236 On the Geographical Distribution of Inaects. 



River Amazons, and the sea. This region has been explored 

 only along the sea-coast : it is very rich in Lepidoptera and 

 Hymenoptera, but inferior to Brazil in Coleoptera. Its spe- 

 cies have a close analogy to those of the latter country, but 

 nearly three-fourths are peculiar to it. 



32d, Eastern Brazil, bounded on the west by the Rio Tocan- 

 tin and the Parana, and on the south by the province of sou- 

 thern Rio- Grande, which is not included in it. This region 

 may be divided into as many sub-regions as there are basins 

 formed by the principal rivers. The portion lying between 

 the ocean and the Sierra de Mantiquiera, is the richest coun- 

 try in the world for every order of insects, but particularly for 

 that of Coleoptera. 



33d, Western Brazil, bounded by the Amazon on the north, 

 Peru and Bolivia on the west, Paraguay on the south, and 

 the preceding region on the east. This immense territory 

 is almost unknown as to its entomological productions. 



34rth, Peru, with its present political boundaries. The 

 whole portion of this region, lying between the Andes and 

 Pacific Ocean, is extremely arid, with the exception of a few 

 valleys, and appears to be extremely rich in Melasomas. The 

 Andes themselves, and the countries to the east, are un- 

 known. 



35th, Upper Peru, or Bolivia. M. Lacordaire has seen none 

 of the productions of this region, except the pretty rich col- 

 lections made by M. d'Orbigny in the province of Santa Cruz 

 de la Sierra. The Coleoptera and Lepidoptera have a fades 

 entirely Brazihan. Many of the species are even identical, 

 some with those of the neighbourhood of Rio Janeiro, others 

 with those of Cayenne. The species proper to the country 

 consist chiefly of Melasomas. 



36th, Paraguay, Southern Brazil, and Eastern Banda. All 

 of these have a very intimate relation to the insects of Brazil, 

 such as occur in this region difiFering in general specifically, 

 particularly as we approach the La Plata. In the province of 

 Rio Grande, numerous species begin to appear, unknown in 

 the vicinity of Rio Janeiro, although belonging to the same 

 genera. 



37th, Tucuman, bounded on the north by Upper Peru, on 



