DURHAM DIFTEEA. 27 



14 (13). Antennae longer than the thorax, plumed in the male 



(II. 10, n). Wings rather narrow (IV. 9-1 1). 



ChIRONOMIDjE (VI.) 



15 (6). Costa continued round the hind margin (IV. 12-14). 



16 (17). Wings, when at rest, roof-like. X-veins only present 



at the base of the wing (IV. 12). 



PSYCHODIDiE (VIII.) 



17 (16). Wings, when at rest, lying flat over the abdomen. 



X-veins on the middle of the wing. 



18 (19). Veins hairy (IV. 13). Culicid^e (IX.) 



19 (18). Veins bare. 



19a (19b). Antennae long. V.4. and V.2. forked. X.4. ending 

 in V.2. (IV. 14). Dixid^ (X.) 



19b (19a). Antennae n-jointed but very short. No veins 

 forked. Ornephelid^: (VII.) 



20 (5). Thorax with a strong cross-seam (VI. 32). 



21 (22). V.6. absent (IV. 15). Ptychopterid^e (XI.) 



22 (21). V.6. present. 



23 (24). V.I. a. ending in the costa, and united to V.l.b. by a 



X-vein (IV. 17-22). Last joint of the palpi usually 

 shorter than the one before it, and never whip-like 

 (VI. 4). Limnobid^e (XII.) 



24 (23). V.I .a. ending in V.l.b., and, except for X.I .a. at its 



base, not united by any X-vein, either with the 

 costa, or with V.l.b. (IV. 23-26). Last joint of 

 the palpi long and whip-like (VI. 5). 



Tipuluxs: (XIII.) 



25 (2). Antennae short, three-jointed, third joint sometimes 



ringed (Plate III.). 



BRACHYCERA. 



26 (140). Wing veining normal. X-veins present. 



27 (32). Third antennal joint ringed, arista, if present, apical 



(III. 1-9). 



28 (29). Costa ending at the apex of the wing (V. i). 



Stratiomyid,e (XV.) 



