11 



tertiary radiiils, oat-h of which bears a single arm, which 

 gives to this ray four arms. On the left side of the azygous area, 

 on the distal side, there are four secondary radials that bear 

 a single arm, and on the proximal side two secondary radials, 

 the last of which is axillary, and bears upon the distal side 

 two tertiary radials that bear a single arm, and on the prox- 

 imal side three tertiary radials, the last being axillary and 

 supporting two arms, which gives to this ray four arms. It 

 will be noticed that the number of arms in each of these rays 

 is the same, but the arrangement is reversed. In one lateral 

 ray there are u^ion each side of the third jirimary radial four 

 secondary radials, tlie last being axillary and supporting 

 two arms, which gives to this ray four arms. In the other 

 lateral ray there are upon each side of the thii'd primary 

 radial two secondary radials, the last being axillary and bear- 

 ing upon each upper slojiing side three tertiary radials, the 

 last of which is axillary in tliree rays and supi)orts two arras, 

 and the other one supports a single arm, which gives to this 

 ray seven arms. In the ray opposite the azygous area there 

 are upon one side five secondai-y radials that bear a single 

 arm, and upon the other side five .secondary radials, the last 

 being axillary and supporting two arms, which gives to this 

 ray three arms. There are, therefore, twenty-two arms in this 

 species. Tlie arms are composed of a double series of inter- 

 locking plates that are deeper than wide, and, as far as pre- 

 served in the tyjiical specimens, show no tendency to flatten 

 toward the superior ends. Pinnules long and dense. 



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

 one followed by two, and then one in the third, and one in the 

 fourth range — in other areas there are six plates — two in both 

 the second and third ranges. In the azygous area there are 

 thirteen iilates. The first one is heptagonal, in line with the 

 first primary radials and fully as large as any of them. It is 

 followed by three plates in the second range, five in the tliird 

 range, three in the fourth range and one in the fifth range 

 that unites with the idates of the vault. Our sijecimens do not 

 di.sclo.se the vault and probo.scis. 



This species is distinguished by the numerous interradials 

 and azygous plates, and by the order and arrangement of twenty- 



