296 
COMPARATIVE ZOOLOGY. 
Fig. 265.—Metamorphosis of an Hemipter, Water-boatman (Notonectcc). 
vae and pupae are active, and resemble the imago. They 
are nearly all vegetarian. Each family produces charac¬ 
teristic sounds (str id illation). The representative forms 
Fig. 266.—Seventeen-year Cicada {Cicada septendecim): a, pupa- b t 
the imago, c, has escaped through a rent in the back; d, holes in 
the eggs, e, are inserted. 
same, after 
twig, where 
