426 Mr. H. Seebohm on the 



and 6th. They also agree with half the Gallinse in the 7th 

 character. 



The sternum of the Pterocletes very closely resembles that 

 of the Columbee ; the external lateral processes are very short, 

 the outer posterior notches are very deep, and the inner ones 

 small or completely ossified in the adult. 



The Pterocletes further resemble the Columba3 in having 

 the humerus pneumatic, and in having no median process to 

 the furculum. 



CoLUMBiE. 



The Columbse appear to be so closely connected to the 

 Gallinse through the Pterocletes, that it seems impossible to 

 exclude them from the Order. The Pigeons are probably 

 more nearly allied to the Sand Grouse than to any other 

 group of birds, although they are born heljjless and naked, 

 which is not the case with the Sand Grouse or with any 

 other group of the Order. The Colurabae possess the fol- 

 lowing characters : — 



1 . They are heterocoelous in the articulation of their dorsal 

 vertebrae. 



2. They are schizorhinal in the bifurcation of their nasals. 



3. The basal phalanx of the hallux is as long as that of the 

 middle toes. 



4. They are typically Galline in the ankylosis of their 

 dorsal vertebrae. 



5. They possess subclavicular processes. 



6. They have basiptcrygoid processes, which articulate 

 with the pterygoids near the middle of those bones. 



They may be diagnosed by their combinations of the 2nd 

 and 3rd characters. 



If we regard the extinct Dodo as belonging to the Columbse, 

 the 6th character would break down in this group, inasmuch 

 as there are no basiptcrygoid processes in the genus Didus. 

 It would, however, be unfair to include extinct species in any 

 group, as it is only by the extinction of species that any clas- 

 silication of groups becomes possible. 



