ASTEROIDEA OF NORTH PACIFIC AND ADJACENT WATERS — FISHER 121 



and 11 mm. broad at base) there is a series of well-developed actinal spines for half 

 the length of the ray. 



Adambulacral spines regularly two on the proximal two-thirds (more or less) of 

 the ray, and frequently irregularly one and two, or one only, on the terminal third. 



The outer spine is the larger, chisel-shaped, slightly expanded, and faintly 

 grooved toward the truncate or rounded tip. The inner is slenderer, a trifle tapered, 

 and less often grooved, and becomes relatively smaller toward the end of the series, 

 which usually dies out, as stated above, in the terminal third of the ray, or even sooner. 

 In the type, contrary to what Xantus says, many of the adambulacral plates are 

 diplacanthid. Scattered irregularly among these, especially distally, are monacan- 

 thid plates. 



Mouth angle not narrowed into a carina; two pairs of contiguous adambulacral 

 plates behind the mouth plates, the first pair larger than the second, firmly joined, 

 while sometimes the second simply touch. The third pair is well separated. The 

 mouth plates are broader than the first pair of adambulacrals, and are broadest on 

 the actinostomial margin, which bears a pair of spines for each plate, or a fan of 

 four. The laterals are short and stubby, with a cluster of small lanceolate straight 

 pedicellariae. The other is about as long as the mouth plates, slightly tapered, and 

 blunt, or truncate. The suboral spine (one to a plate) is still longer, terete tapered 

 and blunt. The first adambulacral is still longer, as a rule, either tapered or not. 

 terete or flattened, blunt or subtruncate. The actinostome is never greatly sunken 

 as in Orthasterias, owing to the short adoral carina of only one pair of adambulacrals. 



Straight pedicellariae of two general sorts: (1) small, ovate-lanceolate, with 

 jaws less than 1 mm. long, and (2) heavy spatulate wedge-shaped toothed ones 

 measuring from 1.5 to 2 mm. long. The latter are very variable in numbers, being 

 fairly numerous or nearly absent. They are broadly wedge-shaped with spatulate, 

 terminally rounded denticulate jaws, and are often as stout as the carinal spines. 

 They are scattered over the abactinal surface, in the intermarginal area, in the actinal 

 channel, and also sometimes (especially when numerous dorsally), on the furrow face 

 of the adambulacral plates. Rarely one occurs on the actinal face of the adambulac- 

 rals. The first sort are present sparsely on the dorsal and lateral surfaces, in the acti- 

 nal channel (especially interradially) and along the furrow face of the adambulacrals. 

 The latter have short peduncles, the jaws being about 0.5 mm. long or less. 



The crossed pedicellariae are numerous and occupy conspicuous cushionlike 

 wreaths surrounding the base of the dorsal and superomarginal spines, and a conspicu- 

 ous pad on the outer side of the outer inferomarginal (absent from inner inferomar- 

 ginal and actinal spine). The diameter of the wreaths is usually a trifle less than the 

 height of spine. On the outer part of ray they nearly touch. The pedicellariae range 

 from 0.32 to 0.44 mm. in length, their salient characteristics having been noted in 

 the generic diagnosis. 



Papular areas small, numerous, irregularly arranged on the dorsum, but in regular 

 intermarginal and actinal series. Papulae dorsally 1 to 10 to an area in close tufts; 

 intermarginaUy about five to eight, in grown specimens; and actinally usually two 

 to five proximally, and one or two distally. 



Madreporic body about 2 mm. in diameter, plane, set on a slant near edge of 

 disk, and with interrupted meandering striae. 



Color: Some specimens received from Scripps Institution and presorved in 

 formalin retained some of the life colors. Integument dark rich green, the pedicel- 



