1891. I 155 



contiguous, and hairy ; in the females they are moderately separated, 



and often only pubescent ; the antennae are short, with a tomentose 



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 



sets ; the wiugs have the fourth longitudinal vein bent in a curve or 



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



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



determine, being very much alike. 



Colour bright metallic or blue-black. 



Pulpi yellow 1. tenehricosa, Mgn. 



Palpi pieeous or black. 

 Abdomen with white reflections. 



Colour blue-black 2. spinicincta, sp. n. 



Colour bronze 3. nitida, Ztt. 



Abdomen without white reflections 4. chaJyheata, Mgn. 



Colour dull black or grey. 

 Legs black. 



Palpi yellow 5. eiliaris, Ztt. 



Palpi black 6. grisea,¥\n. 



Legs pai'tly or wholly yellow 7- disparjFhi. 



M. TENEBEICOSA, MgU. 



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 pieeous 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 ; palpi yellow ; thorar 

 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 botli sexes near 

 Lake Windermere. 



M. SPINICINCTA, S}). n. 



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

 thorax wide and the abdomen oval ; the colour is sliiuy 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 the upper part of the cheeks and terminate 

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

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

 reflections ; antennae short, basal joints pieeous, third joint about equal in length to 

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

 and very shortly pubescent ; epistome very slightly prominent, with long fibrissae, 

 and having a row of bristles extending backwards along the margins of the mouth 



