I. TWO EUMENIDAE. 



(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 tlie 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. Tliis 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 3:30 

 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 



