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^. 



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^;. 



FF. Vein V of the wings simple or two-branched ; cell V 2 

 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. 



CULICID^E. 



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^;. 



KK. Antennae usually longer than the thorax ; 

 legs slender, and with greatly elongate coxae 



(Fig. 518). p. 442 MYCETOPHILID^E. 



JJ. Ocelli absent. 



K. Antennae short, not clothed with long hairs, 



