ASTEROIDKA 1>F NOKTll PACIFIC AND ADJACENT WATKB:? FISIIF.K. .'i75 



touch ill tlic iiiteinidiiil liiii', hut distad tliey are widely separated. In the intcr- 

 nidiiil angle near honier, ciisscrossinp muscle hands ure very evident on uctinal 

 surface, those nearest the margin heLiig largest. In the cotype the grooves arc not 

 nearly so conspicuous as in the type and the actinolateral spines are easily seen 

 through the menihranc, which is not the case in the type. From the first to the 

 ninth or tenth the actinolateral sjiines gradually heconie longer; from ahout the 

 tenth to twentieth they are suheiiual, being between one-fourth and one-fifth K in 

 length; from the twentieth to the fortieth they decrease rii])idly in length, those at 

 tip of ray being e.\cecdingly short. 



Mouth plates as shown in figure, with a broad, free margin. Marginal spines of 

 type, tliree or four, short (one-half as long lus median suture or less), the inner being 

 spaced a little from the other three. Cotype with two or three marginal spines. 

 Suboral spine one, not far from median suture and slightly more than one-third 

 the distance from inner marginal spine to outer eiitl of median suture. Spine 

 short and thick. (See PI. 117, fig. 4.) 



Color in alcohol, bleached ])ink or brownish purijle above, didl reddish pwri)le 

 below. 



Anatomical notes. — Xidamental cavity large, extending beyond tips of actino- 

 lateral spines. Papula? very large and saccular, one to each pa.xilla, except the pri- 

 mary radials, and rising higher than the pedicels, to which they are attached. They 

 sometimes are filled with folds from hepatic cceca. Bii-se of paxilhe with three long, 

 slender processes; the adradial iiaxilhe with two longer jirocesses directed toward 

 margin and a short inesially directed arm. The abactinal skeleton is very open 

 and loose. There is no radial scries of poxilhe. and the adradials do not join across 

 the median radial area. The periproct membrane between the primary radial (or 

 oscular) paxilhe and anal aperture contains thin, large, subcircular or poh'gonal. 

 closely juxtaposed ]dates in mosaic. There are ahout two concentric circles of 

 them. Intestinal c(rcum a rather spacious, simple, or short-pocketed sac between 

 the dorsal stomach and anal aperture. It looks Uke a dilation of the intestine. 

 The stomach and he|)atic coeca essentially as in Pterastrr. First ambulacral 

 ossicle, as in Ptcrastcr, greatly enlarged for the insertion of muscles controlling 

 stomach. vVmpulla^ double; tube feet, with a small button on the end; apparently 

 no Polian vesicles. Madreporic body large, convex, with meandering stria*. 

 Gonads interradial, attached to the membranous interradial septum. 



Type.— Cat. No. 27795, U.S.N.M. 



Type-hcality. — Albatross station 360.'?, Bering Sea, between Pribilof [slaiuls 

 and Uniraak Island (Aleutians), 1,771 fathoms, blue ooze; two specimens. 



Distribution. — Known only from type-locality. 



Remarks. — This large species is allied to //. nobilis, from which it ditlers, as 

 detailed in the foregoing description. It differs from //. rarno.tus Shulen, as does 

 //. Tiobili-s, in having one adambulacral spinelet and specialized paxillar areas. The 

 same differences se|)arate it from //. jxiiUignnaUs Fisher. Both of lhes«i species 

 have the fleshy habit of kahleri. II. i'iolaciu.<t Ludwig (southeast of Acapulco. 

 Mexico, 1,870 fathoms), which also litus one adambulacral sjiine, differs in having 

 a central and about six peripheral paxillar spinelets one-third as long as the 

 central. The abactinal surface is like //. camosus in the form and arrangement 



