BIRDS OP NORTH AND MIDDLE AMERICA, 



695 



nally; two outer primaries with shafts white or yellowish wliite; 

 chest (sometimes breast also, more rarely even upper part of abdo- 

 men) immaculate white, shading posteriorly into grayish, the under 

 tail-coverts, anal region, flanks, and (usually) abdomen being neutral 

 gray; bill blackish terminally, the basal portion brownish or horn 

 color; iris dark brown; tarsi and basal portion of toes and webs 

 light bluish gray in life, drying hght olive or yellowish, the remaining 

 portion of toes and their webs black. 



Immature. — "Under parts and upper tail-coverts barred with vary- 

 ing degrees of ash-brown; very little yellow on the sides of the neck; 

 otherwise similar to adults."" 



Young. — "Ash-brown above, the head darkest; the feathers of 

 the mantle and tail-coverts merely tipped with buff, but without any 

 rufous tint; under parts dull grayish white, barred with ash-brown." ** 



Downy young. — "Grayish brown above and below, much paler 

 than in S. crepidatus." "• 



Adult male.— Wing, 295-327 (309.1); tail (middle rectrices), 263- 

 350 (299); exposed culmen, 27-31.5 (28.6); tarsus," 38-44 (41.1); 

 middle toe, 31-36.5 (32.7).^ 



Adult female.— Wing, 305-317 (313.3); tail (middle rectrices), 

 238-350 (295); exposed culmen, 27.5-30 (28.8); tarsus, 40-42.5 

 (41.8); middle toe, 31-34.5 (32.5).^ 



Breeding on both coasts of Greenland (from extreme northwestern 

 corner southward on western side to Disko Bay, on eastern side to 

 Scoresby Sound), and on adjacent island of EUesmere Land (Cape 

 Union and King Oscar Land), in northern Mackenzie (FrankUnBay; 

 Baillie Island; near Fort x\nderson; Caribou Hills), Yukon (La 

 Pierre House), northwestern Alaska (shores of Kotzebue and Norton 

 Sounds) and Ai'ctic coast of Siberia (Yenesei River; Kolyma delta) 

 to northern Russia (Archangel ; Kanin Peninsula ; Novaya Zemlya) ; 



a Saunders, Cat. Birds Brit. Mus., xxv, 1896, 337. 

 & Sixteen specimens. c gix specimens. 



