52 MIOCENE FAUNA. 



trees, where it fills the air with its monotonous chirping. Re- 

 garded from ancient times as the heralds of summer, and as 

 symbols of the peacefulness of nature, the Cicada are among the 

 best-known insects of southern countries. In Tertiary times 

 the Cicadas enlivened Swiss forests with their joyous choral 

 chants ; afterwards they departed for a warmer region. 



Of the Fulgorinae (lantern-flies and allied forms) one species 

 (Pseudophana amatoria, Heer) dwelt in the forests of QEningen, 

 and lived most probably upon oak trees ; at least, its nearest 

 living relative (P. europaea, Fab.) is met with upon oaks. Of 

 the Membracinae only one species is known at OEningen. 



Cicadellinae form the most numerous family, thirteen species 

 of which occur at (Eningen. Some of them are very small in- 

 sects, resembling the green, yellow, and brown froghoppers 

 which are so abundant in the grass, and which, as larvae, produce 

 what is called "cuckoo-spit^ on herbaceous plants and shrubs. 

 Others are larger party-coloured creatures, the representatives 

 of which live sometimes in warm countries (as in. the case of 

 Cercopis Germari, Heer, fig. 305), and are also found in Swit- 

 zerland (as Cere. Herrichi and Hageni, Heer). An extinct 

 genus (Ledophora) most resembles a Ledra from Madagascar. 



F. Diptera. 



As regards number of species, the Diptera are now the fourth 

 order of insects ; and they occupy the same position in the Mio- 

 cene fauna. They are divided into two great suborders the 

 Nemocera, or those with antennae composed of numerous joints, 

 and the Brachycera, which have very short antennae, containing 

 from* one to three joints. At the present day the Nemocera 

 constitute about one seventh, and the Brachycera six sevenths, 

 of the whole ; but formerly the proportion was very different. 

 The Nemocera, or midge-like flies, first made their appearance ; 

 and the Brachycera followed them. In GEningen the latter, 

 with twelve species, form about one fifth, and the Nemocera, 

 with fifty-one species, form about four fifths of the species ; and 

 the proportions are similar in other countries where fossil dip- 

 terous insects have been found. Of these two suborders of in- 

 sects the Brachycera live principally upon flowers, especially 



