750 SYSTEMATIC SYNOPSIS. — LONGIPENNES— GAYIM. 



gulls. Tail square, or nearly S(i. There are no marked peculiarities of form of this genus, 

 the pattern of coloration being mainly its basis. The numerous species average much under 

 those oi Larus in size (though one at least is among the largest oiLarince)\ they approximate ■ 

 toward Xenia aud lilwdostetltia in some respects, but the tail is neither forked nor cuneate. 



Analysts of Species. 



Tarsus longer than middle toe and claw. 



Bill reddish, feet the same. Length 16.00 or more atricilla 7S6 



Tarsus not longer than middle toe aud claw. 



Bill reddish, feet the same. Length about 14.00 inches frankUni 787 



Bill blacit, feet red or yellow. Length about 11.00 inches pUUculelphia 788 



786. C. atrieil'la. (Lat. ofriC(7/n, black-tail : only applicable to the young. Fig. 510.) Laughing 

 Gull. Black-headed CtULL. Bill longer than middle toe and claw, shorter than tarsus or 

 head, moderately compressed, rather stout for this genus. Culmen and commissure both docurved 

 at the end, the latter somewhat sinuate at the base. GJ-onys considerably concave in front 

 of the angle, somewhat so between the angle and tip ; although tlie angle is well defined, 

 the tip of the biU is so dccurved that a chord from tip to base does not touch it. Middle toe 

 barely three-fourths the tarsus. Adah in summer : Bill and edges of eyelids deep carmine ; 



legs and feet dusky-red; iris blackish. Hocjd 

 deep plumbeous grayisli-black, extending further 

 on the throat than on the nape. Eyelids white 

 ' ■ posteriorly. Neck all round, rump, tail, broad 

 tijis of secondaries and tertials, aud whole under 

 parts, white, the latter wixXi a rosy tinge (hke tl/ 

 mi.Hii, ■- :.Tf¥ ' ^-s^ ^ijj{ ,,f jicach-blossoms). Mantle grayish-pluu"!- 



beous. Outer six primaries black, their extreme 

 tips white; their bases for a very short distance 

 Fig. 510. — Bill of Laughing Gull, nat. size. {Ad on the first, and only on the inner web, and for a 

 nat. del. E. C.) Successively increasing distance on both webs of 



the others, of the color of the back. Adult in winter: Under parts simply wliite, not rosy; 

 ho(jd lost, the head being white, mixed with blackisli. Bill and feet more dull in color. Imma- 

 ture : Bill and feet brownish-black, tinged with red. Plumlietais of the upper parts more or 

 less mixed with irregular patches of light grayish-brown. Primaries whcdly brownish-black, 

 fading at the tip. Secondaries brownish -black cju the outer web. Tail-feathers more or 

 less tinged with plumbeous, and viith a broad terminal band of brownish-black, the extreme 

 tips of the feathers white. Upper tail-coverts white. Young-of-tlie-year ; Entire upper 

 parts, and neck all round, light brownish-gray ; the feathers tipped with grayish or rufous- 

 white, broadly on the scapulars and tertials, the blue of the adults appearing on the wing- 

 coverts. Eyelids whitish ; a dusky S]iace about the eye. Forehead, throat, and under parts, 

 dull whitish, more or less chaided with gray, especially on the breast, whei'e this is the 

 prevailiug color. Wings and tail as before. Length about 16.50 ; extent 41.00; wing 13.00; 

 tail 5.00; bill 1.75, along gape 2.25, its height at nostril 0.45 ; tarsus 2.00; middle toe and 

 claw 1.50. Tropical Am. and temperate N. Am. ; in the U. S. north coastwise in summer to 

 Maine, in the interior to Ohio or beyond ; on the Pacific side to California ; Central America, 

 both coasts, and various W. I. islands ; S. Am. to the Lower Anurzon ; casual iu Europe. 

 By thousands along the Atlantic coa.st during the migi-ations, breeding in colonies anywhere 

 along, M-intering in the South. Nest on the ground, of eel-grass, seaweeds, and other vege- 

 table material; eggs mostly 3, sometimes 2; 2.10X1.55; ground color some olive shade, 

 ranging from dull grayish to dark greenish, thickly marked all over with spots and irregular 

 splashes of brown, blackish, dull reddish aud pale purplish ; sometimes tlie markings chiefly 

 wreathed about the large end. 



