112 INSECTS COLEOPTERA DIAGRAM 6. 



The Dytiscidce swim, and pass part of their life in the water, 

 For this purpose, they have flattened legs, shaped like oars. 

 But they are obliged to come to the surface frequently in order 

 to breathe the air, a store of which they always keep under their 

 elytra, when diving to the bottom of the water. They are essentially 

 carnivorous animals, and even attack newts, and devour them alive. 

 In the evening, they leave the water, spread their wings and 

 fly about. They then fly into rooms, attracted by the light. 

 When touched, they exude from the surface of their body an oily 

 liquid, as white as milk, and extremely fetid. The lame live 

 constantly in water, and are carnivorous like the perfect insect. 

 They have pointed mandibles, which cross each other,, with which 

 they can pinch severely. 



The Gyrinidce are small insects which are seen twisting round 

 like drops of quicksilver on the surface of ponds, where it is very 

 difficult to catch them. They are popularly called whirligig beetles, 

 Their back is black, but is so highly polished as to reflect the 

 light of the sun like a metal button. 



The Hydrophilidce somewhat resemble the Dytiscida? in form 



and habits, but are much larger. 

 These are our largest native water^ 

 insects. Like the Dytiscida? they 

 pass the day in ponds. They swim 

 and fly very well, but walk with 

 difficulty. They can remain under 

 water for a long time, but are never- 

 theless obliged to come to the sur- 

 face from time to time, to breathe. 

 In the evening, they fly about. 

 Their larvae are very large, black 

 and wrinkled, and swim with ease, 

 They live exclusively in the 

 water. They are extremely vora- 

 cious. They are also remarkable 

 for their habit of making themselves 

 Hydrophilus, Male. soft and flaccid, as if dead, when 



