Scleroplegma lanterna (Schmidt, 1879)

Figures 124 a–e

Auloplegma lanterna Schmidt, 1879: pl. III fig. 17.

Scleroplegma lanterna; Schmidt 1880: 56, pl. VI fig. 6; Reiswig 2002: 1384, fig. 2.

Material examined. RMNH Por. 9718, Guyana, ‘Luymes’ Guyana Shelf Expedition, station 49, 7.3333°N 57.05°W, depth 120–200 m, Agassiz trawl, sandy mud bottom, 30 August 1970 .

Description. (Fig. 124 a) Globular, clathrate mass of tubules, 4.5 cm diameter, individual tubules/channels about 0.5 cm diameter. There is no discernible osculum or attachment disc. The specimen is dried and deciduous, so tissue and dermalia are largely absent. Consistency fragile.

Skeleton. (Figs 124 b–c) Apart from the dictyonal framework, and a few stray pentactins and hexactins, there are no further spicules and microscleres. The two to three-layered dictyonal framework (Fig. 124 b) has oval meshes of about 300 µm in diameter formed by beams of 30–70 µm thickness ornamented with bluntly spined ridges. Lychnisc nodes (Fig. 124 c) with apertures of 25–30 µm diameter.

Spicules. (Figs. 124 d–e) A few pentactins (Fig. 124 d), rays 210–240 x 8–9 µm, and a single hexactin (Fig. 124 e), rays about 150 x 6 µm, were found in the dried skeleton.

Distribution and ecology. Guyana Shelf, 120–200 m, elsewhere found near Cuba and the Virgin Islands, 399– 585 m.

Remarks. my deciduous specimen does not allow to contribute to the variation of this ill-known species. There are a few discrepancies with the type redescribed by Reiswig (2002), such as the absence of a central cavity, but generally it conforms to it as far as the absence of spicules allows to conclude.