Holothuria (Roweothuria) arguinensis Koehler & Vaney, 1906

Figure 4B, Table 4

Material examined. CMNI 2021 – 0194, Salamandre, Algeria, 35°55.221’N, 0°03.470’E, 2 m, November 2014, 1 spec. LPVCMRMS2020.207, Ouillis, Algeria, 36°7.436’N, 0°15.219’E, 5 m, June 2020, 2 specs.

Description. Semi-cylindrical body with dorsal surface (Figure 4 Ba) arched, dark brown in color; ventral surface (Figure 4 Bb) sole-like, light brown in color. Several large protuberances in two double rows on the dorsal surface; in addition, dorsal and ventral surfaces separated by several arched protuberances. Anus terminal. Mouth surrounded by 20 tentacles. Cuvierian tubules absent. Collar around mouth thick (about 4.60 mm). Calcareous ring with broad, squarish, radial plates with a shallow anterior notch, almost flat anterior portions and slightly concave posterior margin (Table 4).

Ossicles. Body wall tables (Figure 4 Bc) sometimes with a rectangular disc, spire of straight to slightly arched pillars, parallel to each other. Buttons often shaped in the figure of “8” (Figure 4 Bd) with rough, irregular and prickly margins but with a smooth surface with unequally-sized perforations. Pedicels also with numerous elongated perforated plates (Figure 4 Be) and other rare enlarged plates. Rods of tentacles larger and more complex with an enlarged, branched and perforated middle region, arched (Figure 4 Bf) or straight (Figure 4 Bg).