chap, x.] THE PALAEARCTIC 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), Phytoecia 

 (85 species), Pogonochccrus (22 species), Agapanthia (22 species), 

 and Vesperus (7 species), are altogether peculiar to the Palae- 

 arctic region ; and with a preponderance of Zeptura, 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 Palaearctic 

 regions, are, the Staphylinidae or rove-beetles, Silphidse or 

 burying-beetles, Histeridae or mimic-beetles, Nitidulidae, Apho- 

 diidae, Copridse (especially in South Europe), Geotrupidae or 

 dung-beetles, Melolonthidae or chafers, Elateridae or click- 

 beetles, the various families of Malacoderms and Heteromera, 

 especially Pimeliidae in the Mediterranean sub-region, Curculion- 

 idse or weevils, the Phytophaga or leaf-eaters, and Cocinellidae 

 or lady-birds. 



The number of species of Coleoptera in the western part of 

 the Palaearctic 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 Palaearctic 

 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 all the rest of the globe. 



