The forgotten species Lepto???????chiton alascensis (Thiele, 1909) (Mollusca: Polyplacophora) and its relatives

Leptochiton alascensis (Thiele, 1909) is a member of a shallow marine species complex that spans the North Pacific. This species had been considered a junior synonym of L. rugatus (Carpenter in Pilsbry, 1892), and an ambiguous type locality and limited morphological data has impeded its recogni- tion. Based on the study of the type material of L. alascensis, as well as Asian and American specimens, this species can be distinguished from other closely related chitons. A comparison of this species with its closest relatives was carried out, and its validity as a separate species was confirmed.