THE CRIBELLATE SPIDERS 141 



on its web, placed over the retreat as a rounded net, which soon 

 gathers to its sticky lines an unkempt covering of dust and debris. 

 The web, often more than a foot in diameter, is composed of a 

 series of regular, radiating lines of dry silk over which has been 

 spun many lines of cribellate bands. The touch of an insect vibrates 

 the web, and the disturbance is communicated to the hiding spider. 



The hackled band of Fihstata is composed of four different 

 kinds of silk. The cribellum is combed with a very short calamis- 

 trum, and many tiny loops are produced, which, bundled together, 

 give a most irregular shape to the characteristic threads. The spider 

 is said to lay down a dry line of two threads, to retrace its steps 

 upon this, and then to put down the irregular hackled lines, thus 

 accomplishing its purpose in three operations rather than in a single 

 one as does Amaurobius. 



The female of the common house Filistata is about half an inch 

 long, and is quite variable in color, being light brown, dark brown, 

 or often velvety black. Older specimens are usually much darker 

 than the young ones. The male is pale yellow, smaller, and his 

 slender body is fitted with much longer legs, which, during court- 

 ship, he uses to hold the front legs of the female as the couple 

 parades back and forth in a prenuptial dance. 



The members of this family are considered quite generalized 

 spiders because of the simplicity of their palpi. Nearly a dozen 

 species, some very much smaller than hibernalis, occur in the ex- 

 treme southern parts of the United States. 



THE TYPICAL HACKLED BAND WEAVERS 



In this group are included the great majority of cribellate spiders 

 and almost all of those that occur in the temperate regions. About 

 two hundred species are known from North America, but for the 

 most part these represent only a few different types. The preva- 

 lence of their meshed webs on the ground and on vegetation every- 

 where is an index of their abundance and comparative success. 

 With few exceptions, they are confirmed web spiders and stay in 

 their snares most of the time, walking upright over the bluish sheet. 

 Their sedentary bent has not molded them into such aerial types as 

 in the Uloboridae, but some do climb vertical meshes and are at 

 home in aerial tangles. Three claws are almost invariably present 

 on the tarsi, but they are never aided in their climbing by accessory 



