268 DURHAM DIPTERA. 



XXXIII. 459. 



31 (30). Abdomen nowhere translucent yellow; praesutural 



acrostichal bristles usually distinctly present. 



32 (33). Arista bare ; X.5 2 strongly bent, and not more than 



its own length from X.4. (2032. albipuncta, Ztt.) 



33 (32). Arista distinctly pubescent; X.5 2 straight, and more 



than its own length from X.4. 



34 (35). At most one pair of acrostichal praesutural bristles 



present; eyes bare. irritans, Fin. (2023) 



35 (34). Two pairs of acrostichal praesutural bristles ; eyes 



very short haired. (pena'llata, Rnd.) 



36 (0). Small shining black species, 3 mm. 



37 (38). Mid tibise with a bristle on the fore side. 



(2033. parva, Mde.) 



38 (37). Mid tibise without a bristle on the fore side. 



(2034. glabriatla, Fin.) 



460. Ophyra, Dsv. 



1 (2). Squamae dark. 



2035. Ophyra lencostoma, W. 

 Hesleden, 6 $, August, 1899; Bishop Auckland, 1 $, 

 July, 1900. 



2 (1). Squamae pale. (2036. anf/irax, Mg.) 



461. Drymia, Mg. 

 2037. Drymia hamata, Fin. 

 Hesleden, 12 $ and 5 ?, July-August, 1 899-1 900. 



463. Trichopticus, Rnd. 



1 (11). Abdomen black or grey. 



2 (10). Epistome slightly prominent or flat. 



3 (9). Halteres black or brown. 



4 (5) (6). Hind tibiae with the inner sides bare. 



(2039. cunctans, Mg.) 



5 (4) (6). Hind tibiae with a very long bristle before the inner 



middle. (2042. aatleipes, Ztt.) 



