37 



two secondary radials, the last being axillary, and bearing up- 

 on the proximal sides one tertiary radial, and upon the distal 

 sides two tertiary radials, which gives to this ray four arms. 

 In the ray opposite the azygous area the third primary radial 

 bears upon each upper sloping side three secondary radials, 

 which gives to this ray two arms. There are, therefore, fifteen 

 arm openings to the vault in this species. 



The interradial areas connect with the vault, but they differ 

 in form and in the number of plates. The first plate is about 

 as large as a first primary radial. It is followed in one of the 

 areas by a single plate, in two of the areas by two plates, and 

 in one of the areas by three plates in the second range. In the 

 third range in each case a single elongated plate connects with 

 the plates of the vault. The azygous area is large, and con- 

 tains ten plates. The first one is in line with the first primary 

 radials, and is followed by three large plates in the second 

 range. One of the lateral plates, in the second range, supports 

 two small plates, and, over the middle plate, in the second 

 range, there are two ranges of two plates each, one of the 

 larger of which connects with the plates of the vault. 



The vault is nearly flat, covered with slightly convex, polyg- 

 onal plates, and bears a small subcentral proboscis. No ovarian 

 aperatures can be distinguished. 



This species is distinguished by its general form, flattened 

 vault, peculiar interradial areas and fifteen arms. 



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

 Missouri, and now in his collection. 



BATOCRINUS PLANUS, n. Sp. 



Plate II, Fig. 11, basal view of a cast preserving elevated lines 

 outlining the plates; Fig. 12, summit view of same speci- 

 men, but the outline of the plates is not preserved; 

 Fig. 13, azygous side view of same; Fig. 14, 

 . basal view of another, perfectly preserving 

 the plates, as far as illustrated. 

 Body very much depressed, pentagonal, capacity of the vault 

 equal to or exceeding that of the calyx. Calyx very low, 

 about four times as wide as high, concave in the region of the 

 basals and gently rounding over the first radials toward the 

 margin, Plates convex and radial ridges lobed above, the first 



