ASTEROIDEA OP NORTH PACIFIC AND ADJACENT WATERS — FISHER 91 



specimen from station 3350 two series on either of the radial series of plates is clearly 

 shown. The outer of these two seems to split into two less well defined lines. 



The adambulacral plates are very short— much broader than long, and are 

 oriented somewhat obliquely. The intervals between the plates are longer than the 

 plates themselves. On the furrow margin, on a slight boss, is a single spinule about 

 3 to 3.5 mm. long, gently tapering, and much slenderer than the in fero marginal. 

 Farther along the ray this spinule shortens more rapidly than does the inferomarginal 

 spine. 



Mouth plates small and those of the pair sometimes unequal in length, in such 

 wise that the succeeding adambulacrals, which are joined along the interradial line 

 with their neighbors, alternate with them instead of exactly corresponding. (See 

 pi. 39, fig. 3a.) In form the plates are somewhat like those of the Brisingidae but 

 much compressed. Usually there are two (sometimes three) actinostomial spinelets 

 subequal to the foregoing, although only one suboral spine may be present, as in 

 Plate 39, Figure 3. 



Pedicellariae of two kinds, crossed and straight. The crossed pedicellariae 

 (about 0.35 mm. long) are present on the retractile sheaths of the abactinal and margi- 

 nal spines, never on the plates themselves, nor on the adambulacral spines or plates. 

 (PI. 39, fig. 4a.) The straight pedicellariae (pi. 39, fig. 4) are found sparingly on the 

 oral plates and on the base of the oral spines; on the first few adambulacral plates, 

 especially on the furrow face; occasionally on the marginal plates; very sparsely 

 between the abactinal plates of the base of ray and of the disk. In specimens from 

 station 3186, 3205, 3349, and 3350, from more northern localities than the type, the 

 straight pedicellariae are much more numerous, especially on the furrow face of the 

 adambulacral plates. These pedicellariae have a short peduncle and sometimes 

 occur one on each of several consecutive plates, on alternate plates, or irregularly, 

 especially toward the end of ray. They are more numerous also on the abactinal 

 surface. 



The ambulacral furrow is wide and shallow, and the ambulacral plates are much 

 less crowded than in the Asteriidae. The ambulacral pores between the plates are 

 arranged, in large fully grown rays, in two slightly zigzag series. The tube-feet, 

 however, owing to their posture due to crowding, appear to form four series, except in 

 the narrowed proximal portion of the furrow. The actinostome is very wide, 24 mm. 

 on a disk of 44 mm. diameter. 



Madreporic body small, circular, with radial striations, and situated one to two 

 times its own diameter from interradial angle. . 



Color in life : General tint of disk and rays bittersweet pink (principally the large 

 bouquets of papulae) ; skin whitish mottled and crossed by fine lines of orange scarlet 

 (grenadine red). These lines run down sides of arms and disappear between the 

 inferomarginal spines. Actinal surface cream color, darkest near actinostome, 

 lighter on rays. 



Variations.— The smallest specimen available has 12 rays, 2 of which are decid- 

 edly shorter than the others. In the case of the longest ray, R = 65 mm. while 

 r = 7 mm. This specimen does not materially differ from the large ones except that 

 the ambulacral pores form two straight series and the tube-feet are in two series. 

 There are fewer pedicellariae on the wreaths. 



