186. 
750 SYSTEMATIC SYNOPSIS.— LONGIPENNES — GAVLZE. 
gulls. Tail square, or nearly so. There are no marked peculiarities of form of this genus, 
the pattern of coluration being mainly its basis. The numerous species average much under 
those of Larus in size (though one at least is among the largest of Larine); they approximate 
toward Xema and Rhodostethia in some respects, but the tail is neither forked nor cuneate. 
Analysis of Species. 
Tarsus longer than middle toe and claw. 
Bill reddish, feet the same. Length 16.00ormore ....,.....2.4.4. : . . atricilla 786 
Tarsus not longer than middle toe and claw. 
Bill reddish, feet the same. Length about 14.00 inches . . ee a eee as ee Sranklini 187 
Bill black, feet red or yellow. Length about 14.00inches ..... Be philadelphia 788 
C. atricil/la. (Lat. atricilla, black-tail: only applicable to the young. Fig. 510.) LauGuine 
GuLL. BLACK-HEADED GULL. Bill longer than middle toe and claw, shorter than tarsus or 
head, moderately compressed, rather stout for this genus. Culmen and commissure both decurved 
at the end, the latter somewhat sinuate at the base. Gonys considerably concave in front 
of the angle, sonewhat so between the angle and tip; although the angle is well defined, 
the tip of the bill is so decurved that a chord from tip to base does not touch it. Middle toe 
barely three-fourths the tarsus. Adult in summer: Bill and edges of eyelids deep carmine; 
legs and feet dusky-red; iris blackish. Hood 
deep plumbeous grayish-black, extending further 
on the throat than on the nape. Eyelids white 
‘posteriorly. Neck all round, rump, tail, broad 
tips of secondaries and tertials, and whole under , 
parts, white, the latter with a rosy tinge (like tly 
tint of peach-blossoms). Mantle grayish-plum- 
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 
hab, del: B.C.) successively increasing distance on both webs of 
the others, of the color of the back. Adult in winter: Under parts simply white, not rosy; 
hood lost, the head being white, mixed with blackish. Bill and feet more dull in color. Imma- 
ture: Bill and feet brownish-black, tinged with red. Plumbeous of the upper parts more or 
less mixed with irregular patches of light grayish-brown. Primaries wholly brownish-black, 
fading at the tip. Secondaries brownish-black on the outer web. Tail-feathers more or 
less tinged with plumbeous, and with a broad terminal band of brownish-black, the extreme 
tips of the feathers white. Upper tail-coverts white. Young-of-the-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 space about the éye. Forehead, throat, and under parts, 
dull whitish, more or less clouded with gray, especially on the breast, where this is the 
prevailing 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 Amazon; casual in Europe. 
By thousands along the Atlantic coast during the migrations, breeding in colonies anywhere 
along, wintering in the South. Nest on the ground, of eel-grass, seaweeds, and other vege- 
table material; eggs mostly 3, sometimes 2; 2.10 * 1.55; 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 and pale purplish ; sometimes the markings chiefly 
wreathed about the large end. 
