THE WORLD'S BIRDS. 53 



grey and white, with scarlet bill and feet and 

 white eyes, is common on Australasian coasts. 

 The Burgomaster (L. glaucus), as big as the Great 

 Black-back, but with no black in its plumage, 

 and the small pure white Ivory Gull (Pagophila 

 eburnea) are characteristic Arctic forms, and the 

 two Kittiwakes (Rissa), in which the hind-toe 

 is quite rudimentary, are also northern, though not 

 so much so. In the Red Sea the brown Hemprich's 

 Gull (L. hemprichi] is a familiar species. 



The Terns (Sterna), with straight bills and small 

 feet, are found all over the world, even where gulls 

 are absent during all or most of the year, and 

 breed in any climate. Our Arctic Tern (S. 

 macrura) ranges from the Arctic to the Antarctic 

 Continents. The Noddies, which are dark brown 

 or grey (A nous), or pure white (Gygis), are tropical 

 birds. The White Noddies, like the Marsh Terns 

 (Hydrochelidon), have the feet hardly at all webbed, 

 and in the former the hind-toe is fairly well deve- 

 loped. They lay their one egg on a bough or rock, 

 with no nest. 



One or other of the five species of Skimmers 

 (Rhynchops) is found all round the world in warm 

 climates ; they are like large black-and-white Terns, 

 with the under jaw in the adult twice as long as 

 the upper ; they skim the surface, ploughing it with 

 the long lower jaw, and thus snap up small fish, etc. 



The Skuas (Stercorariince], which have very 

 fully-webbed, strong-clawed feet, and brown 

 plumage, are never found breeding in warm 

 climates. They are predatory and piratical, 

 making other sea-fowl disgorge their prey, and 

 are some of the fiercest of birds. The few species 

 are mostly northern, but our Great Skua, or 

 Bonxie (Megalestris catarrhactes) is represented by 

 very similar forms in southern seas. 



