114 THE STORY OF THE BIRDS 



many of the genera are significantly geographi- 

 cal. Thus Dendrocygna is a tropical genus, its 

 members being found right round the world ; 

 Chenalopex ranges over the Ethiopian and 

 Neotropical Regions ; Tadorna and Casarca 

 (Sheldrakes) are Old World forms ; Chaulelas- 

 mus is confined to the Northern Hemisphere ; 

 Pcecilonetta is common to South America and 

 the Ethiopian Region ; Elasmonetta is peculiar 

 to New Zealand ; Nesonetta (a flightless species) 

 is confined to the Auckland Islands ; Malecorhyn- 

 chus to Australia and Tasmania ; Heteronetta 

 to the southern portions of the Neotropical 

 Region. The cosmopolitan genera are Nettion 

 or Teals, Anas or Typical Ducks, and Spatula 

 or Shovelers ; whilst Querquedula (Garganey) is 

 found over the Northern Hemisphere and the 

 Neotropical Region ; and Dafila (Pintails) is 

 cosmopolitan, with the exception of Australia 

 and New Zealand. The sub-family containing 

 the Diving Ducks and Eiders is almost exclu- 

 sively a Northern Hemisphere one, with the 

 exception of the genus Nyroca (Pochards), which 

 is cosmopolitan ; Metopiana, which is Neotropi- 

 cal ; one of the five species of Fuligula which in- 

 habits New Zealand, the Auckland and Chatham 

 Islands ; and Tachyeres, confined to the Strait 



