46 MIOCENE FAUNA. 



The genus Myrmica is represented partly by small species, all 

 of which differ from those now living in Switzerland, and partly 

 by larger forms, resembling those which occur in the south of 

 France and in North Africa. They are characterized by their 

 large wrinkled heads (fig. 293). 



The Imhoffia differ from the other ants in the large size of 

 the thorax and in the structure of the antennae ; in habit they 

 most resemble the Myrmica and Attce. They constitute a 

 peculiar extinct genus which lived at CEningen (fig. 291) and 

 Radoboj . 



Most of these numerous species of ants probably resided in 

 the forests, and constructed their nests in the earth or in the 

 decaying but dry wood of old trunks of trees. They join 

 with the Termites and the numerous wood-eating insects to 

 testify to the existence, at this epoch, of a luxuriant vegeta- 

 tion and abundance of trees, producing an immense quantity 

 of organic material, the transformation of which was their 

 business. 



Bees form one tribe of the Hymenoptera ; the "Wasps, Sand- 

 wasps, Scoliidse, and Ants a second, that of the Prsedonia ; and 

 the Entomophaga, which pierce caterpillars aud larvae, constitute 

 a third. To this last tribe twelve species from CEningen are to 

 be referred, among which there is an Anomalon, which probably 

 attacked the larvae of the nocturnal Lepidoptera, a Cryptus, and 

 several true Ichneumons (fig. 294) , which most likely laid their 

 eggs in caterpillars. 



Of the family Chalcididae, represented in the present day by 

 an immense multitude of minute species, some of which pass 

 their young existence in the eggs of butterflies, one species 

 (Pteromalinites ceningensis, Heer) is known from CEningen. 



The tribe Phytophaga, to which the saw-flies (Teiithredinidae) 

 belong, is poorly represented, the extant remains of its three 

 species being very incomplete and scarce. 



E. The Rhynchota (Hemiptera). 



Next to the Beetles this order is the richest in species in the 

 Miocene of Switzerland. From CEningen 132 species have been 



