486 GEOGRAPHICAL ZOOLOGY. [PART iv. 



Fossil Butterflies, apparently of existing genera, occur in the 

 Miocene and Eocene formations, and an extinct form in the 

 Lower Oolite ; but these cannot be held to give any adequate 

 idea of the antiquity of so highly specialised a group, which, in 

 all probability, dates back to Palaeozoic times, since one of the 

 Bombycidse, a group almost as highly-organised has been 

 discovered in the coal formation of Belgium. (See Vol. I. p. 168.) 



Order COLEOPTERA. 



GEODEPHAGA, or CARNIVOROUS GROUND BEETLES. 



The Geodephaga consist of two families, Cicindelidee and 

 Carabidse, differing in their form and habits no less than in their 

 numbers and distribution. The former, comprising about 800 

 species, are far more abundant and varied in Tropical regions ; 

 the latter, more than ten times as numerous, are highly charac- 

 teristic of the North Temperate zone, where fully half of all the 

 known species occur. 



CICINDELID^E. (35 Genera, 803 Species.) 



The Cicindelidae, or Tiger Beetles, are a moderately extensive 

 group, spread over the whole globe, but much more abundant 

 in tropical than in temperate or cold countries. More than half 

 of the species (418) belong to the single genus Cicindela, the 

 only one which is cosmopolitan. The other large genera are, 

 Collyris (81 sp.), wholly Oriental ; Odontochila (57 sp.), South 

 American, with species in Java and Celebes ; Tetracha (46 sp.) t 

 mostly South American, but with species in South Europe, 

 North America, and Australia ; Tricondyla (31 sp.), characteristic 

 of the Oriental region, but extending eastward to New Guinea ; 

 Ctenostoma (26 sp.), wholly Neotropical; Dromica (24 sp.), 

 wholly African, south of Lake Ngami and Mozambique ; Therates 

 (18 sp.), wholly Malayan, from Singapore to New Guinea. 



The genera are distributed in the several regions as follows : 

 the Nearctic region has 5 genera, 3 of which are peculiar to it ; the 



