8 



BRITISH FLIES 



(fig. 24), tliougli not always, as in Lcqiliria (fig. 25), until in the families 

 with a very short anal cell {Emimlce, DoHcliopodidcc, etc.) the third 

 antennal joint is comparatively simple, with a terminal style, as in 



Fxo. 25. — Lajihria fava J. 

 X 20. 



Fig. 20. — Empis tcssellala 9- 

 X 30. 



Fi(i. 27. — Dolichopus uiigulatus i. 

 X 33. 



Empis (fig. 26), though the dorsal arista (so characteristic of the Atiieki- 

 cera) does not make its appearance until in some genera of the 

 DolichopocUdce (fig, 27). The antenntB are never very long, rarely as 

 long as the head and thorax together, though they are not uncommonly 

 elongate and porrect, and they are almost invariably similar in the two 

 sexes. 



Wings with an apparently complex venation (thougli the complexity 



is only caused l>y numerous cross- 

 veinlets), as in Nnncstrino. (fig. 

 28), or with a venation well de- 

 veloped hut of a comparatively 

 simple type which extends through 

 numerous families, until the group 

 of families is reached in which the 

 anal cell is drawn back to the base 

 of the wing, after which the venation becomes far more simple until it 

 reaches the most simple form in the Dolichopodidce (fig 29), in which it is 



Fig. 1?>.—Nemestrina Perczii 9 . x 5. 



"twrtmiM„Mim„rt,„,„,„,„„_,„„„.„n>«Tf'' 



Fig. 29. — Dolichopus ungulatvs i. x 12. 



almost indistinguishable from many of the Athericera. The anal cell is 

 always contracted near the hindmaryin, even when it is open as in Lcptis 



