90 Mr. J. I. S. Whitaker on Tunisian Birds. 



Like Alauda cristata theckla, but much paler, and of a 

 light sand-colour. 



Ad. ^. Total length 6 in., wing 39, tail 2*2, culmen 

 *55, tarsi -8. 



Ad. ? . Total length 5-5 in., wing 3G, tail 2, culmen '5, 

 tarsi "8. 



Hab. Tunisian Sahara. 



In my rather large series of Crested Larks from South 

 Tunis, I have several specimens which correspond in some 

 measure with Canon Tristram's description of G. arenicola, 

 but I have placed these under A. macrorhynclia. The large- 

 billed Larks certainly differ among themselves to a consi- 

 derable extent, apart from any difference there may be 

 between the sexes of each individual race, and I have in my 

 collection three fairly distinguishable varieties, coming from 

 different districts, viz. : — No. 1, a very large and very pale 

 bird; no. 2, a smaller and darker bird; and finally no. 3, also a 

 smaller, but a pale bird. I had not, however, intended 

 speaking of these local forms of large-billed Larks, for the 

 present at any rate, or until I had made further and fuller 

 investigation into the matter, but Dr. Koenig, I see, has fore- 

 stalled me in his above-mentioned work on the ornithology of 

 Algeria, although he seems to have noticed but two varieties. 

 While, without doubt, these can merely be looked upon 

 as local, sedentary forms, modified according to the climate 

 and natural characteristics of the district in which each par- 

 ticular form may occur, it is nevertheless highly interesting 

 to notice to what an extent such modification can be, and is, 

 carried by natural causes ; and in no family of birds, perhaps, 

 is this better exemplified than in that of the Larks. 



Apologizing for this digression, and returning to Mr. 

 Aplin's journey, I may say that in the north of the Regency 

 he met with much better luck than in the south, obtaining 

 specimens of several species new to my collection, among 

 others Garrulus cervicalis, Picus numidicus, Gecinus vaillanti, 

 Parus ledouci, and Pycnonotus barbatus, all procured in the 

 neighbourhood of Ghardimaou, where the country is thickly 

 wooded and well watered. 



