ALLEN'S NATURALISTS LIBRA RV 



GAME-BIRDS. 



THE SAND-GROUSE. ORDER PTEROCLETES. 



The sixteen species comprtsing this small Order, intermediate 

 in its affinities between the Pigeons {Columhce) and the True 

 Game-Birds i^Gallhice), are all included in one family, Piero- 

 clidcE. Their general structure presents many striking Colum- 

 bine characters, as in the vocal organs, pterygoid bones, and the 



Fig. 



)f /'. ex list us. 



Fig. 



Skull of /'. exusius. 



presence of basipterygoid processes {bp) in the skull (Fig. i), 

 the shoulder-girdle, sternum, and especially the great deltoid 

 process of the humerus, or upper-wing bone ; but the digestive 

 organs are like those of the True Game-Birds. Among other 

 distinctive characters may be mentioned the " schizorhinal " 



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