Superfamily Argiopoidea 



brownish folium, and many round black dots. The species is 

 rare; it has been found in Florida and Alabama; and is the only 

 representative of the family reported from the United States. 

 Mr. Banks informs me that he has taken this species at 

 Washington, D. C. 



Very little is known regarding the habits of the spiders of 

 this family. They are said to build a horizontal web, which 

 resembles that of the grass spider, Agelena, except that it has no 

 tubular retreat; the spider stands in the centre of the web while 

 waiting for its prey. Nothing is known concerning the structure 

 of the hackled band or of the part it plays in the building of 

 the web. 



Family DICTYNIDS (Dic-tyn'i-dae) 



The Dictynids (Dic-tyn'ids) 



To this family belong the greater number of our species 

 that are furnished with a cribellum and a calamistrum, the 

 Dictynidae including several times as many species as all other 

 families of hackled-band weavers taken together. 



With the dictynids the median furrow of the cephalothorax 

 is longitudinal; the posterior metatarsi are not armed below with 

 a series of spines; the chelicerae are robust, and are furnished with 

 a lateral condyle; the anterior median eyes are dark in colour, 

 the others pearly white; and the lateral eyes of each side are con- 

 tiguous or near together; the tarsi of the legs bear three claws; 

 a cribellum and a calamistrum are present; and the fore and hind 

 spinnerets are of about the same length (Fig. 140, p. 135). 



The dictynids construct irregular webs consisting of a frame- 

 work of plain threads supporting an irregular net-work of the 

 hackled band. Sometimes the supporting threads radiate from 

 the opening of a retreat, with a certain degree of symmetry, 

 giving the web a somewhat regular appearance. 



The structure of the hackled band is most easily seen in the 

 webs of Amaurobius, on account of its coarser nature here than 

 in the webs of other genera. It is a comparatively easy matter 

 to determine the arrangement of the parts of this band with a 

 microscope; but it is difficult to secure a perfectly satisfactory 

 photomicrograph of it, owing to the impossibility of getting all 



274 



