.'^12 PROF. HUXLJiY ON THK ALECTOROMORPHiE. [May 14, 



stauding if I speak of them as the Gallo-coltjmbine series. The 

 best mark of the birds of this series is the sternum, which is almost 

 always very readily recognizable, great as its variations are. 



I have endeavoured to show that the Fteroclomorphce completely 

 connect the Pigeons and the Tetraonine division of the Alectoro- 

 morphcE. M. Blanchard has observed that " les Alectors, c'est-a- 

 dire les genres Crax, Urax, Pene/ojoe, ont des rapjiorts etroits avec les 

 Tetrao, en menie temps qu'ils indiquent I'affinite dont il a ete question 

 entre les deux families des Gallides et des Columbides" (l. c. p. 104). 

 I confess I cannot perceive any close relation between the Peristero- 

 podes and the TetraonincB. On the contrary, the former appear to 

 me to be more directly connected with the GaUince, and especially 

 with Numida. And though there are unmistakeable resemblances 

 between the Peristeropodes and the Pigeons in the form of the feet 

 and in that of the sternum, I am inclined to think, in view of the 

 many differences of these birds, that they do not indicate any very 

 close affinity. 



From the point of view of the Evolution theory, all the Gallo- 

 cohuubiue birds must be regarded as descendants of a single primi- 

 tive stock ; and the relations of the different groups should be capable 

 of representation by a genealogical tree, or phylum as Haeckel calls 

 it in his remarkable ' Generelle Morphologie.' Such a phylum 

 can only be put forward with confidence when a tolerably complete 

 knowledge of the development and of the palseontological history of 

 a group has been obtained. 



But if, with our present information, I were called upon to draw 

 out such a phylum of the Gallo-columbine birds, I should suggest 

 some such scheme as the subjoined : — 



Peristeropodes Alectoropodes 



I I 



Pterocloniorphce > 



Pensteromorphce 

 I 



Tuniiciittorphce 

 CluuadriuiHorpkce 



Heteromorphee 



Tinamomorphoi 

 I 



CARINAT.E RATITiE. 



i I 



Such a scheme implies that all the Gallo-columbine birds have 

 had a common ancestry, and that the Pterodomorphce are the 

 nearest .representatives in the direct line of tiiat ancestry. This, of 



