594 GAVL\ RIDIBUXDA. 



7norc extended, the black hand on the inner edge hroadei' ; the 

 tips ichite, those of the outer tico excepted. In xcinter, the 

 back and wings light bluish-grey ; the other parts white ; the 

 head faintig marhcd icith grey ; a black crescent before the 

 eye, and a blackish-grey patch behind it. In summer, the 

 colours similar, but the head and throat deep brown, becoming 

 brownish-black behind, the lower parts slightly tinged with 

 rose-colour. Young icith the hill flesh-coloured or pale brown, 

 toward the end blackish-brown ; feet broicnish flesh-colour ; 

 the head and nape pale broicn ; ear-coverts ichite ; back and 

 smaller icing-coverts broicn, the feathers edged icith paler ; 

 hind part of back and tail white, the latter icith a broad ter- 

 minal bar of dark-broion ; quills u-ith their outer icebs black, 

 the inner ichite ; lower parts greyish-ichite. 



Male in Winter. — This species, the common " Black- 

 headed Gull," which is generally dispersed in Britain, and 

 permanently resident there, is very similar to the last in 

 colour, and of the same form, but somewhat smaller, with the 

 bill and tarsi considerably shortei-, and the " mask " deep 

 brown instead of leaden-blue. The body is compact, rather 

 slender, the neck of moderate length, the head broadly ovate, 

 much narrowed anteriorly. 



The bill is rather shorter than the head, slender, much 

 compressed, nearly straight, and pointed ; the upper man- 

 dible with the dorsal line moderately decurved beyond the 

 nostrils, which are linear-oblong, four-and-a-half-twelfths 

 long, the tip acute, with a very slight sinus on the margins ; 

 the lower mandible with the angular prominence very slight, 

 the dorsal line slightly ascending and somewhat concave, the 

 sides erect, considerably convex toward the base, the tip acute. 



The aperture of the eye is three-twelfths m diameter ; 

 that of the ear four-twelfths. The feet are of moderate 

 length, and slender; the tibia bare for three-fourths of an 

 inch ; the tarsus much compressed, with eighteen scutella ; 

 the hind toe very small and elevated, with a minute, straight, 

 bluntish claw, its scutella three ; the second with twenty, the 

 third thirty-two, the fourth thirty scutella ; the fourth a little 

 shorter than the third, the webs emarginate, the lateral toes 



