Odontaster hispidus Verrill 1880

Odontaster hispidus Verrill

Odontaster hispidus Verrill, 1880:402; 1894:263; 1895:136; 1899:205, pl. 29: fig. 8, 8a; 1915:119, pl. 13: fig. 6.–Fisher, 1928a: 489.–Gray, Downey, and Cerame-Vivas, 1968:148, fig. 22.

The disc is broad and the five (not uncommonly four or six) arms are short. The form is generally stellate, but may vary from nearly pentagonal to stellate with relatively long arms. The dorsal plates have stellate, imbricating bases and a rounded, elevated, subpaxillate top bearing a bundle of 6–25 spinules. Papular pores occur singly between the plates except in a narrow interradial area and near the extreme tip of the arm. The superomarginal plates are nearly square, confined to the dorsal surface, and covered with dense spinules. The sides of the plates are broadly bevelled and the sutures between the plates are wide, deep, and bare. The odd interradial superomarginal is wedge shaped. The inferomarginal plates extend beyond the superomarginals, defining the ambitus. They are more rectangular than the superomarginals and bear a dense coat of thicker, heavier spines.

The actinal interradial plates are round, compact, and in regular rows parallel to the groove; one series extends nearly to the tip of the arm. These plates each bear several heavy spines, larger than those of the inferomarginals. The adambulacral plates are small, short, and crowded. They bear 2 or 3 stout, heavy furrow spines; the actinal face bears 2 or 3 rows of one or two similar spines. All the adambulacral spines are subequal and thicker than those of the actinal interradial plates. Contrary to Verrill’s description, the mouth plates are small, being no larger than the next adjoining adambulacral plates (Verrill was probably misled by the very dense spination). The two halves are joined by a membranous suture and each bears 5 or 6 heavy spines like those of the adambulacrals. There is an odd, central, recurved spine at the apex. It is not much longer than the other spines, but is very much heavier, and the tip is hyaline. The madreporite, halfway between the disc center and the margin, is of moderate size, hemispherical, and covered with fine, deep gyri.

This species ranges from New England to Florida, in 40–400 fathoms.

MATERIAL EXAMINED.–Oregon II Stations: 10728 (2) [R=35 mm, r=14 mm, Rr=1:2.5]; 10667 (1) [R=37 mm, r=16 mm, Rr=1:2.5]; 10715 (1) [R=32 mm, r=15 mm, Rr=1:2].