59 



series and slightly convex in the interradial spaces. Sutures 

 only moderately concave and slightly beveled. The plates over- 

 lap very little, and the column, which is composed of thin plates, 

 tapers slowly from the calyx. 



Basals covered by the column. Subradials wide and only 

 partly exposed. Primary radials, five in one of the lateral rays 

 and four in each of the other rays. The first one is longer 

 than either of the others and they vary from two to four times 

 as wide as long. The last primary radial in each series is 

 pentagonal, axiliary, and supports the secondary radials. There 

 are four secondary radials in each series in the ray on the 

 right of the azygous area, and three secondary radials in each 

 of the other eight series. The last secondary radial in each 

 series is axillary and supports the tertiary radials. The ter- 

 tiary radials vary in number in the different rays, as may be 

 seen in the illustrations, from four to nine, and the last one is 

 axillary and supports a quaternary series. Another division 

 takes place in the distal arms in each ray, so as to give to 

 each ray twelve arms. The arms infold at the superior end 

 and some of them again divide, but exactly how many our 

 specimen does not disclose. There are, therefore, more than 

 sixty arms in this species. 



The regular interradial areas are of unequal size, long, and 

 lanceolate in outline. In one area there are fourteen plates, in 

 another seventeen, and in another twenty. The inter secondary 

 radial areas are lanceolate and differ very greatly in size. In 

 the one opposite the azygous area there are two elongated 

 plates. In the one on the right of the azygous area there are 

 nineteen plates and in the one on the left of the azygous area 

 there are eight plates. In the intertertiary radial area on the 

 right of the azygous area there are two elongated plates, one 

 following the other, but there are no other intertertiary plates in 

 our specimen. The ray on the right of the azygous area is larger 

 than either of the other rays, more protuberant and contains 

 more inter secondary plates beside the two intertertiary plates. 

 The azygous area is wider and contains more plates than either 

 of the regular areas and is also lanceolate in outline. The first 

 azygous plate broadly truncates a subradial and is followed by 

 two plates in the second range, one of which only truncates it 



