24 BRITISH FLIES 



usually strongly serrated beneath, and the tibiie often with 

 rows of spicules and apical spines or with one or more apical 

 spurs on the hind tibi?e. Venation with the subcostal vein very 

 long mid receivinfj S(wcral siihscqucnt veins before its tip; discal 

 vein curved up and ending before the wing-tip in either the 

 costa or the subcostal vein ; small cross-vein present and 

 placed close to the base of the up])er branch of the postical 

 fork ; discal cross-vein (when distinct) near the end of the 

 discal cell ; posterior cells three, four, or five ; 'pnrfurra very 

 short (except in Merjascdus). X. jMydaidte. 



TJie Mydaithv are usually gigantic or very large exotic flies, l)ut 

 two or three species of moderate size occur in tlie south of Europe. 

 Their peculiar venation distinguishes them from all others, Ijut is not 

 very different from that of tlie ApiocerldiM. 



21 (18) Chsetophorous species in the sense that there are strong and 

 usually numerous bristles on the thorax, scuteUum, and legs, 

 or at least on the sides of the mesonotum, except in the few 

 cases in which dense coarse pubescence is substituted. 



BNERGOPODA. 



Never bare leathery dooking species. Til:)i8e and tarsal joints with 

 apical circlets of spines. Eyes always widely separated in both sexes 

 ( = dichoptic) and usually protruding. Antennae with a simple or 

 jointed apical style or sometimes without any style or arista. Vena- 

 tion with the subcostal vein very long and often receiving the radial 

 vein before its tip ^ praef urea moderately long ; discal cross-vein near 

 the middle^ of the discal cell ; small cross-vein always present or almost 

 so ; posterior cells almost invariably five. Very large to rather small 

 species, and the smallest Asitidce usually bear long pubescence as well 

 as bristles. 



The two families composing the Enekgopoda are closely allied, 

 but yet perfectly distinct. Sometimes {Ajnoceridw) the venation 

 resembles that of the Mydaidm in that the upper branch of the discal 

 vein ends before the wing- tip, while the radial vein and the up]ier 

 branch of the cubital vein end in the subcostal, but that occurs very 

 rarely in the Asilidce (some species of Enur). When dense coarse 

 pubescence is substituted for bristles {Lapliria, etc.) it is of a very 

 different nature from the soft furry pubescence of the Tkomopteka. 

 The Asdiihe are all predaceous. 



The Eneik^opoba may be distinguished from the Dei;matina by 

 the presence of strong bristles on the thorax, and from the Miceophona 

 by their (usually) larger size and much more elaborate venation, which 

 practically always includes five posterior cells and a long pointed anal 

 cell. 



22 (23) Pace short and without any face-beard overhanging the mouth. 

 Palpi spatulate. Antenna3 with a very short style. ScuteUum 

 large and concealing the metanotum. Venation rather similar 

 to that of the Mydaidce as the radial vein and upper branch of 

 the cubital fork curve up and end in the subcostal vein, while 

 the upper branch of the discal vein curves up and ends before 



