COLEOPTEKOUS INSECTS. 243 



LONGICORNES. 



One of the most extensive and important families 

 of the tetramerous section has received the above 

 name, on account of the great length of the anten- 

 nae. Many of the species are of large size, and 

 otherwise remarkable for their forms and habits. 

 The larger and typical kinds are found only in the 

 interminable forests of the tropics, where they fre- 

 quent the oldest and largest trees. The larvae live 

 in the interior of the stems, which they perforate 

 in all directions, and hasten the process of decay. 

 In that state they resemble a large white worm, 

 which is destitute of feet, but is furnished with 

 means of locomotion much better adapted to the ha- 

 bits of animals which pass their lives in cylindrical 

 excavations not much exceeding their own bodies 

 in width. The upper and under sides of most of 

 the segments are covered with small prominences 

 or asperities. When the insect wishes to advance, 

 it contracts its body by bringing the two extremities 

 towards each other, and, fixing its hinder end to the 

 walls of its hole by means of these asperities, it ex- 

 tends the anterior part of its body forwards. This 

 operation is repeated at each successive advance- 

 ment. When the larva has attained its full size, it 

 forms a large cocoon, composed chiefly of saw-dust 

 and gnawed portions of wood, in which it changes 

 into a chrysalis. Before assuming that state, it 



