306 A HANDBOOK OF EUROPEAN BIRDS. 
e 
Order PYGOPODES. 
Family COLYMBIDZ. 
Genus COLYMBUS. 
GREAT NORTHERN DIVER. 
Colymbus glacialis Zzn. 
Adult (Summer): ead and neck velvet-black, with green 
and purple reflections ; beneath the throat a transverse semi- 
lunar white band with black streaks ; on lower neck an inter- 
rupted broad collar, streaked longitudinally with black and 
white; upper parts generally black, copiously spotted with 
white, most conspicuously on the scapulars ; under parts below 
throat white ; bill black, legs and feet blackish, paler on the 
inside ; membranes whitish ; irides brown. Length 32 to 33 
inches ; culmen 3; depth of bill at nostril o°9 to 13; wing 13°5 
to > dail 32)" darsus 35: 
Adult (Winter): Lacks the black throat-bands. 
Young: Upper parts dull brownish-black, some of feathers 
with light margins and a few white spots on scapulars and wing- 
coverts ; inner webs of wing-quills brownish ; tail tipped with 
grey; under parts white; bill chiefly whitish; legs black, 
whitish inside ; toes black, membranes nearly white. 
Distribution : Breeds in North America from Greenland 
to Alaska and southward to the Great Lakes, also in Iceland. 
Occurs elsewhere in Europe principally in winter. May 
possibly have nested in the north of Scotland. 
Habitat: The sea-coast, also on fresh waters inland. 
WHITE-BILLED NORTHERN DIVER. 
Colymbus adamsi (G. 2. Grey). 
Adult: Very nearly resembles C. gdacéalis but is larger, the 
