NEUROPTERA. 



159 



When the pit is finished, it lies entirely concealed except the jaws, which are spread 

 apart horizontally at the bottom. The sloping surface of the pit being as steep as the 

 sand can be piled up, is very easily disturbed, and when an insect ventures over the 



Figs. 231 and 232. — Myrnmleon immaculatua, and M. obsotetus, adult of ant-lions. 



Fig. 233. — Section of pit of ant-lion. 



edge the ant-lion is apprized of it by the falling sand. It immediately begins to throw 

 up sand from the bottom, deepening the pit, and so causing the sand to slip down from 

 the sides, and the insect with it. , The ant-lion then seizes it with its long jaws, and 

 holds it above its head until the blood is all sucked out, when the bloodless carcass of 

 its victim is cast out of its hole. It then repairs the break in the wall of its pit." 



Regarding its habits in confinement, Mr. Emer- 

 ton gives us the following account : — 



" After eating he became more timid, and some- 

 times would not take a second insect. If, however, 

 several were put into the pit at once, he would bite 

 one after the other until all were killed, before de- 

 ciding on which to begin. I fed him two or three 

 times a week, usually with house-flies, cutting their 

 wings off and letting him take them in his own 

 way. In October, having occasion to travel some 



distance, I put him in an ounce bottle half filled with sand, corked him up, and carried 

 hira with me in my bag. In about a weeik I gave him a large house-fly, which he did not 

 catch, not having room enough to make a pitfall. I gave him no more food till the next 

 March. . . . About the first of March, when flies began to be plenty, I commenced to feed 

 him again. He found it rather awkward to catch insects in the bottle, as there was 

 not room enough to make a pitfall, and his inability to move forward made it hard for 

 him to seize an insect, unless he met it directly between his jaws. He soon, however, 

 made pitfalls half an inch in diameter, which answered the purpose. Sometimes he 

 lay on the surface of the sand, with a few grains scattered over his back to conceal 

 him from notice, and his jaws extended on the surface. If a fly was put into the bot- 

 tle it would circle around it, close to the glass, and usually run over the ant-lion's back. 

 He would jerk up his head, and attempt to seize it, which he seldom succeeded in 

 doing the first time. If he caught a leg or wing he was unable to move nearer, and 

 shorten his hold, and the fly escaped. He would often throw up the sand and try to 

 undermine the fly. He would sometimes work an hour in these ways before the fly 

 would get into a favorable position. I fed him every day or two until May 15th, when 

 he spun a spherical cocoon around him, and remained enclosed until June 25th, a very 

 hot day, when he came partly out, and leaving his pupa skin half in the cocoon 

 appeared as a perfect fly, but did not spread his wings completely." 



