302 THE RIVER-SIDE NATURALIST. 



pleasant odour not easily forgotten. You will find that 

 they have the antennae very short ; the two forelegs long 

 and stretching forwards, other legs short and broad ; the 

 eyes are divided by horny processes, making one into two, 

 as it were. They live in the mud in winter, deposit their 

 eggs on the leaves of aquatic plants, and feed on small 

 aquatic insects. 



The GREAT WATER- BEETLE (Dytiscus marginalis; from 

 the Greek word dytes, a diver) is another familiar object 

 coming at times to the surface of the water to breathe. He 

 is a regular cannibal, with an enormous appetite, and will 

 devour anything that comes in his way. It is generally sup- 

 posed that the fish will not touch these beetles, but we are 

 not so sure. At night they often leave the water and fly 



A 



A. THE LARVA. B. THE PERFECT INSECT. 



about, and perhaps as they return to their usual element, 

 when their aerial flight is over, as they touch the surface 

 of the water they may be gobbled up by the great trout, 

 who are lurking about in those hours of darkness. They 

 are about i^ inch in length, of a dark olive-colour. The 

 throat and outer edge of the wing-case has a yellow margin. 

 There are numerous species, varying in size. 



Another very common object is the WATER- BOATMAN or 

 BOAT- FLY (Noctonecta glaucus ; order, Hemiptera; sub- 

 order, Heteroptera). It, too, is a voracious eater, and is 

 extremely partial to tadpoles, and also its own species. It 



