NO. 2180. A NEW SEA STAR FROM KAMCHATKA— FISHER. 369 



feromargiiial granules squamiform, increasing in size toward the outer 

 margin of the plate where they are larger than the corresponding 

 superomarginal granules. The marginal plates have deep fasciolar 

 grooves between their speciaUzed raised ridges. The grooves in the 

 interbrachium are about three-fourths the width or thickness of the 

 intervening ridges, and on the rays about one-half. Unless the 

 granules are removed the grooves are entirely hidden. 



Actinal intermediate plates arranged in very regular series leading 

 from the adambulacral plates to margin, and also in about six series 

 parallel to the adambulacrals. There is an odd interradial series, 

 starting outside a pair of plates opposite the outer end of mouth plates 

 and nearly reaching the margin. The plates have eUiptical, trans- 

 versely oriented pedicels or tabula (separated by fasciolar channels), 

 bearing a paxilhform group of 15 to 18 peripheral and about 12 to 18 

 stouter central spinelets. The spinelets are short, clavate, and are 

 more or less bent or dressed toward the margui, the ends of the cen- 

 tral spinelets being obhquely truncated and somewhat flaring. 



Adambulacral plates with a somewhat tabulate surface, there being 

 a well-defined groove between this and the adj acent actinal intermediate 

 plates, and a shghtly deeper groove separates consecutive plates. 

 The armature consists of a peripheral series of about 13 spines of 

 which 6, or 5, stand on the furrow margin and form a regular comb. 

 These spines are roughly four-sided and blimtly pointed, or round- 

 tipped (the end bemg beveled), and the adoral, as well as sometimes 

 the aboral, are shorter than the central four. The other peripheral 

 spinelets are a little longer than the adjacent actinal intermediate 

 spinelets. Four to six subambulacral spines form usually two series, 

 or a group. In the type there are often two well-defined longitudinal, 

 subambulacral series of four or five spines each, as well as several on 

 the outer edge of the plate. 



Mouth plates prominent and rather narrow at the outer end, and 

 flaring to form a broader lanceolate mner half. Margmal spines about 

 12, largest at the inner end. There is a series of short spines along 

 the median suture margin, a similar series along the center of each 

 plate, and a series of slenderer spinelets along the margin adjacent to 

 the first adambulacral. First adambulacral moderately compressed. 



Madreporic body subcircular, convex, not hidden by paxillae. It 

 is situated nearly midway between the center and mner margin of the 

 superomarginal plates. Striae irregularly radiating, branched. The 

 margin is overhung more or less by paxillae, but these do not spring 

 from the surface as in Dipsacaster. Anal aperture small but distinct. 

 Gonads, both ovaries and testes, in small branched tufts hanging from 

 a genital rachis which lies nearly midway between median radial line 

 and the margm. The tufts extend about half the length of ray meas- 

 65008°— Proc.N.M.vol.52— 17 24 



