138 NATURK STUDY. 



queer Back-swimmers that are most common in the East 

 are very handsome insects indeed. 



The Water-boatmen have fiat backs, and swim with 

 their backs upward. They prefer to rest at or near the 

 bottom of ponds, clinging to the vegetation on which the 

 creatures feed which they in turn catch and feed upon. 

 They take down air with them, something as the Diving- 

 beetles do, and as the air and their bodies together are 

 lighter than the water, they must hold on to something or 

 keep swimming downward, else they rise swiftly to the 

 surface, like a piece of cork. 



The Water-boatmen, known by their flat backs, should 

 be pinned in a row and labeled Corisidse, while the Back- 

 swimmers should be pinned near them and labeled No- 

 tonectidae. 



Not infrequently one will find a big, flat, brown bug in 

 the water, which is the largest of all the bugs in this coun- 

 try. It is often nearly two inches in length, its sharp 

 beak is a quarter of an inch long, and its front legs are 

 grooved so that one part can be closed into another like 

 the blade of a penknife. It can catch and hold small fish- 

 es, sucking the blood and other juices from them at its 

 leisure. As they often fly from one pond to another at 

 night, they are attracted by the electric lights of cities and 

 villages, and are sometimes found lying in the streets in 

 considerable numbers. These big bugs — "Electric-light 

 bugs " some people call them — belong to the family Belos- 

 tomidse, which includes the largest Hemiptera now known 

 anywhere in the world. 



There are four or five other kinds of bugs that live in 

 the water or by it on the shore, which sharp-eyed boys and 

 girls will occasionally find, but they are rather rare, not 

 easily described, and have big names. So for the present, 

 if any such are found, it is best to pin them in a little 

 group by themselves in the Hemiptera box, and wait until 



