SILVERY GULL. 
51 
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 244, to end of claws 214 ; 
extent of wings 53 ; wing from flexure 18 ; tail 7 4 ; bill along the ridge 
24, along the edge of lower mandible 3 ; its depth at the angle f ; tarsus 
24 ; middle toe 2$, its claws -~1- 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, 
