9 



This is a very strongly marked and distinct species, and bears so 

 little resemblance to any other one that has been described that 

 no comparison with any of them is necessary. In form it is 

 somewhat like A. glans, but that is a twenty- armed species, has 

 fewer plates, in the interradial areas, and has only two plates in 

 the second range, in the azygous area. Indeed, they have too 

 little resemblance to each other to make any useful comparison. 



Found in the Burlington Group, at Burlington, Iowa, and now 

 id the collection of Prof. Martin Bischoff, of Buffalo, New York, 

 in whose honor we have proposed the specific name. 



ACTINOCRINUS SPECTABILIS, n. sp. 



Plate III, Fig. 3, azygous side. 



Species below medium size. Calyx obpyramidal, about as long 

 as wide, moderately truncated, most rapidly spreading toward the 

 free arms. Ambulacral openings directed upward, and not visible 

 in a basal view. Badial ridges denned. Interradial areas some- 

 what flattened and cut off from any connection with the vault, 

 except by a single plate in the azygous area. Surface granular. 



Basals form a low cup about two and a half times as wide as 

 high. First primary radials longer than wide, three hexagonal, 

 two heptagonal. Second primary radials about two-thirds as large 

 as the first, hexagonal, and a little wider than long. Third pri- 

 mary radials a little smaller than the second, heptagonal, axillary 

 and support on each upper sloping side a single secondary radial 

 which is axillary and supports, on each upper sloping side, a 

 single tertiary radial, which gives to each ray four arms. There 

 are, therefore, twenty arms in this species. 



In each of the regular interradial areas there are five plates, 

 one, followed by two, in the second range, and two in the third 

 range. In each of the other regular interradial areas there are 

 seven plates, one in the first range, two in the second, two in the 

 third and two in the fourth, the last being cut off from any con- 

 nection with the vault by the union of the tertiary radials. In 

 the azygous area there are sixteen plates. The first one is in 

 line with the first primary radials and of about the same size. 

 It is followed by two plates in the second range, four in the 

 —2 



