CHAP, xiv.] THE NEOTROPICAL REGION. 47 



altogether peculiar, but most of them are more or less closely 

 allied to genera inhabiting Tropical America. Some, as the hand- 

 some Cheloderus and Oxypeltus, have no close allies in any part 

 of the world. Holopterus, though very peculiar, shows most re- 

 semblance to a New Zealand insect. Sibylla, Adalbus, and 

 Phantagoderus, have Australian affinities ; while Calydon alone 

 shows an affinity for north-temperate forms. One species of the 

 northern genus, Leptura, is said to have been found at Buenos 

 Ayres. 



The Lamiidae are less abundant. Nine of the genera are Neo- 

 tropical. Two (Apomecyna and Exocentrus) are spread over all 

 tropical regions. Ten genera are peculiar; and most of these 

 are related to Neotropical groups or are of doubtful affinities. 

 Only one, Aconopterus, is decidedly allied to a northern genus, 

 Pogonochcerus. It thus appears, that none of the Lamiidse ex- 

 hibit Australian affinities, although these are a prominent fea- 

 ture in the relations of the Cerambycidse. 



It is evident, from the foregoing outline, that the insects of 

 South Temperate America, more than any other class of animals, 

 exhibit a connection with the north temperate regions, yet this 

 connection is only seen in certain groups. In Diurnal Lepidop- 

 tera and in Carabidse, the northern element is fully equal to the 

 tropical, or even preponderates over it. We have already sug- 

 gested an explanation of this fact in the case of the Carabidae, 

 and with the butterflies it is not more difficult. The great mass 

 of Neotropical butterflies are forest species, and have been de^ 

 veloped for countless ages in a forest-clad tropical country. The 

 north temperate butterflies, on the other hand, are very largely 

 open-country species, frequenting pastures, mountains, and open 

 plains, and often wandering over an extensive area. These 

 would find, on the higher slopes of mountains, a vegetation and 

 conditions suited to them, and would occupy such stations in 

 less time than would be required to adapt and modify the forest- 

 haunting groups of the American lowlands. In those groups 

 of insects, however, in which the conditions of life are nearly the 

 same as regards both temperate and tropical species, the superior 



