574 THE VOYAGE OF H.M.S. CHALLENGER. 



spine are a number of small forcipiform pedicellariae, which form an ill-defined wreath, and 

 on the boss are distributed a number of isolated, small forficiform pedicellarise. In the 

 interspaces or meshes of the network are numerous thin, pointed papulae, and a few small 

 forficiform pedicellarise are interspersed. A regular longitudinal row of plates form the 

 margin of the abactinal area, which I consider to be the representatives of supero-marginal 

 plates. Each bears a single short, robust, truncate spinelet, which is distinctly chan- 

 nelled or gauge-shaped, and at the base, on the abactinal side, is a moderately thick half- 

 wreath of forcipiform pedicellarise. There are seldom any of these found on the actinal 

 side, but several forficiform pedicellarise may be there instead. In some examples two 

 spines placed diagonally, or even three spines, may be present on a greater or less number 

 of the plates, usually only here and there, and never continuous throughout the ray or 

 sufficient to form the crowded margin characteristic of Asterias amurensis. 



The actinal area of the ray, which extends from the supero-marginal plates above 

 described to the adambulacral plates, is broad and bears midway one double longitudinal 

 series of spines, composed of spines standing in oblique, well-spaced pairs. The spines 

 are equal, robust, truncate, often channelled, and are accompanied on their outer side by 

 a little tuft of forcipiform pedicellarise. In the wide space on each side of this median 

 series of spinelets are numerous papulse and a few isolated forcipiform pedicellarise. 



The armature of the adambulacral plates consists of one spine and two spines alter- 

 nately, so arranged that at first sight there appears to be a single series only ; the single 

 spine and the outer spine of the pairs standing erect and forming a straight regular series, 

 whilst the inner spine of the pairs is placed high in the furrow, and directed horizontally 

 between adjacent tube-feet, and is in consequence generally hidden. The inner spine of 

 the pairs is more delicate than its companion. The outer spine and the solitary spine are 

 equal in size, slightly compressed, truncate at the tip, and sometimes channelled, at least 

 near the mouth ; on the outer part of the ray they are more tapering. Three or four 

 small, elongate, forficiform pedicellarise are attached near the tip on the outer side of all 

 these spinelets. 



The ambulacral tube-feet are quadriserially arranged. 



The madreporiform body is circular, and is placed rather nearer the margin than the 

 centre of the disk. Its surface is slightly convex, and is marked with very fine striations 

 which radiate centrifugally with considerable regularity. There are no spinelets round 

 the periphery of the organ, but two or three isolated forficiform pedicellarise may be 

 present. 



Colour in alcohol, a bleached yellowish white on the actinal surface ; on the abactinal 

 surface the spinelets and an area round their base occupied by the slightly convex boss are 

 a bleached yellowish white, but the interspaces are a uniform dark chocolate brown, the 

 sharply defined colouration giving a very striking character to the species. In one example 

 the whole abactinal surface, excepting only the tips of the spinelets, is a uniform rich dark 



