316 DURHAM DIPTERA. 



XXXVI. 



15 (16). Four pairs of dorso-central bristles, that is at least 



one pair of praesutural bristles present. 



JBlepharoptera, Lw. (511) 



16 (15). Only three pairs of dorso-central bristles, that is no 



praesutural bristles present. 



Tephrochlamys, Lw. (513) 



table op species. 

 506. Helomyza. 



1 (14). Meso-pleurae fine haired. 



2 (7). Arista short haired or pubescent. 



3 (4). Arista with very short pubescence. 



(2253. humilis, Mg.) 



4 (3). Arista distinctly but not long haired. 



5 (6). No dark spot at the end of V.2. 



(2254. inornata, Lw.) 



6 (5). A dark spot at the end of V.2. (iiemorum, Mg.) 



7 (2). Arista long haired. 



8 (9). Tip of the wing clouded, and also showing dark and 



clear spots. 



2255. Helomyza rufa, Fin. 

 Hesleden, 1 ?, 18-8-99; Bishop Auckland, 1 $, 

 3-3-°°- 



9 (8). Tip of the wing without the cloud, although dark 



spots may be present. 



10 (11). Scutellum with fine hairs all over. (nemorum, Mg.) 



11 (10). Scutellum bare except at its sides. 



12 (13). Thorax grey-brown. {fada, Lw.) 



13 (12). Thorax yellow. 



2256. Helomyza pectoralts, Lw. 

 Hesleden, 1 $, 13-8-00; Shull, 1 ?, 7-7-02. 



14 (1). Meso-pleurae quite bare. 



15 (31). Arista plumose. 



16 (22). Arista long plumed. 



17 (19). Mid femora with thorn-like bristles on the underside. 



