18 



In each lateral ray the third primary radial supports upon each 

 upper sloping side two secondary radials the last being axillary 

 and bearing upon each upper sloping side three tertiary radi- 

 als and an axillary plate which supports two arms, which gives 

 to each of these rays eight arms. In the ray opposite the 

 azygous area, there are three secondary radials followed by 

 an axillary plate that supports two arms, in one series, and, 

 in the other, there are three arms, which gives to this ray 

 five arms. There are, therefore, in this species, thirty-two 

 arms. The arms are composed of a double series of interlock- 

 ing plates that show a slight tendency to flatten at the in- 

 curving superior ends, but not to be compared in this respect 

 with Batocrinus Sampsoni. Pinnules long and dense. 



In one of the interradial areas there are three plates, one 

 followed by two smaller ones; in two of the areas there are 

 four plates in each, one followed by two in the second range 

 and one in the third; and in the other area there are five plates, 

 one followed by two in the second range and two in the third. 

 There are seven azygous interradials, the first one heptagonal, 

 in line with the first primary radials and of about the same 

 size. It is followed by three plates, the central one being 

 larger than the lateral ones; and these by two plates, in the 

 third range, and one in the fourth, that is somewhat elongated 

 and reaches the plates of the vault. Vault conoidal, and sub 

 central proboscis smaller than in B. Sampsoni. 



This species will be distinguished by the arrangement of its 

 thirty-two arms from all other species. The same tendency of 

 the arms to flatten near the upper ends has been discovered 

 in other species of Batocrinus that has been overlooked by 

 authors. But where the flattening is as slight as in our 

 specimens of this species, it is probable that other specimens 

 will not show any flattening, and that the character is not even 

 of specific importance, and, moreover, it is probable that it 

 does not exist in younger specimens, which would again tend 

 to destroy its importance. 



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

 in the collection of S. A. Miller. 



