ASTEROIDEA OF NORTH PACIFIC AND ADJACENT WATERS FISHER. 125 



General surface of plates covered with delicate papilliform spinelets, similar to those 

 above, leaving partially or wholly naked a small area about the spines. Many of 

 the plates have on the lower marj;in a small pcdicellaria, composed of three or four 

 spmelets. This is occasionally shared with the adambulacral or actinal intermediate 

 plates, according as one or the other of these is adjacent. These pedicellariie 

 frequently occur far along the ray, but are sometimes very few in number, though 

 not usually so. 



Terminal plate tubercular, slightly wider than long, of a quadrate form, but 

 indented on the side towaril paxillar area. Distally it bears a tuft of spinelets. 



Adambulacral plates with a prommently curved furrow margin bearing a series 

 of six to eight (sometimes as few as five) slightly curved, blunt spinelets. The 

 maximum number of furrow spinelets is probably seven, the eighth and sometimes 

 a ninth continuing the series on the adoral margin of the plate. These two extra 

 spinelets are really members of the furrow series so far as appearance goes. In 

 center of plate is an upright, prominent, sharp, conical spine with usuall}' an acces- 

 sory spinule, situated between it and the adoral margin. On outer edge of plate 

 one or two short pointed spinelets sometimes form part of a pedicellarian appara- 

 tus as mentioned above. At base of these are sometimes two actinal sjiinules, 

 instead of one and a small companion. 



Mouth plates with furrow series of seven or eight spinelets, of which the two 

 or three inner are larger than the rest and the innermost largest of all. About mid- 

 wa}^ between inner and outer ends of plate is a prominent, tapering, actinal spinule. 

 A graduated uneven series of five to seven spinelets follows the median suture 

 border but is very iiTegular, and sometimes there is no order at all in the disposi- 

 tion of spinelets, so that the armature of mouth plates is of little value for classifi- 

 cation purposes. 



Actinal interradial areas with numerous small crowded irregular plates, those 

 adjacent to inferomarginals being smallest and most crowded. In each interradial 

 area there are twenty-five to thirty rather large pedicellariaj, each with from two 

 to five spiniform jaws. These extend some distance along ray on the suigle series 

 of intermediate plates, sometimes straddling the suture between an mferomarginal 

 and an mtermediate plate. In interradial area the pedicellaria3 occupy either one 

 or two plates, but are conical in general form. Smaller intermediate plates 

 \vithout pedicellarife usually have instead one or two slender spinelets. 



Madrcporic body situated about its own diameter from inner edge of supero- 

 marginal plates and surroimded by large pa.xillae. 



Anatomical notes. — Xo superambulacral plates. Dorsal muscle bands promi- 

 nent and extending from about the sixth or seventh ambulacral ossicles (to which 

 the tendon is partly attached) to end of ray. Anus present; intestinal ccecum 

 saccular, with four divisions as m other members of this family; no very distinct 

 dorsal stomach, merely five interradial constrictions forming a dorsal division; 

 hepatic cceca short. Gonad confined to interradial areas. Tube feet with small 

 sucking disks. 



Young. — .V specimen with 11 = 20 mm. (and r=4 mm.) has the general apjiear- 

 ance of the adult, the central spinule of the larger pa.\ilhr being especially conspicu- 



