40 Mr. J. Blackwall on the Structure, Functions, (Economy, 



by Drassus ater chiefly in constructing its cocoon, the remarkably 

 compact texture of which is best explained on the supposition 

 that a copious supply of viscous matter in a state of fluidity is 

 employed in its fabrication ; and the other two, situated on the 

 inferior surface of the spinner, at a greater distance from its ex- 

 tremity than the rest, are minute and almost contiguous. The 

 large papillae vary in number with the age of the animal ; and it 

 is a fact deserving of notice that they are not always developed 

 simultaneously on both spinners, four, five, or six being some- 

 times observed on one, when three, four, or five only are to be 

 seen on the other ; but the two minute ones are present invariably. 

 In May the female deposits 40 or 50 white spherical eggs, not 

 agglutinated together, in a cocoon of a plano-convex figure, at- 

 tached to the under side of stones by its plane surface ; it is of a 

 fine but very compact texture, and measures f^hs of an inch in 

 diameter : when newly constructed it is white, but becomes red- 

 dish before it is abandoned by the young, which, at that early 

 period of their existence, have each inferior spinner provided with 

 two large and two small papillae. The female usually remains 

 upon or near the cocoon, to which she is strongly attached. 



52. Drassus sericeus. 



Drassus sericeus, Sund. Vet. Acad. Handl. 1831, p. 136; Walck. 



Hist. Nat. des Insect. Apt. t. i. p. 619; Koch, Die Arachn. 



B. vi. p. 37. tab. 190. fig. 457, 458 ; Blackw. Linn. Trans. 



vol. xix. p. 113. 

 Filistata sericea, Wider, Mus. Senck. B. i. p. 204. taf. 14. fig. 3. 



1 I have met with Drassus sericeus in several of the northern 

 counties of England and Wales. It frequents the interior of 

 houses, especially such as are old, and is decidedly nocturnal in its 

 habits. Having, like other species of the genus, a climbing appa- 

 ratus consisting of numerous hair-like papillse distributed over the 

 inferior surface of the tarsi, from which an adhesive secretion is 

 emitted, it can run with facility on the perpendicular surfaces of 

 dry smooth bodies. The papillae connected with the terminal 

 joint of each inferior spinner not only vary in number with the 

 age of the spider, the full complement being nine large and two 

 small ones, but a like number does not constantly occur on both 

 spinners of the same individual. 



53. Drassus sylvestris. 



Drassus sylvestris, Blackw. Lond. and Edinb. Phil. Mag. Third 



Series, vol. iii. p. 440 ; Research, in Zool. p. 342. 

 signifer, Koch, Die Arachn. B. vi. p. 31. tab. 188. fig. 452. 



M. Walckenacr has placed the Drassus signifer of M. Koch, 



