16 MIOCENE FAUNA. 



rously represented than the herbivorous forms, the proportion 

 among the existing beetles being as 1 : 3*62. Among the whole 

 number of the Coleoptera of (Eningen the carnivorous species 

 are to the herbivorous as 1 : 4 '62. In the existing Swiss fauna 

 the proportion is as 1 : 3 } in Europe generally as 1 : 3 '87, in 

 North America as 1:4, and in South America as 1 : 9'59. 

 Towards the warmer zones the vegetable -eaters (Phytophaga) 

 increase in number much more rapidly than the flesh-eaters 

 (Creophaga), and predominate in warm climates far more 

 than in the temperate zones. The preponderance of" the Phy- 

 tophaga in the beetle-fauna of the Tertiary strata of Switzerland 

 is by no means so great as in the fauna of beetles in tropical 

 countries; but in Miocene times, vegetable-eaters were in a 

 larger proportion among beetles than in the existing fauna of 

 Switzerland and Europe. 



Of the vegetable-eaters many have no special choice of 

 nourishment, whilst others are exclusively confined to cer- 

 tain species or genera of plants, and on these derive their food 

 from particular organs. We have already noticed (vol. i. p. 309) 

 that many insects that we possess from (Eningen reveal to us 

 the existence of plants which have not yet been discovered. On 

 the other hand we can indicate the food-plants of a considerable 

 number of insects. The poplar-beetles (Lina populeti) most 

 probably lived on the poplars and willows, the Cantharides and 

 Cicadse on the ashes, Ancylochira tincta, Ampedus Seyfriedii, 

 Hyleccetus cylindricus, Acanthoderus sepultus and lepidus, and 

 Syromastes affinis on the pines and firs, the beautiful Chalccphora 

 l&mgata on the almond-trees, Rhynchites silenus on the vines, 

 Chrysomela Calami and Donacia Paltemonis on the reeds and 

 rushes, and Lygaus tinctus on Acerates veterana, all plants known 

 to Prof. Heer from CEningen. 



Delicate aquatic plants served as food to the minute but ex- 

 ceedingly numerous Cyprides, which in their turn afforded 

 nourishment to the larvae of midges ; and these again were pur- 

 sued by the predaceous beetles, larvae of dragonflies, and fishes. 

 The larvae of the ladybirds (Coccinellce) and wasp-flies (Syrphus) 

 settle down among Aphides at the present day, so as to devour 

 them at their ease; and from CEningen Prof. Heer knows of 

 nineteen species of Coccinella and two species of Syrphus and 



