388 DURHAM DIPTERA. 



LVIL 663. 



41 (22). Dorsum yellow or red-brown. 



42 (45). Two pairs of dorso-central bristles. 



43 (44). Colour entirely yellow, except black fore marginal 



abdominal bands ; hind tibiae with two outer and 

 one inner bristle; third antennal joint in the male 

 large and brown tipped. (2852. dorsalis, Beck.) 



44 (43). Entirely yellow ; hind tibiae with two outer, one inner, 



and one hind bristle. {bergenslanimi, Mik.) 



45 (42). Only one pair of dorso-central bristles. 



46 (47) (47a). Fore tibiae with 3-4 bristles ; hind tibiae with one 



hind end bristle and one spur; dorsum brown; 

 pleurae yellow; abdomen black, segments one, 

 two, and part of six yellow, (chlorogastra, Beck.) 



47 (46) (47a). Fore tibiae with one bristle on the middle ; hind 



tibiae with one hind mid bristle and one spur; 

 entirely orange species. {unicalcarata, Beck.) 



47a (46) (47). Fore tibiae with one bristle on the first third ; 

 hind tibiae with one outer basal bristle, and 

 apparently three long spurs ; dorsum orange ; 

 pleurae black; abdomen black with narrow hind 

 marginal bands. (2853- erylhronota, Strobl.) 



48 (13). Halteres blackish brown. 



49 (52). V.3. bearing bristles. 



50 (51). Hind tibiae without bristles, except at the tip ; costa 



with long ciliation; V.2. very weak, generally 

 absent. {agilis, Mg.) 



51 (50). Hind tibiae with two bristles on the middle; costa 



with short thick ciliation. 



2854. Phora curvinervis, Beck. 

 Harperley, 1 ?, 4-6-00 ; Bishop Auckland, 1 $, 

 25-5-02. 



52 (49). V.3. not bristly. 



53 (56). Scutellum with two bristles. 



54 (55). Costa extending far beyond the middle of the wing ; 



fork of V.3. short, and almost a right angle at the 

 base; size 1^-2 mm, (2851- uwspinosa, Ztt.) 



