The biological results of the 'Polaris' Expedition have not yet been published in extenso by Dr. Emil Bessels, whose collections embraced the area up to lat. 82° N.; but sufficient can be gleaned from the official narratives published by the United States Government, and from a communication addressed to the Geographical Society of Paris, by Dr. Bessels, in 1874, pnblished in March, 1875, to show that his Expedition left little unrecorded from the regions visited. A complete list of the Mollusca collected does not appear to have been published; but I venture to surmise that ours will be a considerably fuller list, owing to the many more opportunities we had of dredging.
The dredgings made in Northumberland and Wellington Sounds, by the Expedition under the command of the late Sir Edward Belcher, produced forty-five species,[1] from an area lying between lat. 75° and 77° N. Hayes procured twenty-one species between lat. 78° and 79° N. Our collections embrace thirty-five species, from between lat. 79° and 82° 30' N.
Dr. Gwyn Jeffreys gives one hundred and twenty-two species of Mollusca as procured in Davis Strait, during the cruise of the 'Valorous'[2] in 1875; but his valuable report on the biology of that cruise does not give the distribution in latitude, of the species found in Davis Strait, between the parallels of 60° and 70°. It would be extremely interesting if we were to find, as I apprehend we should, that a diminution of species occurs with each degree of northing, and would bear out my belief that our collections represent very fully and fairly the molluscan fauna between lat. 79° and 83° within the American Arctic Circle.
Mr. Edgar Smith considers it not unlikely that further research will show that the molluscan fauna northward does not change materially from that existing further south in Davis Strait; but I venture to say that this can hardly be expected, for more than twenty degrees of latitude separate the southern limit of Davis Strait from the regions in which our collections were made; and it would be truly remarkable if a fauna should remain unchanged through 1200 miles of latitude—a distance as the crow flies equal to that between Lerwick and Lisbon, or between the British Channel and the Canary Islands. Had our researches been merely confined to the dredgings from the area of Smith Sound and
