ASTEROIDEA OF NORTH PACIFIC AND ADJACENT WATEKS — FISHER. 189 



each scries being graduated in size toward the angle, where there is usually one vcry 

 small spinclet. This marginul angle is nearer the inner than the outer or ahoral 

 end of free margin. On actinal surface is a superficial scries of seven or eight terete 

 blunt spinclcts bordering the suture and on the adanibulacral margin four or five 

 continuing the furrow series, both decreasing in size toward the outer end of plate. 

 A spinelet of latter series sometimes becomes enlarged and stands midway between 

 the two series, forming an actinal spinule homologous with that of the adanibulacral. 



Actinal interradial areas fairly large, but plates extending only one-third 

 length of ray measured alongside, or one-half measured from center of disk. Plates 

 arranged in series extending from adambulacrals to inferomarginals, and covered 

 with comparatively few, spaced, swollen, small spinelets usually forming a circle 

 surrounding an enlarged central spinule. These spinelets have a narrow proximal 

 and a swollen pointed distal portion, and resemble the so-called "barleycorn" 

 spinelets of many Astropectinidte. ^lien dry these spinelets become very slightly 

 slenderer, but retain the characteristic form. 



The channels running interradialh- between the series of intermediate plates 

 form undifl'erentiated fascioles. A small percentage of the specimens have pectinate 

 pedicellariffi or fascioles on the actinal intermediate area or between the adam- 

 bulacral plates. In the latter case a comb of about four spinelets on each plate bend 

 over the transverse suture and meet spinelets of an adjacent plate. This is simply 

 the "postadaml)ulacral fasciolo" transferred to the adambulacral plates. The 

 actinal intermediate pectinate pedicellariie occur mostly over the transverse sutures 

 between proximal plates of the series adjacent to adambulacrals. Three to five 

 somewhat enlarged, slightly flattened spinelets with truncate or rounded often 

 sUghtly flaring tips compose each comb. There is considerable variation in the 

 amount of specialization or differentiation undergone by the spinelets. Some are 

 considerably flattened, especially in the case of the adambulacral pedicellarise. 

 An interradial pedicellaria just back of mouth plates, and one on either side is of 

 fairly frequent occurrence. Rarely a small pedicellaria is found between these and 

 marginal plates. 



Madreporic body fairh* conspicuous, situated midway between center and 

 inner edge of superomarginals; edges overhung by seven to ten paxilla?; outline 

 variable; striations irregular centrifugal. 



Color in life: Abactinal surface dull coral red, rather deep, varying to maroon in 

 small specimens, in which case the abactinal paxillar area is much darker than 

 marginal plates, which are bright coral red; actinal surface of infcromarginal plates 

 pinkish buff; actinal intermediate areas grayish, often tinged with pink; tube feet 

 olive buff torawsienna. A second phase is of the same general tint, but much paler. 



Anatomical iwtes. — Superambulacral plates present but poorly developed, and 

 absent from first two ambulacral ossicles; rudimentary or lacking beyond middle 

 of ray. Gonads forming a single tuft at either side of interradial septum. Anal 

 opening present, small. Intestinal coecum divided into two parts, each of which has 

 three or four irregular branches with a few small pocket-like subdivisions. One 

 Polian vesicle in each interradius. Tube feet with well-developed sucking disks: 

 no deposits in walls. 



