DUEHAM DIPTERA. 45 



IV. 68. 



11 (12). Male thorax pale-haired. Female abdomen black 



above, orange beneath. (387. reticulatus, Lw.) 



12 (11). Male thorax black haired. Female abdomen all 



black. (388. nigriventris, Hal.) 



13 (8). Veins of the hind region much fainter than those of 



the front. 



14 (15). Legs black, male wings milky white. 



(382. leucoptems, Mg.) 



15 (14). Legs all, or partly, orange or pale brown, or if male 



with legs nearly black, then wings brownish. 



16 (17). Hind metatarsus very plump, stigma very prominent. 



Black haired. 



391. Bibio johannis, L. 

 Common. Witton, Escomb, Belburn, Gibsonees, 

 Harperley, Hesleden. 



17 (16). Hind metatarsus rather slender, stigma less prominent. 



(389. varipes, Mg.) 



18 (7). Stigma faint, neither prominent nor sharply bounded. 



19 (20). Hind legs very thin and long, femora and tibia? thin 



at the base, becoming suddenly much thickened 

 from the middle on — club-shaped. 



(394. clavipes, Mg.) 



20 (19). Hind legs neither very thin nor long, femora and 



tibiae gradually thickening from base to tip. 



21 (24). Legs black. 



22 (23). Thorax black haired. (389. varipes, Mg. £) 



23 (22). Thorax pale haired. • (385. femiginatus, L.) 



24 (21). Legs partly or wholly orange. 



25 (26). Abdomen black on both sides. Pale haired. 



390. Bibio laniger, Mg. 

 Common, with johannis, from which its pale hair 

 and faint stigma distinguishes it. Belburn, Shull, 

 Harperley, Escomb. 



26 (25). Abdomen dark above, orange beneath. 



27 (28). Legs all yellow. (389. varipes, Mg. $ ) 



28 (27). Legs mostly black. (385. femiginahis, L. ? ) 



