1920.] of the Mar ocean '■'Middle- Atlas y 281 



Of these, the 5 species apparently coufiued to Mauretania 

 are : — 



RJiamphoronjs clot-bey and Chersoj>hilus dupo)Ui,i\\o Desert 

 Larks, the sole representatives of their genera. 



D'lplootocus )noHssieri, the only representative of its genus, 

 which, however, is near those of the Palsearctic Redstarts 

 and Chats. 



Siihia deserth-ola, a Warbler of the Mediterranean " Melizo- 



plnline'^ type. 



^'umida sahi/i, one of the thoroughly "African'" Guinea- 

 fowls nearest to JX. meleayris. 



Of the remaining 13, all but two are reasonably accounted 

 for by their wide ranging propensities or by transition from 

 the eastward. The exceptions are Otis arahs and FrancoUnus 



bicalraratus, which (even should they prove to differ 



racially from the African species), with the Guinea-foAvl, 



are certainly the most exotic representatives of the 



Mauretanian Avifauna. 



To sum up : even if we include the Tschagra, Bulbul, and 

 Bush-babbler, it must be admitted that the genera and 

 species of the Mauretanian Avifauna, with the so-formed 

 5 per cent. African infusion of species, are remarkably free 

 from complex affinities when compared with those of many 

 other bounding territories of the " Zoographical Regions " ; 

 and, as might perhaps be expected, exhibit nothing of the 

 peculiarities of distribution attributed by Hooker to the 

 plant-species of the Upper Great-Atlas. 



The gap of south-west and south-central Europe between 

 the Maroccan-Atlas and the rest of the vast area occupied 

 by EremophUa alpestrls is curious, but cannot be given 

 more weight tlum that of an isolated exception. 



Now let us review the subject in the light of Racial 

 distribution. 



Out of the 80 si)ecies oonnnon to Mauretania and South 

 Spain, one half of the species are represented in Mauretania 

 by different racial (or subspecific) forms, and if we eliminate 



