I5AKLR : HVDROEIUS FUSCIPES. 



329 



of the elytra above the surface of the water, slightly opening them 

 until the air-supply is renewed, then closing them, thus imprisoning 

 the air; but this beetle utilises the hairs on the under surface of its 

 body, by their aid entangling a large bubble of air, almost continuous 

 from the head to the anal segment, and from which the spiracles are 

 supplied. This huge bubble naturally makes the ventral surface lighter 

 than the dorsal, and consequently brings the former uppermost. 



On the first approach of winter they bury themselves in the 

 mud at the sides of the ponds or streams which they inhabit, and 

 with rare exceptions, do not make their appearance again until 

 the spring, unlike their carnivorous companions, which may be seen 

 disporting themselves throughout the winter on any bright clear day, 

 even when the surface of the water is covered by a coat of ice. 



About the middle of March they emerge from their winter 

 quarters, and about the second week in April the eggs are first 

 laid. These are long and cyclindrical, being about i| mm. in 

 length by about h mm. in diameter. They are enclosed in silken 



Fig. 2. Fig. 3. 



Egg Cocoon on blade of grass. x6. Cocoon cut open, with the eggs in situ. 



cocoons (Fig. 2), from nine to thirteen in each cocoon, and not 

 placed in any regular way, but simply lying loose (Fig. 3). The 

 cocoon itself is attached to the leaves of water-plants or to the 

 blades of grass which hang into the water, and being partly filled 

 with air floats on the surface of the water if, as often happens from 

 one cause or another, it becomes detached. It is formed of closely 



Naturalist, 



