1910.] 153 



tinged than in gregaria, thick veins blackish, thin ones brown, strong and 

 distinct, costa more than ^ and less than f Aving length, the uniformity of 

 its curve broken by a depression just past the insertion of 1st thick vein, 

 1 abont double 2 H 3, angle at fork very large — nearly a right angle, 1st 

 thin vein slightly but plainly recurved at margin ; legs pale yellow, tip of 

 hind femora blackish, hind tibiso arched and the cilia larger and more 

 distinct than in gregaria f mm. or rather more, ruffrons, n. sp. 



25 (2) Costal fringe long. 



26 (33) Meso])leiirse bristly. 



27 (28) Besides the ordinary bristles a remarkably large and spine-like one 



similar to the one in spinata, a7id lying as there close to the root of 

 the wing. 



,? 9 • A. deep black species : Thorax and abdomen black, the spine-like bristle 

 in the fresh state lies flat against the side, directed horizontally backwards, 

 but in drying assumes various positions and more often than not sticks out 

 at right angles to the pleura ; frons more than J broader than long, supra- 

 antennal bristles not large, the upper very wide ajsart and well oiitside an 

 alignment with inner bristles of middle frontal row, the under approximate, 

 quite small and generally concealed by the antennse, antenntje rather lax'ge, 

 palpi black ; wings nearly clear, costa f wing length or a little more, 1 half 

 as long again as 2 + 3, tliin veins fine but distinct, angle at fork large ; 

 legs black, tibial cilia digtinct and bristly but not large ; hypopygium 

 grey, large and knob-like, produced below at the corner next the abdomen 

 to a point on each side armed with some stout hairs, which are continued a 

 little way up the side, the yellowish ventral plate small and narrow, 

 subanal body large and frequently exserted, anal organ of good size, black 

 with a yellow tip about 1 mm. pectoralis, n. sp. 



28 (27) With no such bristle. 



29 (30) Fore tarsi short and distinctly thickened in both sexes. Halteres vari- 



able, from yellow to black. 

 <? ? . Thorax and abdomen black ; frons black, obscurely shining, about ^ 

 broader than long, 4 moderate and nearly equal supra-antennal bristles, 

 the upper ones inside an alignment with inner bristles of middle frontal 

 row, antennse small, palpi yellow ; wings nearly clear, costa f wing length 

 or rather less, fringe full long yet not very long, 1 at least double 2 + 3, 

 angle at fork moderate ; legs from dark yellowish-brown to almost black, 

 tibial cilia very small and niunerous ; the last 2 segments or so of male 

 abdomen margined on each side of the venter with some large and coarse 

 hairs, continued on to the hypopygium in a more delicate form, hypopy- 

 giiun of moderate size, black and somewhat glossy at the base, ventral 

 plate indistinguishable, anal organ small, yellow or dusky yellow... 



abovit 1 mm. involuta, n. sp. 



30 (29) Fore tarsi simple. Halteres not variable. 



31 (32) Halteres deep yellow. 



(? ? . Thorax and abdomen black ; frons somewhat shining, about i broader 

 than long, 4 strong and eqxial supra-antennal bristles {^) nearly equal 



