from the culomj of Natal, in South-eastern Africa. 207 



but it appears to me that Gyps riippelli prefers alighting on trees, 

 if there are any near. In other respects these Vultures resemble 

 Gyps fulvus in their habits, but I have not lieard them make the 

 unearthly noises over their food that Gyps fulvus does. 



[With reference to the very dark colour of the eye in the spe- 

 cimens of Gyps riippelli obtained by Mr. Ayres, it may be re- 

 marked that the colour of the irides in this species appears (ac- 

 cording to the report of different observers) to be subject to con- 

 siderable variation. Dr. Riippell describes them as " white inter- 

 mixed with serpentine fibre-like lines of brown ;" Dr. Brehm as 

 " silvery-grey,^^ and Dr. Vierthaler as " yellowish-brown." Pro- 

 bably these variations may partly result from differences in age. 

 The specimens sent by Mr. Ayres, I should suppose, from their 

 plumage, to be birds of the second or third year. — J. H. G.] 



66. Falco biarmicus, Temm. Latakoo Falcon. 



Male, adult. Eye lightish brown ; legs and skin round the 

 eye bright yellow ; cere and base of the bill bright yellow ; centre 

 of the bill slate-colour ; tip black. 



This bird is very rare here. It is exceedingly quick on the 

 wing when in chase. The specimen sent descended from a great 

 height, with a succession of rapid twists, but happened to come 

 within shot before it reached the small birds which it was at 

 the time pursuing. 



Some time back two of these birds attacked a cat, which was 

 hunting for rats on a bare field not far from the house, and fairly 

 drove her away from their domain ; the cat was obliged to stop 

 every now and then to defend herself. 



67. Nectarinia natalensis, Jardine. Natal Sun-bird. 

 Feeds principally on the nectar of flowers ; will also eat the 



softer kinds of insects ; generally hangs its nest on the outer- 

 most twigs of trees, at no great height from the earth, and very 

 frequently over water. 



68. Nectarinia af ra, Linn. Greater Double-collared Sun- 

 bird. 



Habits and food much the same as those of N. natalensis. 



69. Nectarinia amethystina, Shaw. Amethystine Sun- 

 bird. 



