200 
Psyche 
[September 
that the tegmina, are moved passively as a consequence of the activi- 
ties of the wings. Thus when the wings sweep forwards they appear 
to push against the tegminal margins, causing the tegmina to erect 
and separate at their apices. The backward movement of the wings 
is accompanied by a partial lowering of the tegmina and during 
this their inner margins again become contiguous. When the wings 
Figure 3. Display of female P. spinulosus. Detail (right) shows wing 
movements (see text). (Based on frames of 16mm cine film). 
