12 



two arms. The fourth primary radial in one of the rays is 

 abnormal, or the commencement of development toward some 

 other form, that is unknown, provided other specimens, in this 

 species, do not retain the same character, in which case, it 

 might be a specific character. We have the character preserved, 

 only in the specimen that is illustrated. 



Found in the Keokuk Group, at Boonville, Missouri, and now 

 in the collection of S. A. Miller. 



BATOCRINUS VENUSTULUS, n. Sp. 



Plate I, Fig. 7, azygous side of calyx and arms, a little 



depressed. 



Species medium size. Calyx obcorioidal, twice as wide as 

 high; each radial series bears a low angular ridge from the 

 basal plates to the free arms; interradial areas slightly flat- 

 tened; surface granular; truncated for a medium-sized column. 



Basals form an hexagonal disc one- third wider than the 

 diameter of the column and having a height less than the dis- 

 tance from the column to the margin. First primary radials 

 very little wider than high, upper face slightly arcuate for 

 the reception of the second radials. Second primary radials 

 quadrangular, more than twice as wide as high. Third pri- 

 mary radials pentagonal, a little larger than the second, about 

 twice as wide as high, axillary, and support upon the upper 

 sloping sides the secondary radials. On the distal side of the 

 third primary radial, on the right of the azygous area there 

 are four secondary radials, the last of which is axillary and 

 supports upon each upper sloping side a free arm; on the 

 proximal side there are tw T o secondary radials, the last being 

 axillary and supporting upon the distal side two tertiary ra- 

 dials and upon the proximal side three, the last ones support- 

 ing free arms, which gives to this ray four arms. In the ray 

 on the left of the azygous area, the third primary radial sup- 

 ports, upon each upper sloping side, two secondary radials, 

 the last being axiliary and the proximal series bears on the 

 proximal side two tertiary radials and on the distal side two 

 tertiary radials and an axillary plate that supports two arms; 

 the distal series bears upon each upper sloping side two ter- 

 tiary radials one of which bears an axillary plate that sup- 

 ports two arms. This arrangement gives to this ray six arms. 



