214 BONAPARTIAN GULL,.
had frequent opportunities of seeing the black-hooded males copulating
with the brown-hooded females^so that the colour of the head in the
summer season is really distinctive of theJ ISWS» I found in London a
pair of these birds, of whieh the sexes were distinguished by the colour.
of the head, and which lmd been brought from Greenland. They
were forwarded by me to the E A R L of D E R B Y , in whose aviaries they
are probably still to be seen.
This is certainly the species described in the Fauna Boreali-Americana
under the same name ; .but it is there stated that: ¡the females
agree precisely with the males, their hood being therefore " greyishblack;
1' which ! have never found to be the case. As to the Larus
capistratus of' Bonaparte's/Synopsis, I have nowhere met with a Brownheaded
Gull having the tail ";sub-emarginate and 1 infer that the bird
described by him under that name is merely the female of the present
species-. • -
LARCH BON APART I I , BONAPARTIAN G U L L , Richards. cmd Swains. Fauna Bor.-Amer.
vol ii. p. 425.
BROWN-MASKED G U L L , LARUS CAPISTRATI IK; Mdnap. Amer. Ornith., yoL iv.
Female.
L A R U S CAPI STRATUS , Ch. Bonaparte, Synopsis of Birds of United States, p. 358.
BONAPARTIAN G U L L , Xvtiall, Manual, vol.. M p. 294.
Adult Male in Spring l'lumage. Plate CCCXXIV. Kg . I. :
Bill shorter than the head, nearly straight, slender, compressed.
Upper mandible with its dorsal line straight to the middle,' then curved
and decimate, the ridge narrow, the w§ # slightly convex, the edges
sharp and a little inflected, the tips narrow but rather obtuse, with a
slight notch on each side. Nasal groove rather long and narrow ; nostrils
in its fbre part, longitudinal, submedial, linear, pervious. Lower
mandible with a slight prominence at the end of the anglej which is
long and narrow, the dorsal line then ascending and slightly concave,
the ridge convex,: the sides nearly erect and flattened!." "
Head of moderate size, ovate, narrowed anteriorly, convex above.
Eyes of moderate s i z e .Ne e k rather short. Body rather slender.
Wings very long. Feet of moderate length, rather strong ; tibia bare
below for a short space, covered behind with narrow seutella ; tarsus
compressed, anteriorly covered with numerous !Sc1Ite|}a and three in-
BONAPARTIAN GULL. 215
ferii» seri»: Of transverso scales, laterally with oblong scales, posteriorly
w À oblique smtella. Toes slender,, with numerous seutella;
first extremely small/second considerably shorter than fourth, third
l a n g e s « anterior toes connected by reticulated webs, of which the anterior
margins are deeply concave, the outer and inner slightly marginate,
Claws small, compressed, moderately arehed, rather obtuse, that
of middte»toe with an expanded inner edge.
Plumage fulls close, soft, blended. Wirigs Very long and pointed ;
primaries tapering and rounded, firsi#Ongest, second very little shorter,
the rest rapidly graduated? secondaries obliquely pointed, the rounded
extremity extending beyond the tip of the shaft, which is exterior to
it, the innetfeathers more elongated. Tail of «federate length, almost
even, the middle feathers slightly longer.
Bill black, inside of mouth vermilion. Iris reddish hazel. Feet
«ranges slightly tinged with vermilion ;: 'claws dusky brown. Head
and upper pail of neck sill round, greyish-black, ihat colour extending
half a b i t a i lower on the' throat than oh th"e occiput. A white band
divided by a narrow black line margining thé eye behind ; the remain,
ing parf>f the néck .white ; back,, scapulars and wings, light greyish-
MuSl,' The anterior ridge of the wing, alula, smaller covèrts on the
carpal margin, four outer primary coverts, shaft and inner web of the
outer primary, both webs of second, inner webs of third and fourth
White ; of which colour also are the rump, t â l , and all the lower parts.
Outer.web of first quill, excepting & small portion towards the end, its
tip to the length of hull' an inch, black, as are the ends of the next six,
which however- have a small tip of white, the black on some of them
about an inch long, and running along the inner edge to a considerable
éxteñí"
Length to end of tail 14J inches, to end of wings 15f, to end of
claws ; extent of wings 32i ; wing from flexure lOf ; tail ;
bili along the rittj»« l f f e ' áoñg the edge of lower mandible 1}3 ; tarsus
; hind toe and claw ft ; middle toe 1A ; its claw T«|, outer toe
its claw # ; inner toe f fc its claw Weight « J oz.
Adult Female. Plate GCCXXIV. Fig. 2.
Thé female is somewhat smaller, and resembles the male, but has
the head and upper part of the néck umber brown.