NOVITATES ZOOLOGICAE XXI. 1914. 163 



of F, ocnantlioides remained nniqne in the Paris Museum nntil Mr. D. Foibes, 

 fliirina' bis journey in Bolivia, obiained several specimens of a bird whieli was 

 iileutitifd by Messrs. Sclater & Salvin * as belonging to that species, and wliich has 

 ever since been known under that name in ornithological literature. In the same 

 paper these authors f also published the diagnosis of a supposed new species from 

 South Pern, 0. polionota, stated to differ from O. oenanthoides by its greyish 

 (instead of rufous brown) back, broad white eyebrow, and other characters. Sub- 

 sequently Dr. Sclater ^ referred examples from various Ecuadorian and Peruvian 

 localities to 0. oenanthoides, whose range was given to extend from Western 

 Colombia down to Bolivia. In 1896, however, Count Berlepsch and Mr. Stolzmann § 

 separated the inhabitants of Pern and Ecuador on account of their more brownish 

 head, deep buff superciliary strijie and paler abdomen as 0. oenanthoides brunnei- 

 frous. Finally, in 1907, Count Berlepsch H made known a small, j)ale-coloured 

 subspecies of 0. polio7iota, of which he had received a series from La Paz, Western 

 Bolivia, under the name 0. p. pacifica Berl. 



While investigating the status of various species in D'Orbigny's Bolivian 

 collection I was struck by the fact that neither the locality nor certain colour- 

 characters given by Lafresnaye and D'Orbiguy could possibly apply to the birds 

 commonly called 0. oenanthoides. Further researches led me to the suspicion that 

 (K polionota pacifica Berl. might be the true O. oenanthoides (Lafr. & D'Orb.), 

 which appeared to be the more probable as both species had been discovered in the 

 very same locality, viz. at La Paz, Western Bolivia. Count Berlepsch having very 

 kindly allowed me to take his typical specimen to Paris, I was able to compare it 

 directly with the type of 0. oenanthoides, and found it ])ractically identical. The 

 identity of 0. p. pacifica and 0. oenanthoides being thus established, the nomen- 

 clature of the allied species requires some modification, as I shall show presently. 



The members of that section of the genus Ochthoeca we are dealing with fall 

 easily into two sjiecific groups : 



(a) Upper parts sooty or earthy brown (without rufescent shades) ; upper wing- 

 coverts either wholly uniform or the greater series only narrowly tipped with butfy; 

 sides of head blackish, surmounted by a large pure white superciliary stripe ; throat 

 greyish or whitish ; outer web of the external rectrix white, and a narrow whitish 

 edge at the tip of the remaining rectrices. Here belong 0. oenanthoides and 

 0. polionota. 



{b) Back russet or rnfous-brown, more or less contrasting with the dull brown 

 or even greyish brown pileum ; median and greater wing coverts broadly tipped 

 with deep ferruginous, forming two transverse bands across the wing ; sides 

 of head smoky or rufescent brown ; superciliary stripe yellowish white, buff, or 

 ochraceous ; throat dull brownish ; tail uniform black, without any white edging. 

 Here belong O.fumicolor, O. brtinneifrons, and an unnamed race from Bolivia and 

 South Peru, hitherto erroneously identified as 0. oenanthoides. 



These two groups are no doubt specifically distinct, since representatives of 

 both occur side by side in certain districts, e.g. in Central Peru. The " species " 

 belonging to each of the two sections are, however, very closely allied inter se, and 

 replace one another in different geographic areas, thus constituting what modern 

 systematists are accustomed to call " subspecies." 



* P. Z. S. Land. 1869, p. 600. § P. Z. S. Land. 1896, p. 355. 



t Loc. cit. p. 599. II Oruie 14, 1907, p. 354. 



X Cat. B. Brit. Mvn. 14, 1888, p. 20. 



