THE WHITE IBIS. §\ 



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 5^ 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 slit. 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 1^ 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 l\ 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 3i inches; its width 4^ twelfths. There is a small 

 gall-bladder about ^ 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 cceca, 

 Fig. 2, c c, are reduced to the minimum size, being only 1| 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. VI. 9 



