2 ; () 



distinctive character pointed out in my description of this species will be found to hold good 

 with the two specimens alluded to by Dr. Hartlaub. 



The closely allied forms are important to recognize ; for although to the more casual observer 

 they may appear to unnecessarily complicate the subject by increasing the already large list of 

 known species, the recognition of them is of considerable assistance to those who would study 

 the subject more thoroughly, by restricting the range of certain species, and enabling us more 

 truthfully to point out the true limits of natural zoo-geographical districts. 



It is worthy of note that, of the many West-African species of Sun-birds which have been 

 met with between the Senegal river and the Congo, not one extends its range to any part of the 

 east coast between Cape Guardafui and the Cape of Good Hope ; for I consider Anthodiceta 

 zambesiana certainly distinct, though very closely allied to A. hipodila. Now in North-east 

 Africa this is not the case ; a few of the West-African species finding their way into those 

 districts tend to show that the interior of Africa between the Nile basin and the west coast 

 presents a less formidable barrier, at least for birds, than does Central Africa south of about 

 10° North latitude. 



