INTRODUCTION. XX111. 



the earth, or erovicos in bark, rocks, walls, and posts ; many 

 make silken, tubular or other nests, as well as cocoons of 

 various forms for the reception of their eggs. Some of the latter 

 are exceedingly pretty objects, those, for instance, of Agrocca 

 brunnea, p. 35, pi. ii., fig. la, &ndA.proxima, p, 36, pi. ii., fig. 7, as 

 well as those of Ero thoracica, p. 233, pi. ii., fig. 8a, and Theridion 

 fallens, p. 92, pi. ii., fig. 8. The egg cocoon of the Lycosides is either 

 globular, or flattened at the poles ; those of the Drassides, and of 

 some of the Thomisides are lenticular. The spiders which spin 

 tubular retroats are included in the group Tubitelarim, Latreille. 

 The Dysderides and Drassides bolong to this group, while those 

 which live in a cylindrical hole excavated in the earth, belong 

 to the Latreillean group Territelarice. In this last group are 

 included the various species of trap-door spiders, to which we 

 have no British representative, more nearly allied than the species 

 of Atypus (pp. 2-4, pi. ii., fig. 2). 



Spiders vary greatly in their relative fertility ; and the rarity 

 of some species is probably owing to their limited fecundity. 

 Some produce a large number of eggs, others fewer ; the cocoon 

 of Agroeca brunnea contains about 40 or 50, that of Ero thoracica 

 about a dozen, while that of Oonops pulcher is said to contain 

 usually no more than two eggs. It is probable, however, that 

 the same spider may construct more than one cocoon. 

 Gossamer Spiders. 

 The use of thoir silken lines for travelling through the air 

 must not be passed over without remark. There is, I suppose, 

 no one who has not obsorvod the numerous silken lines, and 

 small, whito, flocculent, flake-like webs floating in the air — 

 especially on a fine day in early autumn. Those aro almost all 

 formod by the young of numerous species of spiders. Whenever 

 and wherever they move spiders appear to leave a bine or linos 

 behind them ; these lines trail along and adhere to every inter- 

 vening object, or else float about, higher or lower, according 

 to the density of the atmosphere ; hence their common use as 

 a local, and generally trustworthy, prognostic of the weather. 

 The flake-like form of gossamer is produced by the aggregation 



