6 



an axillary, tertiary radial that supports upon one side a sin- 

 gle quaternary plate, and upon the other two quaternary 

 plates, which arrangement gives to each of these rays five 

 arms. There are, therefore, twenty-two arms in this species. 



In two of the regular interradial areas there is only a single 

 large plate, in each of the other areas there are two plates, 

 one large, the other quite small. The azygous area contains 

 four large plates and two very small ones. The first one is 

 in line with the first primary radials and rather longer than 

 either of them. It is followed by three large plates, subequal 

 in size, in the second range, and above these, on the left of 

 the central plate, there are two small plates. The azygous 

 area is entirely cut off from the plates of the vault by the 

 union of the quaternary radials. 



The vault is moderately convex and covered with polygonal, 

 highly convex, and nodose plates and bears a large subcentral 

 proboscis. 



This species is distinguished by its general form, twenty-two 

 arms, nodose and subspinous plates and interradial areas. 

 Heretofore, there have been described, from the Burlington 

 Group, ten species, having twenty-two arms, and probably B. 

 proximus is as nearly related to this as any other species 

 though the calyx is much shorter and the radials differently 

 formed, and yet there are more regular and azygous plates in 

 the several areas than in this species. The two species cannot 

 b3 confounded by any one capable of understanding the struc- 

 ture of crinoids. 



Found by C. S. Hodgson, in the Burlington Group, in Adams 

 county, Illinois, and now in the collection of S. A. Miller. 



BATOCRINUS NODULOSUS, n. Sp. 



Plate I, Fig. 4, basal view; Fig. 5, azygous side of calyx; Fig. 

 6, opposite view of calyx. 

 Body medium or above medium size. Calyx broadly truncated 

 below, obconoidal, twice as wide as high, arm openings direct- 

 ed upward at a slight angle. Plates spinous. The hexagonal 

 second primary radials, two plates in the second range, in the 

 azygous area, and the sculpturing bring this species near Ac- 

 tinoerimts. The interradial areas, are, however, cut off from 



