7 6 ALLEN'S NATURALIST'S LIBRARY 



only a foot of which is projecting above water. In Sweden, 

 on a group of large rocky islets in a fresh-water lake, I never 

 found more than one nest on each islet." 



Eggs. Three in number. Ground-tint of a clay- or olive- 

 brown to chocolate, with reddish-brown or black spots and streaks 

 distributed fairly over the whole egg, and seldom forming 

 blotches. Sometimes the dark spots show up faintly, and the 

 grey underlying ones are almost as distinctly indicated. Axis, 

 2*i5-2'45 inches; diam., 1*6-17. 



X. THE GLAUCOUS GULL. LARUS HYPERBOREUS. 



Larus hyperboreus, Gunnerus, in Leem's Beskr. Finn. Lapp. 



p. 283 (1767). 

 Lams glaucus, Fabr. ; Macgill. Brit. B. v. p. 557 (1852); 



Dresser, B. Eur. viii. p. 433, pi. 605 (1877); B. O. U. 



List Brit. B. p. 187 (1883) ; Saunders, ed. Yarrell's Brit. B. 



iii. p. 636 (1884) ; Seebohm, Hist. Brit. B. iii. p. 330 



(1885); Saunders, Man. Brit. B. p. 663 (1889); Lilford, 



Col. Fig. Brit. B. parts xxiii. xxvii. (1893-94)- Saunders, 



Cat. B. Brit. Mus. xxv. p. 289 (1896). 



(Plate CIL] 



Adult Male. General colour above very pale pearly-grey, the 

 wing-coverts like the back ; the marginal-coverts round the 

 bend of the wing white ; bastard-wing and primary-coverts 

 grey; primaries pearly-grey,, with white shafts, gradually 

 becoming white at the ends; the secondaries and scapulars 

 broadly tipped with white; the rump, upper tail-coverts, and tail 

 white ; head and neck all round, as well as the whole of the 

 under surface of the body, pure white; " bill yellow, orange-red 

 at the angle ; tarsi and toes light fleshy pink in life ; iris, 

 yellow; orbital ring, orange" (H. Saunders.) Total length, 

 25 inches; culmen, 275 ; wing, i8'o; tail, 67; tarsus, 2*8. 



Adult Female. Smaller, often considerably so, according to 

 Mr. Saunders, who says there is also considerable difference in 

 the size of individuals, irrespective of sex. 



Adult in winter. Similar to the summer plumage, but having 

 the head and neck streaked with pale ashy-brown. 



Young. Very pale ashy-brown both above and below, the 

 bases of the feathers whiter, the back and wings mottled with 



