214 



THE COMMON SPIDERS 



Fig. 491. Fresh part of the web 

 of Amaurobius sylvestris. 



oval, widest behind, and usually as long as the cephalothorax 

 or longer. The legs are not more than a fourth longer than 

 the body, and slender for so large a spider. The cephalotho- 

 rax is dark brown, darkest in front, and the legs are a little 

 lighter brown, without markings. The abdomen is gray, with 



a double row of oblique yellow or 

 white markings on the hinder half 

 and two curved marks of the same 

 color on the front. These spots 

 sometimes run together, so that the 

 whole middle of the abdomen is 

 light colored. The males have the 

 head narrower and the thorax wider 

 and all the legs longer than the 

 female, and the cephalothorax and 

 mandibles are not so dark colored. The male palpi have the 

 patella as short as wide, and the tibia very short and wide, with 

 a short hook on the outer and a longer and more slender one 

 on the inner side, as shown in fig. 490. The epigynum has 

 a small middle lobe inclosed by two 

 lateral lobes that meet behind, and by 

 this the female can be distinguished 

 from the next species, — Amaurobius 

 ferox. The cribellum (fig. 469) is some- 

 times covered by a fold of the skin, so 

 that it is not readily seen. The cala- 

 mistrum (fig. 470) is a close row of 

 curved hairs on the upper side of the 

 fourth metatarsus, about half its length. In the male the 

 cribellum is rudimentary, and there is no calamistrum. 



This spider makes a large loose web under stones and sticks 

 (fig. 488). In the parts freshly made the loose bands of silk can 

 be seen running irregularly about on the other threads (fig. 491). 



Fig. 492. Tibial joint of male 

 Amaurobius ferox for com- 

 parison with that of Amau- 

 robius sylvestris (fig. 490). 



