256 THE ENTOMOLOGIST. 



with that of Iceland, and thrice more than with that of Lap- 

 land. Jakontsk and Pekin have, of identical species, 1 in 66; 

 Jakoutsk and the Amur region, 1 in 10. The variation of 

 Coleoplera is six times more considerable in latitudes than 

 in longitudes. The genera of Coleoptera of the Amur 

 region belong in a great part to the European Fauna ; and it 

 is only along the south part of this river, from Soungari 

 towards the east, that different generic forms appear, partly 

 those of tropical Asia, such as Metopodontus, Prismognathus, 

 Encyalesthus, Luperodes, Calasposoma, Nodostoma, Cop- 

 tocycla, Languria; partly those of North America, such as 

 Dichelotarsus, Cephalaon, Ophryastes, and Leposoma. All 

 the western part of the Amur region has forms very 

 analogous to those of Daouria, which, intimately allied to 

 those of Siberia generally, are only a continuation to the 

 east of the European Fauna. Some species of North Europe 

 appear much more southward in the Amur region, such as 

 Hylobius arcticus and Oiceoptoma lapponica, which extend 

 to America ; and in this region tropical forms are accompanied 

 by arctic forms, and some genera, such as Epicausta, Myla- 

 bris, Tentyria, and Dorcadion, extend more northward than 

 in Europe. Among the 470 species of Coleoptera, collected 

 along the river Amur and in the most eastern part of 

 Siberia, more than two-thirds are found also in Daouria; 

 500 species have been found in South Oural, and 340 in the 

 western part of the Amur; 126 species are common to 

 Germany and the region of the Amur; 140 species are 

 common to the South Oural and to the west region of the 

 Amur. The line which passes from the North Pole by the 

 Oural, the Sea of Aral, East Persia, to the South Pole, 

 represents the meridian of the productive force of organized 

 bodies, which force becomes more rich and more varied in 

 proportion as it approaches the Atlantic and the Pacific. 

 Austria has 8500 species of Coleoptera ; South Oural, 2500, 

 of which 140 are found in the Amur region. 



With regard to Lepidoptera, Menetries remarks thus : — In 

 following the course of the Amur, European species will be 

 found at each end of the stream, but in the middle of its 

 course, that is towards the south, the Fauna changes 

 suddenly, so that in the most southern part, or from the 

 mouth of the Soungari to that of the Oussouri, there are 



