212 INSECTS OF MASSACHUSETTS. 



of which are fastened to the surface on which it rests on each side 

 of the middle of its body ; and under this, when finished, it passes 

 its head, and gradually works the loop over its back, so as to sup- 

 port the body and prevent it from falling downwards. Though it 

 generally prefers a vertical surface on which to fasten itself in an 

 upright posture, it sometimes selects the under-side of a limb or 

 of a projecting ledge, where it hangs suspended, nearly horizon- 

 tally, by its feet and the loop. Within twenty-four hours after it 

 has taken its station, the caterpillar casts off its caterpillar-skin and 

 becomes a chrysalis, or pupa, of a pale green, ochre-yellow, 

 or ash-gray color, with two short earlike projections above the 

 head, just below which, on the upper part of the back, is a little 

 prominence like a pug nose. The chrysalis hangs in the same 

 way as the caterpillar, and remains in this state from nine to fif- 

 teen days, according to the temperature of the atmosphere, cold 

 and wet weather having a tendency to prolong the period. When 

 this is terminated, the skin of the chrysalis bursts open, and a but- 

 terfly issues from it, clings to the empty shell till its crumpled and 

 drooping wings have extended to their full dimensions, and have 

 become dried, upon which it flies away in pursuit of companions 

 and food. 



This butterfly is the Papilio Jlsterias of Cramer. It is of a 

 black color, with a double row of yellow dots on the back ; a 

 broad band, composed of yellow spots, across the wings, and a 

 row of yellow spots near the hind margin ; the hind-wings are 

 tailed, and have seven blue spots between the yellow band and the 

 outer row of yellow spots, and, near their hinder angle, an eye-like 

 spot of an orange color with a black centre ; and the spots of 

 the under-side are tawny orange. The female differs from the 

 male, above described, in having only a few small and distinct 

 yellow spots on the upper side of the wings. The wings of this 

 butterfly expand from three and a half to four inches. 



During the month of July, the Asterias butterflies may be seen 

 in great abundance upon flowers, and particularly on those of the 

 sweet-scented Phlox. They lay their eggs, in this and the fol- 

 lowing month, on various umbellate plants, placing them singly on 

 different parts of the leaves and stems. I have found the cater- 

 pillars on the parsley, carrot, parsnip, celery, anise, dill, caraway, 



