BIRDS 



183 



open upon a pair of forwardly-directed tubes. All are powerful 

 flyers, and their food consists of fish, various small marine animals, 

 and refuse of various kinds. The strong beak, with sharp, hooked 

 tip, is well adapted to the carnivorous habit. 



The Wandering Albatross (Diomedea exulans) (fig, 124), dis- 

 tinguished by its enormous spread of wing (ID to 12 feet), and 



Fig. 125. Great Auk (Alca impennis] 



found chiefly in southern seas, is immortalized in Coleridge's 

 Ancient Mariner. Almost as well known is the Storm Petrel 

 (Procellaria pelagica) of the North Atlantic, called " Mother 

 Carey's Chicken " by sailors. It is only 6 inches long, and is 

 the smallest web-footed bird found in British seas. 



Order 17. DIVERS and GREBES (Pygopodes) 



The diving birds are distinguished by the modifications they 

 have undergone to enable them to pursue fish. In accordance 



