92 Rev. H. B. Tristram on the Ornithologrj of Palestine. 



Again, in the case of the resident Chats, their extremely 

 restricted habitat is remarkable. Often within very narrow 

 limits they are numerous, yet do not occur beyond these in 

 districts apparently as well suited for their development. This 

 is especially the case with respect to the genus Dromolcea, 

 D. monacha, Riipp., a Nubian bird, which I never found in the 

 Sahara (though it is erroneously given by Loche, who mistook 

 for it the next species, as I ascertained by examination of his 

 specimens), we only met with at the south end of the Dead Sea, 

 about the salt-mountain of Jebel Usdum. Nor has it yet been 

 noticed from Arabia. When in full plumage it is the most 

 elegant of the group. It is the type of Dromolcea, and is more 

 slender and graceful than any other species. The bill is very 

 long and slender, and the tail longer than in any of its 

 congeners. The adult male has not only the head, nape, and 

 belly, but also the whole tail, with the exception of the two 

 median rectrices, spotless white, the rest of the plumage glossy 

 black. In the young male the plumage is more dusky and the 

 white less pure. The female is ashy-brown instead of black. 

 We obtained it in all stages of plumage. 



In the same region, but extending much further into the 

 rocky wilderness and higher up the western shores of the Dead 

 Sea, is D. leucocejjhala, Brehm, a much stouter and more robust 

 though shorter bird, and with a very strong bill. The sexes are 

 identical in plumage; and the whole under surface is glossy 

 black, while the white does not extend nearly so far on the 

 rump as in the last species. With reference to the contrast 

 between their bills, we may remark that while D. monacha lives 

 on the sand and on the salt-hills, this one seeks its food 

 among the rocks above. It was an old acquaintance of mine in 

 the Algerian Sahara, as was also D. leucopygio, Br., of which we 

 procured a few in the rocks above Engedi. The only distinction 

 between these two is the snow-white cap of the former; 

 but in many of my specimens, both African and Asiatic, a white 

 feather or two peeps out on the head of D. leuco-pygia. It is 

 possible the cap is acquired by age ; but certainly both forms 

 breed, and I never found them interbreed. They may do so, 

 yet we generally saw a few of the one type in one locality and 



