III.] DISTINCTNESS OF EXISTING FAUNA. 123 



Hitherto especial stress has been laid on the fossil mammals 

 of Neogaea as entitling the tract to form a primary Distinctness 

 realm, on account of the distinctness of its fauna of the existing 

 from that of the rest of the world during a consider- 

 able portion of the Tertiary epoch. Even at the present day, 

 however, when, as already shown, its mammalian fauna contains a 

 very large admixture of types which have immigrated from the 

 north at a comparatively recent epoch, it still stands widely apart 

 from other regions. On this point may be quoted the admirable 

 summary given in "Island Life" 1 by Dr Wallace, who writes that 

 among the peculiar mammals we have " the prehensile-tailed 

 monkeys and the marmosets, the blood-sucking bats, the coati- 

 mundis, the peccaries, the llamas and alpacas [vicunas and 

 guanacos], chinchillas, the agutis, the sloths, the armadillos, and 

 the ant-eaters ; a series of types more varied and more distinct 

 from those of the rest of the world than any other continent can 

 boast of. Among birds we have the charming sugar-birds, forming 

 the family C&rebidce, the immense and wonderfully varied group 

 of tanagers (Tanagridce), the exquisite little manakins and the 

 gorgeously-coloured chatterers ( Cotingidce) ; the host of tree- 

 creepers of the family Dendrocolaptidce, the wonderful toucans 

 (Rhamphastid<z\ the puff-birds (Bucconidcz), jacamars (Galbu- 

 lid<z), todies ( Todidce), and motmots (Momotida) ; the marvellous 

 assemblage of four hundred distinct kinds of humming-birds 

 (Trochilidce\ the gorgeous macaws (Ara), the curassows (Cracida), 

 the trumpeters (Psophiidcf), and the sun-bitterns (Eurypygida). 

 Here again there is no other continent or region that can produce 

 such an assemblage of remarkable and perfectly distinct groups of 

 birds ; and no less wonderful is its richness in species, since these 

 fully equal, if they do not surpass, those of the two great tropical 

 regions of the Eastern Hemisphere (the Ethiopian and the 

 Oriental) combined." Not less noteworthy among the birds are 

 the screamers (PalctTiiedeidcz) ; the tinamus ( Tinamida), which 

 while outwardly resembling game-birds, agree with the struthious 

 birds in the structure of their skulls ; and the rheas (Rheida), or 

 South American ostriches, whose nearest allies are the true 



1 Pages 50, 51. In this quotation the scientific names of some of the groups 

 have been added. 



