COLEOPTE&OUS INSECTS, 159 



triangular point like a spine. They are likewise 

 distinguished by possessing the power of leaping to 

 some height into th.e air when they happen to fall 

 on their back a provision not required by the Bu- 

 prestidae, probably because the more rounded form 

 of their bodies enables them without difficulty to 

 regain their natural position. The legs of the Ela- 

 teridae are so short and slender, that without some 

 property of this kind they would be as unable to 

 recover their standing as a reversed tortoise. The 

 spring is produced by bending the head and tho- 

 rax backwards, and suddenly forcing the projecting 

 point into the hole designed to receive it, while 

 the action is assisted by the pressure of the elastic 

 elytra and other parts of the body against the plain 

 of position. This operation is attended with a sharp 

 snapping noise, which has caused these insects to be 

 termed click-beetles, in addition to the names of 

 skipjacks and spring-beetles, by which they are like- 

 wise known in England. 



We are but imperfectly acquainted with the me- 

 tamorphoses of these insects, and the larvae of most 

 of them appear to be unknown. The individual 

 described by De Geer (E. undulatus) is long and 

 cylindrical, provided with short antennae, palpi, and 

 six feet. Its body consists of twelve scaly segments, 

 of which the posterior forms a circular plate, fur 

 nished with two blunt points curving inwards : un- 

 derneath there is a large fleshy protuberance, which 

 seems to serve the office of a foot. The grub so 



