﻿EXTERNAL ANATOMY. CRESTS. 41 



deviation, however, leads us to another, of which at 

 present we know but of one example, the Cephalopterus 

 ornatus of Geoffroy St. Hillaire. The crest of this 

 extraordinary bird is immensely large, advancing so 



sharp ridge, suddenly recede from each other, curve out- 

 wards, and form a most elegant drooping line of plumes, 

 hanging over on the sides, so as to shade the face like an 

 umbrella. The figures that have hitherto been given 

 of this rare bird are all taken from the specimen in the 

 Paris Museum, and which has been sadly distorted in 

 the setting up ; a minute examination of this specimen 

 has convinced us that the frontal feathers, instead of 

 being raised over the bill, as Temminck represents 

 them, partly repose and overshadow it, at least as much 

 as do those of Calyptomina and Rupicola. Having 

 now reached the highest development of this form, 

 Nature evinces her usual propensity to return to the 

 more simple form of crest, and she therefore unites the 

 fixed with the mobile structure. The crests of the or- 

 dinary species of Corythaioo is precisely of this de- 

 scription : that part which occupies the front of the 

 head advances forward, and this being the natural 

 position of the feathers, gives us the character of a fixed 

 crest; but the hinder part, which is the longest, is not 

 altogether compressed, although it cannot be said to lie 

 flat on the crown, like those of ordinary birds. We 

 have recently had the opportunity of seeing some living 

 examples of this genus in which the crest appears to be 

 always carried erect; although, judging even from the 



far in front as to 

 touch the end of 

 the bill, and it is 

 compressed in the 

 same manner as 

 that of Rupicola; 



I but the ends of 

 the feathers, in- 

 stead of meeting 

 so as to form a 



