258 KANSAS UNIVERSITY SCIENCE BULLETIN. 



but are sometimes arranged in galleries, the lower cells open- 

 ing into the upper. Over the entrance of this nest is built a 

 fragile earthen tube, in diameter about one-eighth of an inch, 

 the same as that of the burrow, and in length varying from 

 one-fourth of an inch to two inches. 



The number of cells, to a nest, in those which I investigated, 

 varied from one to fourteen. In Rush county, among eleven 

 nests the average number of cells per nest was a fraction less 

 than four. The largest number of cells to a single nest found 

 there was eight. In Ness county the average number of cells 

 per nest, among sixteen nests opened, was six. There I found 

 one nest with fourteen cells and another with ten cells. There 

 were no others with more than eight. At Osborne the average 

 among the four nests excavated was three. Of all the nests 

 excavated during the entire summer I found but three with 

 only one cell. 



In the larger nests the cells were invariably arranged in 

 galleries. The average number of cells to a gallery was be- 

 tween two and three. Of all the nests that I opened I found but 

 ■one gallery with four cells. 



The burrow led into the bank either in a horizontal direc- 

 tion or pointing downward; it never pointed upward. At 

 various distances from the entrance, from one-half inch to 

 five inches, there were openings from the main burrow into 

 cells or into branch burrows leading to cells. 



There was little uniformity in the arrangement of the cells. 

 Yet I have found a number of nests in which symmetry pre- 

 vailed. This was the case in the largest nest that I found, one 

 with fourteen cells. These were arranged in seven galler ies of 

 two cells each. The burrow terminated in one gallery. The 

 other six galleries were arranged in pairs at intervals along 

 the burrow. On the other hand, I found many nests in which 

 all the cells came from the same side of the burrow. Still other 

 nests had a varying number of cells to the gallery. 



The size and shape of the cells was nearly uniform in all that 

 I measured. They were barrel-shaped excavations five-six- 

 teenths of an inch in diameter. The long axis of these cells 

 generally pointed downward. In 20 per cent of the cells thft I 

 noted the long axes were nearer horizontal than vertical. In 

 a few cases the long axis was actually horizontal. 



The burrow and the entrances to the cells were about one- 

 «ighth of an inch in diameter. The burrow was just big enniio-v> 



