and Systematic Arrangement of British Spiders. 335 



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



vol. iii. p, 436. 

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

 Aranea terrestris, Wider, Mus. Senck. B. i. p. 21.5. taf. 14. fig. 10. 

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



fig. 463, 464. 



subterraneus, Koch, TJebers. des Arachn. Syst. erstesHeft, p. 15. 



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



A description of this interesting spider, which I discovered in 

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

 in Caeraanonshire, was originally given in the ' London and 

 Edinburgh Philosophical ^lagazine/ under the name of Cluhiona 

 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 Zoolog\"). Subsequent inves- 

 tigations however, made vrith great care, have sen'cd to conWnce 

 me that it appertains to the Agelenida, 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 triarticulate, are longer than the rest, 

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

 terminal joint; each inferior tarsal claw is pro\ided 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 cylindi-ical cavity in the earth, which is 

 frequently excavated by the animal itself. These facts do not 

 appear to have received that degi'ee of consideration from M. 

 Walckenaer which their importance demands, as he still seems 

 disposed to retain Ccelofes 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 estabUshed 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. 



Ccelotes 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. 



