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. 8. National Museum. 



The following report is of the Isopoda 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 GNATHIIDiE. 

 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 antennae 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. 



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