442 PROF. HUXLEY ON THE CLASSIFICATION OF BIRDS. [Apr. 11, 



Fig. 24. 



Undci* view of the skull of Gypogcranus srrpn/farius ; two-thirds the size of 

 naturo. From a specimen in the Museum of the Eojal College of Surgeons. 



The letters as before. + The basipterjgoid processes. 



In all the other Vultures, Hawks, and Eagles the maxillo-palatines 

 unite with one another and with the largely ossified septum, and 

 there are no basipterygoid processes. 



These, therefore, are, so far as their cranial characters go, the 

 highest of birds of prey, or those which depart most completely from 

 the embryonic condition. 



All the Parrots present wonderfully uniform cranial characters. 

 The rostrum is articulated with the frontal bones by a complete 

 hinge-joint. Not only is this the case, but the jugal arches and the 

 palatine bones are moveably articulated by ligamentous joints with 

 the rostrum. There are no basipterygoid processes. 



The maxillo-palatines are very large and spongy in texture, and 

 unite with one another and with the ossified nasal septum so as to fill 

 up almost the whole base of the beak. Above, however, a nasal 

 passage is left on each side ; and, below, the maxillo-palatines stop 

 short, so that, in the dry skull, a passage, leading into the cavity of 

 the rostrum, is left on each side of the septum. 



The palatine bones have a highly characteristic figure, being very 



