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 
hairy. 
I. Antenne simple in both sexes. 
The genera are Sesia, /Xcocera, Tuyris, ZyGmna, and 
Syntomis, 
IT. Antenne bipectinated in the males, simple in the females. 
The genera are Procris and Arycutra. 
III. Antenne bipectinated in both sexes. 
The genera are Giravucoris, AGLaorr, and Styera. 
Genus Zye@na, I abricius. 
The antennee are simple in both sexes, terminating 
abruptly in a conyoluted 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 in 
the perfect state only for the time necessary for reproduction. 
The caterpillars have sixteen feet. They are smooth, slightly 
hairy, and have not, like those of the Sphinges, a horny appen- 
dage on the last segment. Before changing into pupe 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 
