out towards their extremities in the manner peculiar to 

 this genus. 



Interradials three, the first about twice as large as the succeeding 

 ones. Anal series unknown. 



Column at its junction with the body composed of thick, round 

 joints, that, a short distance below, are separated by thinner ones 

 arranged alternately. 



Surface of the body plates finely granulosa, with a slightly elevated 

 ridge crossing the plates, and extending to the top of the secondary 

 series. 



This species, minus the arms, closely resembles Batocrinus caroli 

 (Hall's sp.) from the same beds, but differs in the number and 

 structure of the arms, that having but sixteen while this has twenty. 



Position and locality : Warsaw beds of the St. Louis group, War- 

 saw, Illinois. 



Illinois State collection. 



ONYCHOCEINUS DISTENSUS. N. SP. 



Body of medium size, composed of smooth, massive plates. 

 Basals concealed by the column. 



Subradials on the anterior side sharply angular beyond the col- 

 umnar facet, forming a low, pentagonal cup. 



Eadials five, the first pentagonal, about one-fourth wider than 

 long ; the second, third and fourth, quadrangular, and nearly as 

 wide as the first, their width being equal to about once and a half 

 their length. The fifth radial is pentagonal, and supports upon its 

 upper sloping sides the divisions of the rays. The arms, beyond 

 the first division, throw ofi^ armlets at intervals of five or six plates 

 to their extremities on the only rays that are preserved in the speci- 

 mens obtained. 



None of the specimens show more than two or three inter-radial 

 plates. The first of these is hexagonal, about as wide as long, and 

 this was apparently succeeded by a series of three smaller plates 

 that are but partially preserved. Anal plates unknown. 



Column round, largest at its junction with the body, and com- 

 posed of very thin, even joints. • 



Position and locality : Chester limestone, Monroe county, 111. 



Illinois State collection. 



TAXOCEINUS FLETCHEKI. N. SP. 



Body, with arms complete, ovate in outline, lobate, composed of 

 thick, massive plates. Basals small, and concealed by the column. 



