236 VERTEBRATA. 



The sternum is either perforated or entire. There are two caro- 

 tids. The gall-bladder is generally absent. 



In the foetal parrakeet the margins of the bill are beset with 

 tubercles, under each of which is a gelatinous pulp, like that of 

 a tooth. 



The bill assists in climbing, and the feet are used as hands, a 

 peculiarity possessed only by these birds and the goatsuckers. 



These birds are monogamous, living in society, and forming 

 their nests in holes of trees. The females have the same rich 

 colours as the males. They feed mostly on seeds and fruits, and 

 scream horribly. They are the only real climbers (hand-over- 

 hand) among birds. Some, as the grey parrot, are known to live 

 to a great age. 



The grey parrot (Psittacus erithacus), ground-parrakeet (Pezo- 

 porus formostu), canary parrakeet (Melopsittacus undulatus), the 

 love-bird (Agapornis Swinderiana), white cockatoo (Plyctolophus 

 sulphureus), the macaws (Macrocercus, sps.), and the green par- 

 rots of Brazil (Chrysotis, sps.) belong to this order. Strigops is 

 an owl-like, nocturnal bird of New Zealand, feeding on roots, &c. 

 It has a keelless breast-bone. 



There are about 430 known species. 



StrigopidcB. Pezoporus. Microglossus. 



Strigops. Platycercus. Plyctolophus =Ca- 

 Palaeornis. catua (Cockatoo). 



Trichoglossida:. Conurus. 



Nestor. Henicognathus Psittacida (Parrots). 



E Macrocercus =Ara = 



T : n --nnmWlli, a Sittace (Macaw). Corylhs. 



LonuB=Domicellus / Agapornis =Psitta- 



(Lory). 8 cl a 



Coriphilus. Ptyctolophid*. Brotogerys . 



Trichoglossus (Par- Nasiterna . Chrysotis. 



rakeet). Nymphicus = Calop- Pionus = Deropty us. 



., sitta. ' Eclectus. 



Macrocercida. Licmetis> Dasyptilus. 



Melopsittacus Calyptorhynchus. Psittacus. 

 =Nanodes. 



Order XII. ODONTOEM^E. 



Jaws with teeth in separate sockets. " Vertebrae biconcave. 

 Sternum with a keel. Wings well developed." 



Extinct " Eeptilian birds " found in the Cretaceous shales of 

 Kansas. The species are supposed to have been carnivorous and 



