THE TROILUS BUTTERFLY. 267 
Latched it is slate-colored above, with a black spot like an 
eye on each side of the third segment, below and behind 
which is a large and long white spot, and the top of the 
eleventh segment is white. After changing its skin, it be¬ 
comes of a pale brownish olive color, the white spots dis¬ 
appear, and on the top of the back we find two rows of 
minute blue dots. When fourteen or fifteen days old it 
changes its skin and its colors again, the back becoming pea- 
green, with blue dots, the sides yellowish, and the head, 
belly, and legs pink ; there is a transverse black line on 
the top of the first segment, and there are two large orange- 
colored spots on the fourth segment, and two of the same 
color, with a black centre, on the third segment. The cat¬ 
erpillar retains these colors from ten to sixteen days, increas¬ 
ing greatly in size during this peiiod, and finally attains to 
the leno-th of two inches or more. It comes to its full 
growth when about four weeks old, and then eats no longer, 
but, deserting its leafy habitation, it seeks a suitable place in 
which to undergo its transformation, previously to which it 
casts off its green coat, and appears in one of an ochre-yellow 
color. It then suspends itself in the same way as the cat¬ 
erpillar of the Asterias butterfly, and within two or three 
days after its last change of skin it moults again, and be¬ 
comes a chrysalis. 
The chrysalis is generally of a pale wood-color, smoother 
than that of the preceding species, and with rather longer and 
sharper ear-like projections. The chiysalids, which are pro¬ 
duced from caterpillars hatched in August and September, 
remain unchano-ed throuo;!! the winter, and are not trans- 
formed to butterflies till the middle of the followino; June. 
It is possible that these butterflies may lay their eggs so early 
as to produce a brood of caterpillars in the summer, and these 
may come to their growth, and pass through their transfor¬ 
mations, before September ; but I have only found the cater¬ 
pillars towards the end of summer. I once discovered them 
on the leaves of the lilac, on which they appeared to thrive 
^uite as well as on the sassafras. 
