262 Dr. 'T. A. Chapman on a lepidopterous 
are expanded, and this it immediately does for a brief 
period. 
In working the jaws, the pupa moves its head up and 
down to the right and to the left, and with also some 
oblique twisting motion; the action of the jaws suggests 
some energy. Their movements and their size relative 
to the pupa might be illustrated by likening them to a 
man’s arm crossed over his chest, as their position of 
rest, and (the elbows being stiff) the arms are then to be 
opened till they can be crossed again with the upper 
one undermost, very much the movement of a cabman 
warming his fingers, though less rapid. The hands 
are not relatively large enough to represent the expanded 
digging extremities of the jaws, whilst the fingers are too 
long for the teeth with which they are armed; so that 
the illustration must not be pushed too much into 
detail. 
When the pupa is reposing after breaking through the 
cocoon, the lightest touch by a needle-point either of the 
jaws, the labial palpi, or the long hairs of the head or 
labrum, at once causes them to work, one might say 
most intelligently, with the obvious object of breaking 
down some impediment in front, the head reaching in 
turn as far forwards and as far to either side as possible. 
T ought to note that of the points arming the end of the 
jaw, one, the largest, is quite curved into hook form, 
pointing backwards, and seems specially designed for 
eripping and tearing the cocoon. 
How are these jaws worked? They and the corneous 
labrum in front of them are empty of any imaginal 
parts, and with the corneous ring-like base to which they 
are articulated, they are cast with the pupal skin a few 
minutes after they have been used; nor does the imaginal 
head contain any muscles adequate to move them with 
the force they display; nor does it present anything 
I can recognise as jaws, though there are some papille 
that probably represent them. 
In the imago examined as soon as the head is free, 
there is a white smooth area above the mavxille and 
between the eyes, which becomes afterwards darker and 
difficult to find, and, I believe, becomes smaller. This 
area is therefore probably expanded during emergence, 
much as the forehead of some Muscide is (Musca, 
Exorista, &c.), and I can imagine no way in which the 
