Allen’s naturalist’s library. 
1 14 
THE GUILLEMOTS. GENUS URIA. 
Uria, 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 /m’*, 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). 
(/>/«/£ CVI.) 
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. 
