Superfamily Argiopoidea 



third than the first. The tibia of the first legs is thickened 



and armed with four pairs of spines below. The lower margin of 



the furrow of the chelicerae is armed with a wide tooth which is 



nearly of the fissidentate type (Fig. 764). 



The following is our only species: 



Onondaga lineata (O. lin-e-a'ta). — The ocular 



quadrangle is black; the remainder of the ceph- 



alothorax is light brown; the abdomen, in 



alcoholic specimens, is dark brown with light 



markings. In fresh specimens the abdomen is 



onondaga line- marked with four longitudinal lines of white 



ATA CHELICERA . . _. , , - , . . . 



of the female hairs. I he length of the body is about one 

 fifth inch. 

 This species is widely distributed in the Atlantic region and 

 as far west as Wisconsin. 



Fig. 764. 



Genus ZYGOBALLUS (Zyg-o-bal'lus) 



These spiders are 

 easily recognized by 

 the characteristic 

 form of the cephalo- 

 thorax. The ocular 

 quadrangle occupies 

 more than one half of 

 the length of the ceph- 

 alothorax, and the 

 thorax slopes very abruptly from 

 behind the posterior eyes. The 

 first pair of legs are much stouter 

 than the others; and the chelic- 

 erae of the males are greatly 

 enlarged. This genus belongs to 

 the fissidentate series; Fig. 765 

 represents the chelicerae of a 

 female; and Fig. 766 one of a 

 male. 



Four species are known to 

 occur in the United States; they 

 are all small, measuring from one 



Fig. 765. 

 CHELICERA OF ZYGOBALLUS BETTINII, FEMALE 



Fig. 766. 



CHELICERA OF ZYGOBALLUS 



BETTINII, MALE 



696 



