472 ARCTIC JAGER.
LESTRIS BUFFONII, Ch. Bonaparte, Synopsis of Birds of the United States, p. 364.
LESTRIS PARASITICA, ARCTIC JAGER, Swains, andBichards. Fauna Bor. Amer. partii.
p. 430.
ARCTIC JAGER, Nuttall, Manual, vol. ii. p. 317.
Adult Male. Plate CCLXVII. Fig. 1.
Bill about the length of the head, rather slender, straight, the tip
curved. Upper mandible with the dorsal line straight, toward the end
curved, the ridge broad and convex, the sides separated from the ridge
by a narrow groove, extremely narrow and convex, the edges sharp and
inflected, the tip compressed, rather obtuse. Nostrils in the fore part of
the nasal groove, nearer the tip than the base, submarginal, pervious,
linear, oblong, wider anteriorly. Lower mandible with the angle long
and narrow, a slight prominence at its extremity, beyond which the dorsal
line is straight and ascending, the sides sloping outwards and convex,
the edges sharp and inflected, the tip obliquely truncate and rather obtuse.
Head rather small, oblong, much narrowed before. Neck of moderate
length. Body rather slender. Feet rather short and of moderate strength ;
tibia bare at its lower part; tarsus anteriorly covered with broad decurved
scutella, on the sides with oblong scales, behind with smaller oblong prominent
scales; hind toe extremely small and elevated, the fore toes of
moderate size, connected by reticulated webs, which have their margins
convex ; the third toe longest, the fourth not much shorter, all covered
above with numerous scutella, the lateral ones margined externally with
small prominent scales directed forwards. Claws of moderate size, curved,
acute, compressed, that of third toe with a sharp inner edge.
The plumage in general is close, elastic, soft, and blended ; the feathers
on the back and wings rather compact and distinct. Wings very
long, rather broad, pointed; primary quills tapering and rounded, the
first longest, the rest rapidly graduated ; secondary rather short, rounded.
Tail feathers of moderate length excepting the two middle, which are
extremely elongated and gradually attenuated, the rest broad and rounded,
there being twelve in all.
Bill greyish-black, the upper part bluish. Iris brown. Feet black,
but with the greater part of the tarsus yellow. The neck and lower parts
are white, the former tinged with yellow ; upper and fore part of head
ARCTIC JAGER. 473
with the space before the cheeks blackish-brown; the lower part of the
hind neck and all the upper parts blackish-grey, the primary quills and
tail-feathers brownish-black, the shafts of the former white.
Length to end of tail 23 inches, to end of wings 15 ; extent of wings
45 ; wing from flexure 12; tail 12; bill along the back 1£, along the
edge of lower mandible If ; tarsus ljfg ; middle toe l 4 j , its claw
T
Adult Female. Plate CCLXVII. Fig. 2.
The Female resembles the male, but the middle tail-feathers are about
three inches shorter.