36 BIRDS OF TUNISIA 



variation in colour, according to age and season, and unless pairs are 

 obtained together, it is not always easy to decide to which of the two 

 species the females may belong. 



The fully adult plumage, whether male or female, is probably not 

 assumed by this aud allied species until after the first breeding season. 



I know of no instance of the female of the present species assuming a 

 dark throat, as appears to be the case, not uncommonly, in the female of 

 S. melanoleuca. 



As mentioned iii the article on the Eastern Black-eared Chat, the 

 proper name for the "Western Black-throated Chat must, no doubt, be 

 that of S. occidentalis, given it by Count Salvadori (Ann. Mus. Civ. 

 Gen. (2) iii, p. 116). 



As stated in my notes on Tunisian Birds {Ibis, 1895, p. 98), both 

 species of Black-throated Chat occur in Tunisia, S. melanoleuca, or 

 the eastern species, being, however, far less coiximon than S. occi- 

 dentalis, its western representative. That the two species are clearly 

 separable is undoubted, the points of difference between them being 

 the same as those between the two species of Black-eared Chat, in 

 addition, of course, to the black throat-band. 



Eoughly speaking, the degree of longitude in which Tunis lies 

 seems to be the meeting point of the two species of Black-throated 

 Chat, and, so far as I am aware, the eastern bird does not occur 

 fiu'ther west than the Regency. 



North of the Mediterranean we find the same holding good in 

 Italy, both species, according to Prof. Giglioli, occurring in the 

 neighbourhood of Florence, which lies nearly in the same degree of 

 longitude as Tunis, S. mslanolcuca being rarer to the west, and S. occi- 

 dentalis to the east of that town, the former, indeed, being unrecorded 

 from Genoa and the western Eiviera, while the latter is unrecorded 

 from Bari, and the extreme east of the Peninsula. 



In Sicily both species occur, though S. melanoleuca appears to be 

 the commoner of the two. 



Although the two species are undoubtedly distinct, it is not 

 impossible they may interbreed in districts where they meet, and that 

 hybrids may occasionally occur. In the Florence Eoyal Natural 

 History Museum, for instance, a male specimen is to be found, 

 obtained from Genoa, which has the narrow black throat-band of 

 S. occidentalis, but the dark scapulars, and the dark under-wing 

 surface of S. melanoleuca. The specimen in question, however, also 



