530 



PITFALL OF ANT-LION : WEB OF SPIDER. 



the Ant-lion digs this pit is extremely curious. After having 

 examined the spot where it purposes to establish itself, it 

 traces a circle of the dimensions of the mouth of its pit ; then, 

 placing itself within this line, and making use of one of its 

 legs as a spade, it digs out a quantity of sand, which it heaps 

 upon its head, and then, by a sudden jerk, throws this some 

 inches beyond its circle. In this manner it digs a trench, 

 which serves as the border of its intended excavation, moving 

 backwards along the circle, until it comes to the same point 

 again ; it then changes sides, and moves in the contrary 

 direction, and so continues until its work is completed. If, 

 in the course of its labours, it meets with a little stone, the 

 presence of which would injure the perfection of its snare, it 

 neglects it at first, but returns to it after finishing the rest of 

 its work, and uses all its efforts to get this upon its back, and 

 carry it out of the excavation ; but if it cannot succeed in 

 doing so, it abandons its work and commences anew else- 

 where. When the inclination of the walls of the pit has 

 been altered by any slip, as almost always happens when 

 an insect has fallen-in, the Ant-lion hastens to repair the 

 damage. 



698. Snares of a still more singular character are con- 

 structed by many Spiders, which spin webs of the finest silk, 

 for the purpose of entrapping their prey. The arrangement 



Fig. 269. ETEIRA DIATEMA. 



of these toils varies according to the species, and sometimes 

 does ijot present any regularity ; but in several instances it is 



