44 



NEMATOCERA. 



Blepharoceridae, p. 148. 

 10. 



9. Wing with a secondary venation, form- 

 ing a spider-web-like network, in 

 addition to the primary characteristic 

 normal venation. (Thorax with an 



incomplete suture) 



Wing without such secondary network 

 venation 



10. Costal vein ending at tip of wing, not 



carried round posterior margin 



Costal vein continued around the whole 

 margin of the wing Cesidomyidae. 



11. Tibiae without spurs; coxse never con- 



spicuously enlarged. Anterior cross- 

 vein, when present, transverse as 



usual 



Tibiae always with spurs ; coxae greatly 

 and conspicuously developed (MYCK- 

 TOPHILIN^E), or, if normal, then the 

 anterior cross-vein placed longi- 

 tudinally (SciARiN^;) Mycetophilidae, p. 44. 



11. 



Chironomidae. 



MYCETOrHILIDJE. 



The MYCETOPHILID^E are a rather well-defined family, distributed 

 throughout the world from the arctic regions to the tropics, but 



Fig. 7. Mycetophila. 



most numerous in temperate climates arid altitudes of four or five 

 thousand feet upwards in warmer regions. They are delicate in 

 structure aud comparatively small or very small in size, for the 

 greater part obscure in colour, blackish, brownish or yellowish, 

 rarely with really vivid colours, but often with paler markings. 



