246 Allen's naturalist's library. 



underlying green shell; the surface is rather smooth but not 

 glossy, and the shell is very fragile. Axis, 27 inches ; diam., 

 1-8." 



THE SWANS. SUB-FAMILY CYGNINv^. 



These birds are so familiar to everyone that a long and de- 

 tailed description of their characters is not necessary. They 

 are distinguished by two features which prevent their being 

 mistaken for any other of the Ducks or Geese : they have no 

 lobe on the hind-toe, and at the same time a remarkably long 

 neck, which equals or even exceeds the length of the bird's 

 body. They further differ from the Ducks and Geese in 

 having the lores bare, but in the Chilian Swan {Coscoroba ccs- 

 coroba) the lores are feathered, and this bird seems to be inter- 

 mediate between the Swans and the Geese. In some of the 

 species the trachea is convoluted and enters the sternum. 



The distribution of the Swans is principally arctic, and 

 they breed in the high north of both hemispheres, but a true 

 Cygnus, the Black-necked Swan {C. melanocoryphus)^ is found 

 in South America. The Black Swan {Chenopsis atrata) is con- 

 fined to Australia, and the aberrant genus, Coscoroba^ to the 

 south of South America. 



THE TRUE SWANS. GENUS CYGNUS. 



Cygnus, Bechst. Orn. Taschenb. ii. p. 404, note (1803). 



Type, C. olor (Gm.). 



Like the Geese, the Swans moult their quill-feathers after 

 the breeding-season, and become equally helpless, being able 

 to save themsejves only by swimming, as they are incapable 

 of flight. As with the Geese, they are then captured by the 

 dexterous natives, and have become extinct in many of their 

 old breeding-haunts. 



With regard to the supposed occurrences of the Trumpeter 

 Swan {Cygnus buccinator) and the Whistling Swan (C. ameri- 

 canus) in England, I cannot do better than quote the opinion 

 of Mr. Howard Saunders as to the worth of the records. He 

 observes : "An immature Swan shot at Aldeburgh in October, 

 1866, and now in the Ipswich Museum, is, in the opinion of 

 Professor Newton, an example of the American Trumpeter 

 Swan, C buccinator, a larger species than the Whooper with a 



