320 
LEPIDOPTERA. 
either a kind of horn or a tubercle on the top of the last 
segment, and, when at rest, sit with the fore part of the body 
elevated. 
Having devoted a large portion of this treatise to a de¬ 
scription of the spinning-moths, my observations on the 
other insects of this order must be brief, and confined 
to a few species, which are more particularly obnoxious 
on account of their devastations in the caterpillar state. 
Those persons who are curious to know more about the 
Sphinges than can be included in this essay, are referred 
to my descriptive catalogue of these insects, contained in 
the thirty-sixth volume of Professor Silliman’s “ Journal 
of Science.” 
Every farmer’s boy knows the potato-worm, as it is com¬ 
monly called; a large green caterpillar (Fig. 142), with a 
kind of thorn upon the tail, and oblique whitish stripes on 
the sides of the body. This insect, which devours the leaves 
of the potato, often to the great injury of the plant, grows 
to the thickness of the fore-fino-er, and the len^xth of three 
inches or more. It attains its full size from the middle of 
August to the first of September, then crawls down the stem 
of the plant and buries itself in the ground. Here, in a few 
days, it throws off its caterpillar-skin, and becomes a chrysa¬ 
lis (Fig. 143), of a bright brown color, with a long and 
slender tonmie-case, bent over from the head so as to touch 
the breast only at the end, and somewhat resembling the 
handle of a pitcher. It remains in the ground through the 
winter, below the reach of frost, and in the following sum¬ 
mer the chrysalis-skin bursts open, a large moth crawls out 
of it, comes to the surface of the ground, and, mounting 
upon some neighboring plant, waits till the approach of 
evening invites it to expand its untried wings and fly in 
search of food. This large insect has generally been con- 
[ 12 A more complete monograph of the Sphinges has been lately published in 
the Journal of the Academy of Natural Sciences of Philadelphia, 1859, Art. V., 
p. 97, by Dr. Brackinridge Clemens, of Easton, Penn. — Morris.] 
