. Key to North American birds; containing a concise account of every species of living and fossil bird at present known from the continent north of the Mexican and United States boundary. Illustrated by 6 steel plates and upwards of 250 woodcuts. Birds. PELECANIDiE, PELICANS. 299 onlj^ at their apex ; the long broad interramal space, and the throat, occupied by an enormous membranous sac. Nostrils abortive. Wings extremely long, in the upper 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
. Key to North American birds; containing a concise account of every species of living and fossil bird at present known from the continent north of the Mexican and United States boundary. Illustrated by 6 steel plates and upwards of 250 woodcuts. Birds. PELECANIDiE, PELICANS. 299 onlj^ at their apex ; the long broad interramal space, and the throat, occupied by an enormous membranous sac. Nostrils abortive. Wings extremely long, in the upper 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 bj^ a triangular crest formed by the union of the greatly developed ascending processes of the palatines" {Huxley). The tongue is a mere rudiment. But the most obvious peculiarity of these birds is the immense skinn}' bag hung to the bill, capable of holding several quarts when distended ; its structure is as follows : 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 oppjosite 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 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
Size: 2173px × 1150px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1870, booksubjectbirds, bookyear1872
