120 ANATID^E, 



Cygnus immutabilis. POLISH SWAN. 



Cygnus immutabilis, Yarrell, Proc. Zool. Soc. 1838, 



p. 19. 



Cygnus immutabilis, Macg. iv. p. 654 ; Gray, p. 189 ; Yarr. 



ed. 2, iii. p. 225 ; id. ed. 3, iii. p. 230 ; Gould, Introd. 



p. cxxiii; Harting, p. 153; Dresser, vi. p. 429. 

 The Polish Swan, Yarr. ed. 1, iii. p. 131. 



Immutabilis = unchanging, from in + mutare ; because the cygnets are as 

 white as the adults (but of. Gurney, P. Z. S. 1876, p. 466). 



Of occasional occurrence in winter on the east coast of 

 England. It is probably a Palsearctic species ; but its exact 

 habitat is undetermined. 



Cygnus musicus, WHOOPER SWAN. 

 Cygnus musicus, Bechstein, Gemeinn. Naturg. Vog, 



Deutschl. iii. p. 830 (1809). 



Anas Cygnus, Linnaeus, S. N. i. p. 194 (1766). 

 Cygnus musicus, Macg. iv. p. 659 ; Harting, p. 59 ; Dresser, 



vi. p. 433. 



Cygnus xanthorhinus, Naum. xi. p. 478. 

 Cygnus ferus, Hewitson, p. 393 ; Gray, p. 188 ; Yarr. ed. 2, 



iii. p. 187; id. ed. 3, iii. p. 191; Gould, v. pi. 9. 

 The Hooper, Yarr. ed. 1, iii. p. 97. 



Musicus = musical ; from Musa = the Muse. 



An annual winter visitant to the United Kingdom, espe- 

 cially the northern districts. It inhabits the Palaearctic 

 Region, breeding in Lapland and Northern Russia. 



[Cygnus americanus. AMEEICAN SWAN. 



Cygnus americanus, Sharpless in Doughty's Cab. 

 Nat. Hist. i. p. 185 (1830). 



Cygnus americanus, Macg. iv. p. 675 ; Gray, p. 189 ; Harting, 

 p. 154. 



Americanus = American. 



One specimen was obtained from an Edinburgh poulterer 

 by Macgillivray in February 1841 ; but none have since been 

 recorded. It inhabits North America.] 



