GaUino-Gralline Group of Birds. 425 



articulate with the pterygoids, as near the palatines and as 

 far from the quadrates as possible. 



5. They are heterocoelous in the articulation of their dorsal 

 vertebrae. 



6. The median process of the furculum is much developed. 



7. The angle of the mandible is produced and recurved. 

 The 4th character is diagnostic ; and so is the combination 



of the 1st and 3rd. 



The Gallinpe may almost be diagnosed by their peculiar 

 sternum. The median xiphoid process is very long and very 

 narrow ; the internal processes are much shorter, and the 

 external processes shorter still. The clefts are so deep that 

 the sternum may be described as all processes. 



The Gallinae appear to be intermediate between the Cryp- 

 turi and the Pterocletes. 



Pterocletes. 

 The Sand Grouse are intermediate between the Columbse 

 and the Gallinse. They present the following characters : — 



1. In the bifurcation of their nasals they are schizorhinal. 



2. The ankylosed sacral vertebrae are preceded by a free 

 vertebra, above which are four ankylosed vertebrae. 



3. They possess subclavicular processes. 



4. They have no vomer. 



5. They possess basipterygoid processes, which spring near 

 the body of the basisphenoid and articulate with the ptery- 

 goids as near the quadrate as possible. 



6. In the articulation of their dorsal vertebrae they are 

 heterocoelous. 



7. The hallux is either very small and elevated, or absent 

 altogether. 



The Pterocletes may be diagnosed in a variety of ways. 

 The 4th character is diagnostic ; but as the vomer is very 

 small in the Columbae, it is safer to combine the 7tli with it. 

 Equally diagnostic is the combination of the 3rd and 5th ; 

 or that of the 1st, 3rd, 6th, and 7th. 



The Sand Grouse agree with the Pigeons in the 1st, 2nd, 

 3rd, and 6th characters ; and with tlie Gallinae in the 2nd 



