THE WHITE IBIS. 
fit 
Young bird killed in September. 
In its first plumage this species is of a dull brown colour all over except- 
ing the rump, which is whitish, and the tail, which is tinged with grey. 
After the first moult, the bill is pale yellowish-orange, toward the base 
greenish ; the naked parts of the head are pale orange-yellow, inclining to 
flesh-colour ; the eye dark brown ; the feet pale blue. The plumage is of a 
dull olivaceous-brown, the quills darker, the tail rather lighter, the hind 
part of the back white, the breast and abdomen white. 
In a female preserved in spirits, the roof of the mouth is flattened,, with 
an anterior median longitudinal ridge ; and the two sides or crura of the 
lower mandible are united for more than half their length from the tip. The 
tongue is triangular, extremely short, being only twelfths in length, flat, 
and extremely thin, broadly emarginate and papillate at the base, the two 
lateral papillae much larger, its upper surface covered with numerous small 
crypts, its tip obtusely pointed. The posterior aperture of the nares is 
linear, with an anterior sdit. The mouth is rather narrow, being only 7 
twelfths in width. The tongue and the general form of the mouth are thus 
similar to those of the Spoonbill ; and the former is entirely different from 
that of the Curlews and Snipes, to which this genus approaches in the form 
of the bill. The aperture of the ear is remarkably small, its diameter being 
only 14 twelfths. 
The oesophagus, Fig. 1, a b c d, is 11 inches long, wide, like that of a 
Heron, its diameter varying from 1 inch to 1J inches, being greater at the 
lower part of the neck, and contracting to 9 twelfths as it enters the thorax. 
The stomach, d efg, is large, muscular, broadly elliptical, 2? inches long, 1 
inch 10 twelfths in breadth ; the lateral muscles strong, the inferior very 
large. The duodenum, g h i, curves in the usual manner, returning upon 
itself at the distance of 31 inches ; its width 4J twelfths. There is a small 
gall-bladder about J inch long, and two biliary ducts ; beyond the entrance 
of which the intestine forms several convolutions, and preserves a nearly 
uniform width throughout. The rectum is 3 inches long, and the coeca, 
Fig. 2, c c, are reduced to the minimum size, being only 14 twelfths in 
length. In this respect, as well as in the structure of the stomach, this bird 
differs entirely from the Heron, to which it approximates in the form of 
the oesophagus, although not in that of the tongue. The contents of the 
stomach are remains of cray-fish and aquatic insects. Its epithelium is 
thick, tough, longitudinally rugous, but not presenting two distinct grinding 
plates. The proventriculus, c, is 10 twelfths in breadth, and its glands are 
of a cylindrical form, about 2 twelfths long, with wide apertures. The 
length of the intestine is 3 feet 9 inches. 
The trachea is 9% inches long, of the nearly uniform breadth of 4 twelfths ; 
Vol. YI. 9 
