LARID.E — THE GULLS AND TERNS — LARUS. 



217 



streaked witli dusky grayish. " The bill is wine-yellow, the lower mandible with an orpiment 

 patch near the end ; the edges of the eyelids yellow ; the feet pale flesh-colored, the claws grayish 

 brown; the iris pale yellow" (Macgillivray). Young, first plumage: Grayish white, the head 

 and neck broadly streaked, the upper parts coarsely spotted with brownish ash-gray ; lower parts 

 nearly uniform light brownish ash, the chin and throat white ; bill wholly blackish ; feet brown- 

 ish. " The bill is very pale flesh-colored 

 as far as the anterior extremity of the nos- 

 trils, beyond which both mandibles are 

 brownish black. The feet are pale flesli- 

 colored, the claws brownish black " (Mac- 

 gillivray), ^ 



Wing, 15.40-16.50 (15.76) inches ; 

 culmen, L65-1.90 (1.75) ; depth of bill 

 through angle, .60-70 (66) ; tarsus, 2.05- 

 2.20 (2.14) ; middle toe, 1.70-1.95 (1.81). 

 [Four adults.] 



This bird is so close an ally of L. glaums 

 that we must confess our inability to give 

 characters whereby it may invariably be 

 distinguished. There appears to be a nearly 

 complete intergradation in size, or at least 

 some of the larger males of Icucopterus are 

 equal to the smaller females of glaucus. A 

 series collected at Point Barrow, Alaska, by 



Messrs. Murdoch and Smith, seems to include a form which is intermediate between the two ; and 

 we are quite in doubt as to which form some specimens should be referred. Mr. Kumlien (" Bull. 

 U. S. Nat. Mus.," No. 15, p. 98), however, gives the following as characters which appeared to be 

 constant in the living and freshly killed birds which came under his notice : — 



" My opportunities for studying leucopterus were not very extensive, and my conclusions may 

 be too hasty ; but still it is worth while for others, that may get better ojiportunities, to observe 

 if the following points of difference are constant : — 



" First. Leucopterus, 24 inches or less ; glaucus, 27 to 32 inches. 



" Second. Tarsus and toes of leucopterus in fully adult birds often orange-red, and not flesh- 

 colored, as in glaucus. 



" Third. Ring around the eye in leucopterus flesh-colored ; in glaucus reddish purple. 



" Fourth. Young of glaucus in first plumage as light as the bird of the second year ; the young 

 of leucopterus nearly as dark as the young of glaucescens. The bill is also weaker and thinner than 

 in glaucus." 



The particulars of the history of this species and of the extent of its distribution 

 are not so well known as they probably would be if its resemblance to Larus glaueus 

 were not so close ; the two species differing cliiefly in that the latter is of larger size 

 than the former. It is difficult, however, if not impossible, to distinguish the two 

 when seen at some distance ; and it is hence not always safe to ajiply to either spe- 

 cies statements as to its actual presence, except only where the identification has 

 been rendered positive by obtaining a specimen of the bird seen. 



The Lesser White-winged Gull is an Arctic species, and its distribution is very 

 nearly identical with that of the Burgomaster. It is found in the northern portions 

 of Asia, Europe, and North America. INIiddendorff mentions it as one of the birds of 

 Siberia, and includes it in his list of those which penetrate to the farthest north. 

 Mr. Wheelwright was informed that this species breeds on the coast of East Finland, 



1 "Bill yellow, the tips black. Edges of eyelids pale reddish-orange ; iris brown. Feet yellowish 

 flesh-color; claws grayish brown " (Audubox). 

 VOL. II. — 28 



