2 British Diving Ducks 
an opportunity of studying on the spot all the best public and private collections in 
Europe, so that I have been able to handle and separate some hundreds of specimens. 
Some of the local races only differ in the matter of size, but a large series from any 
one area generally shows how constant this difference is. 
The following list shows the distinctive characters and distribution of the various 
local races of Eider-ducks during the breeding and migrating season : 
1. Somateria mollissima mollissima (Linnaeus), 1758. — Bothnia, Sweden, the Finnish 
Skerries, the Cattegat. Coming west in winter to the Norwegian coast approximately 
as far as Christiansand and south to the Danish Isles, where a few breed, and possibly 
N. Germany in winter. By far the largest of the European races. Bill of adult male 
olive green. Frontal angles of the bill on the sides of the forehead narrow and pointed. 
Nail- bone yellow. 
2. Somateria mollissima borealis, Brehm.^ — Breeds in Greenland, Davis Straits, 
Baffin Land, Labrador coast, Hudson Bay, Cumberland Peninsula, also in Spits- 
bergen (Koenig and Le Roi), Bear Island, and probably in Franz Josef Land 
{Jackson-Harmsworth Expedition, vol. ii. p. 356). In winter it migrates as far north 
as the St. Lawrence, but in summer the birds that breed there and in Newfoundland 
are S. m. dresseri. A constant character is the deep yellow bill of the adult male, 
legs, and toes. The Greenland birds are smaller than S. m. mollissima or S. m. dresseri, 
and differ from the last named in having the frontal angles of the bill narrow and 
pointed. 
3. Somateria mollissima britannica (sub-species nov.). — The British Isles. Smaller 
than either of the above, as well as the Norwegian birds, but larger than the Fseroese 
race. The bill of the adult male dull olive-green above, shading into French blue-grey 
below^, and again into pale yellowish near the nail. Greenish-yellow near the nail, which 
is bone-yellow ; legs and toes deep brown with a green suffusion.^ 
4. So7nateria mollissima dresseri, Sharpe. — Atlantic coast of North America from 
North Labrador to Long Island, New York. Probably overlaps the Greenland bird in 
its northern range. If the two races are found not to interbreed, Mr. W. Rothschild 
thinks that this bird should be treated as a distinct species {Btdl. Brit. Ornith, Chtb, 
February 24, 1905), and with this view I certainly agree; but on the other hand, my 
friend Mr. Schioler states that S. m. dresseri breeds with the West Greenland Eider, 
and is an occasional visitor at all seasons. Up to date it has never occurred in Europe, 
and it does not frequent the coast of East Greenland. 
The American Eider, as this bird is called in the New World, breeds in New- 
foundland, where I have seen it in summer and autumn, and from Maine north along 
the Labrador coast up to Hudson Strait and south in Hudson and James Bay. Also 
on the north shore of the Gulf of St. Lawrence. On migration it is regularly found 
on the coasts of Massachusetts, and rarely on the seaboard of Virginia. 
The male is easily distinguished by the shape of the naked frontal angles on the 
sides of the forehead, which are broad, rounded, and much corrugated. The colour, too, 
1 Brehm made four or five sub-species of Greenland Eiders which can scarcely be accepted. 
2 The colour of the soft parts of the Eider fades very rapidly, even an hour after death. Eiders in confinement never 
attain the rich colours of wild birds. Gould {Birds of Great Britain, Part XVII.) alone gives a correct representation of 
the bill of a British Eider. If the above characters prove to be constant, I propose to name the British Eider as above. ^ 
