82 



NATUJttX HISTORY OF INSECTS. 



GEOMETRID MOTHS (Phalsenidx). These moths usually 

 have long, slender bodies; the thorax is never tufted, the legs 

 are long and slender, the anterior tibiae are generally unarmed 

 and the hind tibia3 ar* commonly armed with one or two pair 

 of spurs. The head is small and free, or not sunken into the 



Fig. 213. 



thorax, the antennae are usually simple, but sometimes pec- 

 tinate; the palpi are rather small and slender, the wings are 

 usually triangular, broad and thin, and spread out in repose; 

 the stigmata* are wanting. In a few species the females are 

 wingless. 



The caterpillars live exposed upon the leaves; they are 

 naked, and are provided with from ten to fourteen legs; in 

 walking they arch up the middle of the body and bring the 

 hind feet close up to the front ones, thus seeming to span or 

 measure the surface over which they pass, on which account 

 they are commonly called ''Span-worms," or "Measuring- 

 worms." When disturbed they usually drop from their perch 



*A term applied to the' "orbicular" aud "reniform" spots. (See Fig. 121.) 



