Barrows oh Birds of the Lower Uruguay. 
1883.] 
209 
sufficient circumstantial evidence to implicate the present species 
in their construction. 
89. Synallaxis hudsoni Scl . — A strictly terrestrial species 
which does not occur at all at Concepcion. We first saw it at 
Azul late in January, 1881. The first individuals seen were 
flushed from the long, dry grass which grew along the bank of 
the stream at that place. They rose very much like Pipits, for 
which I at first mistook them, although their note is quite differ- 
ent. We soon found that they were not confined to the long 
grass near the stream but were equally plenty in the short grass 
of the pampas. They were afterward met with in all suitable 
localities on the pampas, and even on the meseta of the Sierra de 
la Ventana at a hight of some 2000 feet above the surrounding 
plain. I know nothing of the nest, but as the birds are only 
found on the treeless plains we should expect the nest to resemble 
somewhat that of the species just described. 
90. Placellodomus sibilatrix Doring . — An abundant spe- 
cies among the open woods- along the Uruguay and hardly dis- 
tinguishable at ten paces distance from half a dozen others. Its 
nest, however, is unmistakable. The birds begin by fixing a few 
crooked and thorny twigs among the terminal sprays of some 
slender branch which juts out horizontally from a tree, or rises 
obliquely from near its base, and around these twigs as a nucleus 
more are gathered, until by the time the nest has reached the pro- 
per size its weight has bent the branch so that its tip points direct- 
ly to the earth. Nests which are thus begun at a distance of fif- 
teen or twenty feet from the ground are often only two or three 
feet from it when finished, and a thorough soaking by a heavy 
rain will sometimes weigh them down until they actually touch. 
They are more or less oval or cylindrical in shape and commonly 
about two feet long by twelve or fifteen inches in diameter, and 
contain from a peck to a bushel of twigs and thorns. The nest 
cavity within is small in proportion to the size of the nest, and 
occupies its upper part. It is reached by a more or less direct 
passageway from below, the external opening being very nearly 
at the lowest part of the nest, though sometimes a little shelf, or 
even a pocket, is built on to the side, forming a resting place in 
front of the door. 
The nests vary interminably in size and shape, but are pretty 
constant in the material used — this being almost always irregular 
