146 DURHAM DIPTERA. 



XXIV. 226. 



8 (9). Larger species, 3-4 mm. Male organ of moderate 



size. (1244. germanus, W.) 



9 (8). Smaller species, 2J-3 mm. Male organ very large, 



first joint much compressed and protruding above 

 the back of the abdomen. 



(1243. chczrophylli, Mg.) 



10 (3). Femora black or blackish. 



11 (12). Fifth mid tarsal joint dilated; large species, 5-6 mm. 



(1243. nigriplantis, Stan.) 



12 (11). Fifth mid tarsal joint normal; small species, 3 mm. 



1246. Hercostomus nigripennis, Fin. 

 Wearhead, 2 $, August 1, 1901. 



13 (2). Antennae mainly yellowish. 



14 (15). Tip half of hind tibiae black; fore tarsi black with 



white rings. (1242. chrysozygos, W.) 



15 (14). Hind tibise all pale. 



16 (17). Abdomen all metallic green ; small species, 3 mm. 



(1247. plagiatus, Lw.) 



17 (16). Abdomen reddish yellow at the base ; a tiny species 



(Verrall), 3 mm. (Walker). 



(1239. fulvicaudis, Wlk.) 



18 (1). Lower post-orbital bristles black. 



19 (20). Legs wholly black. (1248. atrovirens, Lw.) 



20 (19). Legs pale, at least on tibiae. 



21 (22). Femora and coxae wholly blackish brown. 



(1250. parvilamellatus, Mcq.) 



22 (21). Femora and fore coxae wholly yellow. 



(1249. nanus, Mcq.) 



227. Hvpophyllus, Lw. 



1 (2). Fifth fore tarsal joint broad, disc-like ; large species, 



5-5^ mm. ( I2 5 r ' discipes, Ahr.) 



2 (1). Fifth fore tarsal joint not broad ; small species, 3 mm. 



(1252. obscurellus, Fin.) 



