THE FOUR-HORNED CERATOMIA. 
323 
length of five or six inches, but, when not in use, is coiled 
like a watch-spring, and is almost entirely concealed be¬ 
tween two large and thick feelers, under the head. 
Amonor the numerous insects that infest our noble elms, 
the largest is a kind of Sphinx, which, from the four short 
horns on the fore part of the back, I have named Ceratomia * 
quadricornis (Fig. 148), or four-horned Ceratomia. On 
Fig. 148. 
some trees these Sphinges exist in great numbers, and their 
ravages then become very obvious; wdiile a few, though 
capable of doing considerable injury, may escape notice 
amono; the thick foliacre which constitutes them food, or will 
only be betrayed by the copious and regularly formed pellets 
are very abundant 
during the months of July and August on the large elms 
which surround the northern and eastern sides of the Com¬ 
mon in Boston ; and towards the end of Aumist, when thev 
descend from the trees for the purpose of going into the 
ground, they may often be seen crawling in the Mall in 
considerable numbers. These caterpillars (Fig. 149), at 
this period of their existence, are about three inches and a 
* Ceratomia, derived from the Greek, means having horns on the shoiilders, a 
peculiarity which I have not observal in any other Sphinx. 
of excrement beneath the trees. They 
