FAUNA OF BARRA 



231 



The species of monkey mentioned above was rather 

 common in the forest ; it is the Midas bicolor of Spix, 

 a kind I had not before met with, and pecuHar, as far 

 as at present known, to the eastern bank of the Rio 

 Negro. The colour is brown, with the neck and arms 

 white. Like its congeners, it keeps together in small 

 troops, and runs along the main boughs of the loftier 

 trees, climbing perpendicular trunks, but never taking 

 flying leaps. The locality seemed to be a poor one for 

 birds and insects. I do not know how far this apparent 

 scarcity is attributable to the rainy weather which pre- 

 vailed, and to the unfavourable time of the year. The 

 months spent here (from January to March) I always 

 found to be the best for collecting Coleopterous insects 

 in this climate, but they are not so well for other orders 

 of insects or for birds, which abound most from July to 

 October. The forest was very pleasant for rambling. In 

 some directions broad pathways led down gentle slopes, 

 through what one might fancy were interminable shrub- 

 beries of evergreens, to moist hollows where springs of 

 water bubbled up, or shallow brooks ran over their beds 

 of clean white sand. But the most beautiful road was 

 one that ran through the heart of the forest to a water- 

 fall, which the citizens of Barra consider as the chief 

 natural curiosity of their neighbourhood. The waters of 

 one of the larger rivulets which traverse the gloomy 



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 Soiimoens ; where, from Ega 

 to Tabatinga, the allied form of Calliste Yeni takes its place. 

 The Ramphastos 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 Soiimoens. 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. 



