16 A Revision of the Genus Haplopelia. 



There is a specimen in the British Museum from " West 

 Africa," which, as is stated on the label, has been compared 

 with the type. This example is rather lighter rufous in 

 colouring than the hens of the other nearly allied forms 

 which I have examined, and it certainly possesses pure 

 white under tail-coverts. 



As the type-specimen and the bird in the British Museum 

 so closely resemble the hen of H. s. poensis, I have little 

 doubt that the male bird (when discovered) will prove to be 

 very closely allied to it, and H. forbesi will then rank as a 

 subspecies of H. simplex. 



For the present I prefer to keep it separate. 



Haplopelia principalis . 



Peristera principalis Hartl. Proc. Zool. Soc. 1866, p. 330 : 

 Prince's Island. 



In my paper on the Birds of Prince's Island I have already 

 pointed out {' Ibis,' 1914, p. 630) that H. principalis cannot 

 possibly be confused with//, s^ simplex, as has been done by 

 Dr. Reichenow. In fact, it is so much more differentiated 

 from the typical form than either H. s. poensis, H. s. in- 

 ornata, H. s. plumbescens, H. s. hypoleuca, or even H. s.jack- 

 soni, that I have here kept it as a distinct species. 



From these five races the adult males may be distinguished 

 at "a glance hji\\e\v pinkish underparts, while in H. s. simplex 

 and tlie subspecies mentioned above the general tone of the 

 under surface is dove-grey. The hens are not so distinct, 

 but, nevertheless, can be easily differentiated. 



It may be that I shall be criticised for considering H. 

 principalis from Prince's Island a species, when I unite birds 

 on the mainland and in the other two islands (Fernando Vo 

 and Annobon) with H. s. simplex — the St. Thomas Pigeon. 

 I have done so, however, as H. principalis shows a per- 

 fectly distinct scheme of colouring in being pink instead 

 of grey, and shows therefore that it has probably been 

 isolated for a considerably longer period than any of the 

 other island-forms with which we are dealing. It can no 

 longer be united with the grey-breasted birds, and must 

 stand as a separate, well differentiated race. 



