Parvamussium intuscostatum (Yokoyama, 1920)

(Fig. 3 G, H)

Pecten intuscostatus Yokoyama, 1920: 156–157, pl. 13, figs 9, 10.

Parvamussium intuscostatum (Yokoyama, 1920) — Hayami 2017: 1198, pl. 499, fig. 3.

Material examined: 16 specimens from the sea slope of Iturup, Urup, and Onekotan Islands (123–350 m) .

Distribution: Northern Honshu to Ryukyu Islands (Japan); Sea of Japan; Sea of Okhotsk; Kuril Islands (50– 591 m) (Scarlato 1960, 1981; Hayami 2000, 2017; Kantor & Sysoev 2005).

Remarks: This is a new record from the region of the Kuril Islands. Scarlato (1960) described Polynemamussium uschakovi Scarlato, 1960, that subsequently was synonymized with Parvamussium intuscostatum (Yokoyama, 1920) (WoRMS Editorial Board 2024) .