ASTEROIDEA OF NORTH PACIFIC AND ADJACENT WATERS — FISHER 41 



others are flattened and broad at the ends. On the larger plates there are one or 

 two pedicellariae from 0.75 mm. to 1.5 mm. in length. Although the spinelets 

 themselves are spaced and slender, owing to the thick skin which invests them and 

 the surface of the plate, they appear to be rather crowded. In alcoholic specimens 

 the spinelets are thick, pulpy, subconical or slenderly ovoid, and touch one another. 

 The sheath is rather thick also on the basal portion of the primary spines. 



The median radial series of plates is prominent, as is also the superomarginal 

 series, and each bears a slender tapering sharp erect spine, about 3.5 or 4 mm. long, 

 articulated to a prominent elevation of the plate. The superomarginals clearly 

 mark the boundary between the sloping abactinal and the rounded lateral faces of 

 the ray. Below the bristling superomarginal spines there are at the base of ray 

 four (further along three, and finally two) longiseries of slender, subequal, bristling, 

 sharp spines which also form transverse series. As on the disk, the general surface 

 is beset with spaced, very delicate, almost capillary spinelets, about 1 mm. long, 

 which in life are sheathed with pulpy membrane that makes them appear robust, 

 papilliform, and fairly crowded on their own plate. Pedicellariae (0.75 to 1.50 mm.) 

 occur rather commonly near the papular areas, or actinally on the membrane of the 

 area, more abundantly on the abactinal than on the lateral surfaces. There are 

 about two zones of them between the midradial and superomarginal angles, while 

 on the sides of the ray they occur between the rows of spines. 



There are two dorsolateral, one intermarginal, and at base of ray 3 (further along 

 2, 1, and 0) actinolateral series of papular areas. In the dorsolateral areas there are 

 usually three or four papulae (two or three on the outer part of ray) ; in the intermar- 

 ginal areas, three or two proximally, and in the actinolateral areas generally one, 

 but sometimes two on the proximal part of ray. 



The carinal plates usually have two prominent rounded lobes laterally '(some- 

 times one) which overlap the smaller, very irregularly lobed adradial plates. These, 

 as shown in Plate 13, Figure 3, are a bit smaller than the mostly four-lobed supero- 

 marginal plates. The lobes of the latter do not touch those of the carinal plates. 

 The adradials do not bear a primary central spine (and are not visible in alcoholic 

 specimens) but have an irregular group of upwards of 10 secondary spinelets. The 

 other plates are four-lobed, and as the furrow is approached the plates are narrowed, 

 and the transverse lobes are gradually shortened. In a specimen from station 4423 

 to 10 carinal plates at the base of ray (measuring 28 mm.) there are 15 to 17 adra- 

 dial plates and 13 superomarginals. 



The adambulacral armature partakes of the bristling character of the general 

 body armature. The prominent plates have a rather slighter keel or ridge into the 

 furrow than usual. This bears a single vertical series of 4 slender terete tapering 

 sharp spines plus one much smaller spinule at the outer end. Spine one (directed 

 into or across furrow) carries a subterminal or terminal cluster of two to five small 

 pedicellariae, or sometimes one fairly large and one or more small ones. Number 

 two is a trifle larger; spines three and four are successively longer, four attaining 

 3.5 mm. at base of ray in some cases; or spine three may be the longest. The alter- 

 nating nonprominent plates have a small spinelet on the furrow margin near the 

 adoral border, and on the median transverse line of plate, a spine about equal to 

 (or a bit longer than) spine four of the prominent plates, and standing almost exactly 



