490 



IBIS. IBIS. 



The birds of which this genus is formed are intermediate 

 between the Tantali and Numenii, some of the larger species 

 approaching the former, while some of the smaller are very 

 similar to the latter. They are also most intimately allied 

 to the Spoonbills, which, in fact, are Ibises with the bill 

 singularly flattened and expanded. The gradation from Ibis 

 Falcinellus, the only British species, to Numenius Arquata, 

 is almost so direct as to leave room for no intermediate form. 

 The digestive organs and many of the habits of these birds 

 are similar, and it does not appear that any unprejudiced 

 person could refuse to admit that the Ibises are very closely 

 allied to the Scolopacina?, although they also have an affinity 

 to the Ardeinae, the gradation to which is completed by the 

 intervention of the genus Tantalus. They are generally of 

 moderate size, with the body ovate, robust in the larger 

 species, rather slender in the smaller ; the neck long and 

 slender ; the head small, oblong, and compressed. 



Bill very long, slender, rather thick at the base, arcuate, 

 tapering, compressed, toward the end somewhat cylindrical 

 and slightly enlarged at the end, which is obtuse ; upper 

 mandible with the dorsal line arched, the ridge rather narrow, 

 more convex toward the end, separated from the sides by a 

 narrow groove, which extends from the base to the tip ; the 

 sides, which at the base are erect and flat, toward the end 

 narrowed and convex, the edges sharp and direct or somewhat 

 inflected, the tip rather blunt and scarcely longer than that 

 of the other; lower mandible with the angle long, very 

 narrow, with a groove extending from it to the tip, the sides 

 erect or a little inclined inwards, and fiat or somewhat con- 

 cave, beyond the middle convex, the edges inclinate and 

 sharp, the tip obtuse ; the gape-line arcuate, commencing 

 before the eyes. 



Mouth rather narrow ; palate flattened, with an anterior 



