436 THE STUD Y OF JNSECTS. 



While still anchored by its legs the midge rests on the sur- 

 face of the water for one or two seconds and unfolds its 

 wings; then freeing its legs it takes flight. The adults 

 emerging from the deeper water were swept away by the 

 current before they had a chance to take wing. The time 

 required for a midge to work its way out of the pupa-skin 

 varied from three to five minutes. 



Family Dixm^: (Dix'i-dae). 



The Dixar-midges. 



These midges closely resemble mosquitoes in size and 

 form ; but they are easily distinguished by the venation of 

 their wings (Fig. 509). 



FIG. 509. Wing of Dixa. 



The wing-veins are not furnished with scales, and are 

 distinct over the entire surface of the wing ; vein I is pro- 

 longed into an ambient vein ; vein II is well 

 developed, but is short, ending in the margin of 

 the wing near its middle, ana before the first fork 

 of vein III ; vein III is four-branched ; vein V is 

 two-branched ; cell V a is not divided by a cross- 

 vein ; and vein III, extends parallel to the mar- 

 gin of the wing to a point on the outer end 

 of the wing. The antennae (Fig. 510) are six- 

 teen-jointed, and differ but slightly in the two 

 sexes ; the legs are very long and slender ; and 

 he caudal end of the abdomen of the male is FlG 5IO 

 enlarged. 



