188 
AMERICAN WHITE PELICAN. 
oblique position, and the sac is expanded. The upper mandible is capable 
of being moved to a considerable extent. 
Below the anterior angle of the eye is a small sac about 5 twelfths of an 
inch in length, with an external aperture of 2 twelfths, and filled with a 
pulpy substance. The nostrils are linear, about 3 twelfths of an inch long, 
and quite concealed by the wrinkles of the skin. The aperture of the 
posterior nares 8 twelfths. The tongue is an extremely small, papilliform 
body, 82 twelfths of an inch long, and 1 twelfth in diameter. The aperture 
of the glottis is linear, 8 twelfths in length, destitute of papillm behind. 
The pharynx is about 24 inches in breadth. The oesophagus, c, at the 
commencement, or opposite the tongue, has a diameter of about 6 inches, 
and contracts until the middle of the neck, where it is 3 inches in width ; at 
its entrance into the thorax at b it 
contracts to 14 inches, but is dilatable 
to 3 inches ; at this part, its inner 
coat is thrown into very prominent 
longitudinal rugas. The structure of 
the oesophagus is similar to that of 
the Loon already described, but its 
muscular coat is much thinner. On 
entering the thorax, it again expands 
to a diameter of 3 inches. Its length 
from the glottis, exclusive of the pro- 
ventriculus, is 2 feet. The proven- 
triculus, c d, when not extended, has 
a diameter of 2 inches, its length 
being 4 inches and 8 twelfths. It is 
marked internally with six longitu- 
dinal broad ridges, about half an inch 
in breadth, and separated by grooves ; 
and its cuticular lining is 1-J twelfths 
thick, of a compact but soft texture, 
elevated into tortuous reticulated 
ridges. The glandules, which are 
cylindrical, the largest 3 twelfths of 
an inch long, 4 twelfth in diameter, 
form a comple te elongated belt. The 
muscular coat is also very thick, its 
inner layer composed of transverse, 
its outer of longitudinal fibres, and 
the greatest thickness of the walls of 
