72 Orthorrhapha brachycera. 



and the upper part of the sides; on the lower part of the sides 

 shilling and sometimes somewhat translucently brownish. It is sparingly 

 clothed with short, black hairs. Venter greyish or brownish, more 

 or less pale, with short hairs. Exterior genitalia small, the lower 

 lamellæ somewhat blade-like, the upper styliform, pointed, somewhat 

 broader at the base; both pairs with short hairs apically. Penis 

 thick at the base, curved upwards and hidden. Sometimes the genitalia 

 are more retracted, and the mentioned structure not or indistinctly 

 seen. Legs slender; front coxæ yellow, posterior coxæ darker, brownish 

 or blackish; femora yellowish to brownish, generally darker towards 

 the apex; tibiæ and tarsi dark brown to blackish. Femora short- 

 haired, only the hind femora with some longer hairs above at the 

 base; tibiæ likewise short-haired, front tibæ with slightly longish, 

 dense hairs below; anterior tibiæ without bristles; hind tibiæ short- 



Fig. 21. Wing of Rh. nigripennis. 



but distinctly haired on both sides and with some small bristles 

 dorsally; tarsi short-haired; the posterior tarsi slightly spinulous 

 beneath, the front tarsi with dense hairs below as on the tibiæ. 

 Wings strongly blackish fumigated, iridescent; they are darkest to- 

 wards the anterior margin, sometimes some shades may be seen, 

 seaming the veins, especially the postical vein, at other times no 

 shades are visible. Veins blackish or brownish, anal vein abbreviated, 

 the discai cell lying before the middle of the wing. Stigma brownish 

 black. Halteres dark brown or black. 



Female. Eyes separated, frons somewhat narrow, black, shining. 

 Thorax black, shining. Abdomen darker or paler brown, somewhat 

 shining. Femora generally more yellow on the basal part; legs haired 

 as in the male, only the dense hairs below the front tibiæ wanting. 

 Wings hyaline, somewhat yellowish tinged. 



Length 2,5 — 4 mm., the latter size only reached by females Avith 

 fully extended abdomen. 



This species can only be confused with the following, under which 

 I shall give the distinguishing characters. 



Bh. nigripennis is a common species in Denmark ; Copenhagen 

 in gardens. Amager, Ordrup Mose, Ermelund, Lyngby Mose, Ørholm 



