CuAP. YII. FAUNA OF BARRA. 343 



the Amazons, so that the great contrast in the forest- 

 clothing of the two rivers cannot arise from this cause. 



I did not stay long enough at Barra to make .a large 

 collection of the animal productions of the neighbour- 

 hood. I obtained one species of monkey ; not more 

 than a dozen birds, and about 300 species of insects. 

 Judging from these materials, the fauna appears to 

 have much in common with that of the sea-coast of 

 Guiana ; but, at the same time, it contains a considerable 

 number of species not hitherto found in Guiana, or in 

 any other part of South America. The resemblance 

 between the eastern shore of the Rio Neg^ro and the 

 distant coast of Guiana, in this respect, appears to be 

 greater than that between the Rio Negro and the banks 

 of the Upper Amazons.* 



The species of monkey mentioned above was rather 



* ]My own material is perhaps not sufficient to establish this view 

 of the relations of the fauna, for it re(j[uires the comparison of an exten- 

 sive series of species to obtain sound results on such subjects. A few 

 conspicuous instances, however, pointed to the conclusion above men- 

 tioned. For example : in birds, the beautiful seven-coloured Tanager, 

 Calliste tatao, the "sete cores" of the Brazilians, a Cayenne bird, is 

 common to Guiana and the neighbourhood of Barra, but does not range 

 further westward to the banks of the Solimoens ; where, from Ega to 

 Tabatinga, the allied form of Calliste Yeni takes its place. The Ram- 

 phastos Toco, or Tocano pacova (so named from its beak resembling a 

 banana or pacova), a well-known Guianian bird, is found also at 

 Barra, but not further west at Ega. In Coleopterous insects such 

 species as Aniara sepulchralis, Agra senea, Stenocheila Lacordairei, 

 and others, confirm this view, being common to Cayenne and the Rio 

 Negro, but not found further west on the banks of the Solimoens. 

 Mr. Wallace discovered that the Rio Negro served as a barrier to the 

 distribution of many species of mammals and birds, certain kinds 

 being peculiar to the east, and others to the west bank (Travels on 

 the Amazons and Rio Negro, p. 471). The Upper Amazons Fauna, 

 nevertheless, contains a very large proportion of Guiana species. 



