POMPILIDJE. 
195 
the smaller the (hitherto undescribed) male, the latter three days ear* 
lier than the former. It is apparent either that the mother wasp lays 
Fig. 105 .— Nest of sceliphron coromanrelicum occupied by 
PSEUDAGENIA CLYPEATA, X 
eggs of each sex alternately or that she can control the sex production, 
or that the greater amount of food stored in the one case makes a female 
imago. 
Fig. 106.— Macromeris violacea yar 
IRIDIPENNIS ; CELL, X H. 
We figure a large compound 
clay nest from which were reared 
P. clypeata. The nest consists 
of an old nest of Sceliphron 
coromandelicum, of which the 
cells were occupied by the 
Pseudagenia ; since the latter 
requires a smaller cell, she 
divides the cells by a partition 
and then utilises them ; but she 
also builds on additional cells 
round the old ones; in Fig. 105 
the large cavities in the middle 
represent old Sceliphron cells, 
(the nest seen from below). the 
smaller holes round cells added 
by Pseudagenia. That the 
cells were originally made by 
Sceliphron is proved by the 
