CHERSOPHILUS DUPONTI MARGARITA 249 



CHERSOPHILUS DUPONTI MARGARITA (Koenig). 



EUFOUS DUPONT'S LARK. 



Alsemon margaritae, Koenig, J. f. 0. 1888, p. 228; id. J. f. O. 1893, 



p. 48. 

 Chersophilus margaritae, Whitaker, Ibis, 1895, p. 98 ; id. Ibis, 1896, 



p. 89. 

 Alsemon duponti margaritae, Erlanger, J. f. 0. 1899, p. 370. 



Description. — Adult male, spring, from Zamas, South Tunisia. 

 Like C. duponti in the disposition of its plumage marking, but of a 

 distinct rufous coloration instead of dark brown. 

 Soft parts and measurements as in C. duponti. 

 Adult female similar to the male, but rather smaller. 



The present subspecies, first recognised and described by Dr. 

 Koenig (J./. 0. 1888, p. 228), differs from typical C. duponti (Vieill.) 

 in being much more rufous in colour. This difference is very pro- 

 nounced and constant within a certain zone, and although, as 

 mentioned in the preceding article, intermediate forms between C. d. 

 margaritcB and the typical dark-coloured G. duponti occur in certain 

 districts, there can be no doubt that the former has a fair claim to 

 rank as a geographical race or subspecies. Examples in my collection 

 from Oglet-Ouhamia, Zamas, Tamerzed, and other places in the south 

 of the Tunisian Eegency, are exceedingly rufous in colour ; others from 

 Mehamla and the neighbourhood of Gafsa are rather less rufous, but 

 are probably identical with Dr. Koenig's type specimens, which were 

 procured from adjacent districts. Specimens which I have obtained 

 from the country lying between Gafsa and Feriana are only slightly 

 more rufous than typical C. duponti, some of them, indeed, being so 

 intermediate in their colouring, that it is impossible to refer them to 

 one form more than to the other. 



The present subspecies probably occurs in Algeria in districts 

 corresponding to those where it is found in Tunisia, and should any 

 form of Chersophilus occur in Tripoli, it probably belongs to the 

 present subspecies, and not to the darker-coloured C. duponti. 



The districts frequented by C. d. margaritce being further south 

 and more or less arid and desert-like, are naturally clothed with a 

 somewhat different description of vegetation from those where 



