in the Eastern Atlas . 
309 
indispensable requisite to their haunts; for I observed it not un- 
frequently in the arid district of Guerah el Tharf. In the map, 
this lake looks a magnificent piece of water; but it is in reality 
what most of the places similarly laid down are, viz. a wide ex¬ 
panse of sand covered with saline incrustation, which only in 
peculiarly wet seasons is flooded with water. There nearly 
always exists in most of these sandy plains a great amount of eva¬ 
poration, which, with the white saline matter on the surface, at 
a distance of a few miles gives all the appearance of a turbulent 
lake. Indeed, so perfect is the deception, that on arriving at 
Ain Beida, we supposed that, when looking on Guerah el Tharf, 
we had in view a magnificent lake; and so we continued to 
believe it, till a morning's ride destroyed the illusion. Sub¬ 
sequently I saw many other instances of mirage, in some of 
which the hills, clouds, and all the surrounding objects were 
perfectly reflected. Near Ain Djendeli, I used frequently to 
notice the present species about the trees that overhang the dry 
stony water-courses that run from the hills into the plain be¬ 
neath. We never found a nest, however, in one of the above- 
mentioned places; and it would seem that the bird prefers a 
moister soil for its breeding-haunts, such as is afforded by the 
lowlands near lake Djendeli, where the Tamarisk-trees grow on 
the banks of the Chemora and the small Ain or spring. The 
nest we found usually placed conspicuously in the fork or on a 
branch of one of these trees, and with apparently no attempt 
at concealment. The heights at which the structure is placed 
vary from one to six feet from the ground. In one instance I 
found a nest among the roots of a tree in a bank-side, in a 
place where one would have expected in England to have found 
the nest of a Robin. The materials employed are the dead 
shoots of the Tamarisk, w T hich form the outside, the inside and 
lining being usually coot's or duck's feathers, mingled with 
wool or camel's hair; and in nine cases out of ten, a small piec e 
of serpent's skin is loosely placed in the bottom of the nest*. 
The number of eggs varies from three to five. They are laid 
about the third week in May. 
* I have since observed other instances of serpent’s skin sirailail} used. 
As to what object the bird has in view in employing such materia , can 
form no conjecture. 
VOL. I. Y 
