420 Rev. H. B. Tristram on the 



The occurrence of this little bird in perhaps the most isolated 

 locality of the whole Sahara is very interesting. 



66. Crateropus FULvus (Desf.). " Erbib el Hadjel," kv&h., 

 i.e. the Adopted Son of the Partridge. 



Tliis bird, discovered by Des Fontaines in the last century, 

 forms one of the features of Saharan ornithology, numerous 

 wherever there are trees either wild or cultivated, and as noisy 

 and garrulous as the Starling, whom it much resembles in its 

 manner of flight. It flies very straight with its long tail ex- 

 panded, and is very wary. Often secreting themselves by threes 

 and fours in a shrub, these birds remain closely concealed, till at 

 the pursuer's near approach they silently steal away close to 

 the ground to the next bush. They are generally in companies of 

 seven or eight. Invariably do they alight at the foot of the tree 

 or bush, and then noiselessly creep up to the very top, descend- 

 mg in line on the other side, except one sentinel who remains 

 perched on the topmost bough to give the alarm of danger. 

 Often as I have watched them, I never saw them omit this pre- 

 caution. The note is very peculiar — chur-churr-r-r — wheer- 

 wheer-wheer. The nest is a loose fabric of sticks and fine roots 

 and straws ; and I was told by the Arabs that they lay a blue 

 egg, which Captain Loche has since had forwarded to him, and 

 of which I have received a specimen. They are considered good 

 eating by the French Spahi officers, and have wonderful medi- 

 cinal qualities according to the Arab Hakeems. I found the 

 flesh bitter and dry. The sexes are alike in plumage. On dis- 

 section I have found the gizzard filled indiscriminately with 

 beetles and seeds. 



67. MoTACiLLA ALBA. (White Wagtail.) '"M'sissi," Arab. 



68. BuDYTES FLAVA. (Ycllow Wagtail.) 



Both extremely abundant wherever there is moisture, saline 

 or fresh, all through the winter. The White Wagtail is both 

 scattered and frequently in vast clouds. Of the Yellow I have 

 found the two varieties flava and cinereocapilla, but did not in 

 the Desert meet with the hghter-coloured extreme, B. rayi, nor 

 with the darker-headed variety, so common in the East, B. me- 

 lanocephala. 



