Field Studies of the Non-Social Wasps 363 
cabin near Kirkwood. A typical carpenter-bees’s old 
hole had been filled in with grass, tightly packed. The 
diameter of the hole at the opening was 7/16 inch (see 
1 in fig. 41). This opening led to a gallery going east 
for a few inches (see 2 in fig. 41), then turned back 
sharply and went toward the west (just below 3) for 8 
inches. <A third gallery which ran parallel with gallery 
3 turned off at a point near figure 2. This third gallery 
is indicated as 5 in the figure, and 6 is its opposite wall. 
The excavation had originally been made by a carpen- 
ter-bee, and various insects had since occupied the quar- 
ters whenever an opportunity occurred. 
Seven large, dead carpenter-bees were entombed in 
that portion of the tunnel marked 7; these were crowded 
close together in a space of three inches, and sealed up 
with a wall of mud; this wall was at ‘‘X,’’ just to the 
left of 3. These bees had evidently died during the win- 
ter, and instead of sweeping them out as debris, the 
next tenant, the Monobia mud-wasp, had merely swept 
them into the far end and sealed them up. The remain- 
der of this tunnel (below 3) had evidently been used by 
the wasp Monobia quadridens, for there were mud par- 
titions to the left and to the right of chamber 9. The 
only evidence, however, of its having been occupied by 
those wasps was the mud partitions, and the hole in 
one of them made by the new Monobia wasp in emerg- 
ing. This gallery, however, now that these wasps were 
gone, had been used by other insects which had made 
their way to the opening at 1 and thence through the 
holes in the partitions. The region designated as 8 had 
been used by a bee whose cocoons are identical with 
those of Osmia cordata. The O. cordata that I know, 
however, build their nests in abandoned mud-dauber 
cells, which they partition into rooms and re-seal, using 
