BIRDS OF NORTH AND MIDDLE AMERICA. 153 



Plectrophenax nivalis Stbjnegek, BuH. U. S. Nat. Mus., no. 29, 1885, 248, excl. 

 syn. part (Commander Islands, Kamtschatka, resident; habits); Proc. U. S. 

 Nat. Mus., X, 1887, 142 (Commander Islands). — Amebican Ornithologists' 

 Union, Check List, 1886, no. 534, part.— Turner, Auk, ii, 1885, 157 (Nearer 

 Islands, Aleutian chain); Contr. Nat. Hist. Alaska, 1886, 172, part (Attu, 

 Atkha,Amchitka, etc., w. Aleutians). — Nelson, Rep. Nat. Hist. Coll. Alaska, 

 1887, 180, part (Pribilof and Aleutian islands; Plover Bay and n. coast 

 Siberia?; habits) .— Townsend, Cruise "Corwin", 1885 (1887), 100 (Pribilofs; 

 Otter I., June 8).— Sharpe, Cat. Birds Brit. Mus., xii, 1888, 572, part (St. 

 Paul I., Pribilofs). 



P.[lectrophena,r1 niralis townsendl Ridgway, Man. N. Am. Birds, 1887, 403 (Otter 



Island, Bering Sea; U. S. Nat. Mus.) . 

 Plectropheriax nivalis townsendi'RrDGV! AY, yi&n.T^i. Am.. Birds, 1887, 592. — Chapman, 

 Auk, V, 1888, 397. — American Ornithologists' Union Committee, Suppl. to 

 Check List, 1889, 12 ; Check List, abridged ed. , 1889, and 2d ed. , 1895, no. 534a. 



Plectrophenax townsendi Sharpe, Cat. Birds Brit. Mus., xii, 1888, 840. 



Passerina nivalis tmonsendi Ridgway, Auk, xv, Oct. , 1898, 324. — American Orni- 

 thologists' Union Committee, Auk, xvi, 1899, 117. 



PASSERINA HYPERBOREA Ridgway. 



MoKAY'S SNOWFLAKE. 



Similar to I*, nivalis townsendi, but with much more white. Adult 

 male with back and scapulars entireh" white, or (rarely) with onlj^ 

 a few narrow streaks of black on the former and the more poste- 

 rior feathers of the latter blotched with black; primarj' coverts 

 (usually the alula also) and basal half or more of primaries wholly 

 white; adult female with pileum and hindneck always white, very 

 rarely with merely a trace of streaks on the former; only two middle 

 rectrices dusky to base, or else next pair dusky on inner web onlj^;^ 

 primary coverts mostly white, usually entirely white; young very simi- 

 lar to that of P. n. townsendi, and not with certainty distinguishable. 



Adult ??ia?e.— Length (skins), 156.21-187.71 (165.61); wing, 109.73- 

 118.62(114.30); tail, 65.53-74.68 (70.61); exposed culmen, 11.18-12.70 

 (12.19); depth of bill at base, 6.35-7.37 (6.86); tarsus, 21.08-23.62 

 (22.35); middle toe, 13.97-16.00 (15.24).^ 



Adult female.— l^'e.ug\h (skins), 162.40-171.96 (159.00); wing, 104.14- 

 109.47 (107.19); tail, 64.01-68.58(66.80); exposed culmen, 10.67-11.68 

 (11.18); depth of bill at base, 6.10-6.86 (6.35); tarsus, 20.83-23.11 

 (21.84); middle toe, 14.48-15.75 (14.99).^, 



Breeding on Hall Island and St. Matthew's Island, north-central part 

 of Bering Sea; migrating in winter to western portion of Alaskan 

 mainland (Nushagak, Kuskokwin River, St. Michaels, etc.). 



Plectrophenax hyperboreus Ridgway, Proc. U. S. Nat. Mus., vii, no. 5, June 11, 1884, 

 68 (St. Michaels, Alaska; U. S. Nat. Mus. ) ; Auk, iii, 1886, 135 (as to vernacu- 

 lar name) , 276 (Hall I., Bering Sea, breeding; St. Matthews I.?).— American 



^ In the female of P. n. townsendi four to six middle rectrices are wholly or chiefly 

 dusky. 



^ Thirteen specimens. 

 ' Fourteen specimens. 



