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." 12 



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-finger, and the length 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 tongue-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 

 tin- Journal of the Aciulcmy of Natural Sciences of Philadelphia, 1859, Art. V., 

 p. !i". Ity Dr. Bracktnrldge Clemens, of Kasion, 1'eim. Moitms.] 



