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. delawarensis, 
Mantle light pearl blue ; primaries black near their ends, with white tips ; bill rather 
small and slender... L. sucMeyi. 
LARUS GLAUCUS, Brim nich. 
The Glaucous Gull; The Burgomaster. 
Larus glaucus, Brunn. Orn. Bor. 1764, 44.— Bonap. Synop. 1828, No. 302.— Rich. & Sw. F. B. A. II, 1831, 416.— 
Nutt. Man. II, 1834, 306.— Acd. Birds Amer. VII, 1844, 170 ; pi. ccccxlix. 
Laroides glaucus, Bruch, Cab. Journ. 1855, 281. 
Leucusglaucus, Bonap. Cons. Av. II, 1856, 215. 
“ Larus consul, Boie.” 
“ Larus glacialis, Macgill ” 
Sp. Ch. — Adult. 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, 195 ; tail, 8J ; tarsus 2 }| ; bill, along the ridge, 2|. 
Hab. —Arctic seas ; Labrador ; New York in winter, rarely. 
Individuals appear to vary considerably from tbe above measurements, some being muck 
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 GLAUCESCENS, Lichtenstein. 
The 'Glaucous-winged Gnll. 
“ Laroidesglaucescens, Licht.” Bruch, Rev. Lar. in Cab. Jour. 1855, 281. 
Leucus glaucescens, Bon. Cons. Av. II, 1856, 216. 
“ Laroides glaucoplerus, Kittl.” Bruch, Rev. Lar. in Cab. Jour. 1855, 281. 
? Larus brachxjrhynchus, Gould. 
Sp. Ch. — Adult. 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. argentatus ;) 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, 7j ; 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. 
Hab. —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 
