ARCTIC MOLLUSCAN FAUNA, 437 
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 Govern- 
ment, 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,* 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’t 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 appre- 
hend 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 
* «Last of the Arctic Voyages,’ vol. ii., p. 392. 
+ Proc. Royal Soc., No. 173, 1876, 
