LARID^E — THE GULLS AND TERNS — LARUS. 



2G1 



coverts, lower and lateral portions of the rump, border of the wing, alulae, primary coverts, and 

 greater portion of the primaries snow-white, the neck and lower parts with a delicate rose-pink 

 blusli iu fresh specimens. Mantle, including upper and middle portions of rump, delicate light 

 pearl-blue. Three outer primaries chiefly white, the outer web of the exterior quill, and the 

 terminal portion (jf all, deep black ; fourtli quill similar to the third, but the inner web pale gray- 



L. Philadelphia, summer plumage. 



ish blue ; fifth and sixth quills pale grayish blue, with a large subterminal black space, and tipped 

 with white (third and fourth quills also marked with a small white apical spot) ; remaining quills 

 pale grayish blue, without white tips, but marked near the end, usually on inner web only, with 

 a black spot. Bill deep black ; iris dark brown ; interior of mouth, with legs and feet, rich clear 

 orange-red ; ^ claws black. Adult, in vnnter : Similar, but head and neck white, the occiput tinged 

 with grayish, and the auricular region marked by a spot of dusky gray. Legs and feet flesh-color. 



Summer adult. 



Young, first plumage : Sides and under part of head and neck, entire lower parts, upper tail-coverts, 

 and basal three fourths of the tail pure white ; crown, occiput, and upper part of the back brownish 

 gray ; a dusky grayish spot on the auricular region ; scapulars and posterior interscapulars grayish 

 umber, tipped with pale buff ; central area of lesser wing-covert region dusky brownish gray ; 

 rest of wing-coverts, edges of secondaries, greater portion of inner primaries, with upper and central 

 portions of the rump, light grayish blue ; band across end of tail black or dusky, the tip narrowly 



1 In some very high-colored specimens the feathers surrounding the naked rim of the eyelids are fine 

 oranse-red. 



