ON THREE NEW SPECIES OF CUMACEA FROM THE SOUTHERN SEA OF JAPAN BY SIGEO GAMÔ Faculty of Liberal Arts & Education, Yokohama National University, Kamakura, Japan The present paper is based on a small collection made by myself at Sado Marine Biological Station, Niigata University and in Mano Bay, Sado Island, from 22 to 28 October 1962. Our knowledge of cumaceans of the Sea of Japan is due to the contributions by Zimmer (1939), Lomakina ( 1952b; 1955; 1958a, b) and Gam6 (1962). Now three new species, Bodotria biplicata (Bodotriidae), P.reudoleucon japonicu.r (Leu- conidae), and .S'r?c/?TM .M?/? (Nannastacidae) are proposed herein. Before proceeding further, I must acknowledge my warmest thanks to Professor Tune Sakai for his kind guidance. I must also express my indebtedness to Pro- fessor Masao Iwasa of the Seikei University and Dr. Huzio Utinomi of the Seto Marine Biological Laboratory, Kyoto University for their valuable advice. Further I must express my thanks to Dr. Takehiko Kitami and other members of the stafff of the Sado Marine Biological Station for their kind assistance rendered me in collecting the material. Also I am greatly indebted to Dr. Isabella Gordon of the British Museum (Natural History) for her kindness in reading the preliminary draft of my manuscript. The specimens which are described in this paper are deposited in the British Museum (Natural History) and in the author's collection. Bodotria biplicata sp. nov. (figs. 1-3) Bodotria sp., Gam6, 1963, pl. 15 fig. 23. Material. - Many a 3, 9 9 (1 3 holotype) obtained by night surface tow-net at Mano Bay. 3 3, 3 9 paratypes in British Museum collection, reg. no. 1963. 6. 17. 1-6 obtained at the same locality. The holotype is an adult male about 2.7 mm long. Its integument is calcified. The carapace is covered with minute netlike patterns and provided with a dorso- median carina which is well marked in the anterior half and becomes less distinct in the posterior half. The postero-dorsal surface is coarsely reticulate and pitted. 242 On each side there are two longitudinal ridges; both are somewhat curved and almost parallel to one another, the upper extends from the postero-dorsal portion to the antero-lateral border and the lower reaches the antero-lateral angle. The length of the carapace is a little less than two-sevenths of the total length of the Fig. 1. Bodotria biplicata sp. nov. A, lateral view; B, anterior portion of body, from above; C, lateral view; D, anterior portion of body, from above. A-B, adult male, holotype; C-D, paratype female specimen with developing marsupium. animal, nearly one and one-third times as long as the width, which is slightly more than the depth. The antennal notch is angularly concave. The antero-lateral angle is obtusely pointed. The ocular lobe is very large, somewhat subtriangular, almost reaching to the apex of the pseudorostrum and beset with eight ocelli. The pseudorostral lobes barely meet in front of the ocular lobe and are broadly truncated. The combined length of all the free thoracic segments is about two-thirds that of the carapace. The first segment is very short, only exposed on the dorsum, the sides are partly concealed. The second is large, about two-thirds as deep as the carapace and nearly three-fourths as wide as the carapace. The second to fifth segments are successively narrowed and furnished with one dorso-median and a pair of dorso-lateral ridges. The abdomen is a little more than half the total length of the animal, each of the first five segments is very plump, furnished with a dorso-median carina .