Dermatomya tenuiconcha (Dall, 1913)

(Fig. 3 M, N)

Poromya tenuiconcha Dall, 1913: 596 .

Dermatomya kurilensis Scarlato, 1981: 427, 428; photos 461, 462.

Dermatomya tenuiconcha (Dall, 1913) — Coan, Valentich-Scott & Bernard 2000: 572–573, pl. 124.

Material examined: 24 specimens from the ocean and sea slopes of Shikotan, Iturup, Urup, Broutona, Simushir, Ekarma, Onekotan, and Paramushir Islands and from the Fourth Kuril Strait (100–490 m) .

Distribution: Sea of Japan; Kuril Islands, Fourth Kuril Strait; Bowers Bank, Aleutian Islands, Alaska, to off La Jolla, California (100– 2,200 m) (Scarlato 1981; Coan, Valentich-Scott & Bernard 2000; Okutani 2000; Kantor & Sysoev 2005; Lutaenko & Noseworthy 2012).

Remarks: Having examined nine specimens from one sample collected from off Iturup Island at a depth of 414 m, Scarlato (1981) described Dermatomya kurilensis Scarlato, 1981, which was synonymized with Dermatomya tenuiconcha (Dall, 1913) by Coan, Valentich-Scott & Bernard (2000). We compared the holotype of D. kurilensis (ZIN 10090) with the holotype of D. tenuiconcha (USNM 266865). They are virtually identical in shape and shell proportions. Therefore, we agree with Coan, Valentich-Scott & Bernard (2000) that D. kurilensis is a synonym of D. tenuiconcha . The species varies in shell height, so some specimens have a relatively more elongated shell compared to the type specimen. Our data has shown that D. tenuiconcha is widely distributed in the North Pacific and inhabits waters all along the Kuril Islands.