抄録
The western part of Japan proper facing the Japan Sea is called the Sanin District, in which the Oki Isls. Are also included in this paper. The writer has been studying the crab-fauna of this district and its adjacent waters in spare times of his onerous duties, as the result of which 90 species of crabs are shown in the list of this paper. Of them 6 species are fresh-water crabs, while 84 species are marine consisting of 3 nothern forms, 50 southern forms, and 31 intermediate forms. Among 50 southern forms 22 species are distributed further northwards, for instance, they are found in the list of crabs of Toyama Bay. The occurrence of southern forms, such as Calappa lophos, C. philargius, Ranina ranina, Paratymolus sexspinosus, Neptunus (Neptunus) sanguinolentus, N. (N.) pelagicus, Atergatis subdentatus, Eucrate crenata, Ommatocarcinus macgillivrayi, Plagusia dentipes and others in the Japan Sea side has never been recorded up to now. These peculialities of the distributions coincide with the course and its largeness of the warm current along the coast of this district.
