46 BRITISH LEPIDOPTERA. 



tection of the eyes, the bases of the antennae and possibly all the head 

 organs. They are somewhat similar in position (one on either side of the 

 head) in the Vanessid pupae, whilst between the double nosehorns are two 

 minute prominences, so that the butterfly pupa has, in reality, an inner 

 and an outer pair of eminences. In Thais the nosehorns of Papilio 

 appear to be modified into the double central knob that carries the 

 hooks to which the girth is attached, whilst in Doritis and Pamassius 

 they are reduced to obsolescence. In Pierids there is a simple central 

 nosehorn, apparently formed by coalescence in the middle line. 



The antenna appear to arise, in the pupa, from the preoral somite 

 of the head and usually are so arranged as to form on either side a 

 boundary enclosing the legs, maxillae and other head-parts — eyes, clypeus, 

 &c. They vary much, but generally bear some relative proportion to 

 those of the imago not only in length, but also in their shape, general 

 appearance and segmentation, although, in some instances, consider- 

 able difference in detail may be observed. The long antennae of Adela, 

 &c, which project beyond the other appendages, remain separate and 

 free to their extremities, and this appears to be so in all incomplete 

 pupae with abnormally long antennae. In obtect pupae, on the other 

 hand, exceptionally long antennae are carefully carried round the 

 margin of the wing (Chapman). The antennae of the pupa, we have 

 said, do not always agree in detail with those of the imago. Moseley 

 noted that in Saturnia pavonia-minor the sheaths of the antennae of the 

 female pupa were large and inflated, with traces of pectination, resem- 

 bling, in this respect, those of the male pupa, but in a reduced degree, 

 although the antennae of the female imago were merely filiform, and 

 concluded that, " in the ancestral Saturniids, the imagines of both sexes 

 must have had large pectinated antennae and that they had not been 

 developed as such only in the male for sexual purposes, but must have 

 been retained in the male and degenerated in the female." Poulton 

 enters (Trans. Linn. Soc. Lond., 2nd series, v., pp. 245-247) into the 

 matter somewhat in detail, and he asserts that " when there is much 

 difference between the antennae of male and female moths, there is 

 always less difference between the antennae of the sexes of their respec- 

 tive pupae." He found this to be so in pupae of the genus Smerinthus, 

 where the difference between the imaginal antennae is not great, and in 

 pupae of Phalera bucephala, Centra rinula, and Xotolophus (Orgyia) 

 antiqua, in which the difference is much greater, and he considers this 

 fact evidence of comparatively recent increase of the sexual differences 

 in the imaginal state. He further observes that Moseley's conclusions 

 as to the antennae of Saturnia pavonia-minor are supported by a more 

 minute examination of the antennae of the female imago. He shows 

 that the degree of degeneration varies greatly in different individuals 

 and that rudimentary sensory hairs are scattered over the reduced 

 equivalent of the highly-developed rami of the male organ. The 

 imaginal antennae of Aglia tan, he also points out, are very different in 

 the two sexes, whilst the corresponding pupal organs are not widely 

 different ; similarly, the antennae of the female imago of Xotolophus 

 antiqua are out of all proportion to the broad pupal antennae, while 

 the male pupal antennae are not much larger than those of the female 

 pupa. He concludes by observing that distinct traces of antennae can 

 be made out upon the pupae of some female Psychids, the imagines of 

 which are "a mere bag of eggs, without limbs or sense-organs," whilst 



