102 
Psyche 
[June 
The two really unique features of the nests of this species 
are the material constituting these parts, as described above, 
and the young bees’ way of getting past these plugs which 
when dried are almost as impenetrable as cement. 
Like many other species, these bees arrive at the final stages 
of their development and emerge successively from the topmost 
Fig. 1 — Nest of Alcidamea producta. Natural size. 
down, or in the reverse order of primogeniture. This sequence 
is apparent at the latter part of the pupal period from the pig- 
mentation of the eyes. The organisms pupate with the head 
toward the exit. 
A typical case in the details of behavior at the time of 
