Mr. J. I. S. Whitaker on Tunisian Birds. 93 



6. Saxicola stapazina. 



I met with the Russet Chat occasionally during my late 

 journey, and more particularly towards the end of it, or after 

 the middle of April. Last year, when in the Regency, and 

 earlier in the season, I obtained a specimen of S. melano- 

 leuca, with the broad black throat-band, so that it woukl 

 appear that both forms occur in Tunis. 



This degree of longitude, broadly speaking, seems to be 

 the meeting-point of the eastern and western forms. In 

 Italy, Prof. Giglioli tells me, both forms occur in the neigh- 

 bourhood of Florence, which lies pretty nearly in the same 

 degree of longitude as Tunis, S. melanuleuca becoming 

 rarer as one goes west, and S. stapazina as one goes east, 

 the former indeed being unrecorded from Genoa and the 

 western Riviera, while the latter is unrecorded from Bari and 

 the extreme east of the Peninsula. 



In talking of these two Chats, it would perhaps be more 

 correct to call them species, as they really seem sufficiently 

 distinct to be separated. Besides the disparity in the breadth 

 of the black throat-band, I notice the following differences 

 between the two, viz. : — 



a. On the forehead in S. stapazina the black marking 



does not extend over and comjiletely round the top 

 of the culmen as it does in >S^. melanuleuca. 



b. The scapulars in the former are light, or cream- 



coloured, while in the latter they are dark, or jet- 

 black. 



c. The inside of the wings in S. stapazina is very much 



lighter in colour than in S. melanoleuca. 



In length of wing, and size generally, I find no differences 

 between the two. The tail-marking varies so much in indi- 

 viduals of the same species that one can scarcely attach 

 much, if any, importance to any diff'erence in this respect 

 between the two species, and the fact of there being more or 

 less white or black may be merely a question of age. 



Although the two forms are, I think, clearly separable, it 

 is not impossible that they may interbreed, and that inter- 



