io6 ALLEN'S NATURALIST'S LIBRARY. 



THE TRUE RAZOR-BILLS. GENUS ALCA. 



Alca, Linn. Syst. Nat. i. p. 210 (1766). 



Type, A. tor da, Linn. 



The Razor-bills belong to the group of Auks which have a 

 sulcated or grooved bill and exposed nostrils, the latter not 

 being encroached upon by the feathering of the base of the 

 bill, as is the case with many genera of the family. In the 

 case of the Razor-bills the nostrils are exposed, and situated at 

 the end of a triangular base on the mandible, but they are not 

 separated by a ridge from the feathers which encroach on the 

 base of the bill, though there is a swollen ridge at the base of 

 the lower mandible, anterior to the nostril. The Great Auk is 

 merely a gigantic form of Razor-bill, with a heavier body and 

 feebler wings than its more active congener, Aha torda, so 

 that while the latter survives to the present day in thousands, 

 the Giant Razor-bill, as the "Great Auk" ought more properly 

 to be called, has succumbed to circumstances and become 

 extinct. 



In addition to the characters given above, the Razor-bills 

 differ from the Great Auk (infra-, p. HI) in the possession of 

 fully developed wings, which reach nearly to the end of the 

 tail. They have also well-marked grooves on the bill. 



The typical species, A. torda, is the only representative of 

 the genus at the present day. 



I. THE RAZOR-BILL. ALCA TORDA. 



Alca torda, Linn. Syst. Nat. i. p. 210 (1766); Dresser, B. 



Eur. viii. p. 557, pi. 619 (1877); B. O. U. List. Brit. B. 



p. 205 (1883); Saunders, ed. Yarrell's Brit. B. iv. p. 55 



(1884); Seebohm, Hist. Brit. B. iii. p. 375 (1885); 



Saunders, Man. Brit. B. p. 679 (1889); Lilford, Col. Fig. 



Brit. B. part xii. (1890). 

 Vtamania torda, Linn. ; Macgill. Brit. B. v. p. 346 (1852). 



(Plate CIV.} 



Nestling. Covered with dense sandy-brown down, mottled 

 with black bases to the feathers ; the crown of the head and 

 sides of face and neck more hoary-grey ; cheeks and throat 



