10 



rapidly spreading toward the free arms. About twice as wide 

 as high. Arm openings directed nearly horizontally. No 

 radial ridges. Plates thick and highly convex or tumid. Sur- 

 face granular. 



Basals form an hexagonal disc, with slight re-entering angles, 

 deeply notched at the sutures, and project cuneiform edges, 

 slightly expanding, below the end of the column. The basal 

 disc is about one-half wider than the diameter of the column, 

 and bears a deep concave depression for the attachment of the 

 column. First radials about one -half wider than long, three 

 hexagonal, two heptagonal, and transversely, highly tumid. 

 Second radials quadrangular, and from two to three times as 

 wide as long. Third primary radials about one-half larger 

 than the second, pentagonal, axillary, and bears upon each 

 upper sloping side secondary radials. In four of the rays 

 there are, upon each upper sloping side of the third primary 

 radials, two secondary radials the last one being axillary and 

 supporting upon each upper sloping side two tertiary radials, 

 which gives to each of these rays four arms. In the ray on 

 the left of the azygous area, there are, on the distal side of 

 the third primary radial, two secondary radials, the last being 

 axillary and supporting, on one side, a single tertiary radial, 

 and upon the other two tertiary radials. The third primary 

 radial bears on the proximal side two secondary radials, the 

 last being axillary and bearing on the distal side two tertiary 

 radials, and on the proximal side one tertiary radial which is 

 axillary and bears on the distal side one quaternary radial 

 which gives to this ray five arms. There are, therefore, in 

 this species twenty-one arms. 



There are two regular interradials in each area. The first 

 one is large and tumid, the second one small. There are six 

 plates in the azygous area. The first one is in line with the 

 first primary radials, tumid and about as high as wide. It is 

 followed by three tumid plates in the second range and by two 

 smaller plates in the third range, that are cut off, by the ter- 

 tiary and quaternary radials, from all connection with the 

 vault. 



The vault is elevated, convex, covered with tumid, polygonal 

 plates, and bears a large, subcentral proboscis. The plate at 

 the base of the proboscis opposite the azygous area is the 

 largest plate connected with the vault. 



This is the first species of Batocrinus, bearing twenty-one 

 arms, that has been described, from the Burlington Group, 



