590 BUJ.LETIN 50, UNITED STATES NATIONAL MUSEUM. 



York; crit.).— Elliot, New and Unfig. N. Am. Birds, pt. 12, 1868 (vol. ii), 

 pi. 53, rear fig., and text (wing figured, in text, as that of L. glaucescens) . — 

 Dall and Bannister, Trans. Cliicago Ac. Sci., i, 1869, 304 (Fort Yukon, 

 Alaska) . 



Larus barrovianus Ridgway, Auk, iii, no. 3, July, 1886, 330 (Point Barrow, 

 Alaska; coll. U. S. Nat. Mus.); Man. N. Am. Birds, 1887, 593.— Turner, 

 Contr. N. H. Alaska, 1880, 125 (St. Michaels, etc.; habits).— Nelson, Hep. 

 N. H. Coll. Alaska, 1887, 51 (habits, etc.).— Chapman, Auk, v, 1888, 393.— 

 American Ornithologists' Union Committee, Suppl. to Check List, 1889, 

 5; Check List, 2d ed., 1895, no. 42, 1. — Henshaw, Birds Hawaiian Is., 1902, 

 126 (Kauai, 2 specs.). — Schalow, Vog. der Arktis, 1904, 146 (synonymy, 

 range, etc.). — ^Brooks, Auk, xxi, 1904, 289 (Comox Bay, Brit. Columbia, 

 Dec. 15, 1903).— Kermode, Provincial Mus. Victoria, 1909, 24 (Comox 

 Bay).— Clark (A. H.), Proc. U. S. Nat. Mus., xxxviii, 1910, 35 (Patience 

 Bay, Sakhalin Island, Sept. 28). 



L[arus] barrovianus Hidgway, Man. N. Am. Birds, 1887, 26. — ^Bryan, Key Birds 

 Hawaiian Group, 1901, 6 (Kauai; Maui). 



L[arus] barrouiianus Palmen, 'Vega'-Exped., 1887, 365, footnote. 



Larus glaucescens (not of Naumann, 1840) Taczanowski, Mem. Acad. St. Petersb.. 

 (7), xxxix, 1893, 1019 (e. Siberia). 



LARUS LEUCOPTERUS Faber. 



ICELAND GULL. 



Similar in coloration to L. liyperhoreus, but much smaller, with 

 relatively smaller bill and feet and longer wing. 



Adults in summer (sexes alike). — Head, neck, rump, upper tail- 

 coverts, tail, and entire under parts, including axillars and under ^ving- 

 coverts, immaculate pure white; back, scapulars, and wings uniform 

 pale gray (between pale and pallid neutral gray, slightly darker than 

 in L. hyperhoreus) , this on remiges fading terminally into white 

 (broadly) ; bill deep yellow or orange-yellow, sometimes greenish 

 yellow terminally, the mandible with a lateral and subterminal spot 

 of red; iris pale yellow; naked orbital ring orange-red (in life); legs 

 and feet pale flesh color (in life). 



Adults in winter. — Similar to the summer plumage, but head and 

 neck streaked with dark grayish, naked orbital ring yellow (in life) 

 and legs ahd feet paler flesh color. 



Young. — Head and neck broadly streaked with brownish gray and 

 grayish white, the upper parts coarsely spotted and mottled with 

 the same; under parts nearly uniform light brownish gray. 



Adult mate. — Wing, 379; tail, 155; exposed culmen, 44.5; tarsus, 

 53 ; middle toe, 48.« 



Adult female. — Wing, 393.7; tail, 165; exposed culmen, 40.5; tar- 

 sus, 53.3; middle toe with claw, 53.3.'* 



'^ One specimen. 



Four adults with sex undetermined measure as follows: Wing, 391.2-419 (404.1); 

 tail (one specimen), 170.2; exposed culmen, 41.9-48.3 (43.8); tarsus (three specimens), 

 2.1-55. 9 (54.6); middle toe (three specimens), 44.4-49.5(47). 



