218 [March, 



increased to three-quarters o£ an inch, moulted July 3rd, increased to 

 nearly one inch, moulted July 14th, increased to one and a half inches 

 or a little more, spun up 27th ; imago August 14th, a female. Each of 

 these larvae, on arrival, possessed all the characters and colours that 

 distinguished them through their changes of skin to the adult state 

 presently to be described. The food supplied to them consisted of 

 various lichens from oak trees, and at first a few leaves also, as I 

 noticed the oak leaves that were sent to me with each larva had been 

 nibbled a little on the journey ; I also gave them Lichen canina, for 

 which they soon showed such a decided preference that it became 

 almost their only nourishment ; when disturbed, they were very lively 

 and active, running quickly over any surface, yet clinging with a firm 

 foot-hold when they choose ; altogether, a great quantity of food was 

 devoured by them, and at times they seem to eat quite voraciously, 

 always on the dark cuticle of the lichen, not seeming to care for the 

 pale fleshy substance beneath. When about to moult, the colours 

 became less vivid and the details less distinct ; at such times the larva 

 would leave its food for the leno cover of its cage, and there spin a 

 patch of silk, and fix itself upon it ; then there seemed to ensue some 

 operation of denuding itself of most of its hairs, but this process I 

 was in every instance unable to witness, it being always effected during 

 the night, generally the first night after the larva had taken its 

 position on the silk ; most of the hairs left remaining were on the 

 second and third segments, nearly all the others appeared to have been 

 bitten off close to the skin, excepting some few mere stumps of various 

 lengths left along the sides ; the actual moult would take place either 

 on the first, second, or third night after this loss of hair, the minimum 

 time with the smallest, and maximum with the largest larva ; after 

 moulting, the first meal was evidently made on the cast skin, as no 

 trace of it could be found beyond the head piece, in every instance 

 save one, when a small fragment of skin remained : this breakfast on 

 its old skin by a hairy larva was to me very suprising ; it seemed, 

 however, to act beneficially, for the next meal on lichen would be a 

 hearty one. I found that after each larva had attained its greatest 

 length, it began gradually to shorten for three or four days before 

 spining its cocoon, although still occasionally feeding, sometimes even 

 ravenously, during this period. 



The full-grown larva, as I have said, varied from one and three- 

 eighths of an inch to nearly one and five-eighths of an inch in 

 length ; was moderately stout in proportion, somewhat cylindrical in 

 figure, tapered a little from the fourth segment to the head, also from 



