328 DURHAM DIPTERA. 



XLII. 



Family XLIL— TRYPETID^E. 



TABLE OF GENERA. 



1 (30). X.5 2 almost perpendicular, the outer hind corner of 



0.5 2 is therefore almost a right angle. 



2 (27). Wings quite clear, or with dark bands, sometimes 



blackish or brownish with large clear spots or 

 bands, but the dark parts or bands are never 

 broken up with little clear or pale spots as if 

 honeycombed or latticed. 



3 (16). X.4. distinctly beyond the middle of 0.5 2 . 



4 (9). Dorsum shining, black or orange, unspotted, neither 



colour nor polish altered by dusting. 



5 (6). Frons very prominent ; profile retreating ; jowls very 



broad ; eyes almost round. 



551. Platyparea, Lw. (2400. discoidea, F.) 



6 (5). Frons not prominent; profile almost perpendicular; 



jowls small ; eyes elliptical. 



7 (8). V.4. beyond X.5 2 straight, or at most somewhat bent 



at the end ; scutellum with only two bristles. 



533. Aciura, Dsv. (2402. rotundiventris, Fin.) 



8 (7). V.4. somewhat bent upwards immediately beyond 



X.5 2 ; scutellum with four bristles. 



Acidia, Dsv. (554) 



9 (4). Dorsum black or yellow, the ground colour always 



somewhat altered by light dusting, and scarcely 

 shining; sometimes broken with shining black spots. 



10 (11). X.6. nearly straight; outer side of O.6 1 without any 



projecting point (VII. 17). Urophora, Dsv. (562) 



11 (10). X.6. sharply angled in the middle; O.6 1 with a pro- 



jecting point at its outer hind corner (VII. 18). 



12 (13). V.4 4 distinctly bent upwards. 



559. Rhacochl^ena, Lw. (2415. toxoneura, Lw.) 



13 (12). V.4 4 straight, or scarcely bent. 



14 (16). Face very short; frons roof-like and very long, so that 



the bases of the antennas are almost on a line with 



the lower orbit ; proboscis very long. 



566. Ensina, Dsv. (2439. sonchi, L.) 



