297 
Ornithology of Not'thern Africa. 
seen afar; his cleat* bright colouring gleams in contrast with 
the universal brown around him. Conscious of his attractions, he 
attempts no concealment, but relies for safety on his watchful 
eye and rapid movements, and, above all, on the snug retreat 
which he always has open before him—his hole in the rocks or 
his burrow in the sand. I think that those who are familiar 
with the habits of this class will at once admit the propriety of 
Cabanis* separation of the genus Dromolcea from the old one 
of Saxicola. Strong as are the structural affinities through¬ 
out the whole, the manners of the living birds are in marked 
contrast. Wherever there are savage ravines, bare cliffs re¬ 
flecting a burning glare on the hungry valley, rent chasms, fear¬ 
ful in the unspeakable stillness which pervades the transparent 
atmosphere around, gorges which strike the intruder with awe, 
as though life, vegetable or animal, had never dared to intrude 
there before, even here may a pair of Rock-Chats of some species 
or other be detected. If a snap shot has been successful, the 
victim generally contrives to escape into some deep fissure to 
die; and frequently it is impossible to recover the spoils. 
Dromolcea leucura is found only in the north of the Desert. 
EP Aghouat may be considered its southern limit; and it alone 
of the class comes up to the foot of the Atlas, on the southern 
slopes of which it is tolerably abundant from Morocco to Tunis, 
breeding among the rocks, building a compact nest of moss and 
hair, and laying ordinarily four eggs, somewhat larger than 
those of the Wheatear, of a rich deep greenish blue, covered 
towards the larger end with rust-red blotches and spots. Its 
song is monotonous, consisting of but three notes; but the call- 
note is clear, loud, and musical. 
34. Dromolcea leucopygia (Brehm, Cab. Journ. f. Orn. 
1858, p. 66). (White-rumped Rock-Chat.) 
Of this bird I had prepared a description as of a new species, 
under the very name given to it by Brehm, before I was aware 
that he had already published it from Nubian specimens in 
Cabanis’ Journal,—a lesson this to naturalists not to allow a 
year and a half to elapse before making public their discoveries; 
for I had obtained a series of specimens a twelvemonth before 
