Dytaster insignis (Perrier 1884)

Dytaster insignis (Perrier)

Archaster insignis Perrier, 1884:253, pl. 9: fig. 5.

Archaster grandis Verrill, 1884: 218.

Dytaster exilis Sladen, 1889:65, pl. 2: figs. 3, 4, pl. 4: figs 9, 10.

Dytaster exilis gracilis Sladen, 1889:68, pl. 2: figs. 3, 4, pl. 4: figs. 9, 10.

Dytastei exilis carinata Sladen, 1889:69.

Dytaster madreporifer Sladen, 1889:70, pl. 3: figs. 3, 4, pl. 32: figs. 5. 6.

Dytaster biserialis Sladen, 1889:77, pl. 10: figs. 3, 4, pl. 13: figs. 3, 4.

The five narrow, elongate arms, and small- to moderate-sized disc of this species are distinctive. The dorsum, covered with small “fuzzy” paxillae, is usually somewhat wrinkled and velvety looking. The crowded, low paxillae are crowned with 5–10 long, slender, thorny spinules; on the midline of the arms, they are fewer and may be reduced to a few spinules without paxillar column. Occasionally a specimen may have a few two-, three-, or four-valved pedicellariae on the dorsal surface near the base of the arms. The superomarginal plates are prominent, mostly confined to the sides of the arms, and each bears a single, large, erect spine near the upper edge. The rest of the plate is covered with fine spinules.

The inferomarginal plates are similar, except that they may bear, in the interradius, more than one spine. The small oval or polygonal plates of the actinal interradial area are imbricate and covered with small spinules; there may be up to a dozen large two-, three-, or four-valved pedicellariae in each interradial area (but in some specimens these may be altogether lacking). Actinal interradial plates extend to about the fifth inferomarginal. The adambulacral plates, rectangular and well separated from one another, bear 8–12 slender, subequal furrow spines in close longitudinal series. The actinal face of the plate bears a random group of small spinelets. Distally there may be a single large spine in the center of the plate. The mouth plates are large, prominent, and distinctive; they resemble somewhat the eletra of a beetle and are covered with small spinelets. Their armature is similar to that of the adambulacral plates, with a cluster of heavier spines at the apex. The madreporite is very large, near the margin, and covered with paxillae which are larger than the rest of the dorsal paxillae.

MATERIAL EXAMINED.–Oregon Stations: 2199 (3) [R=54 mm, r=8 mm, Rr=1:5]; 2572 (1) [R=80 mm, r=9 mm, Rr=1:8]; 2821 (2) [R=57 mm, r=10 mm, Rr=1:6]; 2813 (1) [R=20 mm, r=8 mm, Rr=1:3]. Alaminos Stations: 5B/68–A–3 (1) [R=54 mm, r=9 mm, Rr=1:5]; 7D/68–A–3 (2) [R=50 mm, r=12 mm, Rr=1:5]; 3B/68–A–3 (1) [R=40 mm, r=10 mm, Rr=1:5]; 3B/68–A–7 (1) [R=72 mm, r=13 mm, Rr=1:7]; 4A/68–A–7 (3) [R=8 mm, r=4 mm, Rr=1.2 (juveniles)]; 4E/68–A–7 (8) [R=86 mm, r=12 mm, Rr=1:8]; 12B/68–A–7 (5) [R=8 mm, r=5 mm, Rr=1:2 (juveniles)]; 9/68–A–13 (1) [R=39 mm, r=9 mm, Rr=1:4]; 27/69–A–11 (2).

Blakiaster Perrier

Blakiaster Perrier, 1881a:28; 1885:265. [Type, by monotypy, B. conicus Perrier.]