24 



PBOF. D ARCT W. THOMPSON ON THE 



[Jan. 17, 



The skull of Licmetis (fig. 15) has certain peculiarities. The 

 postfrontal process is exceedingly broad, both in its descending 

 and its posterior ramus, and the supratemporal fossa is accordingly 

 restricted in size. The tympanic cavity is wider open than in the 

 others, the posterior wall encroaching little ; in this respect it 

 resembles the skull of C. roseicapilla. The inner head of the 

 quadrate is exceptionally large. The paroccipital processes are 



■ Pig. 15. 



Licmetis oiasica. 



rather short but very large, and looked at from behind form a 

 transverse ridge ; the area below them and between the meatus 

 and the basitemporal ridges is very well defined, constricted in the 

 middle into a peculiar shape by the lower notch of the meatus and 

 the interruption between basioccipital and paroccipital ridges, and 

 nearly horizontal. The angle of the mandible is more elongate and 

 pointed than in the other Cockatoos. 



In CalyptorTiynclius hatiksi and Calloceplialon galeatum (fig. 16) 

 the orbital ring is formed in the manner characteristic of the 

 Cockatoos, and the region of the squamosal process sends off no 



Yis, 16. 



Callocephalon galeatum. 



projecting lobe such as I have described in C. roseicainlla. In 

 C. galeatum the supratemporal fenestra is wide, and the surface 

 for the origin of the temporal muscle exceptionally large, extend- 

 ing far back on to the posterior surface of the skull. The 



