LESSONS IN ZOOLOGY. 273 



wood or elsewhere. These they line with a soft silk web, some- 

 times arranging a cover that opens and closes like a trap door, 

 as the trap-door spider of Southern Europe and the bird spider of 

 South America. 



The Saltigradse are springing spiders with eight eyes grouped 

 in a square; they do not construct webs. They have stout ante- 

 rior legs and a large arched cephalothorax. 



The Lycosidse, or wolf spiders, pursue their prey by running 

 rather than by leaping. They build holes in the ground, often 

 building little walls around the opening. 



The Laterigradse or crab-spiders have a rounded cephalotho- 

 rax and a flattened abdomen, and the two anterior pairs of legs 

 are longer than the others, so that they run sidewise or backward. 



The Tubitelse or tube spinners, have six or eight eyes in two 

 transverse rows. The two middle pairs of legs are the shortest. 

 They weave horizontal webs, with tubes in which they lie in wait 

 for their food. 



The Inaequitelae, or web spinners, have eight eyes of unequal size, 

 and long anterior legs. They construct irregular webs. 



The Orbitelse, or wheel-spinners. Among these spiders the head 

 and thorax are separated by a groove and the abdomen is globu- 

 lar. The anterior legs are longest and the third pair shortest. 

 They spin a geometrical web, often of faultless symmetry. 



Spiders are especially interesting as objects of study. Many 

 of them have fixed homes where they may be watched and studied 

 during the season. Nearly every group of spiders mentioned has 

 representatives in every part of the United States. If you wish 

 to study burrowing spiders, they are everywhere in the fields 

 along paths, about the yard, often between bricks in sidewalks. 

 A little stream of water will usually force them to the surface. 

 Study the spider; study his house, his family relations, his per- 

 sonal habits, his methods of catching food, etc. 



Almost everybody thinks of the web-spinner as the typical 

 spider, and doubtless more will be interested to study the web- 

 weaving spiders. They are abundant everywhere, and at first may 

 be found more easily than the burrowing spiders. But it makes 



L. S. 18 



