78 DISTRIBUTION OF ANIMALS. [part i. 



of a single representative of a unique order of reptiles, is, as 

 before remarked, of the same character as the preservation of 

 the Proteus in the caverns of Caruiola ; and can give the locality 

 where it happens to have survived no claim to form a primary- 

 Zoological region, unless supported by a tolerably varied and 

 distinctly characterized fauna, such as never exists in a very 

 restricted and insular area. 



Neotrojncal Region. — Mr. Sclater's original name for this 

 region is preserved, because change of nomenclature is always 

 an evil; and neither Professor Huxley's suggested alteration 

 " Austro-Columbia," nor Mr. Sclater's new term " Dendrogsea," 

 appear to be improvements. The region is essentially a tropical 

 one, and the extra-tropical portion of it is not important 

 enough to make the name inappropriate. That proposed by 

 Professor Huxley is not free from the same kind of criticism, 

 since it would imply that the region was exclusively South 

 American, whereas a considerable tract of North America 

 belongs to it. This region includes South America, the 

 Antilles and tropical North America ; and it possesses more 

 peculiar families of vertebrates and genera of birds and mam- 

 malia than any other region. 



Subdivisions of the JVcotrojncal Region. — The great central 

 mass of South America, from the shores of Venezuela to Paraguay 

 and Eastern Peru, constitutes the chief division, and may be 

 termed the Brazilian sub-region. It is on the whole a forest 

 country; its most remarkable forms are highly developed 

 arboreal types ; and it exhibits all the characteristics of this rich 

 and varied continent in their highest development. 



The second, or Chilian sub-region, consists of the open plains, 

 pampas, and mountains of the southern extremity of the con- 

 tinent ; and we must include in it the west side of the Andes as 

 far as the limits of the forest near Payta, and the whole of the 

 high Andean plateaus as far as 4° of south latitude ; which 

 makes it coincide with the range of the Camelidse and Chin- 

 chillidfe. 



The third, or Mexican sub-region, consists of Central America 

 and Southern Mexico, but it has no distinguishing character- 



