172 AMERICAN SPIDERS 



America, and is also common in Europe. An elongate spider meas- 

 uring one sixth of an inch, the adult female has a dusky cephalo- 

 thorax with a paler marginal stripe, and a whitish abdomen heavily 

 marked with dark bands and stripes. Marginata's conspicuous webs 

 are often placed along paths or streams in shady, moist woods. The 

 outstanding delicacy and beauty of the snare are fully revealed 

 when the rays of the sun strike it. There is a maze of threads, ex- 

 tending in all directions and tied to adjacent vegetation, at the 

 center of which is a domelike sheet three to five inches in diameter. 

 The spider hangs below the apex of this dome. Flying insects strike 

 the highest lines of the superstructure, drop among the closer 

 threads, then upon the dome itself. There they are greeted by the 

 spider, which pulls them through the webbing, trussing them up 

 with additional silk lines while making the capture and afterward 

 repairing the rent in the sheet. Sometimes the web is shaken to 

 hasten the dropping of the prey. The lines of the maze and the 

 sheet are slightly viscous, but the drops do not gather into the 

 sticky globules used by the orb weavers and comb-footed spiders. 



The common bowl and doily spider, Frontinella communis, 

 found almost everywhere in temperate and tropical North Amer- 

 ica, is quite similar in appearance to the filmy dome spider. It spins 

 two separate sheets in its snare, the principal one shaped like a shal- 

 low bowl, under which the spider hangs, and the second one a 

 horizontal sheet placed below the spider. A stopping web, largely 

 filling the bowl and extending above it, is tied to twigs of low 

 bushes. Snares characterized by a secondary sheet are spun by 

 various other members of the group. Many smaller linyphiids tie a 

 flat platform web among low plants and move about over the lower 

 surface, but they drop to the ground and run away when disturbed. 



A few of the linyphiids spin no web and have become errant 

 types. Drapetisca alteranda is the best-known American type. This 

 spider is commonly observed sitting flat against tree trunks, where 

 it pursues its prey and around which it scurries when menaced. Its 

 mottled gray and white body closely resembles the bark of aspens, 

 birches, and beeches, on all of which the spider may be found; 

 against such a background it is difficult to distinguish. 



The second principal group of linyphiid spiders, the Erigonmae, 

 or dwarf spiders, consists of small spinners that live obscure lives 

 under debris. The pedipalps of the females usually lack tarsal claws, 

 while those of the males are armed with tibial apophyses. Most are 

 shorter-legged than their relatives, and live closer to the soil, run- 



