19 



There are two large, elongated plates in each interambulacral 

 area, followed by two large plates, that separate the spine-bearing 

 plates and curve over upon the vault. The central spine-bearing 

 plate is surrounded by a circle of eleven plates, which nearly cover 

 the summit. 



There has never been but one fifteen armed species described 

 from the Burlingtou Group, and it has no resemblance to this 

 one, and no comparison is therefore necessary to distinguish it. 

 In general form it bears some resemblance to D. intermedius and 

 D. missouriensis, but it is so widely different, without resorting 

 to the arm formula, that they cannot be mistaken for each other. 

 D. mtermedius is a nineteeu-armed species, and D. missouriensis 

 a twelve-armed species. 



Found by F. A. Sampson, in whose honor we have proposed 

 the specific name, in the Burlington Group, at Sedalia, Missouri, 

 and now in his collection. 



DORYCRINUS FABERI, n. Sp. 



Plate I, Fifj. 8, azygous side; Fig. 9, opposite view; Fig. 10, 

 sioiimit, part of the spines are broken off. 



Species small. Calyx obpyramidal, from two to two and a half 

 times as wide as high, truncated and flanged at the base. Radial 

 ridges angular. Surface granular. Sutures not beveled. Column 

 quite small. 



Basals form a short subliexagoaal disc, two and a half times as 

 wide as the diameter of the column, the upper part being con- 

 stricted and the lower part having a moderately concave depres- 

 sion, for the attachment of the coluain. First primary radials, the 

 largest plates in the calyx, longitudinally angular in the middle, 

 a little wider than long, three hexagonal, two heptagonal. Second 

 primary radials about one-third as large as the first, quadrangu- 

 lar, and from two to t^o and a half times as wide as long. Third 

 primary radials about one- half larger than the second, pentagonal, 

 axillary, and, in four of the rays, support on each upper sloping 

 side a single, secondary radial, which gives to each of these rays 

 two arm openings to the vault. Tn the ray, on the right of the 

 azygous area, the third primary radial bears upon the distal side 

 two secondary radials and upon the proximal side a single .second- 



