TABLE OF CONTENTS. 



Introdtjctoey Observations - - - - I 



Essential Characters of the Orders . - 5 



ORDER XVII. CMBRATORES. SIFTERS. 



Characters of the Cribratores. - - Vol. IV. 571 



FAMILY I. ANSERINE. GEESE AND ALLIED SPECIES 579 



Genus I. Anser. Goose - - - 585 



1. Anserferus. The Thick-billed Grey Goose - 589 



2. Anser segetum. The Narrow-biUed Grey Goose 595 



3. Anser brachyrhjnichus. The Short-billed Grey 



Goose - - - - 602 



4. Anser albifrons. The White-fronted Goose - 609 



5. Anser Canadensis. The Canada Goose - 614 



Genus II. Bernicla. Beenicle-Goose - - 619 



1. Bernicla leucopsis. The White-faced Bernicle- 



Goose . - - - 622 



2. Bernicla Brenta. The Black-faced Bernicle-Goose 629 



3. Bernicla ruficollis. The Red-necked Bernicle-Goose 634 



Genus III. Chenalopex. Fox-Goose - - 637 



1. Chenalopex -^gyptiacus. The Egyptian Fox-Goose 639 



Genus IV. Plectropterus. Spur- Winged Goose 643 

 1. Plectropterus Gambensis. The Gambo Spur- 

 Winged Goose - - - 644 



FAMILY II. CYGNIN^. SWANS AND ALLIED SPECIES 646 



Genus I. Cygnus. Swan - - - 649 



1. Cygnus immutabilis. The Changeless Swan 654 



2. Cygnus musicus. The Whooping Swan - 659 



3. Cygnus Bewickii. Bewick's Swan - - 669 



4. Cygnus Americanus. The American Swan - 675 



