30 ME. A. MUEEAY ON THE GEOGEAPHIOAL EELATIONS OF 



one species of the genus to show that it is present. I have also 

 added a few on the authority of Eadde and others from South- 

 east Siberia. The total number in my list thus purged and 

 augmented is 382 ; but adding the number of the endemical 

 species, of which I have not given tlie names, we start with 608 

 species known to inhabit the extreme east of Siberia. 



Of these the numbers are, in 



Amour 579 



Daurla 297 



Western Siberia, or the districts of the Ural Mountains... 227 

 North and Mid-Europe, as distinguished from East or 



West Europe 213 



East Europe as represented by France and Belgium 184i 



Britain 133 



The Madeiras 10 



The Azores 7 



To which I may add, in anticipation of what I must pre- 

 sently say in speaking of North America, — 



On the western side of North America , 8 



On the eastern side of North America 23 



The details will be found in Table VII. in the Appendix. 



The diminution in identity of species as we go further from 

 our starting-point (wherever we begin) and their replacement by 

 new strains is, it will be seen, exceedingly gradual and equal, 

 and the proportion of identical species persisting through the 

 immense stretch of country embracing Asia and Europe very 

 remarkable. But what is of still more importance in this inquiry 

 is the identity of the genera. Using the w^ord in its large sense, 

 the same genera are spread over the whole region in question ; 

 used in the more restricted sense, adopted by modern naturalists, 

 a similar replacement of one form by another allied one, which 

 we have seen occur in species, takes place also in these groups 

 of species. Thus, in recording the species from the Amour, 

 Motschoulsky has thought it necessary to propose a number of 

 new genera for the new forms j and the proportion of these to the 

 old genera found there was about a fifth. He records 239 

 genera, of which 35 are new. And, curiously enough, this is 

 very close upon the numbers which Wollaston has turned out 

 in his work at the other end of the string on the Coleoptera of 

 Madeira ; he records 236 genera, of which 44 are new. 



