« EelmineJätka »
into the Amazonian valley. Guiana still boasts such remarkable forms as the cardinal chatterer (Phænicocercus), the military chatterer (Hæmatoderus), as well as Querula, Gymnoderus, and Gymnocephalus; but the first three pass to the south side of the Lower Amazon. Here also belong the cock of the rock (Rupicola), which ranges from Guiana to the Andes, and the marvellous umbrella-birds of the Rio Nigro and Upper Amazon (Cephalopterus), which extends across the Ecuadorean Andes and into Costa Rica. Brazil has Ptilochloris, Casiornis, Tijuca, Phibalura, and Calyptura ; while not a single genus of this family, except perhaps Heliochæra, is confined to the exteusive range of the Andes. Almost the same phenomena are presented by the allied Pipridæ or manakins, the greater part of the genera and species occurring in Eastern South America, that is in Brazil, Guiana, and the surrounding lowlands rather than in the Andean valleys. The same may be said of the jacamars (Galbulidæ) and puff-birds (Bucconidæ); but the humming-birds (Trochilidæ) have their greatest development in the Andean district. Brazil and Guiana have each a peculiar genus of parrots; Guiana has three peculiar genera of Cracidæ, while the Andes north of the equator have two. The Tinamida on the other hand have their metropolis in Brazil, which has two or three peculiar genera, while two others seem confined to the Andes south of the equator. The elegant trumpeters (Psophiidæ) are almost restricted to the Amazonian valley.
Somewhat similar facts occur among the Mammalia. At least 3 genera of monkeys are confined to the great lowland equatorial forests and 1 to Brazil; Icticyon (Canidæ) and Pteronura (Mustelida) belong to Guiana and Brazil; and most of the Echimyidæ are found in the same districts. The sloths, anteaters, and armadillos all seem more characteristic of the eastern districts than of the Andean; while the opossums are perhaps equally plentiful in the Andes.
The preceding facts of distribution lead us to conclude that the highlands of Brazil and of Guiana represent very ancient lands, dating back to a period long anterior to the elevation of the Andean range (which is by no means of great geological anti