288 
arachnides. 
joint of the chelicerse presents a series of spines, articulated and 
moveable at base — according to the observations of Dufour — and 
forming a sort of rake. 
The tarsi are less pilose underneath than in the preceding division, 
and their hooks are always exposed. The males of one species, the 
only ones I have seen, have more complicated organs of generation 
than those of the preceding division. The principal and scaly piece 
incloses a peculiar, semiglobular body, terminating in a bifid point, 
in an inferior cavity *. 
These species, in the dry and mountain districts of the south of 
Europe and of some other countries, excavate subterraneous galle- 
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 moveable 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 earth. 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 f. 
Without deciding upon this point, we presume, with him, that the 
Mygale carminnns of France — Nouv. Diet. d’Hist. Nat., art. Mygale 
— is merely the male of the following species : Walckenaer, however, 
doubts it. 
M. ccBmentaria, Lat. ; Araignee ma^onne, Sauvag., Hist, de 
I’ Acad, des Sc., 1758, p. 26; Araignee mineuse, Dorthes., Trans. 
Lin. Soc. II, 17, 8 ; Walck., Hist, des Aran., fasc. HI, x ; Faun. 
Fran9., Arach., H, 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 
deep; edges of the thorax paler. The chelicerse are blackish, 
each one furnished above, 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. 
* On this point I am contradicted by M. Dufour. I was compelled again to 
examine the fact, and have convinced myself that I was not mistaken. It is possible 
the specimens he examined did not present this character. 
f See his excellent memoir entitled “ Observations snr quelques Arachnides 
Quadripulmonaires.” 
