ISELY: EUMENID^ of KANSAS. 259 



for the wasp to enter, but did not permit its turning around 

 while in the nest. The length of the burrow varied greatly, 

 from one-fourth of an inch to five inches. The average dis- 

 tance for the first entrances to cells to the opening into the 

 burrow was one and three-sixteenths inches. In one case 

 which I noted the burrow opened into the first cell within one- 

 fourth of an inch of the outer entrance. 



The earthen walls of the cells and burrows were packed and 

 smooth. They were always harder than the surrounding 

 earth, forming a layer distinct from it, due to the fact that 

 water, and perhaps saliva, was applied to them. 



Earthen tubes projecting from the face of a bank over the 

 entrances of burrows attracted my attention to the first 

 Odynerus colony that I ever observed. These tubes were small 

 and fragile, being only about one-fourth of an inch in diameter, 

 inside measurement. In length they varied from one-fourth 

 of an inch to nearly two inches. Most of those over one-half 

 inch in length curved downward at the distal end. In texture 

 the tube appeared to be made of a network of earthen cords, 

 which were laid close together longitudinally, and with enough 

 wide crossbands to hold them together. I did not note a single 

 tube in which the direction of the strands of network were 

 much longer at the distal end of the tube than near the basal 

 end. At the base the tube walls were solid or with only very 

 small openings. The width of the spaces at the distal end of 

 the tube was about the same as the width of the earthen cords- 



In spite of the apparent fragility of these tubes, they were 

 quite durable when exposed only to natural conditions. While 

 they were so brittle that I had diflSculty in removing them 

 from the bank with a pair of tweezers without breaking them, 

 yet rain and wind appeared to have little effect upon them. 

 I have excavated nests in which all the cells were empty ex- 

 cept for pupal skins, and over some of these burrows were 

 tubes one and one-half inches long. They had been built at 

 least a month before, probably much longer than that, and had 

 been exposed to several rains. The rains left no record of the 

 percentage of tubes they may have destroyed. The fact that 

 the wasps often select sheltered spots as nesting sites indicates 

 that the weather may affect the durability of the tube. Yet I 

 believe that many of these tubes endure for longer than the 

 nest has inhabitants, and far longer than their fragile appear- 

 ance would warrant. This durability is due, I believe, as 



