to an Insect Fauna of the Amazon Valleij. 351 



Species peculiar to the Amazon Valley and Brazil . . 2* 



,, ,, ,, and Columbia . . 3f 



Total number of species common to Amazonia and 



Guiana.. .. .. .. .. .. ..19 



Total number of species common to Amazonia and 



Brazil . . 9 



Total number of species common to Amazonia and 



Columbia .. .. .. .. .. ..12 



A bare enumeration of species without further exhibition of 

 the degrees of resemblance gives but a very inadequate idea of 

 the true relations of faunas. Thus of the eight species given 

 here as peculiar to the Amazon Valley, two, Bolivar and Chabrias, 

 are strictly speaking but modifications, although well defined 

 and fixed, sliowing the strong peculiarities of the Upper Amazon 

 region, of /Eneas and Triopas, peculiar Guiana forms. A third 

 species, Ergeteles, is restricted to the Guiana side of the Lower 

 Amazon, and might be deducted from the exclusively Amazonian 

 species. A fourth Echetus, a remarkable form especially cha- 

 racteristic of, and almost confined to the district of Para, is con- 

 nected with the Gmana Ergeteles through the intermediate form of 

 Echephrun of Cayenne. One only Hierocles, can be considered as 

 more nearly related to forms of a centre of distribution not Guia- 

 nian, being apparently the Amazonian modification of the South 

 Brazilian P. Proteus. Of the confessed local sub-species, the 

 two confined to the delta of the river, Paraemis and Parsodes, are 

 varieties of the Guianian Hippason and Lysander, and are instances 

 of the peculiar modifying effect of the district of country near 

 Para. The others, all varieties of Guiana forms, are confined to 

 the Upper Amazon, and exhibit, in the replacement of colours 

 which constitute the variations, the same effects of local conditions 

 there prevailing as the more fixed sub- or representative species 

 of the locality. 



From the foregoing considerations, added to what has been ad- 

 vanced in the observations and table at the commencement of this 

 article, I think we may conclude that the facts derived from the 

 study of the distribution of the species oC Pap'ilio tend to establish 

 the following propositions: — 1st, that the Amazon region, al- 

 though showing great diversity within itself, chiefly from many of 



* Orsillus. Cinyras. 

 t Za^reus. Evagoras. Autosilaus. 



P. Varus and P. ZacyiUhus have not beea included in these enumerations, from 

 the doubts which see under the head of those species. 



