BIRDS OF NORTH AND MIDDLE AMERICA 637 



Natal down. — Said to be white with pale fulvous wash, becoming 

 grayer with age. 



Adult male.—Wmg 340.3-378 (364.3); tail 203-244 (221.5); ciilmen 

 from cere 20.5-25 (22.8) ; tarsus 53.3-68 (62) ; middle toe without claw 

 45.7-53.3 (49.2 mm.).^^ 



Adult jemale.—\N'm.g&2,Q,%-42^ (402.6); tail 215-259 (239.6); culmen 

 from cere 23-27.9 (25.4); tarsus 58-72 (64.6); middle toe without 

 claw 48.2-55 (52.9 mm.).^^ 



Range. — Breeds from high Arctic latitudes in Greenland (both coasts, 

 Angmagsalik; Egedesminde; Etah; Godthaab; Jacobshavn; Kanga- 

 mint; Nanortalilv; Nordletd; Novasak; Oju; Sukkertoppen, Ymer 

 Island); Ellesmere Island (East Bay); Bafhn Island (Magee Lake, 

 Blackhead Island, Markham Bay, Cape Dorset, Lady Franklin Bay) ; 

 Digges Island, Hudson Strait; Southampton Island; Grinnell Land 

 (Cape Hayes, Cape Frazer, Cape Napoleon — lat. 79°47' N.) ; Victoria 

 Island (Taylor Island); Northwest Territories (Franklin Bay, Cape 



2^ Forty-two specimens from Greenland, Labrador, Alaska, Baffin Island, and 

 Southampton Island. Alaskan birds average smaller than the others, as may be 

 seen from the following figures, but the Alaskan series is small. Greenland birds 

 are slightly larger than Labrador ones, but the difference is small and the over- 

 lapping is great. 



Four Alaskan males.— Wings 340.3-349.2 (346.0); tail 203.2-215.9 (210.8); 

 culmen from cere 21.6-23.3 (22.6); tarsus 53.3-58.4 (57.1); middle toe without 

 claw 45.7-48.2 (47.6 mm.). 



Fifteen Greenland males.— V/ing 355.6-378 (372.3); tail 215-241.3 (224.3); 

 culmen from cere 22.8-24.1 (23.3); tarsus 58.4-68 (62.9); middle toe without 

 claw 47-53.3 (49.7 mm.). 



Three Southampton Island males.— Wing 355-370 (365.3); tail 215-235 (224.3); 

 culmen from cere 24-25 (24.3) ; tarsus 60-64 (62) ; middle toe without claw 48-49 

 (48.3 mm.). 



Thirteen Labrador males.— Wing 342.9-370.8 (360.5); tail 203.2-244 (221.1); 

 culmen from cere 20.2-23 (21.9); tarsus 59.3-66 (62.5); middle toe without claw 

 47-51 (49.4 mm.). 



In all these figures there are probably a number of young birds in the white 

 plumage in which the ages are indistinguishable. 



3' Fifty-nine specimens from Greenland, Labrador, Baffin Island, Southampton 

 Island, and Alaska. 



Four Alaskan females.— Wing 368.3-400 (389.6) ; tail 220.9-259 (243.8) ; culmen 

 from cere 23.3-26.6 (25.2); tarsus 61.4-64.7 (63.4); middle toe without claw 

 48.2-53.3 (52 mm.). 



Four Southampton Island females.— Wing 398-408 (404) ; tail 240-251 (244.4) ; 

 culmen from cere 25-26 (25.4); tarsus 64-72 (68.5); middle toe without claw 

 52-55 (54 mm.). 



Twenty-six Labrador females.— Wing 370-412.5 (393.6) ; tail 228-266.5 (248.8) ; 

 culmen from cere 23-26 (25.1); tarsus 63-68 (65.6); middle toe without claw 

 51-54.6 (52.9 mm.). 



Twenty-three Greenland females.— Wing 368-423 (410.5); tail 215-266 (227.8); 

 culmen from cere 23-27.9 (25.7); tarsus 58-71 (62.4); middle toe without claw 

 50-54.6 (52.7 mm.). 



