PELECANIDZ: PELICANS. 721 
extent 48.00; wing 16.00; tail 8.00, pointed, 12-feathered; tarsus 1.50; middle toe and claw 
3.50; bill along culmen 3.75, along gape 5.00. 8S. Atlantic and Gulf States, very abundant, 
swarmning at its breeding places along the low shores and keys; nest of sticks and weeds, in 
bushes ; egg single, character as before, 2.50 X 1.75. 
o4. Family PELECANIDZ: Pelicans. 
Bill several times as long 
as the head, comparatively 
slender, but strong, straight, 
broad, ilattened, grooved 
throughout, ending with 
a distinct claw-like hook. 
Mandibular rami joining 
only at their apex; the long 
broad interramal space, and 
the throat, oceupied by an 
enormous membranous sac. 
Nostrils abortive. Wings 
extremely long, in the up- 
per- and fore-arm portions, as well as the pinion, with very numerous remiges. Tail very 
short, of 20 or more feathers. Feet short, very stout. Size large. 
The remarkable pneumaticity of the body (shared however by the gannets) has been 
already described. A principal osteological character is, that ‘‘ the inferior edge of the ossified 
interorbital septum rises rapidly forward, so as to leave a space at the base of the skull, which 
is filled by a triangular crest formed by the union of the greatly developed ascending processes 
of the palatiues.” The sternum is short and broad, with shallow emargination on each side 
behind: the fureulum is firmly anchylosed with it. The ececa are au inch long. The tongue 
is a mere rudiment. But the most obvious peculiarity of these birds is the immense skinny 
bag hung to the bill, capable of holding several quarts when distended; its structure is as fol- 
lows: The covering is ordinary skin, but very thin; the lining is skin modified somewhat like 
Fie. 501. — Bill of North American White Pelican. 
‘mucous membrane ; between these ‘‘ is interposed an equally thin layer, composed of two sets 
of very slender muscular fibres, separated from each other, and running in opposite directions. 
The outer fibres run in fascicles from the lower and inner edge of the mandible, those from its 
base passing downward, those arising more anteriorly passing gradually more forward, and 
reach the middle line of the pouch. The inner fibres have the same origin, and pass in a con- 
trary direction, backwards and downwards. From the hyoid bone to the junction of the two 
crura of the mandible, there extends a thin band of longitudinal muscular fibres, in the centre 
of which is a cord of elastic tissue. By means of this apparatus, the sac is contracted, so as to 
occupy but little space. When the bill is opened, the erura of the lower mandible separate from 
each other to a considerable extent [in their continuity —not at the symphysis], by the action 
of muscles inserted into their base, and the sac is expanded.” This organ is used like a dip-net, 
to catch fish with ; when it is filled, the bird closes and throws up the bill, contracts the pouch, 
letting the water run out of the corners of its mouth, and swallows the prey. Pelicans feed in 
two ways; most of them, like our white one, scoop up fish as they swim along on the water ; 
but the brown species plunges headlong into the water from on wing, like a gannet, and makes 
a grab, often remaining submerged for a few seconds. Neither species often catches large fish ; 
they prefer small fry of which several hundred may be required for a full meal. The prevalent 
impression that the pouch serves to convey live fish, swimming in water, to the little pelicans 
in the nest, is untrue; the young are fed with partially macerated fish disgorged by the parents 
46 
