WHITE-FACED BERNICLE-GOOSE. 625 



terminal narrow band of greyish-white ; the grey most ap- 

 parent on the scapulars. The middle, concealed part of the 

 back is grey and black, its hind part black ; the sides of the 

 rump and the upper tail-coverts white ; the tail black. The 

 wing-coverts are light grey, with a band of black and 

 greyish-white narrow margin ; the primary coverts ash-grey, 

 black at the end. The quills are grey at the base and along 

 the outer web, black toward the end, that colour gradually 

 diminishing on the inner ; the shafts of all dusky. 



Length to end of tail 27£ inches ; extent of wings 55 ; 

 wing from flexure 17; tail 5\%; bill along the ridge 1^, 

 along the edge of lower mandible 1 T V; tarsus 2-L|; hind 

 toe 5-, its claw -fa ; second toe 1^, its claw -f^ ', third toe 2^, 

 its claw -f*j ; fourth toe 2, its claw -j^. 



Female. — The female is similar to the male, but con- 

 siderably less. 



Length 24 inches ; extent of wings 52 ; bill along the 

 ridge 1-fc; wing from flexure 16 ; tarsus 2-,^-; middle toe 

 1^, its claw -^j. 



Variations. — Considerable differences as to size occur. 

 The grey on the feathers of the upper parts is more or less 

 extended, the white of the lower more or less pure. 



Habits. — This very beautiful bird occurs in the Northern 

 Hebrides, Shetland and Orkney Islands, where it arrives in 

 October and remains until April. It there more frequently 

 retires to the sea than to the lakes during its periods of 

 repose, or when driven from its feeding grounds. A large 

 flock then presents a beautiful spectacle as the birds sit 

 lightly on the water, and when advancing elevate their 

 necks. Not less beautiful do they seem when on wing, now 

 arranged in long lines, ever undulating, at one time ex- 

 tending in the direction of their flight, at another obliquely 

 or at right angles to it, sometimes in an angular figure, and 

 again mingling together. Their voice is clear and rather 

 shrill, and comes agreeably on the ear when the cries of a 

 large flock come from a considerable distance. 



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