25 



sembles Batocrinu? hngeri, McChesney. That species, however, 

 has tweuty arms, four in each radial series, while this has only 

 eighteen, or two only, in the ray opposite to tlie azygous area, 

 and this feature alone is sufficient to distinguish the species. There 

 are minor difference* in the regular and azygous areas. 



Found in the Burlington Group, at Burlington, Iowa, and now 

 in the collection of A Albers, S. A. Miller and Wm. F. E. Gurley. 

 The specimen illustrated is from the collection of Mr. Albers. 



BATOCRINUS ENODIS, U. Sp. 



Fldte I, Fiij IG, basal view; Fig. 17, azygous side; Fig. IS, 



summit view. 



Species variable in size and in form, one of the specimens ex- 

 amined has a diameter little more than half that of the one illus- 

 trated. Calyx and vault subequal in size, and much alike in form. 

 Calyx saucer-shaped, rapidly expanding from the column to the 

 arms. Ambulacral openings directed upward at an angle of about 

 forty-five degrees, and not visible from a basal view. Surface of 

 the plates plane and smooth, some of those on the vault some- 

 times slightly convex. 



Basals form a low, concave, hexagonal disc, with obscure rei^n- 

 tering angles, having a round, hemispherical depression for the 

 attachment of the column, and about one and a half times the 

 diameter of the column. First primary radials nearly twice as 

 wide as long, three hexagonal, two heptagonal. Second primary 

 radials about half as large as the first, quadrangular, and two or 

 two and a half times as wide as long. Third primary radials 

 somewhat smaller than the first, twice as wide as long, three hex- 

 agonal, two pentagonal, axillary, and in one of the lateral rays, 

 on each side, and in the ray opposite the azygous area, support 

 on each superior lateral side, two secondary radials, the last ones 

 being axillary and supporting on each upper side two tertiary ra- 

 dials, which gives to each of these three rays four arms and four 

 ambulacral openings to the vault. In the ray on the right of the 

 azygous area, the third primary radial bears upon the distal side 

 two secondary radials, the last one being axillary and supporting, 

 on the distal side, two tertiary radials, and, on the proximal side, 

 one tertiary radial, which is axillary and supports upon each 

 upper side a quaternary radial; and bears upon the proximal side 

 —4 



