332 
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 ekersis % 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. 
