114 BULLETIN 50, UNITED STATES NATIONAL MUSEUM 



Lagopus rupestris sanfordi Bent, Smiths. Misc. Coll., Ivi, No. 30, 1912, 1 (Tanaga 

 Island, Aleutian Chain, Alaska; coll. U. S. Nat. Mus.) ; U. S. Nat. Mus. Bull. 

 162, 1932, 225 (habits).— [Editor] Rev. Frang. d'Orn., ii, 1912, 346, in text; 409, 

 in text. — American Ornithologists' Union, Auk, xl, 1923, 517 (Check-list, 

 No. 302g) ; Check-list, ed. 4, 1931, 84. 



Lagopus imitus sanfordi Oberholser, Auk. xxxix. No. 2, 1922, 247. — Peters, Check- 

 list Birds of World, ii, 1934, 2>Z (Tanaga Island). — Salomonsen, Moults and 

 Sequence of Plumages in the Rock Ptarmigan, 1939, 10 (spec). — Hellmayr 

 and Conover, Cat. Birds Amer., i. No. 1, 1942, 208 (syn. ; distr.).— Clark, 

 Smiths. War Background Stud. No. 21, 1945, 78 (list birds Aleutians). 



LAGOPUS MUTUS CHAMBERLAINI A. H. Clark 



Chamberlain's Ptarmigan 



Adult male, summer plumage. — Similar to that of Lagopus mutus 

 toivnsendi but the brownish areas paler, more grayish, the lower back 

 and rump isabella color to ashy wood brown, the dark vermiculations 

 averaging slightly finer ; the feathers of the lower throat and breast cin- 

 namon-buff to very pale tawny-olive. 



Adult female, summer plumage. — Not certainly separable from that of 

 Lagopus mutus toivnsendi, but usually with more pronounced grayish 

 edges to the dorsal feathers. 



Adults in winter. — Like those of L. m. townsendi, judged by birds 

 partly in this plumage. 



Other plumages unknown. 



Adult male.—Wmg 185-202 (193.5) ; tail 97-112 (104.6); bill from 

 anterior end of nostril 10.1-11.7 (10.9) ; width of bill at gape 12-13 

 (12.5) ; height of bill at angle of gonys 7.5-8.6 (8 mm.).^^ 



Adult female.— Wing 183-189 (185.4) ; tail 95-102 (98.3) ; bill from 

 anterior end of nostril 9.1-10.3 (9.8); width of bill at gape 11.1-11.8 

 (11.5) ; height of bill at angle of gonys 7.1-7.2 (7.1 mm.).^- 



Range. — Resident in Adak Island, Aleutian Islands, Alaska. 



Type locality. — Adak Island. 



Lagopus rupestris townsendi Elliot, Auk, xiii, 1896, 26, part (Attu Island). — 

 American Ornithologists' Union, Auk, xiv, 1897, 119, part (Adak Island). 



L{ayopus\ r{upcstris^ toivnsendi Coues, Key North Amer. Birds, ed. 5, 1903, ii, 748 

 (Adak Island). 



[Lagopiis] toivnsendi Sharpe, Hand-list, i, 1899, 247, part (Adak Island). 



Lagopus rupestris chamberlaini Clark (A. H.), Proc. U. S. Nat. Mus., xxxii, 1907, 

 479 (Adak Island, Aleutian Chain, Alaska; coll. U. S. Nat. Mus.). — American 

 Ornithologists' Union, Auk, xxvi, 1909, 295 (Check-list No. 302e) ; Check- 

 list, ed. 3, 1910, 142; ed. 4, 1931, 84.— Laing, Victoria Mem. Mus. Bull. 40, 1925, 

 29 (Adak Island; spec; plum.).— Bent, U. S. Nat. Mus. Bull. 162, 1932, 221 

 (distr., habits). 



Lagopus mutus chamberlaini Oberholser, Auk, xxxix, 1922, 247. — Peters, Check- 

 list Birds of World, ii, 1934, 33 (Adak Island). — Salomonsen, Moults and 



" Twenty-three specimens from Adak Island. 

 " Nine specimens from Adak Island. 



