Pteraster caribbaeus Perrier 1881

Pteraster caribbaeus Perrier

Pteraster militaris A. Agassiz [non Muller], 1877.

Pteraster caribbaeus Perrier, 1881a:13; 1884 [part]:216.

Non Pteraster caribbaeus.–Verrill, 1915:82, pl. 7: fig. 4.–H. L. Clark, 1941:60.

This form is broadly stellate, with a broad disc and five acutely pointed arms. The dorsal surface is moderately inflated. The dorsal membrane is crisscrossed with tough transparent irregular muscle bands which connect the underlying paxillar spines. There are a few calcareous deposits in the membrane, and spiraculae are small to moderate in size, and numerous. The tall slender pedicels of the abactinal plates arise from flattened, broadly lobed bases and support up to a dozen long, fine, glassy spines which protrude a short distance through the membrane. The central osculum is surrounded by five ill-defined valves of 10–15 long, subequal, blunt spines, all webbed together and forming a continuous ring of closely set spines. The actinal surface is relatively small; the membrane is without deposits and is supported by 12–16 long, sturdy, ridged actinolateral spines, the sixth or seventh being the longest and meeting at the ambitus. Occasionally, there are two spines, side by side. The tips of the spines support a broad lateral fringe. There are 5 or 6 long slender adambulacral furrow spines, webbed together in a curved series, and grading from shortest inner spine to longest outer spine. The mouth plates bear, on the side, five small, equal spines, and apically, two longer, stouter spines. There may be up to three long, sturdy, nonhyaline suboral spines, or there may be none. None of the mouth spines are webbed.

This species seems to be confined to the Leeward Islands, in 350–360 fathoms.

MATERIAL EXAMINED.—Oregon Station 6696 (1) [R=36 mm, r=16 mm, Rr=1:2].