THE VICTORIAN NATURALIST. 



support the larva has spun up finally before pupating, and if in 

 addition the neck is firm, it may be guessed that there is a pupa 

 inside, whereas, if it is soft and feels empty at the upper end, a 

 larva can be expected, the neck not being as yet filled up with 

 loose silk. A hard lump at the lower end indicates generally that 

 the larva has been killed by some of its numerous insect parasites, 

 and holes will often show the manner of their escape. The case 

 must not be handled roughly, as the male pupa in particular is 

 very easily damaged. 



It is noticeable that the males as a rule choose a position near 

 the ground when spinning up to pupate, while the females occupy 

 more elevated and conspicuous places, although this course is by 

 no means strictly adhered to. 



As a preliminary to pupation, the larva attaches the mouth of 

 its case very strongly to its support, and fills up all spaces with 

 loose silk. It then turns itself head downwards, and casting its 

 last larval skin, which is pushed up to the top end of the case, 

 assumes the form of a pupa. 



3. Pupa. — Male : black or dark brown, sub-cylindrical, 

 distinctly jointed ; eighth, ninth, and tenth somites fused together, 

 and terminated by a pair of chitinous hooks curved downwards 

 and forwards, representing the anal prolegs of the larva. Slight 

 scars indicate the positions of the other prolegs. Wingcases 

 extend to middle of third somite. Anterior dorsal edges of 

 somites three to eight each with row of adminicula curved 

 forwards ; posterior edges of somites two to five with adminicula 

 curved backwards, all of which can be folded round inwards, and 

 so hidden from sight by contraction of the abdomen. Length 

 about 1^1 inches; diameter at thorax, i^-inch. 



Female pupa longer and stouter than male, wing-cases absent, 

 rudimentary leg-cases not fused to sternum ; colour dark brown, 

 with occasionally posterior edges of segments lighter ; anal hooks 

 less prominent and abdomen less contractile than in male. 



The pupse of both sexes lie head downwards in the cases, 

 and the female, as a pupa, never moves from that position. The 

 male chrysalis, however, works its way downwards, and protrudes 

 itself half out of the lower end of the case before it bursts its skin 

 open and appears as a moth. 



4. Imago. — The male moth is sufficiently well known to render 

 any general description of it unnecessary here. Its extraordinary 

 power of extending its abdomen is perhaps its most peculiar 

 character, and has given rise to its specific name. The female is 

 nearly cylindrical in form, about i^ inches long, and ^-inch in 

 diameter, is destitute of all but the merest rudiments of limbs, and 

 has no wings. The antennae are very small and only three- 

 jointed ; the eyes are also scarcely developed, and the proboscis 

 seems to be altogether absent. There are two small tufts of 



