1919-] Cope Sian .Antonio, Bumos Ayres. 507 



stages of plumage which it undergoes *' (Ibis^ 1912, 

 p. 277). 



In view of the foregoing, it may doubtless be assumed 

 that the Harrier found in Ajo is Circus macropterus (Vieill.) 

 iiut maculosus. 



A clutch of three eggs, collected by Miss Ruunacles on 

 11 November, 1901), appertained to a nest situated under a 

 tuft of esparto in the rincones, and was composed of a little 

 dry grass. The three white eggs are somewhat pointed 

 and rough-shelled.' They average 50x37 mm. 



295. Buteo swaiiisoni Bp. Swainson's Buzzard. 



So far as Swainsons Buzzard is connected with the 

 Argentine Republic (vide Sclater and Hudson's work) the 

 recorded occurrences are limited to two, the tirst taken by 

 Mr. Hudson himself at Conchitas in 1860, and the other by 

 Mr. Frank Withington at Lomas de Zamora in 1886 — both 

 localities being within a few miles of Buenos Ayres. 



Since then Claude Grant collected two individual speci- 

 mens in Ajo on 4 Noveml)er, 1908, and 9 December, 1909, 

 respectively. Both were young birds and males. 



1 have no further information to furnish on the subject. 

 It is satisfactory to learn that the s[)ecies can be added to 

 tlie Ajo list. 



296. Buteo albicaudatus Vieill. White-tailed Buzzard. 

 Hudson is familiar with this species as a migrant, visiting 



the pampas in the spring and autunju in a gregarious form — 

 ''flocks varying from thirty to forty, or as many as one or 

 two thousand birds." 



Claude Crrant does not seem to have met with it during 

 his visits to Ajo. 



With all due deference and reserve I submit the following- 

 extracts from my diary (the only occurrences recorded in 

 forty-five years), and which I would suggest may probably 

 refer to the species in question : — 



" 15 December, 1872. Observed a flock of eleven fine grey- 

 blue Buzzards hovering over Yngleses head-station woods. 



SER. XI. — VOL. 1. 2n 



