THE HUNTING SPIDERS 195 



that it could be dragged, a position that permitted normal hunting. 

 This habit is the badge of the wolf spiders. 



In the remaining vagrant line, the unpaired claw has been lost 

 and the tarsi are supplied with adhesive claw tufts that allow the 

 spiders to climb with great ease. In some of the wandering ctenids 

 Cupiennius and its relatives the fading median claw may still be 

 seen beneath the claw tufts; it serves to bridge the gap between the 

 three-clawed and two-clawed vagrants. The type reaches its acme 

 in the big-eyed jumping spiders, which are the most alert and in 

 many ways the most highly developed of all spiders. Another prin- 

 cipal branch has been the series of laterigrade families culminating 

 in the typical crab spiders. Finally, at the very base of the series 

 are the six-eyed hunting spiders, the remnant of an ancient group 

 that has retained many primitive features. 



THE WOLF SPIDERS 



The handsome wolf spiders of the family Lycosidae are expert 

 hunters that have few peers among their kin, and among all araneids 

 are excelled only by the jumping spiders. They occupy almost 

 every variety of terrestrial habitat, and seem to be at home in all 

 as dominant predators. Some are amphibious types that rarely stray 

 far from water, skating over or diving under the surface when they 

 are menaced. Others have become adapted for a secretive life in 

 areas of shifting, open sands, into which they dig tunnels and on 

 the surface of which they hunt during the night hours. Most nu- 

 merous in prairie regions, the wolf spiders abound wherever a 

 plentiful insect food supply is available among the grass roots, and 

 where the sunshine penetrates all but the densest clumps. 



Many wolf spiders have deserted their hereditary silk-lined cell 

 for a life in the sun. Others, more conservative, return periodically 

 to the retreat; some pass much of their life there, leaving it only to 

 hunt. Quite a few have improved the retreat by changing it into a 

 deep tunnel in the soil, in certain instances closed by a movable 

 trap door. Only one group of wolf spiders, Sosippus, has moved in 

 the other direction that is to say, toward a greater dependency on 

 silk; it spins a sheet web similar to that of the grass spider. 



Except for mere size, which varies widely between tiny quarter- 

 inch Piratas and giant Lycosas, an inch and a half or more long, 

 there is a surprising similarity in appearance among the wolf spiders. 



