Audouin's Gull. 497 
end of the bill a little arched^ the base of the culmen on the 
upper side a little convex ; the angle of the gonys rather 
distinct; the nostrils elongated, somewhat oval, and broad 
(see fig. 12, p. 49i). 
Tail-feathers white at the base, with some blackish trans- 
verse bars (except the outermost one -and sometimes that 
which follows) ; outermost tail-feather white at the end, the 
basal three-fourths of the second and third outside feathers 
and half the others white, all banded with blackish ; these 
bands sometimes not regular and always scanty in the second 
and third, more abundant in the following and in the central, 
all having a subterminal blackish band and with dirty white 
tips. / 
Audouin's Gull, young , in the first dress. 
Bill thinner and more elongated in proportion, with the 
rami of the lower mandible decidedly arched, the space 
between the gonys and the end of the bill longer and much 
more arched, the base of the culmen on tlie upper side more 
flat ; the angle of the gonys clearly distinct ; the nostrils 
straight, linear, and narrower (see fig. 13, p. 495) . 
Tail-feathers pearly grey-white at the base, without any 
blackish transverse band, the light pattern more extended 
on the inner webs of the feathers. They are pearly grey- 
white for about one-fourth of their length, the light 
pattern increasing in extent for three-fourths of the total 
length on the inner webs of all of them except the two 
central (which are black, except at the base) ; in the rest 
they are blackish, tipped with dirty white, and with the 
outermost one edged with white. 
In concluding this note I give a list of the specimens 
in my Collection : — 
a. (5 ad. Island of Elba, August 26, 1883.— ^j; Coll. Eoster. 
Bill from forehead* 1"9 inch, coral-red, with a subapical 
blackish band ; wing 16"6 inches. 
* I always measure the bill from the feathered space down the 
forehead to the tip, and I observe that this space is very much prolonged 
on the base of the bill, so that it appears shorter than it is. 
