LARUS. 299 



P. Wing 13; first quill in adults black, [p. 301, 



with a white subtermiual band .... L. brunneicephalus, 



b'. Mantle dark brown at all ages L. hemprichii, p. 302. 



b. No black or brown head ; mantle grey. 



c'. Wing 12 ; bill and legs red " L. nelastes, p. 303. 



d'. Wing 18 ; bill yellow in adults, legs 

 yellowish. 



c'\ Mantle dark slaty grey L. affinis, p. 304. 



d". Mantle light bluish grey L. cachinnans, p. 305. 



This key applies to adults, young birds are difficult to diagnose 

 except by dimensions. 



1489. Lams ichthyaetus. The Great Blade -headed Gull. 



Larus ichthyaetus, Pall. Rsis. Russ. Reichs, ii, p. 713 (1773) ; Blyth, 

 Cat. p. 288 ; Hume, S. F. i, p. 276 ; Le Messurier, 8. F. iii, 

 p. 382 ; Ball, S. F. vii, p. 233 ; Hume, ibid. p. 497 ; id. Cat. no. 979 ; 

 Leqge, Birds Cei/l. p. 1046 ; Tidal, S. F. ix, p. 94: Butler, Hid. 

 p. 489 ; Biddulph, Ibis, 1882, p. 289 ; Reid, 8. F. x, p. 453 ; Gates, 

 B. B. ii, p. 414; Barnes, Birds Bom. p. 424; Hume, S. F. xi, 

 p. 348 ; Saunders, Cat. B. M. xxv, p. 176. 



Kroikocephalus ichthyaetus, Jerdon, B. I. iii, p. 831. 



Larus innominatus, Hume, S. F. viii, p. 394 (1879) ; Gates, B. B. ii, 

 p. 416. 



Coloration. In summer the \vhole head and upper neck are 

 black except two small patches of white feathers on the eyelids, 

 one above, one below; neck all round, lower parts, tail, and tail- 

 coverts white; mantle (back, rump, scapulars, tertiaries, and wing- 

 coverts) pale grey with a slaty tinge ; first five primaries and 

 their coverts white ; outer web of 1st primary except near the end 

 and a patch of varying extent on the inner web black, and a broad 

 black subterminal bar of varying form on the next 4 or 5 quills ; the 

 remaining primaries grey on the inner web, the grey extending on 

 the secondaries to both webs, only a border of white remaining. 



In winter the head is white, more or Jess mixed arid streaked 

 with brownish black. The black hood is assumed about February . 



Young birds are brown above, the feathers with pale edges ; 

 head mostly white ; lower parts white, spotted and mottled with 

 pale brown on the sides of the neck and upper breast; quills 

 dark brown, the secondaries edged white; upper tail-coverts and 

 basal two-thirds of tail white, terminal third of tail blackish brown, 

 tipped white. There is a gradual change to grey in the mantle, 

 and the amount of black on the earlier primaries decreases with 

 age. 



Bill wax-yellow, with a transverse subterminal black band, gape 

 and tip dull crimson; bill in young birds dark brown; irides deep 

 brown ; legs arid feet dull Indian yellow (Anderson). 



Length 26; tail 7'5 : wing 19; tarsus 3; bill from gape 3 

 to 3-8. 



Distribution. This large Gull breeds in Central Asia from the 

 Caspian Sea to Eastern Turkestan, and migrates in winter to 

 Southern Asia and North-eastern Africa. It has not been obtained 



