Cape San Antonio, Buenos Ayres. 411 



My largest adult specimens measiu'e : — Male, length 24 

 inches, across the wings 57 ; female, length 27, across the 

 wings 61. 



Breeding -Notes. — The nest is always placed on the very 

 summit of a tree sufficiently isolated to command a view of 

 the neighbourhood. Large trees are preferred ; and only in 

 one case (out of six) have I found a nest in what was little 

 more than a bush, a stunted tala about six feet high. All 

 these nests were rather over three feet in diameter ; and one, 

 a disused eyrie, must have been at least five feet high, showing 

 that it had been occupied for several years. They are built 

 of large sticks, some of which are nearly as thick as one^s 

 wrist, and the hollow in the centre cushioned with dry grass. 

 Two eggs seem to be the number generally laid ; and two 

 clutches in my collection measure respectively 2f J] x 2, 2^^ x 

 2^, and 2f ^ x 2^^, 2|g x 2^^ inches. Colour dull white, 

 marked with pale reddish blotches. These nests were taken 

 on 8th December and 29th March, the latter date correspond- 

 ing to the end of autumn. On each occasion I shot the 

 females, but found the males paired again shortly afterwards. 



2. BUTEO ERYTHRONOTUS, King. 



The only appearance of this species was in 1875, in the 

 month of June, when a pair took up their abode in the woods 

 at the head station, both of which I secured. 



3. Urubitinga unicincta (Temm.). 



Not uncommon, though I have only succeeded in obtain- 

 ing three specimens, one being in immature plumage, and, 

 as yet, have never met with a nest. It generally frequents 

 woods, winding slowly amongst the trees and bushes, and 

 keeping at no great height from the ground. Those I dis- 

 sected contained remains of rats and mice. 



4. Circus cinereus, Vieill. 



Common, and essentially a plain-frequenting bird. The 

 rich bright yellow of the legs and feet contrasts very prettily 

 with the slate-blue and cinnamon-coloured plumage. Its 

 flight is low and rather rapid, while, if its quarry should 

 double, it loses no ground ; for it turns something in the 



