956 



SYSTEMA TIC SYNOPSIS. — STEGANOPODES. 



genus. This is the original Booby of Catesby, 1731, pi. 87 ; Pelecanus sula L. 1766, which 

 most authors have called Sula fiber, as I did in Key, 1st ed. 1872, p. 298; S. sula Yrrr. and 

 Des Muks, Rev. Mag. Zool. I860, p. 442 ; A. O. U. Lists, 1886-9.5, No. 115 ; Ridgw. Man. 

 1887, p. 75. It is also Pelecanus leticogaster Bodd. 1783 ; Sula leucogastra of many authors, 

 as of Key, 2d-4th eds. 1884-90, p. 720. 



Note. -S. websteri Rothschild, Bull. Brit. Oru. Club, vii, No. liv, 1898, of the Revillagigedo Islands, will prob- 

 ably be found within our limits. 



Fio. GC9. — Bill of North American White Pelican. 



Family PELECANID^ : Pelicans. 



Bill several times as long 

 as head, comparatively 

 slender, but strong, straight, 

 broad, flattened, grooved 

 throughout, ending with 

 a distinct claw-like hook. 

 Mandibular rami joining 

 only at their apex ; long 

 broad interrarnal space, and 

 throat, occupied by an enor- 

 mous membranous sac. 

 Nostrils abortive. Wings 

 extremely long, in upper- 

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

 to 22-24 feathers. Feet short, very stout; tarsi compressed, reticulate. Size large. Marine 

 and lacustrine or fluviatile. 



The remarkable pneumaticity of the body (shared however by Gannets) has been already 

 described- A principal osteological character is, that "the inferior edge of the ossified inter- 

 orbital 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 

 l)ehind ; furculum is firmly anchylosed with it. Cteca an inch long. Tongue a mere rudi- 

 ment. But the most obvious peculiarity of these birds is the immense skinny bag hung to the 

 bill, capable of holding several quarts when distended. The covering is ordinary skin, but 

 very thin ; the lining is skin modified somewhat lilie mucous membrane; between these "is 

 interposed an equally thin layer, composed of two sets of verj' slender muscular fibres, sepa- 

 rated 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 contrary direction, backwards and down- 

 wards. 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 whicli 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 crura 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 

 llie corners of its mouth, and swallows its prey. Pelicans feed in two ways ; most of them, like 

 mir white one, scoop up fish as they swim along on the water; but the brown species plunges 



