Huxleyia pentadonta Scarlato 1981

Huxleyia pentadonta Scarlato, 1981 (Fig. 2 M, N) Huxleyia pentadonta Scarlato, 1981: 215, fig. 117. Material examined: nine specimens from the ocean and sea slopes of Paramushir Island (214–804 m). Distribution: northern Kuril Islands (Paramushir and Shumshu Islands) (67–804 m) (Scarlato 1981; Kantor & Sysoev 2005). Remarks: Previously, this species was found only in one sample (two specimens) collected from off Shumshu Island at a depth of 67 m (Scarlato 1981). Huxleyia pentadonta Scarlato, 1981, is very similar in shell shape to Huxleyia munita (Dall, 1898) from the northeastern Pacific but has 5 hinge teeth (Scarlato 1981) whereas H. munita has 6 hinge teeth (Coan, Valentich-Scott & Bernard 2000). The left valve of a specimen of H. munita in a photograph given in Coan, Valentich-Scott & Bernard (2000), however, has also 5 hinge teeth. Therefore, we think that the hinge of H. munita needs to be studied more thoroughly. It is quite possible that H. pentadonta turns out to be a synonym of H. munita.