DURHAM DIPTERA. 29 



49 (50). X.4. placed near the middle of the wing, generally 



beyond X.5 1 , at most only a little before it. V.5. 

 with two X-veins, bounding a discal cell (V. 11); 

 or if only one, then X.5. is placed before, or at most 

 only a little beyond X.4. (V. 12). 



Empid^i, part (XXIII.) 



50 (49). X.4. placed very near the base of the wing, V.5. with 



only one X-vein, which is placed far beyond X.4. 

 No discal cell (V. 14, 15). 



Dolichopodid^e, part (XXIV.) 



51 (48). Apex of the wing pointed (V. 16). 



LONCHOPTERID,E (XXV.) 



52 (47). Alulae present. 



52£ (1£). Frontal lunule present (VII. 5). 



CYCLORRHAPHA. 



Flies which escape from the larval skin, through a circular 

 orifice made by pushing off the head end of it (VI. 37). The 

 pupae form a close case. Adults with a frontal lunule. 



52£ (141). Proboscis and palpi present (rudimentary in 

 CEstridae). 



PROBOSCIDEA. 



53 (54). Antennae with a long bristle (III. 39, 40). 



PLATYPEZlDiE (XXVI.) 



54 (53). Antennae with a short spine (III. 48). 



Conopid^, part (XXIX.) 



55 (33). Arista dorsal (III. 27, 33, 34, 41-47, 49-55). 



56 (61). O.6 1 long, extending to, or nearly to, the hind margin 



(V. 18-21I). Abdomen without strong bristles 

 (macrochcetce). 



57 (60). Proboscis of moderate length, generally retracted 



(VI. 12-16). 



58 (59). Vena spuria absent (V. 18). Eyes very large, filling 



the head. 0.4 2 open. Pipunculid^; (XXVII.) 



59 (58). Vena spuria present. Eyes moderate. 0.4 2 closed. 



(V. 19-21). SYRPHID2E (XXVIII.) 



