72 



The vault is broadly and highly convex and bears a small sub- 

 central proboscis. It is covered with polygonal plates that are 

 produced in short, sharp spines. 



This species is probably most nearly related to B. proboscidialis, 

 which was described by Hall as Actinocrinus pro boscidialis, 

 and has generally been referred to Actinocrinus, by later 

 authors, though it is a true Batocrinus. If, however, the 

 character of the vault and proboscis is of specific importance, they 

 may be readily distinguished. In B. proboscidialis the vault is 

 terete conical, and is gradually produced into a large and long 

 proboscis. In this species the vault is broadly convex and bears 

 a email subcentral proboscis. The species are farther distinguished 

 by the following characters. In B. proboscidialis, the surface of 

 the plates of the calyx is marked by short angular ridges, which 

 terminate in a bi-nodose, transverse ridge, on the first radials, 

 and in a strong angular node above; in this species, there are no 

 angular ridges, or bi-nodose, transverse ridges, but the plates are 

 all pyramidal and terminate in angular points. In B. proboscidialis 

 there are four plates in each regular interradial area disposed in 

 three ranges; in this species there are three plates, disposed in 

 two ranges. The azygous areas are also different. But notwith- 

 standing all these differences, both species have the same arm 

 formula and the same number of secondary and tertiary plates, 

 in the calyx, and, therefore, must be nearly related. 



Found by R A. Blair, in the Burlington Group, at Sedalia, and 

 now in the collection of S. A. Miller. 



BATOCRINUS SUB^QUATUS, n. sp. 



Plate IV, Fig. 33, azygous side; Fig. 34, opposite view; Fig 35, 



summit. 



Species small, below medium size, biturbiuate, calyx and vault 

 subequal in capacity. Calyx bowl-shaped, slightly flattened, in the 

 superior part of the interradial areas, about one-third wider than 

 high. Radial ridges undefined. Plates convex. Surface granular. 



Basals form an hexagonal, slightly expanding, disc, truncated the 

 entire width below, by the column, which is supported in a rad- 

 iately lined, hemispherical depression. First primary radials as 

 large as the second and third together, wider than long, three 

 hexagonal, two heptagonal. Second primary radials quadrangular, 



