and Systematic Arrangement of British Spiders. 335 



Clubiona saxatilis, Blackw. Lond. and Edinb. Phil. Mag. Third Series, 



vol. hi. p. 436. 

 Drassus saxatilis, Blackw. Research, in Zool. p. 332. 

 Aranea terrestris, Wider, Mus. Senck. B. i. p. 215. taf. 14. fig. 10. 

 Amaurobius terrestris, Koch, Die Arachn. B. vi. p. 45. tab. 192. 



fig. 463, 464. 



subterraneus, Koch,Uebers. des Arachn. Syst. erstes Heft, p. 15. 



tigrinus, Koch, Uebers. des Arachn. Syst. erstes Heft, p. 16. 



A description of this interesting spider, which I discovered in 

 the spring of 1826 beneath loose fragments of rock on Snowdon, 

 in Caernarvonshire, was originally given in the ( London and 

 Edinburgh Philosophical Magazine/ under the name of Clubiona 

 saxatilis. An examination of specimens procured afterwards in 

 various parts of North Wales, Lancashire and Yorkshire induced 

 me to remove it to the genus Drassus, on account of the curva- 

 ture of its maxillse (Researches in Zoology). Subsequent inves- 

 tigations however, made with great care, have served to convince 

 me that it appertains to the Agelenidte, as it possesses several 

 marked characteristics in common with the spiders of that family ; 

 for example, the anterior part of its cephalo-thorax is compressed ; 

 the superior spinners are Particulate, are longer than the rest, 

 and have the spinning-tubes disposed on the under side of the 

 terminal joint; each inferior tarsal claw is provided with two 

 pairs of fine teeth near the base ; and its web is of a compact 

 texture, having a tube in connexion with it extending, usually, 

 to the extremity of a cylindrical cavity in the earth, which is 

 frequently excavated by the animal itself. These facts do not 

 appear to have received that degree of consideration from M. 

 Walckenaer which their importance demands, as he still seems 

 disposed to retain Ccdotes saxatilis in the genus Clubiona (Hist. 

 Nat. des Insect. Apt. t. iv. pp. 441, 442). With regard to the 

 genus Amaurobius of M. Koch, I may remark, that, as it includes 

 spiders belonging to different families, which are easily distin- 

 guished by their organization, oeconomy and habits, it must, as 

 at present constituted, be rejected by systematic naturalists. 

 The great defect of the genera attempted to be established by 

 M. Koch is, that they are founded too exclusively on the dis- 

 position, form and relative size of the eyes ; consequently, it some- 

 times happens that they comprise species in other respects 

 decidedly incongruous. 



Ccdotes saxatilis pairs in April, and in May the female deposits 

 about 120 spherical eggs of a yellowish white colour, not agglu- 

 tinated together, in a lenticular cocoon composed of white silk 

 of a fine but compact texture, measuring half an inch in dia- 

 meter ; it is generally attached to the inferior surface of stones 

 by a small covering of web, on the outer side of which particles 

 of indurated soil are frequently distributed. 



