128 



INSECT LIFE. 



following label, and immediately after the water- 

 striders, for these insects also belong to the order 

 Hemiptera :- 



Family NOTONECTID^E (No-to-nec'ti-dae). 

 The Hack-swimmers. 



AN ESSAY ON BACK-SWIMMERS (School Work). 

 Write an account of what you have learned regard- 

 ins: back-swimmers. 



O 



THE WATER-SCORPIONS (Field and School Work). 

 Among the strange insects that live in ponds, but 

 come to the surface to obtain air, are the water-scor- 

 pions. These are not so com- 

 mon as the back- swimmers, 

 but as they are found in simi- 

 lar situations, there may be 

 specimens among those insects 

 in your aquaria collected by 

 sweeping the stems of sub- 

 merged plants. If not, search 



for them in the 



places whereback- 



swimmers are 



found. 



There are two 



quite different 



kinds of water- 

 in this 

 In one 



of these, called 

 Nepa (Ne'pd), the body is flat and broad (Fig. 102) ; in 

 the other, called Ranatra (Ran 1 a-tra), the body is long 

 and very slender (Fig. 103). In both, the hind end 



FIG. 102. 



scorpions 

 country. 



FIG. 103. 



