ZOOLOGY. 



the two preceding groups, opaque, and variously coloured by 

 the presence of a sort of scaly dust fixed to the surface. 

 The mouth, as we have already said, has the form of a pro- 

 boscis rolled into a spiral. Finally, these insects undergo a 



Fig. 392. Danais Plexippus. 



complete metamorphosis, and their larvae (Figs. 368, 371, 

 395, 45), known by the name of caterpillars, are provided 

 with feet towards the two extremities of their body, and live 





Fig. 393. Sphinx of the Vine. 



generally on leaves; some envelope themselves in a silky 

 oocoon in order to complete their transformation ; others roll 



