Plate XCVI. 



CENTRITES OREAS. 



(ANDEAN CENTEITES). 



Anthusfuhus . . . d'Orb. Voy. Ois. p. 223 (partim). 



Centrites niger . . . Scl. et Salv. P.Z.S. 1867, p. 987, et 1S6S, p. 589. 



Gentrites oreas . . . Scl. et Salv. P.Z.S. 1869, p. 154. 



Niger: dorso castaneo : remigum priraariorum pogoniis internis albioantibus : long, tota 5'5, alo3 3'2, caudae 2'0. 

 Fern. Pusca : dorso lurid^ castaneo : primariis, sicut in mari, albicantibus, sed ciunamomeo tinctis. 

 Hab. In montibus elevatis Peruvise et Boliviae. 



"When we first received specimens of tliis bird in one of Mr. Henry "WTiitely's recent collec- 

 tions from Western Peru, we failed to detect its distinctness from the well-known Centrites niger 

 of Patagonia and the Argentine repi;blic. At first sight, indeed, .these differences are not very 

 apparent, and d'Orbigny before us had united the two birds under qne name. But the receipt 

 of additional specimens in one of Mr. Whitely's subsequent collections having induced us to 

 look more closely into the matter, we discovered certain constant differences between them, and 

 thereupon described the present species under the name Centrites oreas from its mountain habitat. 



Centrites oreas^ as we shall now show, differs from Centrites niger in two very noticeable 

 characters. In the first place it has the inner webs of the pi'imaries dull white for the greater 

 portion of their length, passing, however, into brownish-black at their extremities. The outer 

 webs of the primaries are also mnch less deeply coloured than in C. niger, in which the whole 

 wing, both externally and internally, is of an uniform deep black. This whitish colouring of 

 the inner webs of the wing feathers is also found m the female of C. oreas : in the female of 

 C. niger, according to our specimens, the primaries are tinged with pale fulvous. A second 

 very obvious difference is in the colour of the back, which in the present bu'd is of a much duller 

 hue, and less tinged with chestnut than in C. niger. We have therefore little doubt that the 

 two species should be considered as distinct, and as representatives of each other in different 

 areas: the one occupying the low plains of the whole southern portion of the South American 

 continent, the other taking its place in the highlands of Peru and Bolivia. 



^Orbigny's notes, which apply as well to this species and its ally, state that it is generally 

 met with in small flocks composed of a small number of males and many females or young birds, 

 and is usually found on well-watered plains or on the banks of brooks and rivers. Like the Larks 

 [Alancla), which it much resembles in habit, they seem to prefer beaten tracks and pathways, 

 and may be frequently noticed running rapidly in such spots or stalking gravely along in search 



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