4i6 BIRD GALLERY. 



come two dimiautive forms of Guillemot represented by the Aiicieat 

 Auk {Synthliborhamphiis antiqum) (389) and the Marbled Guillemot 

 {Brachyrhamphus marmoratas) (398). Of the true Guillemots {Uria) 

 two species, the Common Guillemot, Marrot, or Murre [U. troile) (402), 

 and the Black Guillemot or Tystie [U. grylle) (400), are British breeding- 

 birds ; the Bridled Guillemot [U. troile, var r'mgvia) (401 ) being generally 

 regarded as merely a variety of the former, though some consider it a 

 distinct species. It is not nearly so numerous as the common form and 

 always occurs in company with it. The wonderful range of colour and 

 markings in the eggs laid by the Common Guillemot is well illustrated in 

 the Case exhibited on the right-hand side of the staircase in the Central 

 Hall. The set of specimens showing the seasonal changes of plumage 

 in the Black Guillemot deserves special notice. Briinnich's Guillemot 

 {U. lomvia) (403), distinguished chiefly by its stouter bill and by having 

 the basal part of the upper mandible naked, occasionally visits our 

 coasts as a straggler from the Arctic Ocean. Another regular winter 

 visitor to Britain is the Little Auk or Rotche {Alle alle) (404). The 

 Razor-Bill {Alca torda) (405) is chiefly interesting on account of its 

 resemblance and probable relationship to the Great Auk, which will be 

 found immediately below. The Great Auk or Gare-fowl (Plautus 

 impennis) (406) [PI. V.] is a bird of quite exceptional interest, being now 

 extinct. As may be seen from its diminutive wings it was quite unable 

 to fly, and its extermination was due largely, if not entirely, to the agency 

 of man. The last colony of this bird inhabited the islands near Iceland 

 and was finally exterminated in 1844. Specimens of this bird and its 

 eggs are now regarded as great treasures. 



Order XI. LARIFORMES. Gull-tribe. 



[Cases fphe Gulls, Terns, and Skuas which make up this Order are closely 

 ' allied on the one hand to the Auks and on the othei* to the Plovers 



which follow, and some zoologists regard these three groups as forming 

 but a single Order. Superficially the Gulls bear some resemblance to the 

 Petrels, but may readily be distinguished from the latter by their slit- 

 like nostrils. From the Plover-tribe they may be recognised by their 

 webbed feet, and from the Auks by their long wings and tail and by 

 the carriage of the body, which is horizontal instead of nearly vertical. 

 The predominating colour in the adult birds is white, with a mantle 

 varying in shade from grey to black. The young differ from the adults, 

 being usually mottled with brown or black, and the nestlings are 

 covered with beautifully patterned down. From one to four eggs are 

 laid, usually brown or green heavily blotched and spotted with brown, 

 black, and pale lilac. 



