200 J. H. Emerton — New l^igland Drassidm, 



this flat web, the spider walking along slowly, swinging the spin- 

 nerets from side to side, making a band of very fine threads at each 

 stroke. The web does not appear to be at all adhesive, it merely 

 offers insects a convenient place to rest upon and the spider depends 

 on his quickness of movement for their capture. Large webs usu- 

 ally have many supporting threads running up into fences and 

 bushes and these 'perhaps help to trip the wings of flying insects 

 and cause them to fall on the web, as similar threads do in the webs 

 of Linyphia. 



The pairing of this spider takes place on the web of the female. 

 The female lies still with feet drawn up as if dead. The male lays 

 her on one side under his thorax with her ventral side forward and 

 inserts one of his palpi into the epigynum at frequent intervals for a 

 long time, the soft parts of the palpal organ suddenly swelling and 

 again contracting. When tired with one palpus he turns the female 

 around and over so that she lies on the other side with her head in 

 the opposite direction and uses the other palpus. The eggs are laid 

 in a flat white cocoon, usually covered with a thick flat cone of silk 

 with which considerable dirt is often mixed. The eggs are laid 

 under stones or bark and on fences and buildings of all kinds, where 

 they are partly sheltered, from August to October, and the females 

 often remain and die on or near the cocoon. Adults are occasionally 

 found under leaves in winter, but it is doubtful if any live until the 

 next season. The eggs hatch early in the spring and the young spi- 

 ders come out in May. 



It appears to be the most common spider all over the United 

 States. 



Dysderidse. 



Spiders with only six eyes and with the openings of the tracheae in 

 the front of the abdomen, just behind those of the air sacs, so that 

 they appear to have four air sacs like the Mycjalidm. The family is 

 a small one and the genera differ greatly in the structure of the feet 

 and mouth parts. 



Dysdera interrita Hentz. 



Plate VIII, figures 2, 2a, Ih, 2c, Id. 

 Female 12™"^ long. Cephalothorax 5™"> long and S'""^' wide. The 

 front of the head is wide and curved forward in the middle. The 

 eyes are small and close together. PI. viii, fig. 2. The mandibles 

 are half as long as the cephalothorax and inclined forward and much 

 narrowed toward the end. The maxillae are small, pointed at the 



