Ecological and Behavior Notes 11 



domen, walked backwards for twenty feet and deposited 

 its prey under a loose piece of clay. After walking about 

 for five minutes, probably looking for a desirable hole, 

 she returned to the spider, grabbed it in the same way, 

 dropped it for a few seconds while again she looked 

 about, then returned, picked it up and removed it to a 

 spot under another clod. There she left it again while 

 she investigated an opening under another lump of clay 

 only an inch distant. This at last seemed satisfactory, 

 for the wasp then fetched the spider, dragged it under 

 this lump of earth and remained there for fifteen minutes. 

 Losing patience at last, I lifted the clod and found the 

 spider in a very neat depression, but I could not tell if 

 the hole was natural or a wasp-made one. Both spider 

 and wasp were then taken. 



This wasp also seems to abound until late in the season. 

 At Herculaneum, Mo., on October 18, on the shore of the 

 Mississippi river, about a dozen were seen in the half- 

 hour from 10 to 10 :30 a. m. One in particular was atop 

 a spider, Philodromus sp. [J. H. Emerton]. Approach- 

 ing too near we frightened her away, and she never re- 

 turned for her preyi The spider was probably more 

 frightened than injured, for after a few minutes it 

 seemed to recover its faculties and walked away. 



Pompiloides marginatus Say. This wasp was carrying 

 off a spider, an immature Xystieus sp. [J. H. Emerton], 

 on October 19 at Hematite, Mo. 



Pompiloides subviolaceus Cress. [S. A. Rohwer]. This 

 beautiful wasp was taken while she was foraging about 

 a lot of piled logs at Creve Coeur Lake on August 30, 

 1916. She was also seen carrying away an inmiature 

 Xystieus [J. H. Emerton] at Hematite on October 19. 



Psammochares (Lophopompilus) aethiops Cress. [S. 

 A. Rohwer]. Several individuals of this species were 

 seen flying about the bluffs at Clifton Terrace, 111., on 

 October 28, 1916. The days were then warm, but the 

 nights were so cold that I marveled that they could sur- 



