49 



primary radials and nearly as large, it is followed by two 

 plates in the second range, four in the third, four in the 

 fourth and above these there are three or more small plates 

 but the sutures are too indistinct in our specimen to definitely 

 determine the number. 



The vault is quite convex and bears a central proboscis. It 

 is covered with numerous, highly convex, polygonal plates. 



This species is so well marked that it is unnecessary to 

 compare it with any hitherto described. 



Found in the Burlington Group, at Sedalia, Missouri, by R. 

 A. Blair, in whose honor we have proposed the specific name, 

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



ACTINOCRINUS FOVEATUS, n. sp. 



Plate ZJ, Fig. 25, azygous side; Fig. 26, view opposite the azy- 

 gous area of another specimen, the calyx is a little 

 flattened in both specimens. 



Species medium size. Calyx obconoidal, more rapidly spread- 

 ing in the upper part than below, especially in the region of 

 the secondary and tertiary radials; about one-half wider than 

 high; plates convex, sculptured, more or less stellate; radial 

 ridges angular in the superior part, and angles of the plates 

 depressed. 



Basals short, slightly constricted above; sutures beveled; 

 columner cavity broad and shallow. First radials rather wider 

 than long, except the radial on the left of the azygous area, 

 which is longer than wide, three hexagonal, two heptagonal. 

 Second primary radials about half as long as the first, hexa- 

 gonal, and wider than high, except in the ray on the left of 

 the azygous area, where the second radial is heptagonal and 

 longer than wide. In this ray there is no third primary ra- 

 dial and the second occupies the position of the second and 

 third primary radials. This feature may be abnormal, but as 

 the first plate is larger than it is in either of the other rays 

 the peculiarity must have commenced with the commencement 

 of the growth of the specimen and is not due to any injury 

 that it could have received. The Tact that Shnmardocrinus 

 never had but two primary radials in any of its rays leads 

 one to believe, that, in this species, one of the rays, in its 

 — 7 



