Aquatic Insects 121 



Some delightful beetles known as the 

 " Whirligigs " (Gyrinidce) spend the sum- 

 mer days making endless figures of eight 

 at dizzy speed upon the surface-film ; 

 they also are carnivorous. The eggs are 

 laid in rows on aquatic plants and the 

 larvae are provided with a series of 

 beautifully plumed tracheal gills on the 

 sides of the abdomen. 



Although the very great majority of 

 aquatic insects only frequent fresh water, 

 there are some related to the Skaters 

 that inhabit the tropical seas and are to 

 be found many hundreds of miles from 

 land. They have been observed on calm 

 days skating over the surface of the 

 ocean feeding on dead, floating marine 

 animals. 



As well as the insects that can be 

 termed truly aquatic either as larvae or 

 adults are many to which the term 

 " half-way " insects may be well applied. 

 They are dwellers in mud and dwellers 



