38 



radials. Surface granular. There are pits at the angles of the 

 larger plates in our specimen, but that character is not shown 

 on either of two casts and may not, therefore, be normal. 

 One cast is one-fourth larger than the specimen illustrated. 

 It will be observed, that there is some difference, in the pro- 

 portional size of the plates, and the depressions on the cast, 

 this is because the internal sides of the plates are not like the 

 external surface. It is for this reason, that we cannot always 

 recognize the casts, when we are conversant with specimens 

 having the plates well preserved, and it is, therefore, a matter 

 of gratification to be able to illustrate a species preserved in 

 both ways. 



The basals form a small hexagonal, concave disc which is 

 almost wholly covered with the column. The first radials are 

 quite as long as wide and very slightly rounded from the 

 basals to the second radials, three hexagonal, two heptagonal. 

 Second radials quadrangular, about one and a half times as 

 wide as long. Third radials one-half larger than the second, 

 pentagonal, axillary and support upon each upper sloping side 

 two secondary radials, the last of which are axillary and sup- 

 port the free arms. As near as can be ascertained, from our 

 specimens, there are four arms in each series, which arise 

 from the second secondary radials and are directed horizon- 

 tally. 



The interradial areas are wide and the plates connect with 

 those on the vault. In each regular area there are three plates, 

 one large followed by two elongated plates that unite with 

 three plates belonging to the vault. There are seven azygous 

 interradials, the first one heptagonal, in line with the first 

 primary radials and of the same size. It is followed by three 

 plates in the second range and three in the third range, which 

 unite with four plates belonging to the vault. The vault is 

 convex, and bears a subcentral azygous prominence, with the 

 orifice on top, but whether or not there is a proboscis cannot 

 be determined definitely from our specimens. 



This species would be classed with Sieganocrinus if it had 

 hexagonal, second, primary radials. But, aside from the un- 

 usual, flattened, pentagonal outline, the calyx is that of a true 

 Batocrinus. There is no species described in either genus, 

 with which it is necessary to compare it% 



