Ophiactis hirta Lyman 1879

“Ophiactis hirta sp. nov.

Plate XIII. Figs. 365 - 367.

Special Marks. — Disk finely scaled, and set with short, minute spines. Radial shields small and pear-seed shaped. Four moderately stout tapering arm-spines, the uppermost longest. Two or three minute mouth-papillae on each side. Seven arms.

Description of an Individual (Station 164^a). — Diameter of disk 4.3 mm, Length of arm about 14 mm. Width of arm near disk 1.2 mm. Two or three small, narrow, scale-like mouth-papillae on either side of the very nar­row mouth-angle; and one, wide, flat, and pointed, at the apex; this last may, as in all similar cases, be considered the lowest tooth. Mouth-shields small, of a much rounded diamond-shape; sometimes, nearly circular. Side mouth-shields narrow, of nearly equal width, meeting within. Under arm-plates rather small, as broad as long, bounded without by a strong curve, and within by three sides of an octagon. Side arm-plates stout, projecting laterally in a well marked spine-ridge, meeting neither above nor below. Upper arm-plates a little broader than long, transverse oval, with the inner sides more or less angular. Disk covered with coarse, thickened, irregular scales, those of the under surface being sometimes wholly obscured by a thick skin; those in the centre are largest, but the primary plates are not readily distinguishable; there are small, peg-like spines scattered over the entire surface. There are seven pairs of radial shields, which are small, sunken below the disk-surface, of a blunt pear-seed shape, and separated by a rather wide wedge of three scales. Four smooth, rounded, tapering, moderately stout arm-spines; the upper one longest; lengths to that of an under arm-plate, 1, .8, .7, .7: .5. One stout, oval tentacle-scale. Color in alcohol, gray mottled with pale brown.

Station 164 ^a, 400 fathoms, 1 specimen.”

(Lyman, 1879; 39)