176 tJ"iy> ^^'2. 



55 (54), First division scarcely longer than the other two. Oostal fringe very 

 short. Four nearly equal supra-antennal bristles, the upper ones wide 

 apart 1 mm. brevicostalis. 



Frons dull. 



Costa quite to v:ing middle. 



Frons narrow, longer than broad If mm. anguslifrons. 



Frons broader than long. 



Tibial cilia large and sparse (10 or 11 in number), though not quite as 

 large and sparse as in ciliata and its two near allies. 



. . Iw— 2 mm.' uliginosa. 

 Cilia moderately large and numerous (15 or 16). . 



Fint costal division distinctly shorter than 2nd. Costal fringe very short. 



. . 1^2 mm. flava, Fall, 



63 (62). First costal division distinctly longer than 2nd. Fringe only moderately 



short 1t~14 mm. collini. 



64 (57). Costa much short of wing middle. 



65 (66). Cilia on hind tibioi distinct and fairly large. (Thorax 'black) . 



.. 1^ mm. nigrescens. 



66 (65). Cilia fine and very indistinct. 



67 (68). Thoraw red or yellow. A moderate sized species 1-1^ ram. lutescens. 



68 (67). Thorax black. A very small species f mm. ia(a. 



SECTION D. 

 Costal fringe long or very long. 



1 (50_^. Mesopleuras bristly. {In conformis bristles very tender and not in- 



frequently quite absent) . 



2 (33). Halteres black, sometimes yellow in involuta. 



3 (18). First joint of front tarsi dilated, or the whole tarsus distinctly thickened. 

 ■ 4 (7). Costa conspicuously short of half the wing length, f or less. 



5 (6). First costal division not half as long again as the other two together. 



Fore metatarsus co7ispicuoushj dilated in male, the other joints and the 

 whole tarsus of female slender 1-li mm. manicata. 



6 (5). First costal division at least double the other two. The whole tarsus 



short and thickened in both sexes about 1 mm. involuta. 



7 (4). Costa to wing middle, or nearly. 



8 (11). The metatarsus only dilated, the other joints of both sexes slender. 



9 (10). Wings dusky; fringe only moderately long ; 1 from two to three times 



2 + 3. Hypopygium without bristles. A large species. 



...2 mm. obscuripennis. 



10 (9). Wings clear, or nearly so ; fringe full long : 1 from half as long again to 



twice as long as 2 + 3. Hypopygium with two or three bristles under- 

 neath. A small or tiny species. Pleurae sometimes bare. 



...about f mm. conformis. 



11 (8). The whole tarsus distinctly thickened in the male, but in the female the 



thickening limited to the metatarsus. 



12 (13). Legs more or less yellow. Hypopygium quite bare. 



...1^-lf mm. hortensis. 



