492 ALCIDAL 
Geographical distribution.—Abroad, the Black Guillemot 
breeds on the Faroes, Iceland, and the coasts of the 
Continent of Northern Europe as far east as the White 
Sea. Along the Atlantic sea-board of North America it is 
found nesting from South Greenland to Newfoundland ; on 
migration in autumn and winter it inhabits the North 
Atlantic and the Seas of Europe as far south as about 
lat. 40° N. 
DESCRIPTIVE CHARACTERS. 
PLUMAGE. Adult male nuptial.—General plumage very 
dark brownish-black displaying an iridescent hue of rich 
glossy greenish-purple and a large pure white patch on 
each wing; basal portion of inner webs of primaries and 
secondaries, also the under wing-coverts and _ axillaries, 
white ; tail consists of twelve feathers. 
Adult female nuptial.—Similar to the male plumage. 
Adult winter, male and female.—Top of head, white, 
streaked with black ; back, scapulars, and upper tail-coverts, 
barred with black and white ; rump, nearly white with a 
few streaks of greyish-black; throat, front of neck, chin, 
cheeks, breast, and abdomen (as in other Auks), white ; 
though i in the Black Guillemot this colour is less pure. “ As 
age advances the white winter plumage is less completely 
assumed, very old examples remaining in black plumage 
throughout the year” (W. R. Ogilvie-Grant, Cat. Birds Brit. 
Mus., vol. xxvi, p. 588). 
Immature, male and female. — Resembles the adult 
winter-plumage, but there is only very faint barring of 
white on the back, scapulars, and upper tail-coverts; the 
white patch on the wing-coverts is splashed with brown. 
Birds in their second spring assume dark plumage like the 
breeding-dress, but retain the brownish paéches on the 
white wing-coverts. 
Brak. Black; inside of the mouth vermilion-red. 
Fret. Vermilion-red. 
Iripes. Dark brown. 
AVERAGE MEASUREMENTS. 
TOTAL LENGTH ... ts mes LA emi 
WING Gory 
BEAK ait Bolan Cie 
T’ARSO- METATARSUS ny. ner 54 
Eae oi i, 23 xX iain 
