Hyalinothrix millespina Fisher, 1911a

Mah, Christopher L. & Fujita, Toshihiko, 2020, New species and occurrence records of Japanese Solasteridae and Ganeriidae including a new species of Paralophaster from the North Pacific with an overview of Hyalinothrix, Zootaxa 4750 (1), pp. 67-100 : 90

Hyalinothrix millespina Fisher, 1911a

Fisher, 1911a: 661; Mah 1998: 67 (checklist)

Figure 8 A–E

Comments. This species is only known from the type locality in the Hawaiian Islands and has not been encountered since its original description by Fisher (1911a).

Diagnosis. A stellate species (R/r=4.5), with abactinal plates, round to polygonal in outline displaying 75–100 clear, fine spinelets on each abactinal spine tip, forming an almost fuzzy outline ( Figs. 8A, B ). Papulae one or two to a papular region. Marginal plates slightly larger than adjacent abactinals ( Fig. 8C ). Three or four series of actinal intermediate plates, becoming single series distally. Individual actinal plates, identical to those on abactinal surface, displaying 40–70 spinelets on each spine tip. Furrow spines three to five (mostly four) in a straight series ( Figs 8 D–E). Remainder of adambulacral plates with a brush-like array of 10–20 short subambulacral spinelets.

Occurrence: Known only from Hawaiian Islands (Maui), 232– 282 m.

Material Examined: USNM 27674 Honolua Bay , Pailolo Channel , Maui, Hawaiian Islands, 21º05′45″N, 156º40′50″W, 232–282 m, Coll . USFC Albatross, 1 wet spec., R =4.7 r=1.0.

Figures

FIGURE 8. Hyalinothrix millespina Holotype, USNM 27674. A. Abactinal surface. Scale bar=1.0 cm. B. Close-up of abactinal paxillae. Scale bar=2.0 mm. C. Interradius showing lateral surface. Scale bar=0.5 cm. D. Oral surface. Scale bar=1.0 cm. E. Oral region showing adambulacral plates and spination. Scale bar=0.5 cm.