102 NATURAL HISTORY OF AQUATIC INSECTS CH. 



FIG. 23. Larva of Gnat (Culex). 2, head and prothorax, ventral side. The com- 

 pound eyes, the folded legs, and other parts of the future fly are seen through 

 the transparent larval skin ; 3, antenna of do. ; 4, respiratory tube of do- ; 

 5, extremity of respiratory tube, end view 



