Superfamily Argiopoidea 



ally wide. The abdomen is light gray above, with three indis- 

 tinct darker longitudinal bands, and three pairs of black spots, 

 one pair near each end and a pair near the middle; besides these 

 there are some smaller marginal spots. 



The form of the epigynum is shown in Fig. 602. 



This widely distributed species has been commonly known 

 as Xysticus quadrilineatus, a name suggested by the four longi- 

 tudinal bands on the cephalothorax; it is unfortunate that this 

 name must be dropped for an older but less descriptive one. 



Xysticus vervosus (X. ner-vo'sus). — The female measures 

 from one fourth to one third inch in length; the male, about 

 one fourth inch. The two sexes are similarly coloured and marked. 

 The cephalothorax is yellow with a narrow black line on the 

 margin; it is veined and marbled with brown on the sides; on the 

 middle of the back there is a broad lighter band (Fig. 603). The 

 abdomen is also light yellowish, and is marbled with white, and 

 spotted with brown; there are three or four pairs of irregular, 

 transverse, brown bars, bordered in front with white, on the 

 hind half of the abdomen, and a pair of small spots near the base. 



The central cavity of the epigynum (Fig. 604) is divided 

 by a well-developed guide; and the openings of the spermathecae 

 are conspicuous and situated some distance behind the central 

 cavity of the epigynum. 



In the palpus of the male the terminal apophysis (Fig. 605) 

 is twisted at the end. 



This is a very common and widely distributed species. 



Xysticus triguttatus (X. tri-gut-ta'tus). — The two sexes of 

 this species differ greatly in appearance. The female (Fig. 606) 

 measures one fifth inch in length; the cephalothorax is brownish 

 yellow, the abdomen, almost white; near the hind end of the 

 carapace there are three black spots, which probably suggested 

 the specific name; from the intermediate of these spots there 

 extends on each side toward the eyes a white band which is 

 wide behind and narrow in front; the eye-space is also white; 

 each posterior median eye is on a black spot; and there are irregu- 

 lar dark markings on each side of the carapace; the abdomen is 

 almost white, with a pair of black spots near the base, and three 

 or four pairs of, more or less broken, transverse, black stripes 

 on the hind half. In the cavity of the epigynum there is a pair 

 of dark coloured plates which probably function as a guide. 



538 



