i»iii-J 155 



contiguous, and h.iiry ; in the females the}' arc moderately separated, 

 and often only pubescent ; the antenna) are short, with a tomentosc 

 arista ; the facialia are unarmed ; the cheeks are bare, but the mentum 

 or chin is hairy or bristly ; the abdomen has both discal and apical 

 seta> ; the wings have the fourth longitudinal vein bent in a curve oi* 

 blunt angle, and the first posterior cell opens near the apex of the 

 wing. These flies are not common, and several species are difficult to 

 determine, being very much alike. 



1 (8) Colour bright metallic or blue-black. 



2 (3) Palpi yellow 1. teneby-icosa, Mgn. 



3 (3) Palpi piceous or black. 



4 (7) Abdomen -svitli white reflections. 



5 (6) Colour blue-black 2. spinicincta, sp . n. 



6 (5) Colour bronze 3. nitida, Ztt. 



7 (4) Abdomen without white reflections 4. chalyheata, M.gn. 



8 (1) Colour dull black or grey. 



9 (12) Legs black. 



10 (11) Palpi yellow 5. ciliar is, Ztt. 



11(10) Palpi black Q. grisea,^!^. 



12 (9) Legs partly or wholly yellow 7. dispar,'F\n. 



M. TENEBIJICOSA, Mgn. 



Shining metallic-blue or bronze-black ; eyes contiguous in the male, and separa- 

 ted by about a fourth of the width of the head in the female ; frontal stripe rufous 

 or piceous in the latter sex ; fronto-orbital bristles only extending slightly below the 

 base of the antennae, which are black, and have the third joint about one and a half 

 times the length of the second ; arista thickly pubescent j palpi yellow ; thorax 

 grey upon the front and sides, and marked with four black stripes, the central pair 

 being rather wide apart and narrow ; there are four external dorso-central bristles 

 behind the transverse groove ; abdomen with very slight grey reflections ; dorsal 

 setae weak, and seated upon both the disc and edges of segments ; legs black ; 

 calyptra brown in the male, and nearly white in the female ; halteres yellow ; wings 

 brown in the male, and nearly clear in the female ; apical cross vein slightly curved 

 inwards, outer cross vein sinuous. Not common ; I have found both sexes near 

 Lake Windermere. 



M. SPIXICINCTA, sp. n. 



This, which is about the largest British species (length, 7 — 9 mm.), has the 

 thorax wide and the abdomen oval ; the colour is sliiny blue-black, with white to- 

 mentum and reflections ; the male has the forehead and face rather flat ; the eyes 

 approximate, the frontalia ciliated with very long, strong, and thickly set fronto- 

 orbital bristles, which spread out upon tlie upper part of the cheeks and terminate 

 in a large group or patch opposite the base of the third joint of the antennte ; 

 margins of frontalia black, central stripe rufous or piceous ; cheeks white, with black 

 reflections ; antennne short, basal joints piceous, tliird joint about equal in length to 

 the other two, and black ; arista long and tapering, somewhat thickened at the base, 

 and very shortly pubescent ; cpistome very slightly prominent, with long fibrissa), 

 and having a I'ow of bristles extending backwards along the margins of the mouth 



