244 LAEID^ 



Great Black-backed Gull, Yarr. Brit. B. iii. p. 471 (1843). 



Dominicaniis mariiius, Bruch, J.f. O. ISoS, p. 100 ; id. op. cit. 1855, 

 p. 280 ; Bp. C. JR. xlii. p. 770 (1856) ; id. Consi). Av. ii. p. 213 

 (1857) ; Locke, Expl. Sci. Alger., Ois. ii. p. 177 (1867) ; Olphe- 

 Gall. Fditn. Orn. Eur. Occident, fasc. x. p. 34 (1886) ; Heine ^ 

 Reicheninv, Nommd. Mm. Hein. p. 357 (1890). 



Larus nigripallus, C. F. Dubois, PL Col. Ois. Belg. iii. p. 240 (1860). 



Adult male, in hreeding-plumage. Head, neck, tail, and entire 

 nnderpaits white ; mantle and upper surface of wiugs black, of 

 varying shades, but usually with a tinge of slate-colour ; the sca- 

 pulars and all the secondaries with white tips, which form a strongly 

 contrasted alar bar ; all the primaries broadly tipped with white ; 

 the outermost white for nearly 3 inches, its upper part blackish ; 

 the second similar, with a black spot or a narrow subterminal bar, 

 accoiding to age, on the inner web ; third quill with an indication of 

 white on the shaft, or even a spot in some Greenland examples, 

 blackish above, next the shaft, with a fairly visible greyish wedge 

 ending in white on the inner web ; fourth and fifth quills with 

 more defined grey wedges on the inner webs, and a black subapical 

 bar ; remaining quills slate-grey, except the tips : bill yellow, the 

 angle of the genys orange-red ; eyelid vermilion ; tarsi and toes 

 livid flesh-colour. Total length 28-30 inches, culmen 3, wing 19-20, 

 tail 8, tarsus 3, middle toe with claw 3. The above are the average 

 measurements, but some males exceed these, and have very large 

 heavy bills. 



The female is smaller and has a less robust beak. 



Adult in tvinter. Like the above, with a few greyish striations on 

 the crown and nape, and, as a rule, less vivid colours on the bill. 



Younj. Streaked, mottled, and barred with brown on a lighter 

 surface above and below, the markings on the mantle and tail- 

 feathers darkest, with no well-defined baud on the latter, though 

 the markings are bold ; quills very dark brown with paler or 

 whitish tips : bill dark horn-colour. 



Immature. Restricting the term " young " to a bird of two years, 

 at a later stage black feathers appear on the mantle and the white 

 edges to the secondaries are distinct, but the primaries are still 

 without mirrors. Afterwards the primaries have white tips and 

 the fourth, fifth, and sixth exhibit what may almost be called sub- 

 terminal bars, while the outermost quill shows a subapical mirror 

 of dull white, and the second quill has an iU-defined brownish- 

 white spot ; the tail being still slightly mottled. I do not think 

 that the adult plumage is attained before the bird is in its fifth 

 year, and even then the amount of white on the two or three outer 

 primaries continues to increase with age until the state first described 

 is reached. 



Nestling. Stone-colour above, with sparse and bold black spots 

 on the head and duller brownish mottlings on the back ; under- 

 parts huffish white ; bill very stout and short, blackish basally, 

 yellowish anteriorly. 



JIah. Northern Europe, from the Lower Petchora westward to 

 Iceland, and down to about 50° N. (hreeding) ; in winter to the 



