HORNBILLS.— CLIMBERS. 71 



cry, very similar to the interrupted creakings of a watchman's 

 rattle, and ahiiost, as it. were, the vocal counterpart to the watery 

 tumult amidst which he usually resides. The nest is burrowed 

 in some dry bank above the reach of inundation, to a depth of 

 five or six feet. The female lays six or seven white eggs, and 

 is assisted by the male in the incubation, which continues about 

 sixteen days. 



13. The Calaos, or Hornbilh^—Bucerm^ — are large birds of 

 India and Africa, remarkable for their enormous dentated beak, 

 which is more or less arcuate, surmounted by a crest or promi- 

 nence, often as large as the beak itself {Plate ^-Jig^ 12.) These 

 singular birds hunt mice, reptiles, small birds, and even attack 

 dead bodies. 



ORDER OF SCANSOni.S OR ZYGODAGTYLiE. 



14. In birds of this order the external toe is directed back- 

 wards like the thumb, which arrangement gives them a more 

 solid support, and of which some genera take advantage in 

 clinging to, and climbing the trunks of trees. {Plate ^,fig. 5, 6, 

 7, and 10.) It is from this circumstance they have obtained the 

 common name of Climbers, although, strictly speaking, it is not 

 applicable to all of them, as there are many birds that truly climb, 

 which, owing to the disposition of their toes, do not belong to 

 this group. Every bird that has two toes directed forward, and 

 two backwards, belongs to the order of Scansoriae, or Climbers. 

 The habits of most of the species that belong to it are not known ; 

 and they vary in almost every genus. 



15. The Climbers generally nest in the hollows of old trees; 

 their powers of flight are middling ; like the Passerinae they feed 

 on insects, or fruits according as their beak is more or less 

 strong. It is remarked that in most of the genera that the 

 sternum has two notches behind, which conformation is in 

 accordance with the little strength of the muscles of their wings. 



16. The principal genera m<xy be distinguished by the follow- 

 ing characters : 



13. What are Hornbills ? Where are they found ? 



14. How are the Scansoriee characterised ? Do all climbing birds belong 

 to the order of Scansoriae ? 



15. Upon what do the Scansoriae feed ? Are they very powerful in their 

 wings ? 



16. Wiiat are the principal genera of the order of Scansorise ? 



