VARIATION IN PUP^E. 199 



resemble the perfect insect, but contracted, and as it were 

 destitute of life : tbey have limbs, it is true, which are sepa- 

 rate from each other, but these limbs, as well as the entire 

 body, are covered with a membranous skin. This covering 

 exists in the other pupae, but is of a firmer consistence, imi- 

 tating a kind of bark, and to which the term corticata may 

 be applied, and more completely inclosing the limbs in one 

 general covering. To this kind of metamorphosis, which 

 Latreille considers as comprising the obtected and coarc- 

 tate pupae, he has applied the term pupa obvoluta, ob- 

 serving that the expression obtecta applies to both, and that 

 that of coarctata is too vague ; but surely the structure of 

 the dipterous coarctate pupa (i. e., an incomplete pupa in- 

 closed in the skin of the larva) is much more analogous to 

 the structure of the true incomplete pupa of the bee and 

 beetle*, than it is to the obtected pupa of lepidopterous in- 

 sects ; indeed, it appears quite evident, that if the coarctate 



Figs. 35, Larva 36, Pupa obtecta 37, Imago of a butterfly (Hipparchia pamphilus) . 



section must be sunk at all, it must be in favour of the 

 incomplete, and not the obtected section. 



* In some species of beetles, the incomplete pupa is inclosed in the 

 skin of the larva (Anthrenut, Chilocorus), thus being, in fact, real 

 coarctate pupae. 



