LEPIDOPTERA. 
377 
usually marked with yellow, and often with metallic blue or 
green. 
There are about twenty-five species of swallow-tails in 
America north of Mexico. The following well-known spe¬ 
cies will serve as illustrations. 
The Black Swallow-tail, Papilio polyxenes (Pa-pil'i-o po- 
lyx'e-nes).—The larva of this swallow-tail (Fig. 457) is well 
known to most 
country children. 
It is the green 
worm, ringed with 
black and spotted 
with yellow, that 
eats the leaves of 
caraway in the 
back yards of coun¬ 
try houses. It feeds 
also on parsnip and 
other umbelliferous plants. These 
caterpillars always fascinated us in 
our childhood ; we have spent many 
idle moments in poking them with 
straws to see them rear upward and 
project their yellow horns, which gave 
off a sickening odor. When ready to 
transform the caterpillar crawls away 
to a fence or the side of the house 
and changes to an angular pupa, sus¬ 
pended by the tail and by a little 
silken girth around the middle. 
In the adult the wings are black, 
crossed with two rows of yellow spots, 
and with marginal lunules of the same 
color. The two rows of spots are 
much more distinct in the male than in the female, the in¬ 
ner row on the hind wing forming a continuous band crossed 
Fig. 457. —Papilio polyxenes , 
larva. 
