in Great Britain during the Nesting-season. 75 
throated Diver appears to be the more frequent of the two, and 
extends to Shetland. 
Mr. St. John mentions Loch Endorb, in Morayshire, as a 
locality for the nest. 
Obs.— Colymbus glacialis. Mr. W. Dunbar tells me that once, 
when a boy, he saw a pair of Great Northern Divers, with one 
young one, on Loch Endorb. On the same loch were two or 
three pairs of the Black-throated Diver; so that the two species 
were easily distinguished by the great disparity of size. 
Dr. Saxby writes that he has procured from Yell, in Shetland, 
some eggs which he considers to belong to the Great Northern 
Diver; but I fear that the eggs alone are not to be relied upon, 
as Mr. R. Gray has seen eggs about as large as those of the 
Great Northern Diver, and very much resembling them in shape, 
which were taken from a Black-throated Diver shot on its nest, 
The last-named species, however, does not breed in Shetland, as 
Dr. Saxby has lately remarked (Zool. p. 9525). 
Messrs. Baikie and Heddle inform us that in Orkney the 
Great Northern Diver has been seen during summer on moors 
at a distance from the sea; but, as yet, the fact of its breeding 
in any part of the British Islands seems to need positive 
proof, 
Unt trots (Lath.). Common Guillemot. 
Provinces I.-III. [1V.] VI. VII. X.-XVIII. 
Subprovinces 1-7, (11), 17, 18, 22, 24-28, 30-38. 
Lat. 50°-61°. “ British ” type, or general. 
Formerly the Guillemot used to breed in the cliffs at Hunstan- 
ton in Norfolk. 
The variety which has been distinguished under the name of 
Ringed Guillemot (U. ringvia) appears to occur more frequently 
in the northern counties. It is returned as breeding on Lundy 
Island, the coasts of Wales and Yorkshire, the Farn Islands, 
Ailsa, the Bass Rock, in Aberdeen, Banff, Caithness, and in all 
three groups of isles, and is probably to be met with in most 
other localities where the Common Guillemot is numerous. 
Obs.—Briinnich’s Guillemot (U. bruennicht) is included by Sir 
W. Milner in his List of the Birds of Sutherland, published in the 
