270 SYSTEMATIC ARRANGEMENT. 



Figures "2-5 illustrate the structure of one of the homoptera 

 Cicada atrata, a, native of China Fig. 2. The head seen ir 

 front ; a, a, the eyes ; 6, the three ocelli ; c, c, the antennae : 

 d, the clypeus ; e 9 the labrum ;/, the labium, forming a sheatl 

 for the reception of g^g, the hair-like mandibles, and , , th< 



hair-like maxillae Fig. 3. Part of the mouth ; <a?, the clypeus ; 



c, the labrum ; f '"'" the two basal, and part of the long 

 terminal joint o'f the labium Fig. 4. The seven-jointed an- 

 tennae Fig. 5. Underside of the thorax and abdomen ; T 1 



prothorax ; T 2, mesothorax ; T 3, metathorax ; A, abdomen 



We have already mentioned the comparative ex 

 tent of the different orders, from which it appean 

 that the one. now under consideration is the fourtl 

 in the scale, nearly 25,000 species heing supposed t( 

 exist. Rather more than 60'0 different kinds havt 

 been found in Britain ; but most of these are incon- 

 spicuous insects o'f small size and obscure colouring 



The metamorphoses of these insects may be de- 

 scribed as merely a series of moultings. The larva 

 and pupse are alike active, the latter distinguishabli 

 from the former only by having two small projectioci 

 on the back which conceal the wings and wing- covers 

 The only perceptible difference in apterous specie 

 in their various stages, is that arising from size. 



In proceeding to illustrate this order by a selectioi 

 of a few species from the numerous tribes it contains 

 w.e shall first advert to that section which has beei 

 named, 



HETEROPTERA, 



The distinguishing marks of which it may be of ad| 

 vantage briefly to recapitulate in this place. 



