Vellumnus pygmaeus (Takeda, 1977)

(Fig. 9D)

Planopilumnus pygmaeus Takeda, 1977, p. 131, fig.

5A–C, pl. 6 figs. C–D.

Vellumnus pygmaeus (Takeda): Takeda and Komatsu, 2018, p.181, fig. 6G.

Material examined. Inside of Gesodokkuru Reef, off Arumonogui, Babelthuap I., Palau Is., dredged, ca. 20 m in depth; 1♂(cb 5.7×cl 4.5 mm), NSMT-Cr 30994; July 13, 1980; K. Baba leg.

Remarks. Ng (2010) referred three Pilumnus species ( P. vermiculatus A. Milne-Edwards, 1873, P. labyrinthicus Miers, 1884 and P. penicillatus Gordon, 1930) and two Planopilumnus species ( P. minabensis Sakai, 1969 and P. pygmaeus Takeda, 1977) to his new genus Vellumnus . All the species have typical Pilumnus - type characters, but are distinctive in having the clearly-patterned symmetrical areolets or labyrinth-like pattern of setae on the carapace. Of five known species, V. labyrinthicus, V. penicillatus and V. pygmaeus are generally close to each other in having the labyrinth-like pattern of setae, but their patterns are distinctly different from each other: Miers (1884) and Ng (2010) for V. labyrinthicus; Gordon (1931) for V. penicillatus; Takeda (1977) and Takeda and Komatsu (2018) for V. pygmaeus . The specimen at hand agrees well with V. pygmaeus, especially in having the heartshaped protogastric region, although the epigastric regions of both sides are distinctly isolated by a median longitudinal groove from the median incision of the front.

Distribution. Vellumnus pygmaeus is known from the Ogasawara Islands, 41–105.6 m in depth, and now from the Palau Islands, ca. 20 m in depth, as new to Micronesian waters.