FLIES. 55 



Dipterous fauna. The twenty-eight species from (Eniiigen be- 

 long to five genera, three of which (Bibiopsis, Protomyia, and 

 Myidium) are extinct'. Protomyia speciosa, Heer, represented 

 in fig. 312, is one of the largest species of the genus, which is 

 represented in (Eningen by nine species. Three of them have 

 been collected in Croatia, indicating the wide distribution of the 

 genus in Tertiary times. Still more abundant were the true 

 Bibiones, sixteen species of which occur at (Eningen, some of 

 them being black, others of a light colour with dark spots. 

 Their larvae probably lived in rotten wood and in the rich vege- 

 table mould of the forests. They are flies of considerable size, 

 distinguished by their generally broad wings, their short an- 

 tennae (which consist of from eight to twelve joints), and their 

 thickened fore legs. Some species resemble European and 

 North-American forms (thus B. mcestus, Heer, is like B. po- 

 mona, Linn.), whilst others represent peculiar and apparently 

 extinct types (such as B. elongatus, Heer, fig. 311). Whilst the 

 genus Bibio is at present widely distributed, having eighteen 

 species in Europe and eleven in America, Plecia is confined to 

 South America and the Cape of Good Hope. (Eningen possesses 

 a very fine species of this genus (Plecia hilaris, Heer, fig. 313) 

 with a light-brown body. 



Brachycera are very scantily represented in the Miocene fossil 

 fauna. Nevertheless they form four tribes and five families, but 

 in each case have only a few species. The Xylophagidae furnish 

 two uncertain species. Of the Asilidae there are three spe- 

 cies. Two of these belong to the genus Asilus, flies which lie in 

 wait for other insects, spring upon them after the manner of a 

 cat, and, embracing them with their hairy legs, pierce them 

 with their proboscis. The Tabanidae (breeze-flies) are represented 

 by a single species (Hexatoma ceningensis, Heer, fig. 321), and 

 the Syrphidae (drone-flies) by two, which, like the living forms, 

 are distinguished by their elegantly banded abdomen (figs. 314 

 and 315). 



The true flies furnish an Echinomyia (E.antiqua, Heer), the 

 larvae of which probably lived (like those of E. echinata, Meig.) 

 as parasites upon caterpillars. There are also a small Antho- 

 myia, and two flies with spotted wings allied to Psila. 



The larva represented in fig. 323 probably belonged to some 



