Marine Isopoda from the North Atlantic ¹

Abstract

THE papers before us form two of the valuable series of reports now being issued by the Danish Government, through the Zoological Museum at Copenhagen, on the resulfs of the exploration of the deep sea in the neighbourhood of Greenland, Icelam and the Faroes. They constitute a monograph of the Isopoda and Tanaidacea of that region, and their importance may be judged from the fact that, whereas previously only fifty-three species of Isopoda were known from the area surveyed, Dr. Hansen records 242 species, of which 125 are described for the first time, and establishes eighteen new genera. This satisfactory result is due to the methods of collecting introduced by the author during the expedition. The mud brought up in the trawl and dredge was carefully sifted through fine bolting silk, and the results of the sifting preserved for future examination. In this way hundreds of small animals, which could not have been collected by any other means, were discovered. This method may be recommended to naturalists in charge of future expeditions for the exploration of the deep-sea fauna. We can speak from personal experience of the efficacy of a modification of Dr. Hansen's methods which has been used with great success in the exploration of the deep water to the west of Ireland, where the use of fine silk tow-nets attached to the dredge and trawl has revealed a wealth of species undreamt of by earlier British marine biologists.