300 
Rev. H. B. Tristram on the 
moment the female issued from another hole close by, and 
escaped. On further search, I found a small chamber with last 
year’s nest, and another passage out, by which the remaining 
bird had escaped. The Arabs say that they use old snake- 
holes, and make a second exit themselves, for security from the 
large carnivorous lizards, which are their great enemies. The 
retreat is always just under a bush, no doubt for the sake of 
greater consistency in the sand, which otherwise would certainly 
fall in and choke the inhabitants. I found new nests in process 
of construction as early as January. The fragments of old eggs 
which I picked up are, as might have been expected, of a blue 
colour. There is, as will be seen from the Plate, a remarkable 
difference in plumage between the male and female, thus refer¬ 
ring it rather to Saxicola than to Dromolcea. 
37. Saxicola cenanthe. (Wheatear.) 
38. Saxicola stapazina. (Stapazine Chat.) 
39. Saxicola aurita. (Eared Chat.) 
These three Chats occur in the northern portion of the Hauts 
Plateaux, but are merely winter visitants. 
40. Saxicola lugens, Licht. S. leucomela, Temminck, 
PI. Col. 257. (Mourning Chat.) 
This bird, in habits very like S. philothamna, but less con¬ 
fined to the bushy portions of the Desert, does not appear to 
come so far north even as the M*zab country. It dwells in the 
boundless deserts of the Touareg, south of the furthest French 
imaginary line. It was only here, and in the Chamba country, 
south-west of Waregla, in lat.30° 50', that I obtained specimens. 
It is very shy, and possesses great powers of flight. 
41. Saxicola deserti, Rupp. (Desert Chat.) 
In the general distribution of its colours this Chat very much 
resembles the S. stapazina , but the bill and tarsi are at least half 
as long again, and the black of the throat extends much further, 
the rufous head and back being exchanged for a more sombre 
isabel colour. There is no sexual distinction of plumage. Like 
the last-described, it is restricted to the south of the Sahara, but 
resorts to the level, shrubless Salt-plains, hopping along the 
