11 



and its arm formula, therefore, is sufficient to distinguish it 

 from all other species. In form, it approaches B. laetus which 

 has twenty-two arms, but may also be distinguished from it 

 by the azygous area and other peculiarities. 



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

 Missouri, and now in the collection of S. A. Miller. 



BATOCRINUS BASILICUS, 11. Sp. 



Plate J, Fig. 10, azygous side; Fig. 11, opposite view; Fig. 12, 



summit view. 



Body medium or below medium size and somewhat biturbi- 

 nate, though the calyx is decidedly larger than the vault. 

 Calyx truncated below and obconoidal above, though spreading 

 most rapidly as the free arms are approached About twice as 

 wide as high. Arm openings directed horizontally. No radial 

 ridges. Plates convex. Surface granular. 



Basals very short and form a low hexagonal disc, with slight 

 re-entering angles. The basal disc is about one-third wider 

 than the diameter of the column and bears a shallow, radiately 

 lined, concave depression for the attachment of the column. 

 First radials a little wider than high, three hexagonal, two 

 heptagonal, with the superior sides slightly arcuate. Second 

 radials quadrangular, about half as wide as the first radials, 

 but two or three times as wide as long. Third primary radials 

 about the size of the second, pentagonal, axillary and bear upon 

 each superior sloping side two secondary radials, the last one 

 of which is axillary and bears upon each upper sloping side, 

 in three of the rays, a single tertiary radial, which gives to 

 each of these rays four arms. In each ray adjoining the azy- 

 gous area there is, on the distal side of the distal second, 

 secondary radial, an axillary tertiary radial, which bears upon 

 each superior sloping side a single quaternary radial, and on 

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

 of the proximal second secondary radial, two tertiary radials, 

 and on the proximal side a single axillary tertiary radial, 

 which bears upon each upper sloping side a single quaternary 

 radial, which arrangement gives to each of these rays six arms. 

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



There are three plates in each regular interradial area, one 

 followed by two small ones in the second range that do not 

 connect with the vault. There are ten plates in the azygous 

 area. The first one is in line with the first primary radials, 



