82 • [^P»'"' 



angles are distinctly convergent, it is impossible to run it down into 

 its proper " Section " by means of Brauer's " Table I " (Verb. z.-b. 

 Ges. Wien, xliii, p. 463, et seq^.'), the following summary of its prin- 

 cipal characters may, perhaps, be found useful, since the original 

 description by Meigen, and the subsequent one by Egger, are probably 

 inaccessible to most British Dipterists. 



^ . Length, 6 mm. (2| lines). Face with a roio of bristles on each side between 

 the facial ridge and the eye ; arista distinctly pubescent to the tip ; palpi, tip of 

 scutellum, tips of femora beneath, and tibicB {except at the base) orange-rufous ; 

 abdomen cylindriform, shining blaeh, orange-rufous on sides of second segment and 

 on those of the first posteriorly, rather more than the anterior halves of the second, 

 third, and fourth segments occupied by transverse bands of yellowish-silvery pollen, 

 interrupted by a shining blacJc median stripe ; hypopygium shining blacJc, beneath it 

 two vertical orange-rufous lobes. 



Head squarish when seen in profile, clothed with greyish pollen ; front broad, 

 slightly narrower than the eye, with black median stripe occupying one-third of its 

 width ; orbital setce, three on each side ; antennse black, tips of first and second 

 joints orange on inside ; the pubescence on the arista easily seen when examined 

 with a platyscopic lens of medium strength ; the row of setae on the face is formed 

 by the continuation downwards of the frontal series on each side ; it terminates a 

 little above the lower margin of the eye, and the three lowest bristles are the 

 strongest ; eyes bare ; facial angles convergent, contracting the clypeus immediately 

 above the oral margin in front ; vibrissse stout, oral setae confined to the facial angles ; 

 oral margin, and the depression behind the facial angle on each side rufous. Thorax 

 grey, with three black stripes, and clothed with strong bristles. Abdomen without 

 discal macrochsetse, the marginal ones confined to the second, third, and foui'th 

 segments ; first segment with a shimmering poUinose patch on each side of the 

 median stripe, which is here broader. Hypopygium shining black ; immediately 

 below it two vertical spatulate lobes, which are orange-rufous posteriorly. Wings 

 somewhat greyish ; terminal portion of fourth vein but slightly concave outwards ; 

 first posterior cell narrowly open, or closed on margin of wing, which it reaches 

 shortly before the tip ; no appendix to angle of fourth vein ; costal spine {Rand- 

 dorn) conspicuous ; setae on the third vein confined to one or two (one of which is 

 of considerable size) at its extreme base, where a thickened spot marks the point of 

 divergence of the second and third veins. Legs black, the tips of the femora 

 beneath (in the case of the middle and posterior pairs more extensively than in that 

 of the front pair), and the tibiae, except rather more than the basal third, orange- 

 rufous ; anterior claws long and slender. 



$ . For the sake of completeness, I translate the following remarks from 

 Egger's paper {loc. cit., p. 298) : " In the female, which was unknown to Meigen, 

 the basal joints of the antennse are yellow, the abdomen is flattened oval in shape, 

 shining dark brown, with bright white bands on the anterior margins of the rings, 

 and a black dorsal stripe. The sides are not translucent ; the legs are for the most 

 part yellow, only the anterior femora are black right to the extreme tip ; the tarsi 

 brown." 



