MORPHOLOGY OF THE LEPIDOPTEEOUS PUPA. 261 



Fig. 7. x 8. The outline of the left wings of a female pupa of Hybernia defoliaria. Although the 

 imaginal wings are very unusually degenerate (see fig. 9), those of the pupa are seen to be 

 well formed and of considerable size. The margin of the hind wing is distinctly seen in its 

 normal position, parallel with the dorsal margin of the fore wing, and occupying the right side 

 of the figure. A comparison of figs. 7 and 9 points to the very recent date of the degeneration 

 of the wings in the females of the genus Hybernia. 



Fig. 8. x 8. The outline of the left antenna of the female pupa of Hybernia defoliaria, shown in the 

 last figure. The antenna is seen to be broad and well developed, and out of all proportion to 

 the filiform degenerate structure which is formed within it (compare fig. 9) . 



Fig. 9. x 8. The head and thoracic segments of the female imago of Hybernia defoliaria, as seen from 

 the left side. The moth represented in this figure emerged from the pupa, parts of which are 

 represented in figs. 7 and 8. The antennae are thread-like and degenerate, and the wings are 

 so small that they are usually considered to be altogether absent. They are shown in the 

 figure as minute pouch-like extensions of the body-walls, which are closely applied to the sides. 

 The fore wing is more distinct than the other, its surface being marked by a large squarish 

 dark spot. In contradistinction to these rudimentary organs, the wings and antennas, the 

 unusual size of the legs is very striking. This extreme development of the legs is rendered 

 necessary in order to enable the insect to move about and deposit its eggs. 



Fig. 10. x 7. The outline of the left fore wing of a female pupa of Orgyia antiqua. The wing was 

 somewhat flattened. 



Fig. 11. x 7. The outline of the left fore wing of a female imago of Orgyia antiqua. Here also we 

 meet with proof of recent degeneration ; for the imaginal structure is much smaller than the 

 pupal structure within which it develops. 



Fig. 12. xlP5. The male pupa of Fumea nitidella, as seen from the left side. The parts showu in 

 the next figure were detached from the pupa. The drawing was made from an empty pupal 

 shell, so that the ventral margin of the fore wing is rolled inwards to some extent. The pupa 

 is well formed, and contrasts in a remarkable manner with that of the female (fig. 14). 



Fig. 13. xl4 - 5. The head, antennas, and limbs of the male pupa of Fumea nitidella represented in the 

 last figure, as seen from the ventral aspect. These parts also are seen to be extremely well 

 developed. 



Fig. 14. x 14-5. The female pupa of Fumea nitidella as seen from the right side. The difference 

 between the sexes is very marked (compare with figs. 12 and 13). The female pupa is never- 

 theless far less degenerate than the imago which emerges from it. The imaginal wings 



5' 



are minute tubercles, so that the insect is described as " wingless " ; those of the pupa are seen 

 to be small but quite distinct. Their small size leads to the uncovering of the first abdo- 

 minal spiracle, which is concealed in all pupas with normally-developed wings. The pupal 

 antennas are also larger than those of the imago. Although the degeneration of the female 

 Fumea is doubtless far older than that of Orgyia or Hybernia, a comparison between pupa and 

 imago clearly shows that it is not very ancient ; for the pupa, although degenerate, is still a 

 long way above the condition to which the imago has sunk. 

 Fig. 15. x 14-5. The anterior part of the female pupa of an unnamed Psychicl, as seen from the 

 ventral aspect and somewhat from the right side. The wings are distinct, although very rudi- 

 mentary ; they are in the form of small pouches. The first abdominal spiracle is uncovered as 

 in fig. 14, and is shown on the right side (left side of figure). The three pairs of thoracic legs 

 and the antennas (A) are distinct, although very small. The eye (E) is extremely minute, and 

 the mouth-parts are in a very rudimentary condition. The female moth does not emerge from 

 the pupal shell, and is a mere sack full of eggs, bearing no traces of limbs, wings, &c. Never- 

 theless the pupal prothorax splits in the middle line, and some of the hairs of the included 

 SECOND SERIES. — ZOOLOGY, VOL. V. 39 



