I. TWO ETJMENIDAE. 
(a) Odynerus Dorsalis, Fabre. 
On September 2d, just before noon, I was walking through a 
cornfield and chanced upon a wasp that had just dropped clumsily 
on the ground between the blades of a clump of grass. I had, 
several days before, seen another individual of the same species 
drop down in a similar place and caught her without searching the 
premises. This time, however, having become more suspicious, I 
waited and watched. The wasp moved about slowly for a while, 
always looking at me with what seemed a stare, which was due to 
two yellow spots like eyes on the sides of her face. Gradually she 
walked further back; and as I stooped, I saw under the grass five 
neat mud cells. One of these was open and contained several small 
caterpillars (cotton- worms) already stored away. Soon the wasp 
flew away, presumably after more prey; I should have awaited her 
return and watched every step of the work of storing and building 
had not some digger wasps engaged my attention at the time. I 
therefore left the place before the wasp had returned. At 2 :30 
I went back to ascertain Mme. O.’s progress and found that 
the open^cell had been closed with an out-turned saucer-shaped mud 
lid and that another cell had been begun. By 6 :30 in the evening 
this was finished though still open and was occupied not by cater- 
pillars, but by the wasp herself, which was lying inside and looking 
contentedly out. At 11:25 o’clock the next day the wasp must 
have been at work for several hours, for the cell had been nearly 
filled with caterpillars, which is the condition shown in Fig. 3. At 
11 :52, she came back carrying another caterpillar in her mandibles. 
I had pulled away some of the grass-blades above the nest and 
had my camera set up to take the picture of the nest. But this dis- 
concerted her very little, and I was surprised at the ease with 
which she became accustomed to the change. After once flying 
away for a minute and circling about once or twice, she settled and 
placed the caterpillar in the nest. This was done in a peculiar 
manner. The wasp laid the caterpillar down at the opening of the 
cell and supported herself with her fore-feet on the edge. She then, 
with her mandibles, passed the caterpillar on as far as she could 
reach, took a second hold and pushed it on further, repeating the 
operation until the whole length of the caterpillar was inside. 
