COLEOPTEEOUS INSECTS. 
159 
triangular point like a spine. They are likewise 
distinguished by possessing the power of leaping to 
some height into the 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 w ith a sharp 
snapping noise, w hich 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. undulaius) 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 
