WHITE-THROATED SPINE-TAIL arr 
open ground, its flight being only from bush to bush ; 
and though it is not timid, it is hard to detect it in 
its stronghold, and to hear it one would imagine 
that it was perched overhead on a tree, when it is 
hidden all the time in the brushwood at the roots.” 
This habit of concealing itself so closely inclines 
me to think that this species, rather than S. albescens, 
was the bird described by Azara, although in both 
species the language is nearly the same. I have 
nothing to add to the above account from Azara, 
except that in the love-season this species has a low, 
strange-sounding little song, utterly unlike its usual 
strident cry. When singing, it sits motionless on 
the summit of a low bush in a dejected attitude 
with head drawn in, and whispers its mysterious 
little melody at intervals of half a minute. 
WHITE-THROATED SPINE-TAIL 
Synallaxis albescens 
Above, forehead grey, crown pale chestnut; sides of head and 
neck, back, and tail pale earth-brown; upper wing-coverts pale 
chestnut, wing feathers olive-brown ; beneath white, faintly washed 
with earthy brown, under wing-coverts fulvous ; length 5.3 inches. 
THis species, although by no means abundant in 
Buenos Ayres, is met with much more frequently 
than the S. spixi, which it closely resembles in size, 
colour, habits, and language. It is indeed an unusual 
