330 ZOOLOGY OF THE AMAZON DISTRICT. 



of the north-western tributaries of the Rio Negro, so that it 

 seems probable that distinct species of this genus inhabit the 

 opposite shores of the Amazon. 



The cock of the rock, Rupicola crocea, is, on the other hand, 

 an example of a bird having its range defined by a geological 

 formation, and by the physical character of the country. Its 

 range extends in a curving line along the centre of the moun- 

 tainous district of Guiana, across the sources of the Rio Negro 

 and Orinooko, towards the Andes ; it is thus entirely com- 

 prised in the granite formation, and in that part of it where 

 there are numerous peaks and rocks, in which the birds make 

 their nests. 



Whether it actually reaches the Andes, or occurs in the 

 same district with the allied R. Peruviana, is not known, but 

 personal information obtained in the districts it inhabits, 

 shows that it is confined to the narrow tract I have mentioned, 

 between i south and 6 north latitude, and from the mountains 

 of Cayenne to the Andes, south of Bogota. 



Another bird appears bounded by a geological formation. 

 The common red-backed parrot, Psittacus festivus, is found 

 all over the Lower Amazon, but, on ascending the Rio Negro, 

 has its northern limit about St. Isabel, or just where the 

 alluvial country ends and the granite commences ; it also 

 extends up the Japura, but does not pass over to the Uaupes, 

 which is all in the granite district. 



The fine blue macaw (Ara hyacinihina) inhabits the borders 

 of the hilly country south of the Amazon, from the sea-coast 

 probably up to the Madeira. Below Santarem, it is sometimes 

 found close up to the banks of the Amazon, but is said never 

 to cross that river. Its head-quarters are the upper waters of 

 the Tocantins, Xingu, and Tapajoz rivers. 



As another instance of a bird not crossing the Amazon, I 

 may mention the beautiful curl-crested Aragari (Pteroglossus 

 Beauharnaisii), which is found on the south side of the 

 Upper Amazon, opposite the Rio Negro, and at Coari and 

 Ega, but has never been seen on the north side. The green 

 Jacamar of Guiana also (Galbula viridis) occurs all along the 

 north bank of the Amazon, but is not found on the south, 

 where it is replaced by the G. cyanocollis and G. maculicauda i 

 both of which' occur in the neighbourhood of Para. 



