Solaster notophrynus Downey 1971

Solaster notophrynus Downey

Solaster notophrynus Downey, 1971a:39, fig. 1.

This large, handsome species has a broad disc and seven short, broadly based arms tapering to a small point. The dorsum is inflated and moderately thin. The papular pores are single and numerous, and the papulae are unusually large. The abactinal plates are Y-shaped or cruciform, with long imbricating lobes, irregular on the central disc and midarms, but in regular, oblique-transverse rows elsewhere. Small, low, well-spaced pseudopaxillae bear 10–40 minute thorny spinules. Narrow interradial bands of fused plates have few or no papulae. The superomarginal plates are indistinguishable from the adjacent abactinal plates. The high-crescentic inferomarginal plates are confined to the actinal surface; they are about three times as wide as long, and bear numerous small spinules on the crest. Bare spaces between the inferomarginals are about twice the length of the plate. The well-spaced actinal plates are in irregular chevrons, one row extending nearly three-quarters the length of the arm. They may be small and round, or larger and elongate, and bear 4–14 small spinules. The curved adambulacral furrow margin bears 4 or 5 setose spines, and a transverse ridge on the actinal face of the plate bears 6–8 longer, stouter, acute spines.

The mouth plates are wide and prominent, with 8–10 long, tapering, webbed oral spines, the central pair longest, and a pair of fans of 4 or 5 smaller setose spines, one above the other, at the sides; the face of the plate is covered with small setose spinules, and the suture is wide and bare. The madreporite is small and nearly hidden by enlarged pseudopaxillae; it is located nearer the margin than the center, at the top of a patch of fused interradial abactinal plates. Internally, an interradial strut between the mouth and the body wall is a single column of plates embedded in a strand of tissue supporting the abactinal roof.

MATERIAL EXAMINED.—Oregon Station 5929 (1 holotype) [R=114 mm, r=49 mm, Rr=1:2.3].