Linckia bouvieri Perrier 1875

Linckia bouvieri Perrier

Linckia bouvieri Perrier, 1875c:414.–Studer, 1884:24: Koehler, 1909b:632.–Madsen, 1951:214, pl. 15: fig. 2.–Downey, 1968: 42.–Gray, Downey, and Cerame-Vivas, 1968:148, fig. 21.

Linckia nodosa.–Verrill, 1915:93, pl. 13: figs. 2–2a, pl. 29: figs. 1a, 1b.

This species has a small disc and five long, thick, and flabby cylindrical arms, slightly constricted at the base and tapering to an acute terminus. Owing to the size of the papular areas, the skeleton is looser than in the two previous species, and the animal has a flaccid appearance. It is the largest of the western Atlantic Ophidiasteridae. The disc dorsum has a large, tumid, hemispherical central plate, with a ring of 5–7 similar plates around it; these primary plates are separated by small tumid and nontumid plates. The inconspicuous anus is at the base of the centrodorsal plate, surrounded by slightly enlarged granules. The abactinal surface of the arms bears about five irregular rows of plates (some enlarged like the primary plates of the disc) connected by small, narrow ossicles.

The large papular areas between the marginals and on the abactinal surface are separated by small, narrow, elongate ossicles; there are 10–40 pores per papular area. The superomarginal plates are similar to the inferomarginals–subtriangular, somewhat imbricate, and connected to them by narrow slender ossicles. There are 3–5 rows of crowded actinolateral plates, irregular except for the row next to the adambulacrals. The actinal plates overlap from inferomarginals to adambulacrals. The plates of the row overlapping the adambulacral plates are larger and regular. The entire surface is densely covered with small granules; those on the marginals and major actinal plates are noticeably larger. The adambulacral furrow spines consist of one broad, flat spine and one small, slender spine per plate, with a broad, flat, circular subambulacral spine on the actinal face. The mouth spines are similar. The madreporite is large, raised, and covered with very fine gyri. The oculars are of moderate size, raised, and usually covered with granules (the granules may be worn off in large specimens). There are no pedicellariae.

The known distribution of this species is North Carolina to Florida, Yucatan, and the Cape Verde Islands, in 35–300 fathoms.

MATERIAL EXAMINED.—Oregon Stations: 4938 (1) [R=134 mm, r=14 mm, Rr=1:9]; 4939 (1) [R=144 mm, r=16 mm, Rr=1:9].

Ophidiaster L. Agassiz

Ophidiaster L. Agassiz, 1835b: 191. [Type, by original designation, Asterias ophidiana Lamarck, 1816.]

Body wall rigid, abactinal plates well developed, in regular longitudinal series; no spines on abactinals; skin uniformly granulose; papular areas in eight series, only one below inferomarginals in each side; rays cylindrical; madreporite small, simple.

Of the known species of Ophidiaster reported from the area covered here, only O. guildingii is represented in this collection. O. alexandri is known only from a few specimens, and its distribution is limited to the northernmost part of the area under study (Florida and Georgia), in 200–276 fathoms. O. pinguis is known only from the type, which was from off southwest Cuba, in 320 fathoms. It is superficially very like Hacelia superba. A fourth species, O. bayeri, from Florida, was described by A. H. Clark (1948) from a single immature specimen in very poor condition. I have been unable to distinguish any characters on which this species might have been based.