30 BIRDS OF TUNISIA 



" (c) The uudei'-siu'face of the wiugs, both primarieb and 

 secondaries, is of a light colour, sometimes quite white, instead of 

 being black. 



" The adult male of the Western bird, moreover, does not seem 

 to assume, as a rule, the si 1 very-white plumage on the head and back 

 found in adult examples of S. aurita in spring, but remains always 

 more or less cream coloured. 



" On the other hand, the Western bird is generally whiter on the 

 throat and underparts than the Eastern bird. 



"In some specimens of the Western form there is very little 

 black on the lores, some examples, indeed, having none at all, although 

 probably this is exceptional. 



" The measurements and soft parts are the same in both forms. 

 As in the case of the two species of Black-throated Chat, the meeting- 

 point of the two species of Black-eared Chat is probably, roughly 

 speaking, about the tenth degree of east longitude. From Tunis I 

 have both forms, although the Western is by far the conjmoner of 

 the two ; in fact, out of some twenty specimens in my collection, 

 only one is of the Eastern form. All my specimens from Algeria 

 and Marocco are of the Western form." 



The validity of the name S. caterince having been disputed, I 

 subsequently wrote on the subject as follows [Ibis, 1903, pp. 408- 

 410) :— 



" In order to arrive at a satisfactory solution of this question of 

 names (for apparently the distinctness of the two forms or species 

 is now recognised by most ornithologists), it is necessary to examine 

 and carefully consider previous descriptions of the Black-eared Chat, 

 with a view to ascertaining, so far as may be possible, to which form 

 they refer. 



"Taking first Vieillot's (Enanthe alhicoUis (" Nouv. Diet." xxi., 

 p. 424, 1818), the description given of this bird, although in many 

 respects applying equally to both forms, when taken as a whole 

 applies far better to the Eastern form than to the Western. To 

 begin with, the plumage of the upper parts in the Western form 

 could never correctly be described as of a "beau blanc," even 

 " legerement teint de roux," &c., the upper plumage of this form 

 being distinctly cream coloured. On the other hand, in the Eastern 

 form these parts are of a fine white. Secondly, the words " une 

 bande noire traverse et enveloppe I'oeil" are certainly more applic- 



