in the pupe of Heterocerous Lepidoptera. 101 
I find “dehiscence” —a term employed in Botany to 
describe the method in which the seed-vessels break up 
for the escape of the seed—meets the occasion. 
On dehiscence these covered portions of the incom- 
plete pupa become more or less fully exposed, and the 
appendages show an independence of each other quite 
at variance with ideas formed from the dehiscence of the 
obtected (Macro) pupa. In some Tinee, even before 
emergence, the appendages and segments of the pupa— 
though apparently fused together—separate, on the least 
violence being applied, almost as perfectly as they would 
in the imago, without any fracture or tearing occurring: 
this would be quite impossible in an obtected (Macro) 
pupa. 
The pupa of O. antiqua, female, interestingly illustrates 
the obtected pupa, and the fixity of the character of the 
fifth and sixth abdominal segments only being free ; the 
wings and appendages are so short as not to reach the 
fourth abdominal segment, which might thus very 
easily be free, but there is no movement between it and 
the third either before or after dehiscence. 
Certain other characters of the pupex of the group 
with the seventh abdominal segment free in the male, 
which result from, or rather constitute, their ‘‘ ncom- 
plete” structure, may now be noted. 
In this pupa the head-coverings separate from the rest 
of the pupa in dehiscence, yet remain attached to one 
another in one piece,—that is, the plate covering the 
head and eyes; the antenne-cases and the cases of the 
mouth parts separate from the rest of the pupa in one 
piece. In the Macro pupa these parts usually separate 
from each other; the head-cover is often one piece ; the 
two antenne-cases are separate, and the mouth-pieces 
may be separate, but more usually the mouth-pieces 
remain in one portion with the leg-coverings, and the 
antenne-cases either with these or with the wings; 
whilst in the few cases (in Sphinges, Notodonts, and 
allied Bombyces) in which the head-coverings remain in 
one piece, they do so because they remain attached to 
the leg- or wing-coverings ; they never remain in one 
piece when detached from the rest of the chrysalis-case. 
And similarly for the other segments in the Incomplete, 
the pupal coverings of the wings, legs, &c., separate 
more or less from each other and retain their attachments 
