•1<J s, Goi\:) : 



outer side. In one interradius, one of the first superomarginals 

 carries two spines of nearly c<]ual size and much smaller than 

 the principal spine of its fellow. The first superomarginal presents 

 a wart-like form on the abactinal side, and a bluntly keeled ridge 

 on the outside which is covered with small roudi conical Granula- 

 tions. The remaining superomarginals each carry a large 

 conical spine, exactly similar to that of the first superomarginal 

 and hardly smaller as far as about the middle of the arms, but 

 gradually decreasing in size from thence towards the tip. Some 

 of the plates may carry in addition one or two, or exceptionally 

 three, smaller spines. There is besides a more or less complete 

 circle of very small spines around the base of the principal 

 spine, to which the accessory spines usually belong. Each 

 superomarginal presents, like the first plate, a wart-like form 

 on the abactinal side, and is separated from the next one 

 by a more or less soft tissue, when seen from the outside. 

 The number of superomarginals is 43 for one of the complete 

 arms. The superomarginals as a series are more elevated than 

 the paxillar area and form a conspicuous rim on the abactinal 

 side. 



fnferomarginals — Only the first inferomarginals are coincident 

 with the superomarginals, all the rest are alternate, and from the 

 second or third plate on they are directly contiguous to the 

 adambulacral plates to which they are closely applied. Each plate 

 carries a transverse series of three or four large spines, of which 

 the one nearest the abactnial side is largest, being only slightly 

 smaller than the principal spines of the superomarginals, and the 

 one at the opposite en4 is the smallest. The modal number of 

 spines for the inferomarginals is three. There is a more or less 



