Superfamily Argiopoidea 



Pachygnatha brevis (P. brev'is).— This is our largest species, 

 the body measuring nearly one fourth inch in length, and it is 

 of bright colours. Figure 421 represents an immature male. The 

 net-work of lines on the abdomen is dark brown. In living 

 specimens the folium is brick-red, with central and marginal dark 

 lines; the central line separates two rows of light yellow spots. 

 On each side of the abdomen there is a light yellow stripe bordered 

 with dark. 



Genus GLENOGNATHA (Gle-nog'na-tha) 



This genus is closely allied to the preceding; but it differs 

 in the position of the posterior spiracle, which is situated nearly 

 midway between the epigastric furrow and the spinnerets. 



The following is the only described species from our fauna. 



Glenognatha emertoni (G. em-er-to'ni). — The male measures 

 a little ,more than one fourth inch in length. It was taken in 

 Arizona. Nothing has been published regarding the habits of 

 the species. 



Genus TETRAGNATHA (Te-trag'na-tha) 



The abdomen is long and slender and bears the spinnerets 

 at or near its end. The endites are parallel and dilated at the 

 distal end (Fig. 419); the lateral eyes on each side are usually 

 distant. The chelicerae are without a lateral condyle. 



These are orb-weaving spiders; they are common on plants 

 and other objects in the vicinity of water and some of them occur 

 on grass in drier places. They are striking in appearance on 

 account of their slender form, the great length of their legs, and 

 the large size of their chelicerae (Fig. 419). The chelicerae are 

 sometimes of enormous size, especially in males. 



The webs (Fig. 422) are either inclined or horizontal. They 

 are of moderate or large size. I have seen horizontal ones, built 

 over a race of running water, that were two feet in diameter. 

 These had an open hub, a notched zone of .four or five turns, a 

 broad free space, and from thirty to forty viscid spirals. 



In all webs that I have seen made by spiders of this genus the 

 hub was open; but in some there was no free space. 



When at rest on a branch the spiders assume a very char- 

 acteristic attitude; the body is closely applied to the branch, the 



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