350 



THE GREAT WATER-BEETLE. 



THIS insect (dytiscus margmalis) is a more constant 

 inhabitant of the water than the mole cricket is of the 

 earth, remaining there in all the stages of its existence, 

 even after it has become winged, and only, as is sup- 

 posed, using that apparatus for enabling it to range from 

 pool to pool, in quest of more abundant prey. Its 

 flights are generally in the twilight or during the night. 

 Whether it may or may not capture land insects during 

 its flight, has not been ascertained, but it bites lustily 

 when an attempt is made to keep it prisoner in the 

 hand. From the rapidity with which it dashes from 

 the surface of the water to the bottom, it has got the 

 name of the " plunger." It is a large beetle, flattish 

 and broad for its length, and of a very compact form. 

 The head is rather small, compared with the body, 

 but the mandibles are strong, hard, and have a 

 powerful articulation; the eyes are placed so promi- 

 nently in the head, that the insect can readily see in all 

 directions; and its motions in the water along the 

 bottom, and even into the mud, are almost all as rapid 

 and vigorous as its plunging. 



