BOSTON ZOOLOGICAL SOCIETY. 19 



die. The mature larva or caterpillar has the head and 

 body pale green, deeper on the sides, variegated with dark 

 green spots. 



In P. achemon the body is fawn-color, with the hinder 

 parts of the segments white. The anterior wings are 

 about the same color as the body, with a number of dark 

 brown spots near the edges; the posterior are pink with 

 several reddish brown streaks; the under surface is roseate. 

 The mature larva is light green, varying to pale reddish 

 brown, with six cream colored spots on each side, and has 

 a tubercle in place of a caudal horn, which is gradually 

 dropped as the insect moults. It measures from two to 

 four inches. 



While at rest, the head and first three segments of the 

 caterpillars of both species are withdrawn within the 

 fourth segment, which gives them a very peculiar appear- 

 ance. When they have attained the full size they con- 

 sume great quantities of the leaves of the woodbine, 

 grape, and other vines. Crawling from the vines in 

 August, they enter the earth to transform, and appear in 

 the mature or moth state during the last of June and the 

 first of July. I have known them, when confined, to 

 pupate and come to maturity on the surface of the ground. 

 The name hawk-moth is given them in the mature state, 

 from their habit of hovering in the air while taking their 

 food. They may be seen during the twilight flying with 

 great swiftness from flower to flower, the honey of which 

 they extract. In this operation they much resemble hum- 

 ming birds, for which they are often mistaken. 



I have been informed, by one who has raised a number 

 of specimens, that a certain species of Tachina is para- 

 sitic upon these moths in the immature state, but am unable 

 with the given data to arrive at any conclusion as to the 

 specific name. 



