Spiders captured in Canada. 77 



21. Theridion sisyphum. 



Theridion sisijphum, Walck. Hist. Nat. des Insect. Apt. t. 2. 

 p. 298; Latr. Genera Crust, et Insect, t. 1. p. 97; Ilalin, Die 

 Arachn. B. 2. p. 47. tab. 58. fig. 132. 



Theridion lunatum, Simdevall, Vet. Acad. Handl. 1831. p. Ill ; 

 Koch, Die Arachn. B. 8. p. 74. tab. 273. fig, 645. 



Araneus imfv^j Lister, De Aran. p. 53. tit. xiv. fig. 14. 



Genus Pholcus, Walck. 

 22. Pholcus phalangioides. 



Pholcus phalanffioides,^ hick. Hist. Nat. des Insect. Apt.t. 1. 

 p. 652; Latr. Genera Crust, et Insect, t. 1. p. 99; Hahn, Die 

 Arachn. B. 2. p. 34. tab. 50. fig. 119; Blackw. Linn. Trans, 

 vol. xix. p. 125. 



The spider referred to by Mr. Jesse in his ' Scenes and Tales 

 of Countiy Life/ pp. 202 and 203, as remarkable for the rapidity of 

 its vibratory motions when disturbed, is, I have no doubt, Pholcus 

 phalangioides, which frequents ancient buildings in the south of 

 England, and, like Epeira diadema, Theridion quadripunctatum 

 and some other species, has the habit of violently agitating itself 

 when anything suddenly touches its lines. This vibratory mo- 

 tion, which in the case of Pholcus phalangioides appears to acquire 

 its maximum of velocity, is produced by the partial contraction 

 and extension of the joints of the legs in quick succession, as I 

 have ascertained by occasioning specimens of Epeira diadema to 

 continue the action till it became so slow, in consequence of the 

 fatigue experienced by the animals, that there was no difficulty 

 in determining the manner in which it is efiected. This singular 

 proceeding is evidently intended by the spider to communicate 

 motion to its snare and thus to cause the struggles of any insect 

 entangled in it, by which means it is directed with certainty to its 

 victim. 



I may here remark that the large spider alluded to in the same 

 publication, p. 339, as peculiar to Hampton Court, and there 

 named the " Cardinal," most probably is the Tegenaria domestica 

 of arachnologists. 



Family Epeirid^. 



Genus Epeira, Walck. 



23. Epeira affinis. 



Length of the female /g ths of an inch ; length of the cephalo- 

 thorax |^ ; breadth y^^ ; breadth of the abdomen ^ ; length of an 

 anterior leg -fij ; length of a leg of the third pair |f . 



Cephalo-thorax compressed before, moderately convex, with a 

 large indentation in the medial line of the posterior region ; it is 



