168 SILVERY GULL. 



slightly convex, the edges sharp, inflected, arcuato-declinate towards the end, 

 the tip rather obtuse. Nasal groove rather long and narrow; nostril in its 

 fore part, lateral, longitudinal, linear-oblong, wider anteriorly, pervious. 

 Lower mandible with the angle long and narrow, the outline of the crura 

 curved, the dorsal line beyond the prominence slightly concave, the sides 

 erect and nearly flat, the edges sharp and inflected. 



Head rather large, oblong, narrowed anteriorly. Neck of moderate 

 length, strong. Body full. Feet of moderate length, rather slender; tibia 

 bare below; tarsus somewhat compressed, covered anteriorly with numerous 

 scutella, laterally with angular scales, behind with numerous small rectan- 

 gular scales; hind toe very small and elevated, the fore toes of moderate 

 length, rather slender, the fourth longer than the second, the third longest, 

 all scutellate above, and connected by reticulated entire membranes, the 

 lateral toes margined externally with a thick narrow membrane. Claws 

 small, slightly arched, depressed, rounded) that 'of the middle toe with an 

 expanded thin inner margin. 



The plumage in general is close, full, elastic, very soft and blended, on the 

 back rather compact. Wings very long, broad, acute, the first and second 

 quills nearly equal, the rest of the primaries rather rapidly graduated; 

 secondaries broad and rounded, the inner narrower. Tail of moderate 

 length, even, of twelve rounded feathers. 



Bill gamboge-yellow, with a large orange-red patch inclining to carmine 

 towards the end of the lower mandible. Edges of eyelids gamboge; iris 

 silvery white. Feet flesh-coloured; claws brownish-black. The head, neck, 

 lower parts, rump and tail, are pure white; the back and wings pearl-grey or 

 light bluish-grey, very slightly tinged with purple; the edges of the wing 

 and the extremities of all the quills, are white. The first six quills are 

 brownish-black towards the end, that colour including the outer webs and 

 the greater part of the inner of the two first, and on the rest gradually 

 diminishing, so as on the sixth merely to form a bar; first quill with a patch 

 of white about an inch and a half long on both webs near the end; second 

 with a circular white patch on the inner web, the tips of all white. 



Length to end of tail 23 inches, to end of wings 24^, to end of claws 21^; 

 extent of wings 53; wing from flexure IS; tail 7i; bill along the ridge 2^, 

 along the edge of lower mandible 3; its depth at the angle f; tarsus 2\\ 

 middle toe 2\, its claws f|. Weight 1 lb. 10 oz. 



The Female is similar to the male, but somewhat less. 



Young in November. 



Bill brownish-black, paler at the base of the lower mandible. Edges of 

 eyelids greenish-grey; iris hazel. Feet purplish flesh-colour; claws brown- 

 ish-black. The general colour of the whole plumage is light purplish-grey, 



