of North-Eastern Africa. 409 



3. H. coNCOLOR (Gould^ Birds of Eur. tab. 25). 



The true H. concolor is rare in the tropical parts of North- 

 Easteru Africa. I obtained specimens on the Bahr el Abiad, 

 from Tigreh (Mareb and Valley of the Takasseh) and from Am- 

 hara (Lake of Tana and. sources of the River Takasseh). I 

 found this bird always singly, and in countries covered with 

 forest, between 2000 and 6000 feet above the level of the sea. 

 The iris is dark brown, and the eye remarkably large. The 

 West- African form {F. ardosiaceas, Vieill.), which is found also 

 in Madagascar, is specifically different from the East- African. 



4. H. RUFicoLLis, Sw. (Swains. Birds of West Africa, tab. 2.) 

 This species is not scarce, and is found in pairs on the Blue 



Nile, southward from the 14th degree to Eazogloa, nearly always 

 on Dolleb-palms. It is only occasionally found in Abyssinia 

 and along the Bahr el Abiad. 



5. H. .ESALON (Gm.). 



I have found not rarely old and young specimens of this 

 pretty species in Egypt, between the winter and the month of 

 May, especially in the more northern parts. It resorts by pre- 

 ference to the acacias and sycamores in the cultivated portions of 

 the country. 



6. H. HORUS, Heugl. [Falco gracilis, A. Brehm in Nauman- 

 nia, 1856, p. 232, cum fig.) 



I have rarely observed this species in the rocky deserts of 

 Egypt and Nubia. A. Brehm has described a young specimen 

 of this species, killed by myself in August 1851 near the so- 

 called " Fossil Forest,'^ at the Mokatam Mountains. The figure 

 published by him is from a drawing made by me from nature. 

 The young specimens of this species are very similar to those of 

 F. eleonorce, but the two birds are decidedly different. The 

 plumage of the old bird is not known to me, but only an inter- 

 mediate coloration, with the upper parts slate-blue, spotted with 

 darker colouring, as in F. ruficollis. 



The Falco semitorquatm of Sir A. Smith is said by De Filippi 

 (Rev. Zool. 1853, p. 289) to occur on the upper parts of the Bahr 

 el Abiad, but I suppose that that learned ornithologist has con- 

 founded it with my H. castanonotus. So far as I know, Falco 



2f2 



