DIPTERA. 423 



C, Antennae consisting of more than five distinct segments, the 

 segments beyond the second not consolidated; cell VIII of 

 the wings but slightly narrowed at the margin of the wing, if 

 at all ; palpi usually elongate, and composed of from three to 

 five segments. 



D. Small moth like flies, with the body and wings densely 

 clothed with hairs and scales. Wings with from nine to 

 eleven longitudinal veins, but with no cross-veins except 

 sometimes near the base of the wings (Fig. 500). p. 428. 



PSYCHODID^E. 

 DD. Flies that do not resemble moths in appearance. 



E. Dorsum of thorax with, a distinct V-shaped suture (Fig. 



503). p. 429 TIPULID^E. 



EE. Dorsum of thorax without a distinct V-shaped suture. 

 F. Vein V of the wings three-branched ; cell V 2 divided 



by a cross-vein (Fig. 527). p. 448 RHYPHID^E. 



FF. Vein V of the wings simple or two-branched ; cell V a 

 not divided by a cross-vein. 



G. Wings with a network of fine lines near the outer 

 and inner margins in addition to the veins (Fig. 506). 



p. 432 BLEPHAROCERIDJE. 



GG. Wings without a network of fine lines. 



H. The margin of the wings and each of the wing- 

 veins fringed with scales (Fig. 512). p. 437. 



CULICIDjE. 



HH. The wing-veins with or without a fringe of hairs, 

 but without a fringe of flat scales. 



I. Anal veins entirely wanting; vein V wanting or 

 at most represented by a single unbranched fold 

 (Fig. 522). p. 444 CECIDOMYIID^E. 



II. Anal veins present or represented by folds ; vein 

 V present or at least represented by a fold which 

 is usually branched. 



J. Ocelli present. 



K. Antennae shorter than the thorax; legs 

 comparatively short and stout ; coxae not un- 

 usually long, p. 449 BIBIONID/E. 



KK. Antennae usually longer than the thorax; 

 legs slender, and with greatly elongate coxae 



(Fig. 518). p. 442 M YCETOPHILIDJE. 



JJ. Ocelli absent. 



K. Antennae short, not clothed with long hairs, 



