544 ARACHNIDA ORDERS ARANEIDA AND ACARINA. 



The Uloboridce&re an unimportant family in England; but Comstock quotes 

 from Dr. Wilder the following curious account of the use of the triangular 

 web of Hyptiotes cavatus (Hentz), a common species in the United States: "Its 

 web is most often found stretched between the twigs of a dead branch of pine 

 or spruce. At first sight this web appears like the fragment of an orb web, 

 but a little study will show that it is complete. ... It consists of four plain 

 lines corresponding to the radiating lines of an orb web, and a series of 

 double cross lines. . . . From the points where the radiating lines meet, a 

 strong line extends to one of the supporting twigs. Near this twig the spicier 

 rests, pulling the web tight so that there is some loose line between its legs. 

 When an insect becomes entangled in one of the cross lines, the spider sud- 

 denly lets go the loose line, so that the whole web springs forward, and the 

 insect is entangled in other threads. The spider then draws the web tight, 

 and snaps it again. This may be repeated several times before the spider 

 goes out upon the web after its prey." 



The Epevrid&f or garden-spiders, are large and handsome spiders, with a 

 rounded abdomen, and moderately long hairy legs, the first pair longest. 

 They have eight eyes irregularly arranged in two rows. 

 Garden-Spiders. They spin circular webs, and await their prey either near the 

 centre of their web, or in a place of concealment close by. 

 The commonest species, Epeira diadema (Clerck), is nearly an inch long, and 

 has a green abdomen marked with white or yellow spots in the form of a 

 cross. One North American species, Argiope riparia (Walckenaer), is re- 

 corded to make a large egg-sac, in which the young pass the winter ; only 

 those emerging from it in spring which have not been devoured by their 

 fellows in the interval. Other species have the same curious cannibal 

 habit. 



The Gastracanthidce are a very curious family of exotic spiders, with hard, 

 horny, angular bodies, and sometimes with a long curved spine projecting on 

 each side at the extremity of the abdomen. They are 

 often of very varied colours. Many writers include 

 them in the Epeiridce. The species figured is Gastra- 

 cantha fornicata (Fabr.). It is reddish (probably 

 yellow when alive), with the head, thorax, and some 

 round spots on the abdomen, blackish ; and it inhabits 

 Ceylon, Java, and Australia. 

 Fig. i9.-(Gastracantha To the Agelenida, a large family in which the eyes 

 fornicata.) Nat. size. are arranged in two curved transverse rows, belong our 

 common house-spiders, which are too well-known to 



need description, and which spin their cobwebs wherever they are left for a 

 day or two undisturbed. Another very interesting species is the water- 

 spider, Argyroneta aqtiatica (Linn.), which dives beneath fresh water, enclosed 

 in a shining bubble of air entangled in the hairs of its body, and constructs 

 a silken subaqueous dome, which it fills with air like a diving-bell, in which it 

 waits for prey, hibernates, and deposits its egg-cocoons. 



To the allied family Theridiidce, belong several large and handsomely- 

 coloured spiders found in Southern -Europe, New Zealand, and elsewhere, 

 which are much dreaded on account of their poisonous bite. 



