THE CHIEF COLEOPTEROUS FAUNiE. 11 



the general faoies is the same, and a large proportion of the 

 genera are the same, and it will be still greater when we get 

 rid of the feeling that the genera must necessarily be different, 

 because they come from such a distant country. Some of the 

 species are scarcely distinguishable from our own, and even the 

 relative proportions of numbers of species and genera in different 

 groups are the same. 



My conviction is, that there has been certainly one, possibly 

 two, great continental routes of communication between the 

 northern and southern hemispheres, both now lying buried in 

 the ocean, — the one at the bottom of the Atlantic, the other in 

 the depths of the Pacific ; and I hope, from an examination of 

 the traces left on the ruined piers which mark the course of 

 these ancient viaducts, to show the course that they took and 

 the inhabitants that used them. 



If any one, following in the steps of Sir Charles Lyell, ob- 

 jects to such a wholesale erection of continents on the ground 

 of their magnitude, I have only to remind them of the vast 

 extent of land which has appeared above water since the Tertiary 

 epoch. Some drying up of the ocean during that period no 

 doubt has taken place, but nothing sufficient to account for the 

 immense tracts of country which have become dry land ; and it 

 is not a matter open to argument or discussion, but a mathema- 

 tical necessity, that if land, previously below the water, comes 

 above it, a corresponding quantity of land which was previously 

 above it must then go below it. 



Let us now turn to the three great stirpes, and pass each of 

 them in review, trace their course, and determine their limits. 

 I shall begin with the microtypal stirps (with which we are 

 most familiar). It is the most extensive of the whole, being 

 distributed over the whole world, with the exception of the In- 

 dian, African, and Brazilian regions ; and even they, from va- 

 rious exceptional causes, have a greater or less tinge of it in 

 their faunas. It contains some minor faunas, and these, again, 

 a number of subfaunas. The Europeo-Asiatic region is one of 

 these minor faunas, and of it the Atlantic islands, the Me- 

 diterranean, and the Mongolian are subfaunas. Taken as one 

 fauna, the Europeo-Asiatic extends from the Azores east to 

 Japan, the whole of that vast space being inhabited entirely by 

 the same type and, for the most part, by the same species, a 

 few only dropping oflf here and there, and being replaced by 



