DURHAM DIPTERA. 367 



LI. 637. 



15 (12). All femora with a stripe on the middle. 



{lineola, St?eg.=plamfro?is, Lw.?) 



16 (7). Third antennal joint partly yellow. 

 16a (16b). Wings distinctly brownish. 



(2703. meigetiii, Lw., and ringens, Lw.) 

 16b (16a). Wings not browned. 



17 (22). Legs all yellow. 



18 (19). Vertical triangle black with two yellow spots ; sterno- 



pleural spot all black. (didyma, Ztt.) 



19 (18). Vertical triangle without yellow spots. 



20 (21). Vertical triangle very small ; abdomen four-banded. 



2710. Chlorops scalarts, Mg. 

 Hesleden, i $, August, 1897. 



21 (20). Vertical triangle long, conical ; abdomen three- 



banded. (Chloropisca trifasciata, Stseg.) 



22 (17). Fore femora with a dark stripe on the middle outside, 



and the hind tibiae ringed. 

 22a (22b). Vertical triangle black, small, long, and narrow. 

 2708. Chlorops lata, Mg.=disa'cornis, Lw. ? 

 Hesleden, 1 ?, August, 1896. 



22b (22a). Vertical triangle shining brownish yellow and 

 large. {hirsuta, Lw.) 



23 (4). Small species, under 2 mm. 



24 (25). Scutellum dark. {Chloropisca obscurella, Ztt.) 



25 (24). Scutellum yellow. 



26 (36) (37). X-veins only moderately approximated ; V.4 3 not 



more than three and a half times V.4 2 . 



27 (29a) (30). Abdomen yellow with two dark spots on the 



second segment. 



28 (29). Vertical triangle very small. 



(hypostigma, Mg.=.?ninuta, Lw. ?) 



29 (28). Vertical triangle large. ( Chloropisca parvula, Ztt.) 

 29a (27) (30). Abdomen blackish brown ; side margins and 



tip yellow. {humilis, Lw.) 



30 (27) (29a). Abdomen yellow below, black above. 



31 (34) (35). Legs all orange. 



