7g [September, 



the ventral feet, which, like the base of the anal pair, are bright 

 crimson ; the whitish-yellow stripe on the side of the eleventh segment 

 continues downward beneath the spiracle on the twelfth ; fi'om the top 

 of the white horn-like hump, which is divided by a thin line of black, 

 a whitish stripe descends on either side in a slight backward curve, and 

 the anal flap is margined with yellowish ; the anterior legs are pale 

 green, sometimes tipped with red, and with a black hook. 



When full fed, all the green colours of the larva change to brown, 

 and it becomes restless until it finds the moss and leaves needful for 

 its retirement and the construction of its cocoon. 



The cocoon varies in length from 1 inch 4 lines to 1 inch 7 lines, 

 and is of long-elliptical shape, being from 6 to 8 lines in width ; it is 

 composed of an open-worked reticulation of coarse black or black-brown 

 silk threads, with round or broad oval interstices ; the fabric is extremely 

 strong, tough and elastic, covered externally with moss and birch leaves 

 firmly adherent. About a week or ten days before the time of emergence, 

 the cocoon is pushed by the enclosed pupa from a prone to a vertical 

 position, the upper end is ruptured, and the pupa protrudes its head 

 through the opening and continues by degrees to advance, until it is 

 exposed as far as the end of the wing-covers ; fixed in this position, it 

 remains quiet a longer or shorter time until the insect is able to escape, 

 though in two or three instances the pupa had worked itself out entirely 

 free from the cocoon before the moth could be disclosed ; on ex- 

 amination, the pupa could be seen to be well furnished with means for 

 facilitating such movements, as described below. 



The pupa itself measures in the male a length of 12 to 14 or 15 

 lines, in the female from 17 to 18 lines, or occasionally a little more ; 

 it is very stout, the diameter across the bulkiest part at the end of the 

 wing-covers in the male, ranges from 4 to 4^ lines, in the female, 6 

 lines ; the head has the mouth-parts a little produced in a squarish 

 form, flanked by the curved antenna-cases in high relief ; from thence 

 the head is bluntly rounded above in an unbroken swelling curved 

 outline to the end of the wing-covers, including the thorax and upper 

 abdominal rings ; the moveable abdominal ring is very deeply cut, and 

 those below are well defined, the last ring ending with a prolonged 

 flattened caudal process tapering a little to the squarish extremity, 

 where it has a margin of hooks and bristles ; the surface is remarkably 

 dull, and rough everyAvhere, except in the divisions between the 

 moveable rings, yet even there it is quite dull ; the roughness on the 

 head, thorax, u]iper rings and wing covers is striated, granulous, or 



