ON SO ME SPECIES OF THE 



F. (com.) chaDfres, I should term it an accidental varie- 



leucoce- o ? 



phalus, Xy ^ , 



* In the opinion of BecksteiNj the White-headed Falcon is 

 specifically the same as the F. lagopus of Gmelin, the Roughs 

 legged Falcon of the British Zoology, (App.) To the same 

 species, Dr Shaw refers the Dusky Falcon of the Arctic Zoology, 

 and MoNi AGU thinks it probable, that the Booted Falcon, the 

 Falco pennatus of Brisson, upon future investigation, will also 

 be found synonimous with the F. lagopus, I have examined 

 several specimens of the Rough-legged Falcon, but they varied 

 so much in colour, that I am still ignorant of the fixed state of 

 plumage in that species. I have, however, little doubt, that 

 Pennant's Dusky Falcon is in reality one of its varieties. 

 Whether Beckstein's opinion concerning the F. ( communis ) 

 leucocephalus be correct or not, can only be determined by the 

 examination of a suite of specimens. With regard to the other 

 supposed variety, the F. pennatus, I may observe that it is on- 

 ly known to naturalists from the description of Brisson. Its 

 native country seems quite unknown. The F. lagopus, from 

 ■which I do not believe it to be distinct, is found in Denmark, 

 Norway, and the Alps of Switzerland. Its geographical dis- 

 tribution, however, will be greatly extended, if, as Latham 

 supposes, ( 2d Supplement, p. 24. No. 14.) it is synonimous with 

 La Buse Gantee of Vaillant, a species met with in the country 

 about the Cape of Good Hope, particularly in the Forest of 

 Hottinquas. This last mentioned variety, apcording to La- 

 tham, has a less mixture of white in its plumage ; a circum- 

 stance which we are naturally led to expect frorti the difference 

 of its physical position. 



Buffon was of opinion, that the F. leucocephalus, Briss. 

 pas a variety of his Common Falcon. As the latter species is 



