THE DOUBLE-CRESTED CORMORANT. 
139 
The Double-crested and the Florida Cormorants are very nearly allied, 
their forms, and the structure of their plumage, being precisely similar. 
There is. however, a very considerable difference in size, as will be seen on 
comparing their measurements and average weights as given by me. The 
bills are similar in form, but their colours differ, as do those of the eyelids ; 
but in the breeding season these birds may readily be distinguished by the 
temporary tufts or crests behind the eyes, which in P.jloridanus consist of 
a mere line of single feathers curved downwards, while in P. dilophus they 
are of considerable breadth, and composed of about forty recurved feathers. 
In the absence of the crests, the difference in size affords the principal means 
of distinguishing them. 
Female. The mouth of this bird, and those of the other Cormorants, 
differ from those of all the birds hitherto examined and described in these 
volumes, in having the posterior aperture of the nares placed much farther 
forward, commencing nearly opposite the anterior angle of the eye, and in 
this species only 10 twelfths long, with a very prominent ridge on each 
side, running backwards over the hind part of the palate, which is flattened. 
The width of the mouth is 1 inch 4 twelfths ; but the lower jaw can be 
dilated to 2 inches, there being a joint on each side at the base, as in Herons. 
The tongue is a very diminutive ovato-lanceolate, thin, strongly carinate 
body, i inch in length, 3 twelfths in its greatest breadth, with two basal 
knobs placed close together. (Esophagus 16 inches long, at its commence- 
ment 2\ inches in width, afterwards 2 inches; contracting to I 3 inches as it 
enters the thorax, and again dilated into a sac 2i inches in width, a b, which 
is directly continuous with the stomach, that organ seeming to form its 
fundus. Its muscular fibres are very distinct, the external being transverse, 
the internal longitudinal ; the inner coat is thrown into prominent longi- 
tudinal plicae. The stomach, bed, is of a roundish form, 2 inches 2 twelfths 
in diameter ; its muscular coat extremely thin, being reduced to a single 
series of slender muscular fibres ; the inner coat quite smooth and soft, as is 
that of the pyloric lobe, d, which is £ inch in diameter. The proventricular 
glands, which are very numerous, form a belt, of which the greatest breadth 
is 1 inch 9 twelfths, but at one place only 1J inches. The lobes of the liver 
are extremely unequal, the right being 4 inches, the left only 2 ; the gall- 
bladder 1 inch 9 twelfths in length, oblong, 4 twelfths in breadth. The 
duodenum, d e fg, which is 3J twelfths in breadth, curves upwards at first 
to the length of 9 twelfths, d e, then bends round the stomach, ascends on 
the left side to the upper part of the proventriculus for the length of 6£ 
inches, retraces the same course until it reaches the liver, then passes down 
the right side, and is convoluted, forming twelve turns in all. It measures 5 
feet 10 inches in length its width in the duodenal part is 41 twelfths 
