108 PARA. . Chap. III. 



as Coleoptera, and thus render their existence unne- 

 cessary. The large proportion of climbing forms of 

 carnivorous beetles is an interesting fact, because it 

 affords another instance of the arboreal character which 

 animal forms tend to assume in equinoctial America, a 

 circumstance which points to the slow adaptation of 

 the Fauna to a forest-clad country throughout an 

 immense lapse of geological time. 



The large collections which I made of the animal 

 productions of Para, especially of insects, enabled me to 

 arrive at some conclusions regarding the relations of 

 the Fauna of the south side of the Amazons Delta to 

 those of neighbouring regions. It is generally allowed 

 that Guiana and Brazil, to the north and south of 

 the Para district, form two distinct provinces, as regards 

 their animal and vegetable inhabitants. By this it is 

 meant that the two regions have a very large number 

 of forms peculiar to themselves, and which are supposed 

 not to have been derived from other quarters during 

 modern geological times. Each may be considered as 

 a centre of distribution in the latest process of dis- 

 semination of species over the surface of tropical 

 America. Para lies midway between the two centres, 

 each of which has a nucleus of elevated table-land, 

 whilst the intermediate river-valley forms a wide extent 

 of low-lying country. It is, therefore, interesting to 

 ascertain from which the latter received its population, or 

 whether it contains so large a number of endemic species 

 as would warrant the conclusion that it is itself an inde- 

 pendent province. To assist in deciding such questions 



