INSECTA. 179 



variegated lower surface. The caterpillar, one inch and 

 a half in length, is forked at the posterior extremity, and 

 has, on the head, two branching horns. Proceeding 

 from the egg in late autumn, it lives, during the winter, 

 on the beech, willow, aspen, and ash, and changes in June 

 into a yellowish, tuberculated pupa, which, after hang- 

 ing suspended, head downwards, for two weeks, is trans- 

 formed into a living insect. 



The Apollo (tachyptera apollo), plate 24, fig. 4. Is 

 one of the handsomest and rarest of the butterfly race. 

 Produced in mountain regions. The body is blackish ; 

 wings, yellowish- white, partially transparent, with large 

 black figures ; inferior pair, ornamented with eye-like 

 spots, which, white in the middle, are vitreous, and show 

 distinctly on the under side ; are enchased with settings 

 of red and black. The finely-haired caterpillar is vel- 

 vety black, spotted with orange and speckled with blue ; 

 lives mostly on the houseleek ; makes a slight cocoon, in 

 which it is transformed to a chrysalis, at first yellow- 

 green, but afterwards brown, that after a period of six 

 weeks, comes forth a butterfly. 



3 . AERONAUTS. 



Large butterflies, with wings often partially transpar- 

 ent; posterior wings mostly one-forked. Their flight is 

 high, with a graceful sailing motion, only varied by an 

 occasional stroke of the wings, which, stronger than 

 those of the other Diurnse, enable them to maintain a 

 more continuous and steady flight. The wings of tlie 

 ^Eronauts differ from those of all the other Diurnae, 

 being capable of greater expanse, and admitting of freer 

 action to the body. The caterpillar, thicker in the mid- 



