280 DURHAM DIPTERA. 



XXXIII. 474. 



25 (26). The second and third segments of the abdomen each 



with three black spots, the two side ones round, 

 the middle one long. {brevis, Rnd.) 



26 (25). Abdomen otherwise marked. 



27 (32). Abdomen partly translucent yellow ; when not so, 



then the mid tibiae inner side with the pubescence 

 scarcely visible. 



28 (29). Hind femora under side near the tip with a tuft of 



long hairs. (fasciculata, Lw.) 



29 (28). Hind femora without the tuft of hairs. 



30 (31). Mid tibias inner side with very short pubescence ; 



thorax rather pale brown. 



2143. Hoinalomyia ca?iicularis, L. 

 This is the very abundant small house fly, the 

 commonest victim of the sticky fly-papers. 



31 (30). Mid tibiae inner side with longer pubescence ; thorax 



blackish brown. {difficilis, Stein) 



32 (27). Abdomen nowhere translucent ; pubescence of the 



mid tibia? distinct. 



33 (44). Mid metatarsus inner side with a thorn at the base. 



34 (35). Genitalia with a remarkable tuft of bristles pointing 



downwards. {barbata, Stein) 



35 (34). Genitalia simple. 



36 (37). Eyes remarkably hairy. (hirticefis, Stein) 



37 (36). Eyes at most slightly pubescent. 



38 (39). Whole length of hind tibias inner side long haired. 



(2144. armata, Mg.) 



39 (38). Inner side of hind tibiae with only the usual bristles. 



40 (41). Squamae and halteres black ; small species, 3-4 mm. 



2145. Homalomyia aerea, Ztt. 

 Wynyard, 1 $, May, 1902. 



41 (40). Squamae and halteres lighter, at most brownish ; mid 



sized species, 4^-5 mm. 



42 (43). Eyes slightly separated ; hind under side of hind 



femora quite bare. {cothtirnaia, Lw.) 



