SPHINXES. 151 
interesting from its protective mimicry, is the larva of Ceratomia 
quadricornis. ‘This larva is green, of the exact tint of the underside 
of the elm leaf, and along its sides are a number of oblique light 
Larva of Ceratomia quadricornis. 
lines. A line down its back is serrated, and on the forward part of 
the body are four soft green horns, also serrated. While this insect 
Ceratomia quadricornis. 
is at rest clinging to the midrib on the underside of the elm leaf it 
is a difficult creature to see, and one may gaze directly on it and still 
think he is looking at a slightly curled leaf. The light line down 
