334 Mr. C. H. B. Grant on Birds collected in Argentina , 
The nest is placed either in the fork of a large tree or on 
the ground under a tuft of grass or a thistle, &c.; when in 
such a situation it is merely lined with a little wool or 
rubbish, but in trees the nest is composed of sticks and lined 
with grass or wool. Three eggs appears to be the complete 
clutch. 
Ten eggs were brought home, collected between Nov. 4 
and Dec. 28 ; they vary considerably in the arrangement of 
the markings, some being marked evenly all over and others 
having the bulk of the markings at the obtuse end. 
190. Milvago chimachima. 
Ibycter chimachima Sharpe, Cat. B. i. p. 39. 
a. £ ad. Puerto San Juan, Paraguay. Aug. 26, 1909. 
191. POLYBORUS THARUS. 
Polyborus tharus Sharpe, Cat. B. i. p. 31 ; Arg. Orn. ii. 
p. 81. 
a. ? ad. Luiconia, Ajo. Nov. 19, 1908. 
b , c, d. $ $ nestling. Luiconia. Nov. 19, 1908. 
e. ? young. Los Ynglases, Ajo. Feb. 9, 1909. 
/. ? young. „ „ Mar. 3, 1909. 
g . ? ad. ,, ,, Mar. 20, 1909. 
The adult female taken in November is in full plumage 
and very much worn ; it was the parent of the three 
nestlings. 
Irides brown, orbits and cere orange-chrome ; bill pearly 
slate-coloured; legs and toes lemon-yellow, nails black. 
The adult female, shot on March 20, is not really fully 
adult, inasmuch as the feathers of the breast are barred as 
in the old bird, but have broad white shaft-streaks ; new 
feathers are appearing in this region, and these are as in the 
fully adult, while the hind-neck, ear-coverts, and fore-neck are 
more strongly tinged with rufous. This appears to point to 
an immature stage, intermediate between the young and fully 
adult bird. 
I can add little to the excellent notes given by Mr. Hudson 
in the ‘ Argentine Ornithology/ except to say I have never 
seen one of these birds take living prey, and have always 
