MIDGES. 53 



those of herbaceous plants, and whole swarms of them may be 

 seen sunning themselves upon the flowers of Umbelliferous and 

 Composite plants; whilst the Nemocera frequent woods and 

 copses, and particularly favour damp watery regions. Their 

 larvae live sometimes in water, sometimes in the humid soil of 

 woods and forests, or in rotten wood ; and a great number of 

 them live in fleshy fungi. Widely spread damp forest-land, 

 traversed by small streams and interspersed with morasses, 

 furnishes the chief conditions for the luxuriant development of 

 the Nemocera ; and these favourable conditions existed in abun- 

 dance during the Miocene epoch. Of the species obtained from 

 GEningen, from the analogy of allied living insects, the larvae of 

 five lived in water, of fifteen in fungi, and of thirty in moist 

 ground and rotten wood. 



The feather-midges (Chironomi) appear in spring in countless 

 swarms on the shores of the Swiss lakes, and are distinguished 

 by their elegantly feathered antennas ; they lay their eggs in 

 the water, in which they pass the whole of their young states. 

 Of these insects there are preserved at GEningenboth the aquatic 

 pupae and the active aerial forms. Of one species (Chironomus 

 Gaudini, Heer, fig. 316) the pupae are abundant, and several of 

 them are generally found near each other. These pupae occur 

 on two slabs from (Eningen, side by side with the winter eggs 

 of the Daphnics. 



The Mycetophilidae (fungus-midges) are very delicate little 

 creatures, the white maggots of which are often met with in 

 great numbers in fleshy fungi. At (Eningen there are two 

 genera, Mycetophila (with nine species) and Sciara (with six 

 species) ; and the specimens (small and extremely tender) are, for 

 the most part, beautifully preserved, as may be seen from figs. 

 317, 318, and 319. 



Of the little gall-midges (Cecidomyidae) , which cause gall-like 

 swellings on leaves, no perfect insects have come to the know- 

 ledge of Prof. Heer. On poplar-leaves from CEningen there is 

 a formation of galls (fig. 322) exactly agreeing with that pro- 

 duced by the Cecidomyia salicis of the willow, and thus leaving 

 no doubt that in Miocene times such flies were already in ex- 

 istence. 



