2i 4 AMERICAN SPIDERS 



common lynx has penetrated farther north than our other species 

 and is found all over the United States, being especially abundant 

 in the West, where it lives on sagebrush and similar plants. 



The habits of these lesser lynxes are quite similar. All are plant 

 spiders, run on low bushes and herbs, and there place their discoidal 

 egg sacs suspended in a little web. 



THE WATER SPIDER 



It has been pointed out that the name "water spider" is reserved 

 for Argyroneta, one of the most amazing of all animals, a land crea- 

 ture that has taken to life in an alien medium. Argyroneta is not 

 truly aquatic, since she must still have air to sustain life, but she has 

 transferred her aerial environment to a situation beneath the surface 

 of the water, and there remains for prolonged periods. Although 

 found only in Europe and temperate Asia, Argyroneta is included 

 here because no general book on spiders would be complete with- 

 out some mention of her extraordinary behavior. 



In appearance Argyroneta is a very ordinary spider about half 

 an inch long, plainly clothed in dark brown raiment and unmarked 

 by a contrasting color pattern. Nothing in her physical aspect indi- 

 cates proficiency in swimming or diving; no appendages are present 

 that might serve as effective instruments to propel her or to main- 

 tain her beneath the surface. Severely plain when outside the water, 

 once Argyroneta dives she becomes a shiny, silvery bubble, trans- 

 formed from a drab gnome into "an elfin fresh from fairyland." 



Many spiders shun the water. Others, it has been seen, live near 

 it all their lives, and often move over the surface or crawl beneath 

 it to stay for short periods. Argyroneta is the only spider that can 

 live entirely in the water and that is able to swim and move about 

 without having contact with submerged objects. Most spiders are 

 able to survive immersion for limited periods because they take a 

 bubble of air with them, held closely to their bodies over the air 

 spiracles. Argyroneta supplies her primary need for oxygen by 

 mounting to the surface and raising her abdomen to capture an air 

 bubble. Just how long can she stay under without renewing this 

 supply? It has been calculated that if it were possible for her to 

 lie motionless in the water, theoretically the armor of air would last 

 about sixteen hours. However, Argyroneta is an active swimmer and 

 expends her oxygen supply more quickly, making it necessary to 

 come to the surface at frequent intervals. 



