28O C. H. TURNER. 



circle. The dirt gets upon the head by falling from above and 

 from the sides, as the larva burrows backward through the soil. 

 Some of this material comes from the outer edge as well as from 

 the inner. While constructing its pit, the larva often pauses. 

 After each rest it usually continues in the direction that it was 

 going. On rare occasions, it does turn about and go in the 

 opposite direction. This is usually when it has met some ob- 

 struction. 



To test the matter more thoroughly, a sufficient portion of each 

 of the forelegs of an ant-lion was amputated to render them 

 much too short to be of value in shovelling soil on to the head. 

 As soon as it was returned to its glass, the larva burrowed back- 

 ward into the soil. For four days it remained beneath the surface. 

 On that day it excavated a small pit. The next day the pit had 

 been enlarged. On this day it was fed with ants (Formica 

 subsericea). The ant-lion was then removed from the soil and 

 examined under a simple microscope. The legs had not re- 

 generated; each stump was covered with a ball of soil. This ant- 

 lion had constructed its burrow without using its front feet as 

 scrapers with which to load dirt on the head. 



The force with which an ant-lion tosses the materials from its 

 pit is astonishing. Often they are cast several inches beyond the 

 rim. Sometimes the larva encounters particles which cannot 

 be disposed of with a toss of the head. When these are not too 

 heavy the insect has an unique method of disposing of them. 

 The insect backs up the side of the pit with the obstacle poised 

 on the posterior portion of its abdomen and deposits it beyond 

 the edge of the pit. Although this behavior is described by 

 Bingley (19), most writers do not mention it. Perhaps it sounds 

 too much like a fairy tale; yet it is comparatively easy to induce 

 an ant-lion to behave in this manner. I frequently induced it 

 either by placing a small stone in the center of the ring of a pit 

 that was being constructed; or, by depositing a similar object in 

 the bottom of a completed pit. When the stone is placed in the 

 center of the ring, as the ant burrows spirally inward, there is 

 sure to come a time when the stone will fall into the furrow. 

 When the ant-lion returns to that point it encounters the obstacle. 

 Usually it burrows under the object and continues on part of 



