68 THE ENTOMOLOGIST. 
On the 25th of September, several passed into the 5th age. 
One of these I detected at the very instant of beginning its 
moult. The first rupture of the old skin was certainly not on 
the back, but across the breast of the prothorax, extending back- 
wards by a lateral rent on each side. The new face was early 
freed, and carried the old face on the lip and jaws, to be removed 
only by rubbing against surrounding objects, when the body was 
two-thirds denuded. The skin drags upon the dorsal region long 
after the sides: the long declined tubercles seem difficult of 
liberation. } 
The head appeared very small for the 5th age of so gigantic 
a moth; and so, indeed, did the whole larva. As the old skin 
was pushed off in folds, the farina flew about on the currents of 
air in the room, like the finest flour, and accumulated in little 
heaps on the leaves below. In general, these tiny heaps of dust 
are the only remains left where a moult has occurred; for the 
larva evidently devours its own exuvie. I wished to witness this 
operation ; but, in neither of the moults that had occurred under 
my eye did the larva, after his labours, take any notice of the 
exuvie. Nor did this one for a while; but, by-and-by, he turned 
his head round slowly, and began to munch the exuvie, holding 
it up bodily in his mouth, till two-thirds were gone, when, the 
residue falling to the ground, he took no trouble to go down the 
twig to look for it. 
LARVA.—bBth age. 
The ground-colour is now a pale yellowish green, or green-white ; face 
and lip the same; clypeus edged by a black line, forming a conspicuous 
triangle ; jaws black. Pre-anal plate, and posterior edges of the last pro- 
legs, bright mazarine-blue, studded with the usual skin-cellules (glands ?) 
which are here blue-black. Tubercles tinted with azure at their tips; the 
lowest series on the first five segments slenderer than the rest, of deep 
indigo hue. Feet, prolegs, and edges of all the segments, tinted with 
azure; two black bands surround each proleg, of which one is marginal ; 
hindmost proleg painted with a broad ring of light scarlet, inclosing an 
azure area, as in the 4th age. Five days after this moult, the larva, when 
resting contracted to one inch and three-fourths in length, is half an inch in 
vertical height at the middle, and one-third of an inch in transverse 
diameter. Crawling it extends to two and a half inches. ‘There is an 
increased tendency to raise the tubercles from their imbricate recumbent 
position; especially in crawling, when they are nearly erected. ‘The waxy 
