The pinnotherid crab, Pinnothera obesa Dana, 1852, was originally described on the basis of material from Fiji, but its taxonomic status has long been obscure because the original description and figures are too brief and schematic by modern standards and the types are also lost. Examination of newly collected material from Fiji revealed the presence of two intertidal pinnotherid species assignable to the genus Arcotheres Manning, 1993, one of which is herein identified with Dana's taxon. A neotype is designated for Arcotheres obesus n. comb. in the interest of nomenclatural stability, and a detailed redescription is given. Arcotheres obesus is morphologically similar to A. exiguus (Bürger, 1895) and A. rotundatus (Bürger, 1895), and differentiating characters are discussed. The species is also reported from Peninsular Malaysia. The second species is new to science, here described as Arcotheres ocularius, and is most similar to A. palaensis (Bürger, 1895) and A. arcophilus (Bürger, 1895). The new species is also recorded from Lombok, Indonesia. Arcotheres obesus and A. ocularius n. sp. are associated with bivalve mollusks of the genera Gafrarium spp. (Veneridae) and Anadara spp. (Arcidae), respectively.
The genus Myotis includes the largest number of species in the family Vespertilionidae (Chiroptera), and its members are distributed throughout most of the world. To re-evaluate the phylogenetic position of East Asian Myotis species with respect to Myotis species worldwide, we analyzed mitochondrial gene sequences of NADH dehydrogenase subunit 1 and cytochrome b from 24 East Asian individuals as well as 42 vespertilionid bats determined previously. The results suggest that: (1) some individuals having the same species name in Europe and Japan do not form a monophyletic clade, indicating that some bat species exhibit morphological convergence, (2) Japanese Myotis mystacinus forms a sister relationship with Myotis brandtii (Palaearctic), and both species are included in the American clade implying that an ancestor of these species originated in North America, and (3) the Black whiskered bat, Myotis pruinosus, is endemic to Japan and forms sister relationships with Myotis yanbarensis and Myotis montivagus collected from Okinawa (Japan) and Selangor (Malaysia), respectively, implying that M. pruinosus originated from the south. The systematics of Japanese and East Asian Myotis bats were revisited by considering their phylogenetic relationships. Our study provides the first extensive phylogenetic hypothesis of the genus Myotis that includes East Asian and Japanese species.