118 [May, 



short and stout and wholly yellow. In other respects as pleuralis... 



li — 2 mm. diversa, n. sp. 



69 (68) Wings deeply tinged loith yeUomish-hroion ; angle at fork usually acute. 



(J 9 . Thorax variable, usually black, but often tinged with red or even wholly 

 reddish-yellow, pleural bristles tender and equal, abdomen black with no trace 

 of any greyish gleam ; costa well beyond middle of wing, 1 distinctly less than 

 2 + 3, especially in the female; legs yellow, browner in the darker forms, 

 fore tarsi rather stout in both sexes, hind femora much dilated, and tibial cilia 

 large and strong ; hypopygium grey and of moderate size, subanal body small 

 but rai-ely exposed, the yellow ventral plate short and broad, and the anal 

 organ stout and of a clear yellow 2 — 2^ mm. variabilis, ». sp. 



70 (65) First costal division about twice as long as the second and distinctly 



longer than the second and third together. 

 S $ . Thorax and abdomen black, the latter with a greyish gleam as in pleuralis 

 and rftwrsa, pleural bristles simple ; supra-antennal bristles smaller than in the 

 three preceding species but like theirs practically equal, palpi pale yellow and 

 of not more than ordinary size ; wings tinged with yellowish-brown, costa 

 barely to middle of wing ( <? ) to middle (?), angle at fork as in pleuralis; 

 legs yellow tinged more or less with bi'own, fore tarsi slender, tibial cilia 

 distinct, but rather weak ; male abdomen with a tendency to hairiness at the 

 end, hypopygium rather small and grey, armed with some small and incon- 

 spicuous bristles much as in pleuralis, subanal body small and not infrequently 

 exposed, ventral plate yellow, large and rounded at the end, anal organ clear 

 yellow, short and stout, practically filling the posterior outlet of the hypopy- 

 gium 1^ mm. subpleuralis, n. sp. 



71 (38) Meso-pleurx bare. Hind tihiie ciliated with distinct bristles. 

 1'2 (73) Middle and hind tibix tvith bristles on both sides of the seam. 



$ 9 . Thorax and abdomen yellow, 3rd and 4th abdominal segments abbreviated, 

 especially in female, and more or less blackened dorsally but leaving in male 

 a broad dorsal line of the ground colour ; frons black much dusted with grey, 

 of moderate proportions and with the central line very faintly impressed, 

 supra-antennal bristles moderate, the under pair half the size of the upper, 

 antennae orange, palpi yellow with very large and coarse bristles ; wings and 

 veins yellowish, costa beyond middle of wing, fringe very long and coarse, 1 not 

 longer than 2 ; legs yellow, hind femora dilated and not blackened at tip, fore 

 tibise ciliated with fine and small bristles, mid tibiae with 2 bristles close to the 

 base on inner side of seam and 4 — 6 on the outer side extending about half way 

 down the shaft, hind tibiae with 7 or 8 large ones irregularly placed on the 

 inner side and a single smaller but quite distinct one on the outer, close to the 

 base ; hypopygium often partially concealed within the lengthened 6th segment, 

 ajial organ large and yellowish with the pair of terminal bristles very small ; 

 ovipositor large and exserted 3 mm. melanocephala, v. Ros. 



73 (72) Middle and hind tibix only ciliated on inner side of seam {normal). 



74 (75) Halteres black. 



i $ . Thorax and abdomen black ; frons black, scarcely shining, about 5 broader 



