1927 ] Parasites and Habits of Dianthidium pudicum Cresson 195 
Three of the four cells were finished. The second was to the 
right of the first; the third to the left of the first; and the fourth 
above and over the first, being attached to the rock above and 
partially covering the finished cell. At 9:46 a. m. the bee re- 
turned pollen laden, from a collecting trip. She entered the cell 
head first, and stayed within 20 seconds. She then came out, 
backed in to deposit the pollen and remained 35 seconds. Later 
in the day, when she was collecting resin, it was observed that 
she averaged 7 minutes in securing a load. She carried the lump 
of light colored resin in her mandibles and deposited it in the 
anterior part of the unfinished cell. 
September 2. At 3 p. m. a fifth cell had been made. The 
sky being overcast, the bee was inside resting. The cell was above 
the second and parallel to the fourth. The opening was down, as 
has been found true of all others observed in the process of 
construction. Later in the afternoon, the bee was seen to be 
smoothing the inside of the cell with her mandibles. 
September 4. To-day, a sixth cell was partly finished and 
the bee was seen for the last time and no further work was done. 
The nest was taken home September 26. 
Notes on Construction of Cell. 
Considerable time was spent in observing the bee construct- 
ing the cells. The resin, which had been placed in the anterior 
part of the cell after each collecting trip, was used as needed. 
The bee would take some of the resin and place it on the edge of 
the cell, often between two pebbles. Then she would fly to the 
ground and select a pebble, sometimes from very near and again 
as far as six feet away. The pebble was carried in her mandi- 
bles to the nest, where the legs and thorax were used to fit it 
into place. It is worthy of note that the bee endeavoured to 
place the pebble where she had previously put the resin. If the 
pebble did not hold, as was sometimes the case, she would get 
some more resin and place it usually on the same spot. 
The pebble dropped was never immediately utilized again, 
but a new one selected. However, since she often gathered 
those near, she sometimes later used the ones previously tried. 
