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82. Sylvia nana deserti (Loche). 



This beautiful little Warbler, with its pure white underside and an upperside 

 exactly of the colour of the sand-dunes, is by no means rare in the sandy desert, 

 whether it is flat or forms dunes of considerable height. Koenig only came across 

 it 50 km. south of Touggourt, but we found it on the sand-dunes between Uumash 

 and Biskra, and wherever tiiere was sand of some extent, from near Kef el Dohr 

 southwards, between Biskra and Touggourt, while in the valleys between the dunes 

 on the way from Touggourt to El Oued, with scanty vegetation of Limoniastrum, 

 Ephedra, Callujonuin, Aristida pnngeii/s (" Driu "), here and there an Euphorbia 

 yui/oni<ui<i, and very fesv other i)lants, it was not rare at all. It is, however, 

 absent from all stony desert and sebcha. As a rule we found it somewhat shy 

 and wary. 



The song, whicli is sometimes uttered during a short flight, like that of Si/lc/a 

 cominunis, but mostly while sitting on a bush, is a pleasant typically sylviine song, 

 not very unlike that of <S'. communis. 



The nest is rather deep, somewhat shaped like that of a Keed Warbler, 

 though of course not woven round stems, but placed in a fork of a branch or 

 twig. The nests we found were conspicuous enough, from 3 to 'ih feet from the 

 ground in Ephedra or Calligonum bushes. They were composed of grasses, stalks 

 and leaves, interwoven with Gnaphalium blossoms, and softly lined with wool and 

 cobwebs or bits of thread. Diameter of cup 2 — 2'5 in., depth 2^ — 2>\ in. 



The three eggs are white or pale greenish, spotted with pale olive-brown and pale 

 grey shell-marks. The markings form an ill defined ring or are mostly confined to 

 the big end. The eggs of a clutch we funnd on April G, 1U09, about 4i) km. west of 

 El Oued, measure 16'5 x 12'4, 16'2 x 12'4 and 154 x 12 mm. A week later, on 

 April 13, we found two empty nests, on which the birds were sitting I 



Koenig {.Jonrn. J. Orii. 1895, pi. 1), figured botii sexes, but the male (in the 

 foreground) is much too red, not isabelline enough, and the female (in the back- 

 ground) looks ipiite difl'erent*. In fact the se.Kes are perfectly alike in every way I 

 We have collected 25 skins. Their wings measure : S 50 — 59, mostly 50 — 57 mm. ; 

 ? 64 — 57'5, mostly 55 — 50 mm. 



The iris is bright sulphur-yellow, or bright lemou-yellow ; feet cream-colour 

 (sometimes more yellow) ; upper bill and tip of lower horn-brown, lower and cutting 

 edge of upper pale flesh-colour. 



83. Sylvia melanocepliala melanocephala (Gm.) 



We found this bird common near Biskra, Hammam Meskontine, and Algiers, and 

 one male was shot near Kef el Uohr, south of Biskra, March 28, 191)9, but we could 

 not say if it was breeding so far south ; this last specimen has a strong rosy tinge 

 on the sides of the abdomen, which we do not find so well marked in any other male 

 in our collection. 



The form from the Western Canary Islands \_S. melanocephala leucogastra 

 (Ledru)] is well distinguishable by its smaller size alone. Dr. Sassi's failure to 

 recognise it {Orn. Jahrbuch, 1908, p. 34) was probably due to his not separating the 

 examples from the Eastern Islands, which belong to S. m. melanocephala. 



Hartert ( I'yy. pal. Eatinu, i. p. 593) raised the ipiestiou, if the form from 



* Comparmg various copies, we found tliat they were not all ahke, but the faults were the 

 same iu all of them. 



