264 FIFTH REPORT OP THE ENTOMOLOGICAL COMMISSION. 
of tin- fourth, fifth, sixth, and seventh dorsal joints, while from each side of the bead 
ii long plume-like tuft of black hair projecting forward and outward. A simi- 
lar plume projects upwards from tin- la^t dorsal joint. The hairs composing these 
plnmes ere coarse, barbed, knobbed, and arranged in wets of oneqoal length, thus 
giving the plumes a turbinate appearance. 
r>tj><itioii. — Six days after the third moll a portion of the larvai spin up: all 
produce male moths. The female caterpillars, which up to this time have been nndis- 
tingnishable from the male caterpillars, undergo a fourth (and, as it appears from 
more recent experience, in some instances even a fifth) molt and acquire twice the 
size of the male caterpillar. This last, when full grown, measures about twenty 
millimeters in lengtn. The cocoon spun by the male caterpillar is of whitish or yel- 
lowish c(dor and sufficiently thin to show the insect within. It consists of two | 
the hairs of the tufts and brushes of the caterpillar being interwoven with the outer 
layer. The female cocoon is correspondingly larger, of gray color, and much more 
solid and denser than the male cocoon. The male chrysalis (Fig. 13 d), which is soon 
formed within the cocoon, is of brownish color, sometimes whitish ou the ventral 
side, and covered ou the back and sides with fine white hairs. The female chrysalis 
( Fig. 102 e) is much larger than the male, and otherwise differs, especially in lacking 
the wing-sheaths and in having on the three first segments after the head transverse 
flattened protuberances composed of scales, which are much less visible in the male. 
The duration of the pupa state is less thau a fortnight. 
Tht imago. — The male (Fig 102 e) is a winged moth with feathery antennae and very 
hairy forelegs. The general color is ashy-gray, the front wings being crossed by un- 
dulated bands of darker shade, with two black markings on the outer edge near the 
tip and a white spot ou the inner edge also uearthe tip. He may frequently be seen 
sitting on the trunks of trees or on the shady side of houses, etc., as he rests during 
the day and flies only after dusk, often being attracted by light. The female (Fig. 
102 a) is totally different from the male in appearance and resembles a hairy worm 
rather than a moth, since she possesses the merest rudiments of wings. She is of a 
pale gray color, the antenna' beiug short and not feathered, the legs rather slender 
and not covered with long hairs. She has consequently no power of flight, and is 
barely able to walk. After working her way out of the chrysalis and cocoon she 
takes her place on the outside of the latter, and patiently awaits the approach of the 
male. Here she also deposits and protects her eggs in the manner already mentioned, 
after which she drops exhausted to the grouud and perishes. The white mass cover- 
ing the eggs is at first viscous, but soon dries, becoming brittle, and is impervious 
to water. 
Hibernation. — The species hibernates normally in the egg state, but occasionally a 
living chrysalis may be found in winter-time. Ou January 30, 1874, we received 
from Mr. Hunter Nicholson, from Knoxville, Teuu., a newly-hatched female, and this 
had, no doubt, prematurely issued from a hibernating chrysalis. This is, however, 
quite exceptional, and the different climatic conditions to which the specieais sub- 
jected in its wide distribution do not seem to alter the normal mode of hibernation. 
Xnmber of annual generations. — In the latitude of Washington the species is two- 
brooded, the imagos of the first generation appearing in the first part of June, those 
of the second generation in September and October. On several occasions we have 
fouud, however, that a portion of the caterpillars from one and the same batch of 
eggs would be feeding while the rest had already transformed to imagos. The result 
of this retardation and irregularity in development is that caterpillars may be fouud 
continuously throughout the season from Juue till October, and that there is, conse- 
quently, no distinct dividing line between the two generations. In the more northern 
States the species is single-brooded, the caterpillars appearing in the months of July 
and August. 
Xatural enemies and parasite*.— The fact that the caterpillar makes no effort to 
conceal itself shows that it enjoys immunity from enemies, and notably from birds. 
