I 



<") no 

 OOO 



GEOGEAPHICAL DISTEIBUTION OF SPECIES. [Ch. XXXVIII. 



America 



having Australian affinities^ it has 



been justly 



rem 



in Europe in the Eocene 

 AmAriPQTi Species are much 



Miocene 



assumm 



than from Australia, where the genus in question has not 

 hitherto been met with, whether in a fossil or living state. 



In this great province, the Neotropical, as indeed in every 

 other to which we shall afterwards allude, the larger part of 

 f"Ka GT^PPiPs fiTc^, senarable from each other bv lines of demar- 



cation, whether in the animal or vegetable kingdoms, suf- 



ficiently clear to enable naturalists to agree for the most part 

 in their systems of classification; but exceptions could be given 

 in every great division, whether of the vertebrate or inverte- 

 brate class, where species occur which pass one into the other 

 by so many intermediate gradations that scarcely any two 



same 



ship. Thus for example, Mr. Bates observed in the valley of 

 the Amazons swarms of a gregarious species of butterfly of 

 the elegant genus Ileliconius^ which is peculiar to tropical 

 America. It abounds in the shades of the forests presenting 



some 



m 



A conspicuous member of the group is IT. 



Mely 



New 



It is very common 



Amazo 



on the south side of the river, in the dry forests behind 



But it is absent from other parts of the valley. 



em 



and shape, but 



Hied species, H. Thelxiope. 

 differing in colour, takes 



its place. Both 



species have the same habits, and they have ahvays been con- 

 sidered by entomologists as specifically distinct; bu.t Mr. 



came 



cation of tlie other ; for he found that in those forest tracts 

 which were intermediate in character between the dryer air of 

 Ohydos and the moister air of the rest of the great valley the 



Heliconii 



the two reputed species alluded to. 



H 



from 



^ 



S 



