LEPIDOPTEROUS INSECTS. 25 



slender, compressed, cylindrical or conical, with 

 the third joint very distinct. 



The caterpillars in this family have all sixteen feet, and are 

 destitute of a horn at the posterior extremity of the body. 

 Some inhabit the interior of vegetables ; others are naked and 

 lairy. 



I. Antennae simple in both sexes. 



The genera are SESIA, ^EGOCERA, THYRIS, ZYGJENA, and 

 SYNTOMIS. 



II. Antenna? bipectinated in the males, simple in the females. 



The genera are PROCRIS and ATYCHIA. 



III. Antennae bipectinated in both sexes. 



The genera are GLAUCOPIS, AGLAOPE, and STYGIA. 



Genus ZYG^ENA, Fabricius. 



The antennae are simple in both sexes, terminating 

 abruptly in a convoluted club, at least in one of 

 the sexes, and destitute of a tuft at the extremi- 

 ty ; the lower palpi are cylindrico-conical, rising 

 above the hood ; abdomen nearly cylindrical and 

 obtuse ; wings sloped ; spines at the extremity of 

 the legs very small. 



The insects of this genus fly seldom, and that to very short 

 distances, and are inactive in their habits ; usually found on the 

 plants where the female deposits her ova. Both sexes live iu 

 ;he perfect state only for the time necessary for reproduction. 

 The caterpillars have sixteen feet. They are smooth, slightly 

 lairy, and have not, like those of the Sphinges, a horny appen- 

 dage on the last segment. Before changing into pupae they in- 

 close themselves in a solid cocoon, which they form along a 

 branch or leaf, and the perfect insect is produced in a short time 

 after. 



VOL. III. C 



