Superfamily ArgiopoiJca 



"The colour of all of the species is gray, with sometimes a 

 little yellow or pink in the lighter parts. The cephalothorax has 

 usually, but not always, a dark border at the sides and a middle 

 dark line that widens and becomes lighter toward the eyes. The 

 abdomen has a wide middle stripe like Aranea, scalloped at the 

 sides and crossed at the hinder end by two or three pairs of trans- 

 verse spots. In front it is almost white or tinted with pink or 

 yellow, and narrows almost to a point, with a much darker spot 

 on each side, The sides of the abdomen are marked with oblique 



Fig. 471. PALPI OF MALES OF ZILLA 



a, '/.'Ma alrica b, Zilla x-notala 

 c, Zilla molilalia (after Emerton) 



Fig. 472. EPIGYXA OF ZILLA 

 a, Zilla alrica b, Zilla x-notala 

 c, Zilla montana (after Emerton) 



dark marks that extend underneath. The sternum has a light 

 middle stripe. Under the abdomen is a dark middle stripe, with 

 light each side of it." 



The three species resemble each other so closely that it is 

 almost impossible to distinguish them except by an examination 

 of the palpi of the males and the epigyna of the females. 



The spiders of this genus usually make an incomplete orb 

 of the form which 1 have designated as the zilla type of orb web 

 (Fig. 470); but sometimes they make a complete orb. 



Zilla atrica (Z. at'ri-ca). — See above for the more general 

 characteristics. The palpi of the males are as long as the whole 

 body, with the femur and tibia both slightly curved and the 

 tarsus and bulb small (Fig. 471, a). The epigynum of the 

 female is of the form shown in Fig. 472, a. 



459 



