BTTCEEOTID^. 347 



Suborder BUCEROTES. 



(By W. R. OGILYIE-GRANT.) 



-Bill large or very large, supported internally by cellular bony 

 structure. Base of the culmen mth a variously-shaped casque, in 

 some species of large size while in others it is rudimentary and 

 only indicated by a slight compressed keel. In the majority the 

 casque is closed, hollow, and supported by bony tissue ; but in 

 Bucorax it is more or less open anteriorly, and in RhinopJax the 

 anterior wall is solid, while the posterior part is nearly filled up 

 with parallel bony columns. 



Palate desmognathous. Basipterygoid process absent. Episternal 

 process perforated to receive the bases of the coracoids. Sternum broad 

 behind, with two shallow notches. .Skeleton unusually pneumatic. 



Caeca none. 



Hallux connected with the flexor perforans dirjhorum, and not 

 with the flexor hngus haUucis. Flexor perforcms digitorum split 

 into branches, of which one leads to the first digit, one to the 

 second, and generally one to the third and fourth. 



Margins of the eyelids furnished with strong lashes. 



Spinal feather-tract not defined on the neck, which has no lateral 

 bare tracts. Tail-feathers ten. After-shaft none. No down- 

 feathers. Oil-gland tufted. Under wing-coverts do not cover the 

 basal parts of the quills *. 



Egg white. Young hatched naked and helpless. 



This suborder comprises one family only, the Hornbills. 



Family BUCEROTlDiE. 



Range. Africa, Austro-Malayan Region, and India. 



Eei/ to the Genera. 

 I. Casque hollow ; back of the neck and middle 

 of back feathered 

 A. Tarsus long, about twice as long as the 



middle toe and claw BIJCORACINM. 



_,_,,, 1. Bucohax, p. 349. 



a. larsus short, shorter or about equal to the 



middle toe and claw BUCEROTINM. 



a. Tail subquadrate ; the middle tail-feathers 

 hai-dly longer than the outer pair. 

 a'. Chin and throat feathered. 



a". Crest of long soft feathers ; casque 

 larg^e, elevated, and compressed or 

 rudimentary, scarcely rising above 



the lerel of the culmen. Plumage [p. 416. 



black and white. [Size large.] 1(3. Bycanistes", 



* No doubt tlie loud noise made by many of these birds when flying is 

 caused by the air rushing between the bases of the quills. 



