PELECANID^: PELICANS. 



721 



extent 48.00 ; wing 16.00 ; tail 8.00, pointed, 13-feathered ; tarsus 1.50 ; middle toe and claw 

 3.,50 ; bill along culmen 3.75, along gape 5.00. S. Atlantic and Gulf States, very abundant, 

 swarming 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. 



per- 



54. Family PELECANID..E : Pelicans. 



Bill several times as long 

 as the head, comparatively 

 slender, but strong, straight, 

 broad, flattened, grooved 

 throughout, ending with 

 a distinct claw-like hook. 

 Mandibular rami joining 

 only at their apex; the long 

 broad inten-amal spac«, and 

 the throat, occupied by an 

 enormous membranous sac. 

 Nostrils abortive. Wings 

 extremely long, in the up- 

 and fore-arm portions, as well as the pinion, with very numerous remiges. Tail very 



Fig. 501. — Bill of North American White Pelican. 



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 palatines." The sternum is short and broad, with shallow emargination on each side 

 behind : the furculum is firmly ancliylosed with it. The c(Eca are an 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 

 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 bUl is opened, the crura of the lower mandible separate from 

 each other to a considerable extent [in their continuity — not at the sjnnphysis], 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 svnm 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 



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