842 U. S. p. R. R. EXP. AND SURVEYS — ZOOLOGY GENERAL REPORT. 



Mantle pale bluish gray ; primaries marked near their ends with black, the tips being 



white ; bill yellowish green crossed with a black band. (Pr. Bonaparte puts this species 



in Larus.) , L. delaivarensis. 



Mantle light pearl blue ; primaries black near their ends, with white tips ; bill rather 

 small and slender L. sucJdeyi. 



LARUS GLAUCUS, Briinnich. 



The Glaucous Gull; The Burgomaster. 



Larus glaucus, BrInn. Cm. Bor. 1764, 44.— Bonap. Synop. 1828, No. 302.— Rich. & Sw. F. B. A. II, 1831, 416.— 



NuTT. Man. II, 1834, 306.— Aud. Birds Amer. VII, 1844, 170 ; pi. ccccxlix. 

 Laroides glaucus, Bruch, Cab. Journ. 1855, 281. 

 Leucus glaucus, Bonap. Cons. Av. II, 1856, 215. 

 " Larus consul, HoiE." 

 " Larus glacialis, Macgill " 



Sp. Ch. — ^dult. The head, neck, rump, tail, and entire under plumage pure white ; the back and wings are of a light bluish 

 gray ; the edge of the wing, the ends of the first primaries, and the shafts and tips of the others white. Bill gamboge yellow, 

 with a spot of reddish orange near the end of the lower mandible ; irides light yellow ; legs and feet flesh color. 



Length, 30 inches ; alar extent, 60 ; wing, from flexure, ]9| ; tail, 8^ ; tarsus 2^ J ; bill, along the ridge, SJ. 



Hab. — Arctic seas ; Labrador ; New York in winter, rarely. 



Individuals appear to vary considerably from the above measurements, some being much 

 smaller ; but Capt. Sabine found one example to measure 32 inches, with an extent of wing of 

 65 inches ; its tarsus was 3^ inches in length, and its bill 4 inches. 



The young have the upper plumage pale yellowish white, mottled with very pale brown ; 

 breast and abdomen gray ; tail white_, irregularly spotted with pale brown ; bill yellow for two- 

 thirds its length and terminating with blackish brown. 



LARUS GLAUCESOENS, Lichtenstein. 



The 'Glaucous-winged Gull. 



" Laroides glaucescens, Light." Bruch, Rev. Lar. in Cab. Jour. 1855, 281. 

 Leucus glaucescens, Bon. Cons. Av. II, 1856, 216. 



" Laroides glttucoplerus, Kittl." Brdch, Rev. Lar. in Cab. Jour. 1855,281. 

 ? Larus brachyrhynclms, Gould. 



Sp. Ch — .idult. Head and neck white, streaked with gray ; under surface, rump, and tail pure white ; back and wings light 

 pearl blue (same shade as in L. argentalus ;) the primaries are of the same color, but rather darker, with well defined white 

 tips ; on the first quill the white extends on the tip for about two inches and is crossed by a bar of the same color as the prima- 

 ries ; iris white ; bill yellow, with an orange red spot on the angle of the lower mandible ; legs and feet flesh color. 



Length, 27J inches ; wing, 16| ; tail, 1\ ; bill along ridge, 2|, deep at base, 11-16, at angle, 12-16 ; tarsi, 2 9-16 ; middle toe 

 and claw, 2^. 



Young mottled with grayish white and cinereous ; the quills and tail bluish ash ; bill black, in some specimens yellowish at 

 base ; legs and feet dusky flesh color. 



Hah. — Northwest coast of North America. 



In the collection are a number of specimens of this fine gull, from quite young to fully adult ; 

 it is nearly equal in size to L. glaucus, but with a less powerful bill and more slender tarsi. 



I have not seen the original description of L. glaucescens, the locality of which is Kamtschatka, 

 but the description of it by Bruch in his "Revision der Gattung Larus, Linn." in Cabanis 



