144 GENUS PLYCTOLOPHUS. 



narrowed and acute, overhanging the lower mandi- 

 ble ; the tomia or cutting edges sinuated or toothed ; 

 under mandible narrower than the upper ; the tongue 

 thick, fleshy, and smooth ; nostrils lateral, in the cere 

 at the base of the bill ; head crested, the crest com- 

 posed of two rows of acuminate feathers, the tip di- 

 rected forwards, and which can be erected or de- 

 pressed at will ; cheeks plumed ; tail rather short, 

 even ; plumage compact, the tips of the feathers 

 rounded, truncate ; feet robust ; tarsi short and re- 

 ticulated. 



The Cockatoos, so called from the usual call-note 

 of the species, form a well marked genus, readily 

 distinguished from the other groups of the Psittaci- 

 dse by their light and uniform colour, which is white, 

 or white tinged more or less, according to the species, 

 with sulphur-yellow or rose-red, by their peculiar 

 shaped crest, and by their short and even tail. The 

 massive and powerful bill, as well as the robust scan- 

 sorial feet of this section, evidently point to the si- 

 tuation they hold in the family ; and, with the near- 

 ly allied genus Calyptorynchus and some other forms 

 which sustain the connexion with more distant groups, 

 they are considered as representing the Rasorial 

 group of the family. They are natives of Australia 

 and the Indian Isles, where they inhabit the woods 

 and forests of these luxuriant climes. They feed 

 apon the seeds of various trees and plants, being 

 able, with their powerful bill, to break the stones of 

 tl*e hardest fruits. Their nidification is similar to 



