DURHAM DIPTERA. 319 



XXXVIII. 523. 



37 (36). Wings covered with brown spots, which are larger 

 and darker near the fore margin. 

 2304. Sciomyza schoenherri, Fin. 

 Hesleden, 2 ?, August, 1902. 



526. Tetanocera, Dum. 



1 (10). Wings not freckled. 



2 (3). Front region of the wing with a long brown cloud ; 



V.4 4 clouded. 



2322. Tetanocera elata, F. 

 Hesleden, 2 $ and 1 ?, August, 1 899-1 900. 



3 (2). Front region not clouded, nor V.4 4 . 



4 (5). Frons shining all over. 



2323. Tetanocera Icevifrons, Lw. 

 Bedburn, 1 ?, July, 1902. 



5 (4). Frons always with dull places in the middle. 



6 (6a) (7). Frontal and vertical orbits and a crossband above 



the antennae, all shining ; dorsum striped. 



2324. Tetanocera sylvattca, Mg. 



Hesleden, 1 $, August, 1902 ; Bedburn, June, 1905. 



6a (6) (7). Frontal orbits dull, a shining space beneath the 

 ocelli; dorsum unstriped. (2325. unicolor, Lw.) 



7 (6) (6a). Only the vertical orbits shining, the entire frons dull. 



8 (9). Large species, 9-10 mm. ( 2 3 2 7- robtista, Lw.) 



9 (8). Smaller species, 7-8 mm. 



2326. Tetanocera ferrugmea, Fin. 

 Hesleden, 4 $, August, 1902. 



10 (1). Wings freckled. 



11 (14). Dorsum with dark stripes. 



12 (13). Second antennal joint shorter than the third. 



(2328. punctata, F.) 



13 (12). Second antennal joint as long as, or longer than the 



third. ( 2 3 2 9- coryleti, Scop.) 



14 (11). Dorsum with brown or black spots. 



15 (16). Femora with black rings. ( 2 33o- umbrarum, L.) 



