The article elucidates the species composition of chitons of the genus Placiphorella distributed in boreal waters of the northwestern Pacific Ocean, including a new species, P. kurilensis sp. nov. This species inhabits only waters near the Kuril Islands at depths from 40 to 100 m. It has a uniform walnut coloration of tegmentum, sparse arrangement of bristles near the valves, and a ratio of the antemucronal area length to the length of the tail valve postmucronal area of 3.1–3.4.
B. I. Sirenko (Mon,) studied this question.