ii4 ALLEN'S NATURALIST'S LIBRARY. 



THE GUILLEMOTS. GENUS URTA. 

 Una, Briss. Orn. vi. p. 70 (1760). 



Type U. troile (Linn.). 



In the true Guillemots there are no sulcations on the bill 

 and no wattles on the face. The bill is compressed and 

 slender, sometimes rather long, its length from the gape 

 equal to or exceeding that of the middle toe and claw ; the 

 nasal aperture is hemmed in with close-set plumes, extending 

 to the upper shelf of the nostril. 



I. THE COMMON GUILLEMOT. URIA TROILE. 



Colymbus troile, Linn. Syst. Nat. i. p. 220 (1766). 



Uria troile, Macgill. Brit. B. v. p. 318 (1852); Saunders, ed. 

 Yarrell's Brit. B. iv. p. 69 (1884); id. Man. Brit. B. p. 683 

 (1889) ; Lilford, Col. Fig. Brit B. part xxi. (1892). 



Aka troile, Dresser, B. Eur. viii. p. 567, pi. 621 (1877); 

 Seebohm, Hist. Brit. B. iii. p. 388 (1885). 



Lomvia troile, B. O. U. List Brit. B. p. 206 (1883). 



(Plate CVL) 



Adult Male in Summer Plumage. General colour above smoky- 

 brown, the head, neck, and throat paler and more earthy-brown, 

 the rest of the upper parts being gradually darker ; wings like 

 the back, the secondaries tipped with white, forming a bar ; under 

 surface of body white from the lower throat downwards, the 

 line of demarcation passing obliquely downwards to the sides 

 of the back ; the sides of the body and flanks streaked with 

 sooty-grey, the feathers being edged with this colour ; thighs 

 brown ; the under wing-coverts white, the lower primary-coverts 

 ashy ; quills dusky-brown below, whitish towards the base of 

 the inner web ; bill black ; legs and feet olive ; irides hazel. 

 Total length, 17*0 inches ; wing, 7 '9. 



Adult in Winter Plumage. Differs from the summer plumage 

 in having the throat white like the rest of the under surface ; 

 the cheeks also white, as well as the sides of the neck from 

 just behind the eye ; the lores, feathers round the eyes, and a 

 broad streak along the top of the ear-coverts, black. 



