Barrows on Birds of the Lower Uruguay. 
89 
1S83.] 
with the cold they only flew when hard pressed, and were then 
almost inevitably swept by the wind directly into the waiting 
mouths of the birds. Selecting a bush on which a peck or two 
of the insects were clinging, I would dislodge them by a sudden 
shake, and in an instant become the centre of a flock of voracious 
birds, which seemed to have lost all fear and were intent only on 
the helpless insects, which were snapped up often within a foot 
or two of my face. 
The dragon-flies were of medium size, having a spread of per- 
haps 2J to 3 inches. They did not cling to each other like bees 
or locusts but simply crowded as near as possible, clinging so 
thickly to twigs and leaves as to hide entirely the color of the 
foliage and transform green mimosas into shapeless masses of 
gray and brown. 
12. Progne tapera (firm .). — This species appeared in the 
spring at about the same time as the preceding — about the middle 
of September — and for some time I did not distinguish it from 
the female of that species. 
In general habits the two species are quite similar, but the notes 
are somewhat different and the present species is more often found 
away from the houses than is the common Martin, nor does it, 
so far as I know, ever breed under the eaves of dwellings. Prob- 
ably the greater number breed in natural hollows of trees, or in 
the abandoned nests of other birds. I once noticed several hov- 
ering about Woodpeckers’ holes in a tall dead tree, and early in 
November, 1880, saw a female carry a feather into a deserted nest 
of the Oven Bird ( Furnarius rufus ), where I caught her in my 
hand as she was arranging the materials of a nearly finished nest. 
13. Progne elegans Baird. — Specimens were taken at Ba- 
hia Blanca, where the birds were abundant, and they were fre- 
quently seen in the Sierra de la Ventana. While at Carhue and 
Puan — March 21 to April 9, 1881— none were seen, but the 
weather was so cold that doubtless they had then gone north. 
At Concepcion this species was never observed. 
14. Hirundo (Tachycineta) leucorrhoa ( VieilV ). — Go- 
londrina (Swallow). — By far the most abundant Swallow at 
all points visited. Arriving from the north early in July, it remains 
through the summer and does not leave until the following April. 
Abundant alike in the crowded streets of Buenos Aires and on 
the monotonous pampas, it is known everywhere by the name 
