48G GEOGRAPHICAL ZOOLOGY. [part iv. 



Tossil Buttertiies, 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 Paleozoic times, since one of the 

 BombycidiT, — a group almost as highly-organised — has been 

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



Order— COLEOPTERA. 



Geodepiiaga, or Carnivoeous Ground Beetles. 



The Geodephaga consist of two fiimilies, Cicindelidte and 

 Carabidffi, 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, wliere fully half of all the 

 known species occur. 



CIC1NDEL1D.E. (35 Genera, 803 Species.) 



The CicindelidiTe, 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 Cicindda, the 

 only one wliicli is cosmopolitan. The other large genera are, — 

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

 American, with species in Java and Celebes ; Tetracha (40 sp.), 

 mostly South American, but with species in South Europe, 

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

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

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

 wholly African, south of Lake Ngami and Mozambique ; Thcratcs 

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



The genera are distributed in the several regions as follows : — 

 the Ncaictic region has .1 genera, 3 of which are peculiar to it ; the 



