BRITISH FLIES 



29 



29 (26) Wings pointed at the tip ; venation abnormal, as the radial and 

 cubital veins end close together at almost the wing-tip; no 

 obvious cross-vein, and the discal cell absent or reduced to a 

 short middle basal cell. Face with strong bristles round the 

 mouth-margin. Thorax with bristles but no pubescence. 

 Eyes widely and equally separated in both sexes. Antennoe 

 short and porrect with a long subdorsal arista. Colour 

 always dull yellowish, brownish, or greyisli, but never green 

 or metallic. ACROPTERA— XV. LoxcHOPTERiD/ii;. 



Fio. 51. — Lonchojiti-ra httea <£. x lOA. 



The Lonchopteridce are limited to the genus LonchojAera, which is 

 not known to have any obvious ally in the whole of the Diptera. 

 The species are small and very few in number, but some of them are 

 very common. They are easily recognised by their colour and their 



Fio. 52. — Loiiclioptcra Iristis ?. x 16. 



peculiar venation, and they are the only group of Dipteea in which 

 the venation is conspicuously distinct in the two sexes (figs. 5], 52). 

 The short basal cells and the divergence of the cubital and radial veins 

 close to the base _ of the wing may indicate relationshii) to the 

 Dolichopoclidce, while the bristly face and frons may indicate a still 

 closer relationship to the Phoriche ; and the male genitalia in all three 

 families may indicate affinities. 



30 (25) Wing-veins extremely abnormal and quite distinct from those of 

 any other Dipteea;* anterior veins up to the cubital vein 



* The genus Aspistes in the Bihionidce has a similar venation. 



