ASTEROIDEA OF NORTH PACIFIC AND ADJACENT WATERS— FISHER 135 



specimens, and the capitate end is marked by four to eight unequal channels. It 

 resembles a miniature drill. 



The superomarginals are situated low on the side of the ray and separated from 

 the inferomarginals by only a narrow channel often completely eovered by the \\ reaths 

 of pedicellariae. The spines are similar to the dorsals, one to each plate, and the series 

 is sometimes a bit irregular, near the base of the ray, in large specimens. The infero- 

 marginal spines are a little heavier and longer than the supcromarginal, yellowish in 

 color, and form a transverse oblique series of two, or sometimes three, on the outer 

 part of the ray. The spines are flattened and broadened at the tip, are irregularly 

 channeled, and sometimes shallowly gouge-shaped (especially well marked in the 

 Saghalien and Bering Island specimens). On the outer part of the ray the iufero- 

 marginal and supermarginal spines are so close that they appear as one transverse 

 series of three (or four), but the superomarginal spine is usually blackish. 



The actinal channel is very narrow as the actinal plates are small, spineless, and 

 not visible without special preparation (see Skeleton). The adambulacral spines, 

 two to a plate, are, therefore, close to the inferomarginals, the outer spine being of 

 about the same length as the adjacent inferomarginal, while the inner is shorter and 

 slenderer, and set slightly lower on the edge of the furrow margin. The spines are 

 slender, terete, slightly tapered, and blunt. There arc about 33 adambulacral plates 

 opposite 10 inferomarginals starting with the second or third. 



The mouth angle is not deeply sunken but is fairly broad, and composed of the 

 mouth plates and two pairs of contiguous adoral adambulacral plates. The mouth 

 plates are fair-sized, being as long as the first 2 adambulacral plates in medium-sized 

 specimens and as long as the first 3.5 or 4 in the large examples. The armature 

 consists of a very short and a much longer, terminally flattened, tapering or un tapered, 

 narrow to fairly broad, blunt, actinostomial spine (four to each angle) and either one 

 or two tapering, slender, suboral spines, which with the first half-dozen adambulacral 

 spines are longer than the rest of the adambulacrals. First one or two adambulacral 

 plates with only one spine. The mouth plates are plentifully provided with rather 

 large, mostly unguiculate, straight pedicellariae, and forms intermediate between 

 these and the ordinary lanceolate furrow pedicellariae. (See pi. 02, figs. 2, 2a.) 

 One or two large pedunculate pedicellariae spring from the middle of the combined 

 oral plates, and often the following one or two pairs of adambulacrals carry a simi- 

 lar one. Less strongly unguiculate, smaller pedicellariae (1. to 1.5 mm.) on long 

 peduncles are found on the actinostomial border, singly or in clusters of two or three, 

 these being homologous with the lanceolate furrow pedicellariae, which are often 

 very numerous — two to four on the proximal adambulacrals and two on the distal. 

 These oral and proximal adambulacral pedicellariae are rare in nanimerms. 



Owing to the very numerous abactinal plates, the papular areas are small, the 

 abactinal containing, in large specimens, upward of 5 to 10 papulae, or in some cases 

 several more, especially on the disk, where the areas are poorly defined; the inter- 

 marginal areas have five to eight, or as few as only two or three in small specimens; 

 the actinal areas have one in small specimens and two or three in the largest. 



Crossed pedicellariae, measuring in large specimens about 0.38 to 0.43 mm. in 

 length, are very numerous, and form massive wreaths around the abactinal and super- 

 omarginal spines, and half-wreaths on the outer sido of the inferomarginals. These 

 wreaths frequently touch one another in alcoholic specimens. The pedicellariae 

 differ slightly but constantly from those of nanimensis in having a heavier terminal 



