LARUS. 27 
J’. Wing 17.00, or less; culmen 1.90, or less. Adult: Exactly 
like L. leucopterus, except in the coloration of the pri- 
maries; length about 23.00-24.00, wing 15.00-17.00, 
culmen 1.60-1.90, depth of bill through angle .55~.66, 
tarsus 2.10-2.40, middle toe (with claw) 2.15-2.30. 
Hab. Western coasts of North Atlantic, from Cum- 
berland Gulf south, in winter, to New York. 
45. L. kumlieni Brewst. Kumlien’s Gull. 
J’. Wing 18.25, culmen 2.35. Adult: In plumage exactly like 
LL kumlieni ; depth of bill through angle .80, tarsus 3.05, 
middle toe (without claw) 2.40. Hab. Norton Sound, 
Alaska......seeeee 46, L. nelsoni Hrensu. Nelson’s Gull. 
e*. Second quill deep ash-gray, either to the extreme tip, or else with 
very small white tip and small white spaces some distance 
from the tip, on one or both webs. 
Adult: Mantle pearl-gray, darker than in any of the pre- 
ceding. In winter, head and neck clouded (not streaked) 
with sooty gray. Young: Prevailing color deep ash- 
gray, nearly uniform, and inclining to plumbeous, be- 
low, but above relieved by a coarse irregular spotting 
of grayish white or pale dull buff, the head and neck 
indistinctly streaked with the same. Immature (second 
year ?): Similar, but mantle mixed with pearl-gray, 
and lower parts with whitish. Length 23.70-27.75, 
wing 16.25-17.30, culmen 2.20-2.60, depth of Dill 
through angle .80-.90, tarsus 2.35-2.90, middle toe 
(without claw) 2.05-2.45. Eggs 2.88-2.03. Hab. 
Coasts of the North Pacific and Bering’s Sea, from 
Japan northward, across through Aleutian chain, and 
south, in winter, to California. 
44, L. glaucescens Naum. Glaucous-winged Gull. 
d*. Darker spaces on primaries black. 
e. Shafts of primaries, in black subterminal spaces, white. 
Adult: Mantle dark slate, the primaries mostly black, 
with white tips and spots near end; rest of plumage 
pure white. In winter, top of head and hind-neck 
streaked with dusky. Young: Above dusky, the feath- 
ers bordered with pale buffy; quills blackish, with 
narrow whitish tips; tail dusky, crossed by a narrow 
subterminal band of grayish, or brownish, white ; 
head, neck, and lower parts white, the top of head and 
hind-neck streaked, the lower parts clouded or irregu- 
larly spotted with grayish brown. Downy young: 
Grayish white, the upper parts marbled or irregu- 
larly spotted with dull grayish; head with numerous 
