THE EUMENIDAE 347 



upwards. He saw more than one wasp entering and leaving 

 a single burrow, and thinks that undoubtedly several indi- 

 viduals live and work in harmony together. Ashmead says 

 nothing of their burrowing habits, but Comstock 13 and 

 Iseley 14 say. that this species bores in solid wood. Tandy 15 

 found a nest in a groove in the lower side of a block of 

 cypress wood as it lay in a lumber pile. On the upper side 

 of the block he found "six small partly decayed places" 

 which he says bear evidence of the wasp's efforts to make 

 its own tunnels for its home, but each of these burrows in 

 turn had been abandoned because of the silicified layers in 

 cypress wood. His data offer no guaranty that these six 

 places had been made by this insect, but we are glad to 

 know that it had readily conformed its work to its splendid 

 opportunity and adopted the long mechanically-made groove 

 for its fine twelve-celled nest. This behavior is, we think, 

 in no wise exceptional, but it is in perfect harmony with the 

 cases which we have observed, which will be discussed later. 



Following are our observations on the mud-carrying 

 activities of this wasp. 



On a sandy area beside Fox Creek, near Allenton, Mis- 

 souri, our attention fell upon a small spot of loam, where 

 a few plants were sparsely growing. In the middle of an 

 afternoon in July, a M. quadridens came to this earthy 

 area, bit at the dirt and flew away leaving a most spot. 

 It appeared at first that she was digging a hole there 

 and had flown away for more water. She returned five 

 times, at intervals of from five to ten minutes, and repeated 

 this performance precisely, each time in a different spot; 

 she wet the ground with water or saliva, bit out a chunk 

 of dirt, rolled it into a ball with her mandibles and with 



13 According to Kellogg, Am. Insects, p. 502, fig. 702. 1905. 

 14 -Kans. Univ. Sci. Bull. 8: 245. 1913. 

 15 Ent. News 19: 231. 1908. 



