312 Orthoirhapha brachycera. 



Geographical distribution : — Europe down into Spain ; its northern 

 limit is in Denmark, and it occurs in England, where the first specimen, 

 a female, on which Loew described the species, was taken. 



21. MedeteFus Fisch. 



Species of small or medium size; the colours are metallic, but 

 more or less hidden by a greyish or brownish pruinosity, and gener- 

 ally only slightly visible; sometimes they are quite dark and non- 

 metallic. Head a little broader than thorax; it is a little broader 

 than high, and somewhat narrowed downwards; it is not arched 

 behind, but somewhat excavated above. The vertex is distinctly and 

 broadly excavated, the ocellar tubercle slightly prominent. Frons 

 broad, but much decreasing in breadth towards the antennæ; there 

 are ocellar and outer vertical bristles, and a pair of small postvertical 

 bristles, placed quite distantly at the upper eye-corners, so as to be 

 taken for the uppermost of the postocular bristles; on the posterior 

 side of the ocellar tubercle are a pair of exceedingly small bristles. 

 Eyes large, somewhat oval, narrowed downwards; in the living 

 specimens they are metallic green, generally with the upper corner 

 reddish, and sometimes banded ; they are bare. The facets are slightly 

 enlarged towards the epistoma in both sexes. The eyes are well 

 separated, and the epistoma is of the same breadth in both sexes, oi- 

 only slightly, almost imperceptibly broader in the female. The post- 

 ocular bristles are somewhat strong, they form a single row along 

 the eye-margin, but on the low^er half of the occiput there is a second 

 row more inwards; above the oral aperture are no bristles; the upper 

 bristles are short or quite short. Antennæ placed near to each other, 

 rather high above the middle ; they are short, the second joint simple, 

 the third short and rounded, or slightly elongated and pointed oval; 

 in a few cases it has in the male an emargination in or at the apex; 

 the arista is subapical or almost apicaP, considerably or much longer than 

 the antennæ; its first joint is quite short. The first antennal joint is 

 bare, the second has small bristles at the apex, the third is distinctly 

 haired ; the arista is more or less, generally quite short-pubescent. 

 The epistoma with clypeus reaches to the low^er rpargin of the eyes; 

 the clypeus is about quadratic, its separation from the epistoma is 

 distinctly marked by a straight or somewhat angular, transverse keel 

 or ridge. Proboscis thick and strong, and strongly chitinised; it is 



1 I think the arista is in reality always subapical, placed in both sexes in a 

 (variously shaped) emargination, but this is generally very shght and scarcely 

 observable. 



