ANATIDA—SWANS. 193 
Distribution : Inhabits-most of the Palearctic region. 
Habitat: Both inland and salt waters. 
POLISH SWAN. 
Cygnus immutabilis Yarr. 
Adult: Resembles C. o/or in most respects, but the 47/7 is 
redder and the tubercle decidedly smaller ; legs and feet slate- 
grey; irides brown. Length about 60 inches; culmen 3'5 ; 
wing 21°5 to 27.5, tail 6°8 ; tarsus 4. 
Immature Birds: Back white, suffused with buff; bill 
differing from adults only in having the red parts pale pinkish ; 
legs and feet dull grey. 
Distribution: Probably inhabits the Palearctic region, 
has sometimes occurred during winter in England. 
Habitat: Similar to that of C. odor. 
WHOOPER SWAN. 
Cygnus musicus Lechst. 
Adult: Loral region, dasal portion of bill with part of nasal 
depression yellow; edges of mandibles, nostrils and anterior 
portion of bill black; irides brown; legs and feet nearly 
black. Length about 60 inches; culmen 3°75; wing 23:5 to 
eos = tatl.8*9 ;.tafsus. 4°3. 
Immature Birds: Plumage pale ash-brown, paler beneath, 
shading into white on abdomen ; bill, legs and feet dull flesh- 
colour. 
Distribution: Found throughout most of the Palearctic 
region, breeding within the Arctic Circle. 
Habitat: Similar to that of preceding. 
BEWICR’S SWAN. 
Cygnus bewicki Varr. 
Adult: Bill with a large patch at either side of basal por- 
fo) 
