ASTEROIDEA OF NORTH PACIFIC AND ADJACENT WATERS — FISHER. 301 



tain upward to ten minute isolated grains or plates, sometimes bearing a small 

 spinelet. Papulae conspicuous, three to ten to an area. Spinelets three to five to 

 a fascicule, dehcate, pointed and thorny. Tiiey are relatirehj smaller than in long- 

 ispina, being 1 to 1.5 mm. long. The tufts of spinelets arc situated at the intereection 

 of the skeletal pieces, on slightly raised tabula or bosses, and also one or two may 

 occur on the iiiternodcs. The spinelets attached to the grains in the papular spaces 

 are much smaller. 



Marginal ])lates small, the two series well separated by large irregularly (juad- 

 rate ])aj)ular areas containing four or five papula\ Occasionally one of these areas 

 is bisected longitudinally. Intermarginal plates small, extending" nearh' to end of 

 ray. They arc one of the elements of the transvei-se bars connecting infero- and 

 superomaiginal ])latcs. The latter are about the same size as the abactinal pseudo- 

 paxilla^, but the inferomarginals are larger, with about eight to ten spinelets. 



Actinal intermediate ])lates small, extending about half length of ray (as in 

 longispina), but on the disk and base of ray there are numerous plates, as the 

 inferomarginal series bend outward and reach the ambitus at the interradial angle. 

 Along the interradial lino from the mouth to the inferomarginal plate five or six 

 intermecUate plates can bo counted. These bear one to four short papilliform 

 spinelets. A row of papuUc along ray between inferomarginals and intermediate 

 plates and numerous papidiB among intermediate jjlates of disk. 



Adambulacral jdates with an unusually long spinelet in the furrow (2 nmi.) 

 and an irregular transverse row of five or si-x sjnues, of which the inner is long and 

 slender (twace as long as ^vidth of ]>late), the next two or three decreasing gradually, 

 and the outer one, two, or three are commonly much shorter than the rest. Some 

 of the longer spines are flattened, grooved, or bifid at the tips. The marginal 

 mouth spines are often conspicuously grooved or flattened. 



Type.^C&t. No. 277S4, U.S.X.M. 



Type-locality. — Albatross station 4784, near Attn Island, Aleutian Islands, l.So 

 fathoms, coarse i)cbbles; one specimen. 



Remarks. — Although the specimen upon which this race is based is quite dif- 

 ferent m general appearance from longispina, an analysis of its characters shows 

 many points of close similarity. The general tj^pe of armature, including that of 

 the adambvdacral and mouth plates, is the same. Both species have the long 

 furrow spinelet and the bristling series of adambulacral spines, with certain trivial 

 differences. 



The features in whidi the two forms depart the most widely from one another 

 are in respect to the wide-meshed skeleton of aleuiica and the larger actinal inter- 

 radial areas. The abactinal papular areas contain numerous minute ])lates or 

 grains, some of them bearing small sjiinelets. 



The present form is much more closely related to longispina than to any other 

 known species, and in view of the many points of resembhmce it has been made 

 a race of that species. More specimens may show aUutiva to be even nearer 

 l<mgispina than the tv^pe indicates. 



