31 



arms to the species. We have, however, only three specimens 

 showing any of the arms, but one of them has five bifurcating 

 rays showing part of ten arms. The general form and parts 

 preserved leave little doubt that the species has thirty free 

 arms. 



There are three regular interradials in each area — one large 

 plate followed by two small ones. They are below the tertiaiy 

 radials and do not reach the vault. There are seven plates in 

 the azygous area. The first one is in line with the first primary 

 radials and of about the same size; it is followed by three 

 plates in the second range, two in the tlih-d range and one in 

 the fourth, which unites with the plates of the vault. 



The vault is conoidal and has a capacity about equal to that 

 of the calyx. It is covered with plain and slightly convex, 

 polygonal plates, and l^ears a moderate- sized subcentral pro- 

 boscis. No ovarian jiores have been seen in any of our speci 

 mens and there appears to be no evidence of their existence. 



This species is distinguished ijy its general form, hemispher- 

 ical calyx and conoidal vault, fifteen ambulacral openings to the 

 vault and thirty free arms. Any one capal)le of distinguishing 

 a Batocrinus will at once know the species from these peculiar- 

 ities. 



'Found by S. A. Miller, in the Keokuk Group, at Boonville, 

 Missouri, and now in his collection. 



BATOCRINUS HETKROCLITUS, n. Sp. 



Plate J, Fig. 37, basal vieiv; Fig. 38, azygous side; Fig. 39. 



summit view. 



Sj)ecies rather below medium size. Calyx and vault subequal, 

 and together somewhat trochiform. Height of the calyx about 

 one third the diameter, and ambulacral openings directed hori- 

 zontally. Radial series i>roject at the margin, so as to notcli 

 the circumference at the interradial parts. Radial ridges well 

 defined and angular. Surface granulai-. Column round and 

 small. 



Basals form an hexagonal disc or very low cup two and a 

 half times the diameter of the column. First primary radials 

 wider than long, three hexagonal, two hejitagonal. Second 

 primary radials quadrangular, and from two to three times as 



