158 ANHINGA OR SNAKE-BIRD. 
of the Cormorants and Pelicans. The sternum in particular is almost 
precisely similar to that of the Crested Cormorant, so that without 
entering very minutely into its description, no differences could be 
pointed out. 
Both mandibles are concave within ; the palate flat, with two longi- 
tudinal ridges ; the posterior aperture of the nares linear and 9 twelfths 
long, the anterior or external aperture entirely obliterated. The lower 
mandible has a distinct oblique joint at about a third of its length, 
enabling it to be expanded to the extent of an inch and a half. The 
pouch, which is small, is constructed in the same manner as that of 
the Pelicans and Cormorants; its muscular fibres running from the 
lower edge of the mandible downwards and backwards, and a slender 
muscle passing from the anterior part of the hyoid bone to the junc- 
tion of the crura of the mandible. The tongue is reduced to a mere 
oblong knob, 13 twelfth long, and 3 twelfth in height. The aperture 
of the glottis is 3 twelfths long, with two roundish thin edged flaps be- 
hind, destitute of papille. There is a small bone appended to the oc- 
cipital ridge, } inch in length, as in the Cormorants. 
The cesophagus a 6, is 17 inches long, exceedingly delicate and dilat- 
able, with external longitudinal fibres, the transverse fibres becoming 
stronger towards the lower parts. Its diameter when moderately dilated 
is 13 inch at the top, 1 inch farther down, at its entrance into the tho- 
rax, 9 twelfths, and finally 14 inch; but it may be dilated to a much greater 
extent. The proventricular glands, instead of forming a belt at the lower part 
of the wsophagus, are placed on the right side in the form of a globular sac, 
about an inch in diameter, communicating with the cesophagus, b, and sto- 
mach, d. For two inches of the lower part of the cesophagus, 4, or at that 
part usually occupied by the proventriculus, the transverse muscular fibres 
are enlarged, and form an abrupt margin beneath ; on the inner surface 
there are four irregular series of large apertures of gastric glandules or 
crypts. The proventriculus itself, c, is composed of large crypts of irre- 
gular form, with very wide apertures, and covered externally with 
muscular fibres. The stomach, dd, is roundish, about an inch and three 
quarters in diameter, with two roundish tendinous spaces, ¢, and fasciculi 
of muscular fibres ; its inner coat thin, soft, and smooth. It opens by 
an aperture a quarter of an inch in diameter into a small sac, f, precisely 
similar to that of the Pelican, which has a muscular coat, with a soft 
even internal membrane, like that of the stomach. The pylorus has a 
