!2ti 
parts, rump, and tail of a perfect white; 
back, scapulars, and wings of a pure bluish 
ash-colour; quills towards the end of a 
deep black, upon the two exterior ones a 
long white space ; all of them, as well as 
the scapulars and secondaries, terminated 
with white ; beak greenish blue at its base, 
of an ochre yellow at its point ; mouth 
orange ; irides brown ; naked circle round 
the eyes reddish brown ; feet bluish ash- 
colour, with yellowish spots. 
The old birds, in the breeding season, 
have the head, back and sides of the neck 
of a perfect white ; the beak of an ochre 
yellow 5 the naked circle of the eyes bright 
vermillion ; the feet of a light ochre yel- 
low, but spotted with bluish ash-colour; 
the rest of the plumage as in winter. In- 
dividuals are met with, both in summer 
and winter, at the end of whose two first 
quill-feathers there is no white spot, or a 
very small one. 
The habits and manners of this species 
are the same as those of the rest of the 
genus ; they are spread all over the globe, 
and are the most common and numerous 
