Clarifications of the identities of Paguristes balanophilus Alcock, 1905 and P. calvus Alcock, 1905 (Crustacea, Decapoda, Anomura, Paguroidea, Diogenidae), and the description of another broadly distributed new species

Paguristes balanophilus Alcock, 1905, a species mistakenly included in the Japanese paguroid fauna, is redescribed and illustrated from material discovered amongst the collections of the Muséum national d’Histoire naturelle, Paris, and the Natural History Museum, London. A lectotype is designated and the species distribution is restricted to Arabian and Andaman Seas. A supplemental and detailed description, with illustrations, for a poorly known species, Paguristes calvus Alcock, 1905, is provided. The distribution of this species is expanded to include not only the northern Bay of Bengal and the Red Sea, but also the Andaman Sea. The general appearance of these two species is similar in having unequal chelipeds with one row of spine on the mesial face of the dactyl, and unarmed telson; however, Paguristes balanophilus is easily distinguished from P. calvus by the covering of closely-spaced tuberculate spines studded with bi- or trifid, acute spinules, circumscribed by tufts of short setae on the dorsal surface of chelipeds. Additionally, a new species of the genus Paguristes s.s., P. simplex n. sp., with a disjunct distribution is described from Madagascar and northern Western Australia. This new species has subequal chelipeds with one row of spine on the mesial face of its dactyl and unarmed telson but can be distinguished from other known species of the genus Paguristes s.s., by having small, subovate, non scalloped marginally female brood pouch and strongly asymmetrical lobes of the telson.