r.UCEROTIDAE 



391 



tlu^ unwieldy body acting as a groat drag, though couuterhahinccd 

 by the |»U('uiuaticity, or air-containing nature of the bones, which 

 is perliaps greater in Hornbills than in any other birds. On the 

 wing a sound is generally produced like that of a steam-engine, 



Fig. 82. — Horulnll. Dirhncemshicornis. Female ami young. (From Malay Archipelago.) 



possibly due to the open nature of the quills : l)ut R]iino2)lai' , 

 Jjerenieornis, Anorhinvs, and AnfJiracoceros malaharlcKs are said 

 to Hy noiselessly. In some species the wing-action is regular ; 

 in others, rapid strokes alternate with sailing movements on out- 

 spread pinions; the head is usually drawn in and the tail depressed; 

 while Hocks proceed in single file. Individuals alight heavily, and 



