209 
chest streaked, breast and under wing- 
coverts spotted, and flanks barred with 
black; thighs and under _ tail-coverts 
strongly barred with blackish slate ;_ bill 
bluish, tip black. Juvenile: above dark 
brown, unbarred at first ; tail with fainter 
and narrower bars ; below whitish, heavily 
and broadly streaked all over with dark 
brown. More mature birds have the upper 
parts of a more blackish brown than grey 
shade until quite old, the bluish shade 
being then most evident on the rump. 
{*310e. Falco rusticolus candicans Gmel., S.N., 1., Circumpolar ; 
p. 275 (1788). [Islandia et Scotia,” errore, breeding in 
type loc. subst. Hartert—Greenland. | Greenland, 
Labrador and 
Arctic America 
(E. of Alaska), 
Arctic Europe 
and Asia! 
Greenland Falcon. 
[Albinistic form]. Larger; wing ¢ 365- 
380, 2 408-428 mm.; bill yellow in old 
birds ; [white phase]: general colour pure 
white ; the feathers above mostly marked 
with a black or dark brown bar or spot 
towards tip; head with a few streaks of 
black ; tips of primaries black, inner webs 
usually with notches obsolete ; tail white 
with more or less obsolete bars on central 
feathers ; below white, usually with a few 
blackish or brownish striations and spots on 
(Spitsbergen (?), 
Novaya Zem- 
bla (?)57 Este 
Kamtschatka 
and Bering Is.) ; 
in winter to 
Brit. Isles, 
N.W. Europe, 
sides. [Dark or primitive phase]: above Canada and 
1 If the Asiatic birds south of the polar circle are a constant grey-backed race, 
and distinguishable as a dark breeding race, they would be called Falco rusticolus 
uvalensis (Sewertz. and Menzb.), [Orn. Geogr. Europ. Russl., i., p. 288, tab. 3 (1882)— 
Ural Mins., Russia], but we lack data as to this and only know that both grey- 
backed and white birds occur in Arctic Asia. On Bering Island, according to 
Stejneger, the white bird breeds and not the grey-backed one, which he says only 
comes in winter. Thelatter has been named F. grebnitzkit (Sewertz.), but the name 
is a synonym of uralensis. I have examined two white resident birds and three 
immature birds in the United States National Museum, and find them smaller 
than usual candicans (wing ¢ 358-362, Y 385-400), but at Tring are both grey-backed 
and larger white winter birds from Bering Island. The name obdsoletus of Gmelin, 
it should be stated, has 7 pages priority over candicans, but is based on the melanistic 
variety, and is for that reason best discarded in favour of candicans. 
