CHAP. X.] 
THE PA LAS ARCTIC REGION. 
180 
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), Phytcecia 
(85 species), Pogonochcerus (22 species), Agapanthia (22 species), 
and Vespents ( 7 species), are altogether peculiar to the Palm- 
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 Palmarctic 
regions, are, the Staphylinidse or rove-beetles, Silphidse or 
burying-beetles, Histeridm or mimic-beetles, Nitidulidm, Apho- 
diidse, Copridm (especially in South Europe), Geotrupidae or 
dung-beetles, Melolontliidm or chafers, Elateridae or click- 
beetles, the various families of Malacoderms and Heteromera, 
especially Pimeliidse in the Mediterranean sub-region, Curculion- 
idse or weevils, the Phytophaga or leaf-eaters, and Cocinellidse 
or lady-birds. 
The number of species of Coleoptera in the western part of 
the Palmaretic 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 Palsearctic 
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 w^ould be at least doubled, since w T e 
cannot suppose that Europe, with the Mediterranean basin, can 
contain more than one-fifth of the wdiole 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 all the rest of the globe. 
