132 TRANSFORMATIONS OF INSECTS. 
is slightly crested. When the caterpillars are full grown they 
spin a slight cocoon of silk amongst the leaves or in the bark, 
and the chrysalis becomes covered with a curious purple or blue 
efflorescence, which makes it look like the skin of ripe plums 
or grapes. Some of the American species are very large, and 
although very little is known about their metamorphosis, they are 
worth mentioning on account of the sombre colours of such species 
as Erebus strix, which is common in the Brazils ; its wings, which 
EREBUS STRIX. 
are of a pale grey colour with black or grey ornamentations, are 
nearly seven inches across. 
Before concluding this notice of the first great division of 
the Noctuina, we ought not to pass on without considering the 
curious habits of the caterpillar of one of the species of the genus 
Scopelosoma. ‘The larva lives upon the oak, beech, and elm trees, 
and is a dark black-brown insect, with three white lines on the 
back of the second segment, and a white spot on most of the 
others below the spiracles. It is very common, and, according 
