BIRDS OF NORTH AND MIDDLE AMERICA. 153 



Plectrophenax iiiraJk Stejxe(;er, Bull. 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). — American 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. 

 PaulL, Pribilofs). 



P.\Je(irophenax'] nivalis toirnsendi RidCxWay, INIan. N. Am. Birds, 1SS7, 403 (Otter 



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

 Plectrophenax nivalis toivnsendi'Ri'DGVc AY , Man. N.Am. Birds, 1887, 592. — ChxVPman, 

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

 Check List, 1889, 12; Check List, abridged ed., 1889, and 2d ed., 1895, no. 5.34a. 



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



Passerina nivcdis toirnsendi Ridgway, Auk, xv, Oct., 1898, 324. — American Orni- 

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



PASSERINA HYPERBOREA Ridgway. 



McKAY'S SNOWFLAKE. 



Similar to J*, nivalis tmvnse7idi, but with much more white. AcIuU 

 male with back and scapulars entirely white, or (rarely) with only 

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

 rior feathers of the latter blotched with black; primaiy c-overts 

 (usually the alula also) and basal half or more of primaries wholl}^ 

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

 rarel}' with merel}^ a trace of streaks on the former; only two middle 

 rectrices dusk}^ to base, or else next pair dusky on inner wel) onl}-;^ 

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

 lar to that of P. n. townsmdi^ and not with certainty distinguishable. 



Adult male.— Length (skins), 156.21-187.71 (165.61); wing, 109.73- 

 118.62(114.30); tail, 65.53-7J:.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 (15.21).- 



Adult female.— 'hQw^ih (skins), 152.40-171.96 (159.00); wing, 104.1-4- 

 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 hyperhoreus 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. toirnsendi four to six middle rectrices are -wholly or chiefly 

 dusky. 



^ Thirteen specimens. 

 ^ Fourteen specimens. 



