124 Baron R. K. von Warthausen on the Nidification 



The notice of a pair of Falco lanarius having bred on the 

 Pyramid of Cheops in May 1851 (v. Heuglin, ' System. Ue- 

 bersicht der Vogel N.-O. Afrika's') is erroneous, as has been 

 admitted by the author of that report. 



2. Falco eleonor^, Gene. {Falco arcadicus, Linderm.) 



Heuglin observed four adult pairs of this bird in the Archi- 

 pelago of Dabalak, on the 30th August 1857, on a reef formed 

 by madrepores, and shot two pairs of them. All the adult birds 

 which he observed or shot were, contrary to Bonaparte's account 

 and figure, uniform fumigated-grey with a whitish hue and a 

 lighter throat. 



There were three nests found, two of which were situated 

 below prominent rocks, immediately above the surface of the 

 sea, at a height of about 30 feet. The third was in a cleft of 

 a rock in the middle of the cliff. They were not true nests, but 

 only rather shallow cavities on the sandy surface, and contained, 

 the first, two young ones and one egg ; the second, two young 

 ones ; and the third, one young and one egg. 



The only egg in my possession is 16 lines long and 13| broad, 

 whereas Thienemann (Fortpflanzungsgesch. der Vogel, tab. 52. 

 8 a, b.), in accordance with the size of the bird, states the length 

 to be 18i lines and the breadth 15 lines. J\Iy specimen, which 

 has perhaps been altered by incubation, is of a nearly uniform 

 yellowish-white, slightly spotted with reddish. I conclude from 

 its small size that it is not fully developed. It is covered with 

 dirt, and too imperfect to determine its weight. Fragments of 

 the eggs from which the young ones were hatched are more or 

 less distinctly dotted and spotted with reddish-brown, the ground- 

 colour being reddish-yellow. The shell is delicate, in grain in- 

 termediate between that of Falco tinnunculus and Falco subbuteo. 



The young birds have white down, and the naked parts 

 of a reddish olive-colour. They all died before the juvenile 

 plumage was completed ; in this state they very much resemble 

 Falco subbuteo. A broad black moustache is very distinct ; the 

 upper parts are dark grey, the margin and tip of each feather 

 being i-eddish-ferruginous ; the lower parts are reddish-ferru- 

 ginous, with dark-brown spots along the shafts. 



