112 EGGS OF BEITISH BIRDS. 



as lat 68°. On the American continent it breeds in Labrador, 

 and possibly on the islands of some of the great lakes south of the 

 Arctic circle and east of the Rocky Mountains, as it has occurred 

 in Alaska. 



Like those of all other Gulls, the nests of this bird are care- 

 lessly made, and are little more than a depression in the grass or 

 heath, or even a niche in the bare rock, roughly lined with dead 

 grass, seaweed, and occasionally ornamented with a twig or two 

 round the edge, or a few feathers or sheep's wool in the middle. 

 North of the Arctic circle I have taken fresh eggs during the first 

 half of June, but in Scotland the first eggs are laid a month or 

 more earlier. 



A full clutch of eggs is three, but two are not unfrequently 

 found. They vary very slightly, and are usually greyish-brown in 

 ground-colour, sometimes very slightly tinged with olive, and 

 occasionally pale brown. The spots are seldom much larger than 

 a pea, often very irregular in shape, sometimes elongated into 

 streaks, and, as a rule, evenly but sparingly distributed over the 

 surface, though it is not uncommon to find eggs where they are 

 more abundant on the large end. The surface-spots are dark 

 brown, and the underlying spots brownish-grey. The eggs vary 

 in length from 3'2 to 30 inches, and in breadth from 22 to 

 2'0 inches. 



The eggs of the Great Black-backed Gull are on an average 

 larger than those of any other British Gull ; but small examples 

 are indistinguishable from those of the Glaucous Gull, and from 

 large examples of the Herring Gull. 



THE GLAUCOUS GULL. 

 (Larus glaucus.) 



Plate 32, Figs. 4, 5. 



The Glaucous Gull is only a winter visitor to the British 

 Islands, appearing somewhat irregularly. It is a circumpolar 

 bird, breeding in the Arctic Ocean on the shores of both Conti- 

 nents. Athough at Vardo the Glaucous Gull breeds on the 

 precipitous cliffs, Harvie-Brown and I afterwards found its nest 

 on one of the low flat islands which separate the lagoon of the 

 Petchora from the Arctic Ocean. 



