( 54 ) 

 16. Ancistrops strigilatus (Spix). 



Than Spix, Av. Urns, ii. p. 26. tab. xxxvi. fig. 1 (1s2j.— no locality). 



Nos. 892, 094. ? ad., <J ad., 2:!. vi.. 22. v. 06. " Iris brownish grey, bill and 

 feet grey." 



Thi'M' l.inls are to bo considered topotypical. Although Spix gives no locality, 

 his specimen was certainly obtained on the Brazilian Amazons. An example from 

 the Napo, East Ecuador, differs from the Teffe birds by 1 icing rather more blackish 

 on the head and mantle, and by the olive greyish stripes on the sides of the 

 belly being more distinct. 



In this species, the S3 are always much larger than the ? ?, as will be 

 seen from the following measurements : 



S ad., Teffe': wing 101; tail SO; bill 22 mm. — ?, Teffe' : wing 91 ; tail 70 ; 

 bill 22 mm. 



S ad., Rio Juruti (Mns. Paulista) : wing 100 ; tail 81 ; bill 22 mm. 



? ad., Rio Jnrna (Mns. Panlista) : wing 87 ; tail 77 ; bill 22 mm. 



47. Xenops genibarbis genibarbis 111. 



Xenops genibarbis Illiger, ProJr. Syst. Mamm. et Av. p. '213 (1811. — Cametii, Lower Amazons). 

 Neops rufieaudut Yieillot, Analyse Ornith. elan. p. 08 (1816. — "la Guiane," sc. Cayenne). 

 Xenops approximans Pelzeln, Sih. Ber. Akad. Wien. mathem. Naturwiss. CI. xxxiv. pp. 113, 133 

 (1859. — Rio Madeira, Rio Negro, etc.). 



No. 903. (J ad., 25. vi. 06. " Iris brown."— Wing 07 ; tail 48 ; bill 15 mm. 



The determination of this specimen involved a complete revision of the 

 geographical forms of X. genibarbis. In addition to the large series in the Tring 

 Museum, I had the advantage of studying Natterer's specimens kindly lent by 

 Dr. Lorenz, of Vienna, and I examined also several examples in the British 

 Museum. Pelzeln had already recognised that the Amazonian form was quite 

 distinct from the one inhabiting South-east Brazil; but unfortunately he considered 

 the latter to represent true X. genibarbis and separated the former as X. approximans. 

 Specimens from Parti and Santarem, Lower Amazonia, however, prove to be 

 inseparable from those of Cayenne (N. ruficaudus) and Amazonia (A", approximans). 

 Both these names are, therefore, pure synonyms of X. genibarbis, while the small, 

 short-billed race of S.E. Brazil requires to be rebaptized. The geographical forms 

 of the group have to stand as follows : 



a. X. genibarbis genibarbis 111. 



Hub. < 'avenue ; Brit. Guiana ; Venezuela on the Orinoco and Caura Rivers ; 

 Colombia (Bogota collections; Antioquia) ; Eastern Ecuador; and the whole of the 

 Amazonian basin from Pant to the eastern slopes of the Andes in Pern. 



Characters. Bill strong and stout ; ground-colour of the nnderparts earthy 

 brown, sometimes, especially in young birds, with a slight rufescent tinge; throat 

 dirty white, the feathers edged or freckled with dusky ; foreneck distinctly mottled 

 or spotted with whitish. Crown, as a rule, striated with buff or whitish. 



Obs. Two topotypical birds from the Lower Amazons (Para and Santarem) 

 have the crown warm rufescent browu with scarcely any light striatious, which 

 arc always more or less pronounced in the majority of my specimens from other 

 localities. Quite similar examples, however, are before me from Bogotd, and 

 Gaavabamba in North Peru, while others from the same places have the pileum 



