BRITISH BIRDS. 207 



in a crevice ; it is less pyriform than that of the Common 

 Guillemot and greyish (or brownish) white, boldly blotched 

 and spotted with brownish-black ; 2'8o by 1*95. 



376. Alea impennis, Linn. GREAT AUK. 

 Hab. Formerly coasts and islands of North Atlantic. 

 Now apparently quite extinct. 



GENUS CCIV URIA, Brisson (1760). 

 Bill about as long as head, straight, pointed, strong and 

 compressed ; tip of upper mandible slightly decurved and 

 indented ; nostrils basal, lateral. 



377. Uria troile (Linn.). COMMON GUILLEMOT. 



Hab. Coasts and islands of North Atlantic. 



Adult : upper parts, chin and throat deep uniform brown; 

 below white ; bill and feet blackish, webs greenish. In 

 winter throat is chiefly white. Length 16*00 ; wing 775. 

 The Ringed Guillemot (U. lacrymans of Macgillivray and 

 Yarrell) is now admitted to be merely a variety of U. troile. 



Breeds very abundantly on all our rocky coasts. Egg : 

 very pyriform in shape ; varying from greenish-white to 

 sea-green or even reddish-brown, streaked and heavily 

 blotched with blackish-brown ; 3*10 by 2*00. 



378. Uria bruenniehi, Sab BRUNNICH'S GUILLEMOT. 



Hab. Arctic regions ; almost circumpolar. 



A very rare straggler, only two or three examples having 

 apparently been actually obtained on our coasts. The 

 late A. G. More excluded it from the Irish list. 



379. Uria grylle (Linn.) BLACK GUILLEMOT. 

 Hab. Coasts and islands of North Atlantic. 

 Adult : black, with a large white patch on the wing- 

 coverts ; bill black ; iris hazsl ; feet red. In winter 



