BRITISH SPECIES OF DIPTEROUS GENUS FANNIA 137 



21 (26). Mid metatarsus with a thorn on the ventral surface near 



the base. 



22 (23). Whole ventral surface of hind tibia with long hairs. 



11 armata, Mg. 



23 (22). Hind tibia not remarkably haired. 



24 (25). Squamae and halteres black; small species, 3 to 4 mm. 



12 cerea, Ztt. 



25 (24). Squamae and halteres almost brownish; larger species, 4J 



to 5 mm. 13 umbrosa, Stn. 



26 (21). Mid metatarsus without a thorn. 



27 (30). Mid tibia ventral surface with a tubercle. 



28 (29). Mid femora bare at base on ventral surface. 



14 vesparia, Mde. 



29 (28). Mid femora on ventral surface bristled to the base. 



15 coracina, Lw. 



30 (27). Mid tibia without a tubercle, almost the apical half 



thickened. 



31 (32). Hind femora with a fasciculus of hairs on the postero-ventral 



surface near the tip. 16 kowarzii, Verr. 



32 (31). Hind femora without a fasciculus at this part, either bare, 



or with a few bristles. 

 ^t, (34). Apical third of mid tibia distinctly but not greatly 

 thickened ventrally. 1 7 verrallii, Stn. 



34 (2,3)- Mid tibia either quite straight or with more than apical 



third thickened. 



35 (40). Mid tibia with more than one antero-dorsal bristle. 



36 (37)- Calyptra black, halteres yellow; dull black species. 



18 nigra, Mall. 



37 (36)- Calyptra pale yellowish. 



38 (39). Shining blue-black species ; hind femora with postero- 



ventral surface bare. 19 carbon aria, Mg. 



39 (38). Black species ; basal one-third of hind femora, postero- 



ventral surface, bristled. 20 poly duet a, Stn. 



40 (35)- Mid tibia with only one antero-dorsal bristle. 1 



41 (42). Hind tibia without the preapical bristle, mid femora with 



three strong bristles on the antero-ventral surface besides 

 the ordinary bristles. 2 1 sociella, Ztt. 



42 (41). Preapical bristle present on hind tibia. 



43 (44). Genitalia remarkably large and strong. 



22 glancescens, Ztt. 



44 (43)- Genitalia not exceptionally large. 



1 Sociella, Ztt., has several bristles near the apex on this side, but these may 

 be considered as apical. 



6 s 



