176 ARACHNIDES. 



ries, which are frequently two feet in depth, and so extremely tortu- 

 ous, that, according to Dufour, it is frequently impossible to trace 

 them. At the mouth, they construct a movable operculum with 

 earth and silk, fixed by a hinge, which, from its form, nicely adjusted 

 to the aperture, its inclination, its weight, and the superior position 

 of the hinge, spontaneously shuts, and completely closes the entrance 

 of their habitation, forming a kind of trap-door, which is scarcely 

 distinguishable from the surrounding eartlf. Its inner surface is 

 lined with a layer of silk, to which the animal clings, in order 

 to keep its door shut and prevent intruders from opening it. If it 

 be slightly raised, it is a sure indication that the owner is within. 

 Unearthed by laying open the gallery front of the entrance, it be- 

 comes stupified, and allows itself to be captured without resistance. 

 A silken tube, or the nest properly so called, lines the inside of the 

 gallery. M. Dufour thinks that the males never excavate. Inde- 

 pendently of his having found them under stones only, they do not 

 seem to him so well prepared with organs adapted to such work(l). 

 Without deciding upon this point, we presume, with him, that the 

 Mygale carminans of France — Nouv. Diet. d'Hist. Nat., art. My- 

 GALE — is merely the male of the following species: Walckenaer, 

 however, doubts it. 



31. caementaria, Lat.; Araign^e magonne, Sauvag., Hist, de 

 I'Acad. des Sc, 1758, p. 26: AraignSe mineuse^ Dorthfes., Trans, 

 Lin. Soc. II, 17, 8; Walck., Hist, des Aran., fasc. Ill, x; Faun. 

 Fran9., Arach., II, 4; Dufour, Ann. des Sc. Phys., V, Ixxiii, 5. 

 The female Mason Spider, as it is called, is about eight lines 

 in length, of a reddish colour, verging on a brown more or less 

 deepj edges of the thorax paler. The chelicerae are blackish, 

 each one furnished abo\e, near the articulation of the hook, 

 with five points, of which the internal is the shortest. The 

 abdomen is of a mouse-grey, with streaks of a darker hue. 

 The first joint of all the tarsi is furnished with small spines. 

 The hooks of the last have a spur at their base, and a double 

 range of acute teeth. The mammillae are but slightly prominent. 

 According to Dufour — Ann. des Sc. Phys,, V, Ixxiii, 4 — the 

 supposed male, of which I have made a species, 31. cardeicse, 

 differs from the preceding individual in the greater length of 

 its feet, in the hooks of the tarsi, which are twice the number 

 of the other, but have no spurs, and in the diminibhed length of 

 its mammillae. A more apparent character may be found in the 



(1) See his excellent memoir entitled, "Observations sur quelques Arachnides 

 Quadripulmonaires." 



