PACKARD] INSECTS AS ARCHITECTS. 303 



six liiinclrecl individuals, eacli Ij'ing at the bottom of its hole. 

 Mr. Emerton has described, in the "American Naturalist" 

 (iv, p. 70')), the habits of our Mijnneleo immaculatiis (Fig. 

 233, with the larva seen from beneath, and the pupa). It 

 digs a pit in the sand an inch deep and two inches iu diam- 

 eter. Mr. Emerton thinks the ant lion begins its hole by 

 making a circle and afterwards throwing out the sand from 

 the centre. "In digging he used his flat head and jaws, 

 which were pushed under several grains of sand and then 

 jerked upwards, throwing their load sometimes as far as 

 six inches, and alwa3's far enough to avoid lea\iug a ridge 

 around the pitfall. When the pit was finished he was en- 

 tirely concealed beneath it, as in Fig. 233, except his jaws, 



Fig. 233. 



Ant Lioii and its pit. 



which were spread apart horizontally at the bottom. The 

 surface of the pit being as steep as the sand could be piled 

 up was very easily disturbed, and when an insect ventured 

 over the edge the ant-lion was apprised of it at once by the 

 falling sand. lie immediately began to throw up sand from 

 the bottom, deepening tlie pit, and so causing the sand to 

 slip down from the sides and the insect with it. The ant- 

 lion seized it with his long jaws and held it \^\^ above his 

 head, until he had sucked all he wanted from it, when he 

 threw the remainder out of the hole and repaired the trap. 

 . . . After eating he became more timid and sometimes 

 would not take a second insect. If, however, several were 



15 



