1907] On the Nesting Habits of the Psen Barthi Viereck. 253 
NEST. 
The entrance to the nest was usually marked by a quantity of 
sawdust scattered about without definite form or arrangement. 
The nest remained open during the absence of the wasp though 
material was at hand with which it might easily have been closed 
to intruders. Frequently the entrance was in the side of a crack 
which extended into the log and in this event the sawdust was in 
large part carried to the surface and deposited there. A short 
gallery, smooth and evenly rounded, from three to four milli- 
meters in diameter, led perfectly straight or rather tortuously to 
the cells. . The accompanying drawings and measurements will 
illustrate. In all nests the cell was rather sharply divided from 
the gallery by a ridge formed by the abrupt incline into the bowl 
of the cell. In shape these varied to a considerable degree, the 
oval in some form being maintained however. The cell was pro- 
visioned with from three to five leaphoppers which were in the 
majority of cases mixed with a little sawdust. These, presum- 
ably, were stung to death as neither the ones taken from the 
wasp immediately on her return from a hunting expedition nor 
those in any of the cells responded to stimulation with forceps, 
fingers or alcohol and they soon dried up. All the nests except 
number three were in the log. This nest was found in the debris 
which littered the ground about one foot from the log proper, the 
entrance being concealed under several chips of wood. Thence 
it took its course downward irregularly, then horizontally and 
finally in a sweeping curve downward to the cell. This irregu- 
larity was not due to a desire on the part of the wasp to avoid 
obstructions as where a piece of wood was encountered the wasp 
bored its way through instead of around it, at least three pieces 
of wood, none larger than three-fourths of an inch in any diameter 
being thus perforated. The cell itself occupied the center of a 
snvdV square piece not over one inch each way. 
