CHAP. X.] THE PALZZARCTIC REGION. 189 
much more abundant in the southern than the northern half 
of the region. Several Oriental genera extend to Japan and 
North China, and a few Ethiopian genera to North Africa. 
Thirteen genera are confined to the two north temperate regions. 
Several large genera, such as Dorcadion (154 species), Phytacia 
(85 species), Pogonocherus (22 species), Agapanthia (22 species), 
and Vesperus (7 species), are altogether peculiar to the Pale- 
arctic region; and with a preponderance of Leptura, Grammop- 
tera, Stenocorus, and several others, strongly characterise it as 
distinct from the Nearctic and Oriental regions. 
The other families which are well developed in the Palearctic 
regions, are, the Staphylinide or rove-beetles, Silphide or 
burying-beetles, Histeride or mimic-beetles, Nitidulide, Apho- 
diide, Copridz (especially in South Europe), Geotrupide or 
dung - beetles, Melolonthide or chafers, Elateride or click- 
beetles, the various families of Malacoderms and Heteromera, 
especially Pimeliide in the Mediterranean sub-region, Curculion- 
ide or weevils, the Phytophaga or leaf-eaters, and Cocinellide 
or lady-birds. 
The number of species of Coleoptera in the western part of 
the Palearctic region is about 15,000, and there are probably 
not more than 2,000 to add to this number from Siberia. 
Japan, and North China; but were these countries as well 
explored as Europe, we may expect that they would add at 
least 5,000 to the number above given, raising the Palearctic 
Coleopterous fauna to 20,000 species. As the total number of 
species at present known to exist in collections is estimated (and 
perhaps somewhat over-estimated) at 70,000 species, we may 
be sure that were the whole earth as thoroughly investigated 
as Europe, the number would be at least doubled, since we 
cannot suppose that Europe, with the Mediterranean basin, can 
contain more than one-fifth of the whole of the Coleoptera of 
the globe. 
Of the other orders of insects we here say nothing, because in 
their case much more than in that of the Coleoptera and Lepi- 
doptera, is the disproportion enormous between our knowledge of 
the European fauna and that of almost al) the rest of the globe. 
