2. Note, however, the presence of the con- 

 spicuous white feathery gills which form tufts at the 

 side of the head. 



3. Note that the nymph and larvae do not rise 

 to the surface to breathe as do those of mosquitoes. 



Fig* 33. Nymphs of Chironomus and Corethra 



4. Note the curious rhythmic bending movement 

 of the larvae and nymph of Chironomus which, when 

 they are present in numbers, gives the mud at the 

 bottom of the pool a curious appearance. 



LITERATURE 



Miall. Aquatic Insects 



