CLASS INSECTS. 



399 



that they have come to divide them into a certain number of 

 orders, to which have been given the names of coleoptera, 

 orthoptera, neuroptera, liymenoptera, lepidoptera, he- 

 miptera, diptera, rhipiptera, anoptures, and thysanoures. 

 539. The coleoptera, as well as the orthoptera and the 

 neuroptera, are formed to be nourished on solid substances, 



Fig. 378.-Vrillette Fig. 379.-Scarabeus (or Alescus), Fig. 380.-Dermeste 

 (Ptinus.) Sacred Beetle of the Egyptians. du Lard. 



whether animal or vegetable, and are furnished for this pur- 

 pose with mandibles and jaws adapted for the division of this 

 kind of food (Fig. 356). They have two pairs of wings, but 

 those of the first pair are not adapted for flight, and constitute 

 a sort of hard and horny bucklers called elytra (a, Fig. 

 348). 



The wings of the second pair are, 

 on the contrary, membranous, trans- 

 parent, and too long to be concealed 

 under the elytra without being folded 

 across; sometimes they are alto- 

 gether wanting, and then the insect 

 cannot fly ; this is the case with the 

 charancon (the weevil) which destroys 

 our granaries, and is remarkable for its 

 head, prolonged into the form of a beak. 



The coleoptera undergo complete metamorphoses. The 

 larva resembles a worm with a horny head, whilst the rest of 

 the body is almost always soft (Fig. 381) ; its mouth is formed 

 in the same way as that of the perfect insect ; the three rings 



Fig. 381. The May-bug, 

 or Cockchafer. 



