33 2 THE STUDY OF INSECTS. 



rigid and motionless for hours. When in this attitude they are 

 supposed to resemble the Egyptian Sphinx, and so the typical 

 genus was named Sphinx and the family the Sphingidae. 

 But we think they deserve the name independently of their 

 habits because of the riddle they constantly propound to us 

 as to why they wear this horn on the rear end of the body 

 instead of on the head, where it ought to be in order to be of 



Fig. 408. — Sphinx chersis, larva. 



any use whatever as a horn. These caterpillars are usually 

 of some shade of green and often are ornamented with a 

 series of diagonal stripes along each side. 



Most species pass the pupa state in the ground in simple 

 cells made in the earth ; some, however, transform on the 

 surface of the ground in imperfect cocoons composed of 

 leaves fastened together with silk. 



Nearly one hundred species of Hawk-moths occur in 

 this country. The following are some of the more common 

 ones. 



