A REVIEW OF THE MYSIDACEA 51 



mature female, 19 mm. Sea of Okhotsk : Albatross station H3710, 2 

 females. California : Albatross station 4541, 1 immature female. 



Distribution. — A widely distributed species in the boreal waters of 

 the Arctic Ocean, extending southward on the eastern slope of the 

 Atlantic to the British Isles, Bay of Biscay, and the Mediterranean, 

 and on the western slope to the deep water off the coasts of New 

 England. All the known Pacific records are listed here. 



Remarks. — Smith's original record of this species from the Ameri- 

 can coast probably refers to the specimens from Fish Hawk station 

 891, which are the only specimens collected in 1880 of which I can find 

 any trace. Smith, however, gives the depth from which his specimens 

 were collected at 500 fathoms, whereas the depth at station 891 was 

 only 310 fathoms. Fowler's note (1912) of this species is based on 

 Smith's record. 



The most interesting records in the list are those from the Bering 

 Sea, the Sea of Japan, and the coast of California. The occurrence of 

 this species in the Bering Sea area is perhaps not unexpected, as several 

 Arctic species are known to have penetrated into the northern part 

 of the Pacific as well as into the Atlantic. I could not detect any 

 differences from the typical form in the specimens from this region. 

 The specimens from Albatross station 3710, in the Sea of Japan, are 

 doubtfully identified with this species. They are much smaller in 

 size, 16 mm., as against 28 mm. for adult B. arctica, and moreover they 

 are badly damaged. As far as I could see they presented no features 

 at variance with B. arctica, and they are provisionally recorded as 

 belonging to that species. The single specimen from the California 

 coast, Albatross station 4541, is immature but again no special differ- 

 ences from B. arctica could be detected. I give a figure (fig. 8) show- 

 ing the salient characters of this species as a means to its identification. 



BOREOMYSIS SIBOGAE Hansen 



Bvreomysis sibogae Hansen, 1910, p. 25, pi. 2, fig. 3 a-e. — Illig, 1930, p. 414. 



Occurrence. — Albatross station H3710, 2 females. 



Distribution. — Known heretofore only from the waters of the Dutch 

 East Indies (Hansen, 1910) and the Indian Ocean (Illig, 1930) and 

 now from the Sea of Okhotsk. It is probably a bathypelagic rather 

 than a bottom-living form. 



Remarks. — The two specimens are very defective but appear to 

 belong to this species. They differ from B. arctica in the very much 

 shorter rostral projection and in their smaller size. They were taken 

 in company with both B. arctica and B. rostrata. 



