130 
& I. Smith — Crustaceans of the Atlantic Coast. 
The differences between the deep-water faunae of the two regions, as 
shown in this list, are probably wholly accidental, the species which 
are not known to be common to both regions, being new or, at least 
on the western side of the Atlantic, little known species which will, 
most likely, eventually be found to inhabit both regions. 
The facts above presented show conclusively, I think, that, as far 
as the Thoracostraca are concerned, the fauna from Cape Cod Bay to 
Labrador is essentially a continuous one, or at least that there are no 
changes in it comparable with the differences betAveen the fauna 
south and that north of Cape Cod Bay. An uncompleted investiga- 
tion of the distribution of the Amphipoda sustains these conclusions, 
which appear to be essentially in harmony with the facts at present 
knoAvn in regard to the distribution of the Mollusca and of other 
groups of the better known marine animals of the region in question. 
Of the fauna of the east, or Atlantic, and of the north coast of 
Labrador, very little is at present known, but I believe no species of 
crustaceans, which are not found also in the Gulf of St. Lawrence or 
further to the south, have been recorded from this region, and the 
very close resemblance between the fauna of the northern part of the 
Gulf and that of the Greenland seas (to which I shall presently 
allude) renders it very improbable that the fauna of the east and 
north coasts of Labrador differs essentially from that of the northern 
part of the Gulf of St. LaAvrence. The close relationship existing 
between the marine fauna of Greenland and that of northern Europe 
has long been observed and fully admitted by European zoologists, 
but the similarly close relationship between the marine fauna of 
Greenland and that of the coasts of the continent of North America 
itself, as well as the similar relationship between the fauna of the 
latter region and that of the seas of northern Europe, has not been 
so generally recognized by them and has recently been strenuously 
controverted.* This has probably been largely due to the fact that 
* Dr. J. Gwyn Jeffreys : Preliminary Report of the Biological Results of a cruise 
in H. M. S. Valorous to Davis Strait in 1875. Proceedings Royal Society, London, 
vol. xxv, p. 188, 1876. 
The Rev. A. M. Norman, however, appears to have fully recognized the true rela- 
tion between the faunae of the eastern and western sides of the North Atlantic, and 
also the American rather than the European character of the fauna of the Greenland 
seas; and in this very report arrives at conclusions the reverse of those of Mr. 
Jeffreys. Mr. Norman has, in a letter received since these pages were written, very 
kindly communicated to me his general conclusions in regard to the fauna of the 
North Atlantic, and I am pleased to find that his investigations in nearly all the 
classes of marine Invertebrata, have led to conclusions essentially the same as those 
resulting from my special study of the Thoracostraca. 
