EPEIRIDAE 407 



which spiii circular or wheel-like snares, the highest form of 

 spider industry, together with a few forms so closely allied in 

 structure to orb- weaving species as to be systematically insepar- 

 able from them. It is practically co-extensive with the Argio- 

 pinae, Tetragnathinae, and Nephilinae of Simon's Argiopidae in 

 the Histoire naturelle des araignfas. 1 



No one is unfamiliar with the orbicular snares, the structure 

 of which has already been described with some minuteness (see 

 p. 344), and some of the spiders which construct them are 

 among the best known members of the order. 



It is impossible here to deal with the multitudinous forms 

 embraced by this family. We must mention those genera richest 

 in species, and some others of special interest. It will be con- 

 venient to indicate eight sub-families or groups, which include 

 most of the forms likely to be met with. These are the THE- 



1UDIOSOMATINAE, TETRAGNATHINAE, ARGIOPINAE, XEPHILINAE, 



EPEIRINAE, GASTERACANTHINAE, POLTYINAE, and ARCYINAE. 



(i.) The THERIDIOSOMATINAE are a small group which might 

 with equal propriety be classed with the Theridiidae or the 

 Epeiridae. Theridiosoma argenteolum is a rare spider in Dorset- 

 shire. It is a minute spider, one-twelfth of an inch in length, 

 with silvery white globular abdomen variegated with reddish 

 brown, and yellow cephalothorax with darker caput. Some 

 allied spiders spin a roughly circular snare. 



(ii.) The TETRAGNATHINAE consist chiefly of two genera, Pachy- 

 gnatlia and Tetragnatha. The first consists of spiders which are 

 not orb-weavers, but live in herbage, especially in swampy places. 

 Two .species, Pachygnatha clerckii and P. degeerii, are common in 

 England, and a third, P. listeri, is sometimes met with. They 

 are rather striking, prettily marked spiders, with strongly 

 developed chelicerae. 



The species of Tetragnatha are true orb-weavers, and may easily 

 be recognised by their cylindrical bodies, elongated chelicerae, and 

 long legs, stretched fore and aft along the rays of their webs. Five 

 species have been recorded from England, and the genus contains 

 at least a hundred species in all ; almost every country in the 

 world, regardless of its latitude, supplying examples. 



1 I.e. as developed in the course of the work, not as set forth on p. 594 of vol. 

 i., where five sub-families are established (Theridiosomatinae, Arciinae, Eurycor- 

 rainae, Araazulinae, Poltyinae), which are afterwards merged in the Argiopinae. 



