Like many other South- American Swallows the nesting-habits of the present species 

 vary with locality, and the observations recorded above should be compared with the 

 following interesting observations of Mr. W. H. Hudson : — 



" I have already spoken in former communications of all but one of the species of Ili- 

 rundinidas that visit us in this region ; the bird I have yet to describe is the Atticora cyano- 

 leuca — the Gohndrina de los tlmoneles negros of Azara, and the smallest of our Swallows. 

 I cannot say what are the limits of its range, as my wanderings have not extended far in 

 any direction, and I have never yet been in any region where it is not well known. In 

 Buenos Ayres these Swallows appear early in September, coming before the three species 

 of Progne that visit us, but preceded by the H'wundo leucorrhoa. They are bank-birds, 

 breeding in forsaken holes and burrows (for they never bore into the earth themselves), 

 and are consequently not much seen about the habitations of man. They sometimes 

 find their breeding-holes in the banks of streams, or in peopled districts in the sides of 

 ditches, and down in wells. But if in such sites alone fit receptacles for their eggs were 

 found, the species, instead of one of the commonest, would be rare indeed ; for on the 

 level pampas most of the watercourses have marshy borders, or at the most but low and 

 gently sloping banks. But the burrowing habits of two other animals, the Vizcacha 

 (Lagostomus trichodactylm) and the Minera ( Geositta cunicularia) have everywhere 

 afforded the Swallows abundance of breeding-places on the plains, even where there are 

 no streams or any other irregularities in the smooth surface of earth. 



" The Geositta bores its holes in the sides of the Vizcacha's burrows ; and in this 

 burrow within a burrow the Swallow lays its eggs and rears its young, and is the guest of 

 the Vizcacha and as much dependent on him as the Wren or the Swallow we call 

 domestic is on man ; so that in spring when this species returns it is in the village of 

 the Vizcacha we see them. There they live and spend the day, sporting about the 

 burrows, just as the domestic Swallow does about our houses. The nest, constructed 

 of dry grass lined with feathers, is placed at the extreme end of the burrow, and contains 

 five or six white, pointed eggs. After the young have flown, they sit close together on a 

 weed, thistle-top, or low tree ; and the parents continue to feed them many days. 



"As in size and brightness of plumage, so in language also is this Swallow inferior to 

 his congeners, his only song consisting of a single weak, trilling note, much prolonged, 

 whicli the bird repeats with great frequency when on the wing. But sometimes he 

 utters two notes ; and then the second note, though much the same, is longer and more 

 inflected than the first ; yet his voice has ever a mournful monotonous sound. If a 

 rapacious bird or a Fox chances to intrude upon the burrows when they are breeding, 

 these Swallows summon each other with cries indicative of fear and anxiety ; but even 

 then these cries are neither loud nor shrill. When flying, these Swallows glide along very 

 close to the earth, and when weary settle down (contrary to the custom of other Swallows) 

 and rest on the level grassy plains. Like other birds of this family they possess the 

 habit of gliding to and fro before a rider's horse to snatch up the little twilight moths 

 startled from the grass. Seldom does a person ride on the pampas in summer without 



