ROCK PTARMIGAN. 153 



LA GO PUS RUPESTRIS. 



Geographical Distribution. — Arctic America, Alaska to Labra- 

 dor, south to Gulf of St. Lawrence, Greenland. 



Adult Male in Summer. — Head, neck, and upper parts, gray, 

 barred with black, and irregular rusty bars on the head, back of 

 neck, upper back and scapulars, and black blotches on upper 

 part of back; wings, like the back; primaries and outer second- 

 aries, white, with brownish black shafts on the primaries; upper 

 tail-cov^erts, gray, barred with black, and occasionally rusty, some 

 feathers with white tips; tail, blackish brown, lighter on margins; 

 breast, dark brown, feathers barred with white and black; entire 

 rest of under parts and legs, pure white; lores, black; bill, black. 

 Total length, 14 inches; wing, 7I; tail, 4I. Specimen from 

 Labrador. 



Adult Female in Summer. — Shot Jul}^ 31. Head, entire upper 

 parts, and wings, black, irregularly barred with white and deep 

 buff, feathers generally tipped with white, broadest on upper 

 tail-coverts, many of which have their outer margins deep buff; 

 tail, smok^'-brown, tipped with white; throat, breast, and flanks, 

 ochraceous, barred with black, some white feathers showing; 

 middle of abdomen, white; crissum and under tail-coverts, och- 

 raceous, barred with black; feathers on thighs and legs, white; 

 primaries, white, with pale brown shafts; secondaries and most 

 of the wing-coverts, also white; bill, black. Total length, about 

 13 inches; wing, 7; tail, 4^. Specimen from Quickiock Falls, 

 Labrador. 



