Aquatic Insects 117 



forms, being long, somewhat flattened 

 and having no legs. It is a very sluggish 

 creature, passing most of its time at the 

 surface where it hangs head downwards. 

 At the apex of the abdomen is a rosette 

 of bristle-like filaments which, in con- 

 junction with two spiracles, acts as the 

 breathing organ. When fully grown the 

 larva sometimes burrows into the bank 

 and sometimes floats at the top of the 

 water. Pupation takes place within the 

 larval skin. 



There is a large fly known as the 

 f< Drone Fly " (Eristalis) that has an 

 aquatic larva commonly called the " Rat- 

 tailed Maggot." This larva, a somewhat 

 repulsive-looking creature, lives in putrid 

 water where it feeds upon the accumu- 

 lated filth. The body, which is certainly 

 maggot-like, is furnished with a tele- 

 scopic tail composed of three parts 

 capable of sliding one within the other. 

 This remarkable tail can be extended to 



