GREAT NORTHERN DIVER. 99 



duration of immersion being just one minute. Fresh-water 

 loughs are not uufrequently visited by this species ; and 

 there are many instances of its occurrence in inland waters 

 in various parts of the United Kingdom. 



This species visits the Faeroes, although it has not been 

 known to breed there, and it is abundant on the coast of 

 Norway from autumn to spring, a few pairs being believed 

 by Mr. Collett to nest on the shores of the fresh-water lakes 

 on the holms and islets. Up the Baltic it appears to be 

 rare, and in Northern Russia its range can hardly be traced 

 beyond the White Sea. On migration this Diver occurs 

 down to the Mediterranean, and for a considerable distance 

 up that inland sea ; also in the Black Sea ; and immature 

 birds visit the lakes and inland waters of the Continent 

 nearly every year. Vernon Harcourt includes it in his list 

 of the birds of Madeira. 



Iceland appears to be the nearest locality in which the 

 Great Northern Diver breeds in any considerable numbers, 

 and there a pair or so may be found on nearly every lake. 

 It occurs on both the east and west coasts of Greenland, 

 breeding in the southern districts ; and it is common in 

 North America, nesting from about 70° N. lat. down to 

 Connecticut. In winter it ranges southwards as far as the 

 lakes of the table-laud of Mexico. Westward it can be 

 traced to the Pacific slope of the Eocky Mountains, where 

 Mr. J. K. Lord obtained adults in full breeding plumage, 

 which are in the British Museum, together with similar 

 examples collected by Mr. Bernard Ross at Fort Simpson. 

 From the latter place there are also adult specimens of a 

 closely-allied species, Cohjmhus aclamsi, which is a larger 

 and more robust bird, with a bill of a pale yellow colour — 

 instead of jet-black, as in our species — and with the under 

 mandible much up-curved ; the white spots on the back are 

 very much larger, and the neck below the nape is purplish- 

 blue, without any of the greenish tinge apparent in our bird. 

 In the birds of each species found at Fort Simpson there are 

 no gradations, but, on the contrary, their respective charac- 

 teristics are most strongly defined, and, so far as tho adults 



