Abstract
The purpose of this series of papers is to clarify the identity of each Calcinus species from Japan and adjacent waters and to establish a descriptive catalogue of the species. There has been much and serious taxonomic confusion and misidentifications in the literature. This report considers Calcinus pulcher Forest and C. lineapropodus Morgan & Forest. Since the original as well as subsequent descriptions of C. pulcher have been brief and insufficient, a detailed redescription and illustrations are provided. Confusion between C. pulcher and C. anani is clarified. Calcinus lineapropodus, a species very closely related to C. pulcher, and a taxonomic enigma in Japanese literature, is redescribed in detail. Minor but reliable morphological distinctions between C. pulcher and C. lineapropodus are provided. Mouthparts of the two species are described for the first time.
