LARID^ — LARINjE : GULLS. 753 



R. ro'sea. (Lat. rosea, rosy.) Wkoge-taileo, or Ross' Rosy Gull. Adult: White, 

 rosy-tinted; a black collar, but no hood; mantle pearly-blue; primaries marked with black; 

 bill black, gape and edge of eyelids red; feet vermilion. Length 14.00; wing 10.50; bill 

 0.75, very slender; tarsus little over 1.00 ; tail 5.50, euneate, the graduation being one inch. 

 Young extensively mottled with blackish. Arctic regions; a circumpolar species, chietiy 

 inhabiting the Arctic coasts of N. Am. and Siberia, though known to come southward to the 

 Fseroes and Heligoland in Europe, and to St. Michael's in Alaska. This exquisite gull, famed 

 for the beauty of its plumage, remained until recently one of the rarest of birds in collections ; 

 only about a dozen being known to exist, not one of them in any American museum. In 1879, 

 Mr. R. L. Newcomb, naturaUst of the ill-fated " Jeannette," secured eight spechnens on the 

 Siberian coast, only three of them, however, being preserved. Mr. E. W. Nelson took one at 

 St. Michael's, Alaska. More recently, a very large number of specimens have been secured at 

 Point Barrow, on the Arctic coast of Alaska. 



XE'MA. (A nonsense word — sonus sensu carens.) Fork-tail Gulls. Tail forked (here 

 only in Larince). Head hooded, with a more or less evident darker collar. Bill black, with 

 light tip. Size moderate and smaU. With a general bearing toward Chraicocephalus, in the 

 hooded head and other features, the genus is distinguished from this or any other group of 

 Larince by the tern-like character of the forked tail. 



Analysis of Species. 



Small : Wing 11 inches or less ; tail lightly forked ; a definite black collar bounding the hood ; feet black 



sabinii 790 



Large : Wing 16 inches or more ; tail deeply forked ; black collar inconspicuous ; feet reddish . . furcata 791 



X. sabinii. (To E. Sabine.) Fork-tailed GuLL. Adult, breeding plumage: Bill black 

 to the angle, abruptly bright chrome from angle to tip. Mouth bright orange ; eyelids 

 orange; legs and feet black. Hood uniform clear deep slate, bounded iuferiorly by a ring, 

 narrowest on the nape, of velvety-black. Lower part of neck all round, tail and its coverts, 

 four inner primaries, secondaries, greater part of greater coverts, tips of tertials except the 

 innermost, and whole under parts, pure white. Mantle slate-blue, extending quite to the tips 

 of the inner tertials. Edge of wing from the carpal joint with the bastard wing, black. First 

 five primaries, \vith their shafts, black; their extreme tips, and the outer half of the inner 

 webs, to near the end, white. Other primaries white, the sixth with a touch. of black on the 

 outer web. Emargination of tail 1.25 inches. Length 13.75 ; wing 10.75; bill 1.00; along 

 gape 1.50 ; height at angle 0.30; tarsus 1.25 ; middle toe and claw same. Adult in winter: 

 Without the hood. Young-of-the-year : Tail forked, nearly as in the adult. BiU small 

 and weak, flesh-color and dusky. Legs apparently flesh-colored. No hood nor collar. 

 Most of the head, the back of the neck, and upper parts in general, slaty-gray, transversely 

 waved with brownish-white ; each feather being tipped with this color. Under parts white. 

 Tail white, wnth a broad terminal bar of black, an inch vride on the central rectrices, 

 growing narrower on the others successively ; on the outermost sometimes invading only 

 one web. This black bar very narrowly edged with white. Wings surprisingly similar to 

 those of the adult, but the white on the inner webs more restricted, and the white tips very 

 small or wanting altogether. Dimensions a little less than those of the adult. Young not 

 distinctly resembling the same age of Ch. Philadelphia. Arctic America, both coastwise and 

 in the interior, irregularly south in winter through the U. S. ; Bermudas ; Peru ! Europe. 

 Common enough in high latitudes, but seldom seen in the U. S., and still rather rare in col- 

 lections. Eggs 3, 1.75 X 1.25, much like a curlew's in general aspect, brownish-olive, sparsely 

 splashed with brown. 



X. furca'ta. (Lat. furcata, forked.) Swallow-tailed Gull. Immature? Head and 

 n<arly all the neck grayish-brown ; a white mark on each side of the forehead ; mantle gray- 

 ish-white ; tail white, much forked; lesser wing-coverts white; greater slate, white-bordered; 



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