284 C. H. TURNER. 



falls forward and loads the shovel-like head. There is no 

 functional anal opening; hence there is no danger of vigorous 

 thrusts of the abdomen clogging the intestine with dirt. 



FEEDING BEHAVIOR. 



The finished pit is an inverted hollow cone, at the apex of which 

 the wide-open mandibles of the larva, with their sharp teeth, 

 await to grasp any unfortunate that happens to fall therein. 

 What an efficient trap for small creeping invertebrates ! The steep 

 and unstable sides often cause the animals to fall to the bottom. 

 If the intruder does not at once slide to the bottom, its struggles 

 to escape tumble the soil upon the mandibles of the waiting ant- 

 lion. Immediately the ant-lion begins to toss the soil upwards. 

 The claim that the dirt is cast at the struggling creature is 

 erroneous. Digging its mandibles edgewise into the bottom of 

 the side of the pit, the ant-lion shovels out head-load after head- 

 load of soil. It is not thrown at something; it is simply tossed 

 upward and outward. Some of these random shots may take 

 effect; and the constant undermining of the walls of the pit 

 produces miniature landslides which, usually, drag the prey to the 

 bottom of the trap. 



Until something falls into the pit or alights on its treacherous 

 sides, these mandibles of the larva usually rest horizontally in 

 line with the body, which is hidden in the wall of the pit. Or- 

 dinarily the pits appear to be empty, for the mandibles are often 

 covered with fine dirt. Even when the whole head is uncovered, 

 its color harmonizes so perfectly with that of the soil as to render 

 it invisible. As soon as its jaws close upon a creature the ant- 

 lion backs deeper into the walls of the pit and, by interring its 

 victim, subdues it. Thus the ant-lion is enabled to conquer 

 creatures that are much larger and apparently stronger than it. 

 Unless its first few struggles free it, the captive is doomed; for 

 the ant-lion slowly but surely drags it deeper and deeper into 

 the soil, while it feasts on its body juices. To assist in holding 

 the prey while its body contents are being imbibed through the 

 hollow mandibles, each mandible is provided, on its inner 

 surface, with three stout teeth (Fig. 13.4). 



MacLachlan (n), in discussing the feeding of the European 



