LARUS. 25 



with gray, and a dark plumbeous suffusion before and behind eyes. Young : 

 Somewhat like winter adult, but lower part of hind-neck crossed by a black 

 patch, the anterior lesser wing-coverts black, and tail with a broad black 

 band at tip. Downy young : Head, neck, wings, and lower parts immaculate 

 white, the hind-neck and basal portion of wings more or less tinged with 

 buff ; back, rump, and flanks yellowish gray, the down darker at base. Length 

 about 16.00-17.70, wing about 12.25, culmen 1.40-1.50, tarsus 1.30, middle toe, 

 with claw, 1.80. 



b l . Hind toe absent, or very rudimentary. Eggs 2.26 X 1-61. Hab. North 

 Atlantic, south, in winter, to middle Atlantic States and Great Lakes. 



40. R. tridactyla (LINN.). Kittiwake. 



6 2 . Hind toe well developed, though minute, and usually armed with a distinct 

 nail. Eggs 2.36 X 1-63. Hab. Bering's Sea and North Pacific. 



40a. R. tridactyla pollicaris STEJN. Pacific Kittiwake. 



a 2 . Legs and feet bright red (becoming yellowish in dried skins). Summer adult : 

 Pure white, the mantle dark bluish gray, or plumbeous ; five innermost quills 

 plumbeous, the inner webs broadly edged with white, the outer tipped with 

 the same ; five outermost quills black toward ends, the third, fourth, and 

 fifth tipped with plumbeous. Winter adult : Similar, but hind-neck and 

 auriculars washed with plumbeous. Young : Similar to winter adult, but 

 hind-neck crossed by a blackish band, ear-coverts crossed by a smaller black 

 band, and a suffusion of same in front of eye. (No black or dusky on iving- 

 coverts or tail.') Downy young : 'Not distinguishable from corresponding stage 

 R. tridactyla^.}. Length about 14.00-15.80, wing about 13.00, culmen 1.20, 

 tarsus 1.25, middle toe, with claw, nearly 2.00. Eggs 2.28 X 1-66. Hab. 

 Coasts and islands of Bering's Sea. 



41. R. brevirostris (BRUCH). Red-legged Kittiwake. 



GENUS LARUS LINNAEUS. (Page 23, pi. VIII., figs. 3, 4; pi. IX., fig. 3.) 



Species. 1 



Nest a rudely constructed platform of rubbish (sticks, dried grass, etc. the 

 materials varying according to the locality and the species), slightly hollowed, 

 placed among rocks, in marshes, or other localities near the sea-shore or other large 

 bodies of water. Eggs 2-4, ovate, their ground-color some shade of pale brownish, 

 olive, light bluish, greenish, or buffy, irregularly spotted or blotched with brown 

 and lavender-grayish. 



a 1 . Head entirely white in summer. 



b l . Under wing-coverts entirely pure white ; head, neck, entire lower parts, 

 tips of secondaries, rump, upper tail-coverts, and tail uniform pure white; 

 mantle (i.e., back, scapulars, and wings, except primaries) uniform gray- 

 ish, varying in shade from pale pearl-gray to deep slate. 

 c 1 . Pi-imaries uniform pale pearl-gray, fading gradually into white at tips. 



1 The young birds of this genus seldom offering very obvious distinctive characters, this analysis is based 

 on the adults alone. 



4 



