The Two-winged Flies 



mouth side faces up although the rest of the body has its ventral aspect facing 

 down. This larva belongs to one of the midge-like flies of the genus Dixa 

 (Fig. 440), which is the only genus in the family Dixidae, represented by about 

 a dozen North American species. The winged flies (Fig. 442) are found in 

 moist places, densely grown over with bushes or rank herbage, in woods. 

 Although resembling mosquitoes and 

 Chrronomid midges in general appear- 

 ance, they can be readily distinguished 

 from them by the arrangement of 

 the wing- veins (Fig. 444). 



An interesting small group of 

 readily recognizable flies is the 

 family Psychodidae, or "moth-fly" 

 family. The vernacular name comes 

 from the slight resemblance to minute 

 moths shown by these flies because 

 of the hairy broad wings, which are 

 held over the back when the fly is at 

 rest in the roof-like manner of the FIG. 442. 



moths (Fig. 445). The largest of these FIG. 441. Pupa of Dixa sp. (Much en- 

 flies are only about one-sixth of an p^t-Z^o sp. (Much enlarged.) 

 inch long, and are rarely distinguished 



except by careful observers. I have found them especially common in gar- 

 dens near the seashore in California, and also in the overhanging foliage 



FIG. 443. Mouth-parts of Dixa sp., female, l.ep., labrum-epi pharynx; md., mandible; 

 mx., maxilla; mx.l., maxillary lobe; mx.p., maxillary palpus; li., labium; pg., para- 

 glossa; gl., glossa; hyp., hypopharynx. 



of trees and shrubs bordering the swift little mountain streams of the Coast 

 Range. In one of these streams I was fortunate enough to find the 



