1864 



THE PARROT TRIBE 



from New Guinea, all the species of the allied genus {Cyclopsittacus} being distin- 

 guished by the dark color of their beaks. 



THE COCKATOOS 

 Family CA CA T UID^, 



The remaining groups of the order are distinguished from those already noticed 

 by the nature of the under surface of the hook of the beak. This, in place of 

 being smooth or with fine longitudinal striae, is marked by a series of bold trans- 

 verse ridges, running from either side of the middle line in a more or less oblique 

 direction, so as to produce a file-like surface. Moreover, in all cases the tongue is 

 quite simple, being unprovided with any kind of brush or fringe. 



The cockatoos are readily 

 distinguished by the presence of 

 a crest of feathers on the head, 

 which is wanting in all the mem- 

 bers of the next family, with 

 the exception of the peculiar 

 horned and Uvsean parraquets 

 {Nymphicus), respectively from 

 New Caledonia and the island 

 of Uvasa in the L/oyalty group. 

 An absolutely distinctive feature 

 between the two families is, how- 

 ever, to be found in the skull. 

 Thus in all the cockatoos the 

 socket of the eye is surrounded 

 by a complete ring of bone, from 

 the lower border of which is 

 given off a process extending 

 backward to the hinder part of 

 the skull; whereas in the true 

 parrots (JPsittaddai) this ring is 

 generally incomplete, while in 

 such instances as it is entire, it 

 lacks the posterior bony process. 

 As minor characteristics it may 

 be mentioned that the nostrils 

 open in a cere which is not much 

 swollen, and is generally naked, 

 although occasionally feathered. 



The bill is of great depth, and usually very short, the upper mandible being gener- 

 ally much compressed, with its hook at right angles to the axis of the base. In all 

 cases the metatarsus is extremely short. 



COCKATOOS. 



