192 A HANDBOOK OF EUROPEAN BIRDS. 
of rufous in centre; general @g#our of upper and under parts 
dark brown, tinged on chest with rufous. 
Distribution : Found in the extreme east of Europe dur- 
ing migration. Breeding in Northern Siberia. 
Habitat: Probably very similar to that of A. drenfa. 
Genus CHEN. 
SNOW GOOSE. 
Chen hyperboreus (/a//). 
Adult Male: Primaries black, shading into grey at base, 
with white bases to shafts; primary coverts grey; rest of 
plumage snow-white ; bill pale red ; legs and feet darker red ; 
irides hazel-brown. Length 30 to 33 inches; culmen 2 to 2°5 ; 
Wie 17 tO 19; tail6 ; tarsus 2°75 to 3. 
Adult Female: Differs only by being a trifle smaller than 
the male. 
Immature Birds: Differ in having the upper parts 
brownish-grey, the scapular feathers bordered with white ; sides 
of head, rump, tail, and under parts white ; neck and chest suf- 
fused with grey ; bill darker than adults ; legs leaden grey. 
Distribution: A Nearctic species which is also found in 
Eastern Siberia, and occurs not unfrequently on passage in the 
Urals and other European localities. Has been met with in 
Germany, Greece, &c. 
Habitat: Very similar localities to the Wild-Goose. 
Genus CYGNUS. 
MUTE SWAN. 
Cygnus olor (Gme/). 
Adult: Plumage white ; bill red, with large tubercle at base, 
edges of mandibles, nail and orifices of nostrils and _ lores 
black ; irides brown ; legs and feet black. Length about 60 
inches; culmen 3°5 ; wimg 25 to 27 , tail 10; tarsus 4°25. 
Immature Birds: Plumage nearly uniform greyish-brown, 
slightly paler beneath ; bill blackish, showing scarcely a trace 
of tubercle at first; legs pale leaden-grey. 
