42'i PROF. HUXLEY ON THE CLASSIFICATION OF BIRDS. [Apr. 11, 



the boclv ; nor are the pubis and the ischium of the same side united 

 by bone. 



8. The hallux present, as well as the other three digits of the foot. 



9. Only thirty-two precaudal vertebrae. 



10. The feathers without any aftershaft. 



It will be observed that in each of these families of the Ratitse a 

 particular form and arrangement of the bones of the palate accom- 

 pany the other distinctive characters. 



Under view of the skull of Ajiferyx austral is. From a specimen in the Musenui 

 of the Royal College of Surgeons. 



The letters as before. 



III. The order Carinatj5 (Merrem) embraces all existing birds, 

 except the Ratitse. They have the following characters in com- 

 mon : — 



1 . The sternum possesses a keel, and ossifies from a median centre 

 in that keel, as well as from lateral paired centres*. 



* The sternum is thus ossified in all the Carinatse which have yet been exa- 

 mined. The only apparent exception to the presence of a keel is the singular 

 genus Strigops. A knowledge of the ossification of the sternum of this bird is 

 greatly to be desired. 



