264i ON THE DIFFERENT SPECIES OF 
4. Larus argenteus. Silvery Gull. 
L. rostro superae leniter aucto, dorso alisque ccerulescenti- 
perlaceis, pennis apice albis, rectricibus quinque ni« 
gris, alis cauda longioribus. 
Adult, Summer Plumage.~—'Beak moderate, deep, com- 
pressed, slightly gibbous above, gamboge-yellow along the 
edge of the upper mandible, diaphanous at the tip and 
margins of both mandibles, the rest wine-yellow, a deep 
reddish - orange spot on the under; angle bright red; 
length 2 inches, depth |ths. Iris pale yellow, margin 
of the eyes yellow. Feet flesh -colour, claws blackish- 
brown ; tarsus 2^ inches long, middle toe 2|. Wings about 
an inch and a half longer than the tail. Total length S4 
inches, extent 50. Back and upper surface of the wings 
pearl-grey, with a good deal of blue ; a broad oblique 
blackish-brown band passing over the five first quills, so 
large on the outer as to include nearly the whole, diminish^ 
ing to the fifth, on which there is merely a bar near the 
end ; second quill with a black bar across the white of the 
tip ; the colour of the shafts corresponding with that of the 
webs. The rest of the plumage snow-white. 
Adult, Winter Plumage. — Head and neck marked with 
longitudinal streaks of pale brown; in other respects the 
same as in summer, 
Nidification, (Sfc. — ^Nest in a superficial cavity in the turf, 
or on the bare rock, along the shores, and especially in 
rocky islets, composed of withered grass, and sometimes a 
few feathers, commonly pretty perfect. Eggs 3, placed ir- 
regularly, olive-green, sometimes with a good deal of ash- 
