THE HUNTING SPIDERS 205 



similar to the nests of birds and exhibit workmanship requiring 

 quite as much skill. 



One small group of wolf spiders has given up vagrancy in favor 

 of a sedentary existence on the top of a sheet like that spun by the 

 grass spiders. It is generally believed that these sedentary wolves 

 once placed only moderate reliance on silk, and that snare-spinning 

 habits were acquired later in their history. The typical lycosids 

 were probably running spiders at the time they learned to haul their 

 egg sacs about, and the fact that the sedentary wolves still use this 

 practice in their webs suggests that the sheet is a secondary devel- 

 opment. 



The sedentary variety differ only slightly from the typical wolf 

 spiders. The cephalothorax is flatter; the eyes are somewhat more 

 widely separated; the lower margin of the chelicera is usually 

 armed with four stout teeth, in comparison with the three or two 

 of most other lycosids. The legs are rather long, and the tarsi and 

 metatarsi are so thickly covered with hairs as to form quite wide 

 brushes, particularly on the front pairs. The posterior spinnerets 

 are considerably longer than the anterior ones; their apical segment 

 is prominent, and they are probably used to a considerable extent in 

 putting down the fine and closely spun webbing of the snare. 



The sedentary wolves appear to be most abundant in tropical re- 

 gions but some species extend into the southern portions of the tem- 

 perate zoneSosippus floridanus, for example, which spins its funnel 

 retreat under beach debris and lays its sheet over dry sand. This 

 spider is quite dark in coloration, the deep red to brown carapace 

 being marked with a median pale line and broader marginal stripes 

 of white or yellowish hairs. The abdomen is dark gray above, with 

 darker flecks on the sides, and with a broad median stripe, also low 

 in tone, running its full length. The females average about two 

 thirds of an inch. Common Sosippus calif ornicus of Arizona, south- 

 ern California, and adjacent Mexico is quite similar to the Florida 

 species, but much paler, being light brown or even yellow. It bears 

 a close resemblance to some of the large grass spiders, and when 

 moving over the sheet may easily be mistaken for those swift 

 runners. 



THE FISHER SPIDERS 



There is one group of spiders that is rarely observed far from 

 the moist edges of streams and lakes, and that includes some mem- 



