1 88 AN INTRODUCTION TO ENTOMOLOGY. 



are very long, especially in Ranatra : the femora are furnished with 

 a groove into which the tibiae and tarsi fit like the blade of a pocket- 

 knife into its handle. 



Although the Nepidae are truly aquatic insects, the second and 

 third pairs of legs are fitted for walking rather than swimming. 



Of the genus Nepa we have only a single species, N. apiculata. 

 This insect is about two-thirds of an inch in length, not includ- 

 ing the respiratory tube, which measures a little more than one- 

 fourth of an inch. It lives beneath stones and rubbish in ponds, 

 and in the quiet parts of our streams. 



Of the genus Ranatra, our most common species is R. fiisca 

 (Fig. 158). This insect lives in the same situations as Nepa. Owing 

 to the linear form of its body, and to the dirt with which it is 

 usually covered, it is quite difficult to detect the presence of this 

 insect among the rubbish where it is found. Doubtless this resem- 

 blance to a dirty stick aids it greatly in the capture of insects, fish, 

 and other unwary animals upon which it preys. 



Family XIV. — BELOSTOMATlDJi* 

 {Giant Water-bugs.) 



" The family Belosto matidce contains the largest Heteroptera now 

 in existence. These are all wide and flat-bodied aquatic insects, of 

 more or less ovate outline, furnished with powerful flattened swim- 

 ming-legs, the fore tibiae curved as in the preceding family, and fitted 

 for seizing and holding tightly the victims, upon which they pounce 

 from their hiding places in the rubbish or among the branches of 

 water-plants. A remarkable feature of all the genera is in the pres- 

 ence of a pair of flattened, narrow, strap-like appendages at the end of 

 the body, which are extensile, but not concerned with respiration, as 

 in members of the foregoing group". (Uhler.) 



These insects are rapacious creatures, feeding on other in- 

 sects and small fish. Some of the species are of great size. One 

 found in Guiana and Brazil sometimes measures four inches in length. 

 We have in our fauna two common species of the larger Giant Water- 

 bugs. They are Belostoma atnericdnum and Bendcus griseus. These 

 two species so closely resemble each other that they are commonly 

 confounded. 



*Belostomatidse, Belostoma: belos (/3eXoS), a spear ; stoma (orofta), a mouth. 



