Selected species of the family Diastylidae (Cumacea, Peracarida, Crustacea) from the deep-sea of the NW Pacific.

New species of the genera Diastylis, Divacuma and Leptostylis are described. Also a new species of the genus Pseudoleptostyloides, known from the Atlantic, is described for the NW Pacific. Additional information is given on Leptostyloides quadridentata.