ISOPODS COLLECTED IN THE NORTHWEST PACIFIC BY THE U. S. BUREAU OF FISHERIES STEAMER " ALBA-TROSS " IN 1906. By Harriet Richardson, Collaborator, Division of Marine Invertebrates, U. S. National Museum. The following report is of the Isopocla collected by the U. S. Bureau of Fisheries steamer Albatross during its cruise in 1906, from San Francisco to Alaska, the Aleutian Islands, Bering Sea, Kam-chatka, Japan, etc. A large number of specimens were obtained, in-cluding known species and twenty-nine new ones. The new forms are herein described and a list of the known species given with their stations. References to the literature are to be found at the end of the paper. CYMOTHOIDEA or FLABELLIFERA. Family GNATHIID^. Genus GNATHIA Leach. GNATHIA TUBERCULATA, new species. Body oblong, ovate. Head large, squarish, with the anterior margin produced in a rounded lobe and the antero-lateral angles acute. The eyes are small, round, composite, and situated at the base of the antero-lateral angles of the head. The surface of the head is granulate and covered with numerous small spines. The first pair of antenna? have the first two articles short and sub-equal ; the third is twice as long as the second ; the flagellum is com-posed of five articles. The second pair of antennae have the basal article short, the last two articles elongate ; the flagellum is composed of seven articles. The mandibles are large and conspicuous, and project straight in front, with their inner edges contiguous along the middle and the tips crossing. There is a small dentation about the middle of the outer margin. Proceedings U. S. National Museum, Vol. 37— No. 1701. 75
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