598 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 
the back, rump, and flanks irregularly striped or clouded with grayish 
dusky; bill black, broadly tipped with dull yellowish. 
Adult male.—Wing, 411-452 (437.6); tail, 172-186.5 (180.6); ex- 
posed culmen, 53.5-61.5 (58.3); tarsus, 61.5-70 (65.9); middle toe, 
58-66 (62.2).% 
Adult female.—Wing, 413-414 (413.5); tail, 171-177.5 (174.2); ex- 
posed culmen, 53.5-55 (54. ay tarsus, 61.5-63 (62.2); middle toe, 
57-59 (58).° 
Breeding from coast of Washington (Destruction Island; Carroll 
Islet) northward along coast of British Columbia and Alaska, and 
westward over Aleutian Islands to Commander Islands, Kamchatka, 
thence northward to Pribilof Islands, Amak Island, and St. Lawrence 
Island, Bering Sea, Providence Bay, Siberia, and Noatak Bay, and 
Cape Denbigh, Alaskan mainland; migrating southward along Pacific 
coast of United States as far as Guadalupe Island, Lower California, 
and on Asiatic side to Japan (Hakodate). 
{?] Larus glaucopterus Krrrurrz, in Lutke’s Voy. ‘Séniavine,’ French tfans- 
lation, iii, 1836, 272, 280 (Unalaska); Denkw., i, 1858, 259, 335. 
[Larus] glacopterus LicwtensTEIN, Nom. Av. Mus. Berol., 1854, 99 (Bering 
Strait). 
Larus glaucopterus Scuatow, Journ. fir Orn., 1891, 263 (Sitka and Unalaska, 
Alaska). 
(?] [Laroides] glaucopterus Bonaparte, Naumannia, 1854, 211 (Kamchatka). 
Larus] glaucescens Naumann, Vég. Deutschl., x, 1840, 351 (North America; coll 
Berlin Mus.). 
Larus glaucescens LAWRENCE, in Baird, Rep. Pacific R. R. Surv., ix, 1858, 842.— 
Krrtiirz, Denkw., i, 1858, 259, 285, 335.—Barrp, Cat. N. Am. Birds, 1859, 
no. 657.Couss, Proc. Ac. Nat. Sci. Phila., 1862, 294 (monogr.); Check List, 
1873, no. 545; 2d ed., 1882, no. 770; Birds Northwest, 1874, 622 (monogr.).— 
Dat and BANNISTER, Trans. Chicago Ac. Sci., i, 1869, 304 (Sitka and Kodiak, 
Alaska).—Extiot, New and Unfig. N. Am. Birds, i, 1869, Introd. (wing 
figured and name transposed).—Finscu, Abh. Nat. Ver. Brem., iti, 1872, 83 
(Alaska).— Datu, Proc. Calif. Ac. Sci., v, 1873, 32 (Aleutian Islands, resident; 
habits, etc.); v, 1874, 278 (Kyska Island, Aleutians, breeding).—Swinnoe, 
Ibis, 1874, 165 (Hakodate, Japan).—Biaxiston and Prysr, Ibis, 1878, 217 
@ Ten specimens. 6 Two specimens. 
Ex- Mid- 
Locality. Wing. | Tail. poe Tarsu8.| dle 
rien toe. 
MALES. 
Seven adult males from Alaska..............--.2-.02-00--e eee 435.7 | 181.6 58.2] . 64.7 61.9 
Two adult males from Washington (June)...........-.......-- 451.5 | 181 60. 2 67.7 64.5 
One adult male from Pering Island, Kamchatka (June)........ 423 173 55 65 59.5 
FEMALES, , 
One adult female from Alaska (Sitka, June)....-.........--+ 413 171 55 63 59 
One adult female from Fering Island (June).............------ 414 177.5 53.5 61.5 57 
