444 
ANNUAL REPORT OF NEW-YORK 
smooth on its inside, and a little larger than the chrysalis which 
reposes w'ithin it. The cocoon is placed indifferently either in 
a perpendicular, an oblique, or a horizontal direction. 
The chrysalis is of an oval form, twice as long as broad, measuring from 0.60 
to 0.70 in length. It is rounded anteriorly and drawn out into a little horn¬ 
like point at its hind end, furnished with minute hooks at its tip, which are 
fastened into the threads of the ooooon. It is of a brown color with pale clouds 
and the under side of the abdomen whitish. Sometimes it is black and shin¬ 
ing, with scarcely any traces of whitish. Upon the head back and sides it is 
thickly covered with rather long fine white hairs. The three anterior segments 
next to the head have each upon their middle, above, an oval or square trans¬ 
verse spot of a pale clay color, formed of scales which resemble little collapsed 
vesicles or bladders, and each of tlieso spots is crossed by a slender line upon 
its middle. The wing-sheaths appear to be of the same length in both the 
sexes, reaching to the anterior edge of the first abdominal segment. On break¬ 
ing open a female chrysalis, its inside is found filled with eggs which appear to 
be grown to their full size. 
In each instance when I have bred these insects, the moth 
made its appearance on the thirteenth day after the cocoon was 
spun. It therefore begins to appear abroad upon the wing about 
the first of August. We sometimes, however, meet with the 
chrysalis unhatched in the cocoon in the winter. These are 
doubtless individuals which have been later in completing their 
growth and from which moths will be given out early in the fol¬ 
lowing spring. From the gay appearance of the caterpillar one 
would expect a very pretty moth to be produced by it, and will 
be disappointed on obtaining a dark sooty brown thing, little 
variegated with spots or streaks. These moths may sometimes 
be seen resting upon the door posts or the shady side of build¬ 
ings, with their fore legs stretched out in front, and their antennae 
elevated. They frequently enter open windows in the evening, 
attracted by the light. They fly also in the day time. Their 
mode of flight is peculiar, consisting of short jerks or in a flirt¬ 
ing manner. This has probably obtained for insects of a similar 
kind which occur in England, their common name, vaporer moths, 
a term indicating something of a volatile, peevish, hysterical dis¬ 
position. They pertain to the genus Orgyia in the family Arc- 
tiidje and order Lepidoptera, and this species is named leuco- 
stigma or the Pale vaporer moth, in the splendid work of Abbott 
and Smith upon the Insects of Georgia, plate 79. The epithet 
(< pale,” however, is inappropriate for these moths as they occur 
