3^0 DURHAM DIPTERA. 



■LI. 



9 (8). Antennse placed on the edge of the frons, not half 

 hidden, free. 



10 (11). Hind femora much thickened. Meromyza, Mg. (631) 



11 (10). Hind femora not thickened. 



(See Chlorops, &c, page 365). 



12 (13). The spur of the mid tibia? a strong bent thorn; body 



cylindrical ; legs strong, especially the femora ; 

 male organ large. Centor, Lw. (632) 



13 (12). The spur of the mid tibiae a straight weak bristle. 

 14(15). Suckers of the proboscis very long and thin; wings 



more or less darkened; V.3. and V.4. diverging 

 considerably. Capnoptera, Lw. 



15 (14). Suckers short. 



16 (17). Arista white, except at its base, and on account of 



its thick pubescence apparently thickened; palpi 

 black. Anthracophaga, Lw. (633) 



17 (16). Arista not thickened ; pubescence extremely short. 



18 (19). The vertical triangle almost entirely filling the vertex, 



and bordered with a single row of hairs ; entirely 

 black species. Haplegis, Lw. (634) 



19 (18). The vertical triangle even when large not nearly 



filling the vertex. 



20 (21). X.4. and X.5. very close together, sometimes almost 



in a line; V.3., and usually V.2., distinctly bent 

 upwards ; an erect hair at the upper mouth corner ; 

 orbits in species under 2 mm. with a distinct row 

 of hairs. Diplotoxa, Lw. (636) 



21 (20). X.4. and X.5. not specially close together. 



22 (23). The third antennal joint not circular in front, but with 



a distinct upper corner. Eutropha, Lw. (635) 



23 (22). The third antennal joint circular, without a distinct 



upper corner. 



24 (25). Scutellum with its upper side arched, or if rather flat 



at least never with a distinct rim or border-line. 



Chlorops, Lw. (637) 



25 (24). Upper side of the scutellum flat, and marked off from 



the sides by a distinct edge. 



Chloropisca, Lw. (638) 



