September, 1909.] 193 



92 (91) Antennx brown. A minute species, under f mm. 



<?. Very closely- related to tlie last speeies. Thorax dusky reddish, abdomen 

 black ; pi'oportions of frons as in the two preceding species, under supra- 

 antennal bristles minute, palpi yellow ; wings tinged with yellowish-brown, 

 costa variable, sometimes nearly reaching the wing middle, but generally 

 distinctly short of it, 1 about equal to 2 + 3, angle at fork large, and 1st thin 

 vein leaves at the fork with a gentle curve ; legs yellow, lightly dusted with 

 grey, especially in the apical half of the hind femora ; hypopygium grey and 

 very large, larger in all its dimensions than the 6th segment, with a pair of 

 bristles, one above the other and well separated, at each under corner, and 

 short erect hairs on the sides, subanal body generally exposed, very large, and 

 consisting of two parts, one behind the other, the one in front being the shorter 

 of the two, ventral plate small not | mm. discreta, n. sp, 



93 (88) Anal organ of male not minute; even if somewhat short, at least stout. 



Costa of female not swollen. 



9-1 (95) First costal division much longer than the second, generally twice as long. 

 A largish species (If — 2^). 



(J $ . Thorax and abdomen black ; frons fully half as broad again as long, four 

 large, and in male equal, supra-antennal bristles, in female the under pair 

 smaller, but always more than half as large as the upper, antennae of ordinary 

 size, palpi yellow, dusky yellow or (<J) almost black ; wings tinged with grey, 

 especially in female, angle at fork moderately lai'ge ((? ), acute ( ? ), curve at 

 which 1st thin vein leaves gentle ( c? ), fairly bold ( ? ) ; legs from brown to nearly 

 black ; hypopygium small, the dusky anal organ short and stout, filling the 

 posterior outlet, ventral plate yellow, reaching the end of the hypopygium in 

 the quiescent state If — 2^ mm. fusca, n. sp. 



95 (94) First costal division not longer or only slightly longer than the second. 



A smallish species, about Ij mm. 

 (J ? . A black little insect, very liVe fusca. But besides the above, the following 

 points serve to differentiate it : — The male antennae are larger, being rather 

 above the ordinary size ; the supi-a-antennal bristles smaller, the under pair 

 being minute in the female, and never more tlian half as large in the male, 

 though there is considerable variation in this respect, individually as well as 

 sexually ; the angle at fork larger, never acute, and the curve at origin of 1st 

 thin vein as large in male as female ; the legs on the whole blacker ; and the 

 small erect hairs on the male abdomen less conspicuous than in fusca; the 

 hypopygium presents no differences, and as the small subanal body is frequently 

 exposed in this species, the large square-shaped ventral plate comes well into 

 view. Not unfrequently a paler form is met with, in which the halteres are 

 dusky yellow and the legs browner, at the same time the male antennae appear 

 not to be above the ordinary size, and the under pair of supra-antennal bristles 

 rather better developed, but as in all other respects it resembles the type, it is 

 best to consider it only as a variety I3 mm. more or less, angusta, n. sp. 



96 (87) Halteres yellow, or dusky yellow {nudiventris, ^ )• 



97 (100) Sides of male abdomen thickly clothed toith very long and blunt-ended 



hairs. 



