produce but little silk, only enough to give them a foothold on a vertical plane, to bar the opening of their holes, and to bind their prey. Their simple claws are not adapted to the purposes of tools. They are hunters, and live in the hollows of trees, which they do not leave, except to go on the chase. Their eyes are not distributed over the body, like those of other spiders, but are grouped upon an eminence in the middle of the cephalic region, two in front, two on each side, and two looking hindward, in such positions as to command simultaneous views in every direction. The larger, dark-colored species go abroad usually in the dusk and at night, and capture with equal boldness large insects, small lizards, and humming-birds (Fig. 12).
The abbé Sauvage, of Madrid, in 1768, astonished the French Academy of Sciences with the declaration that he had found a spider "that did not stretch any kind of web, but hollowed a burrow in the ground like a rabbit, and added a movable door to it." The species had been observed on the road-sides, around Montpellier, and on the banks of the little river Lez. A little while previously, a traveler, Patrick Browne, had found a nest of similar construction to this, but less perfect, in Jamaica. Since the last century these animals have been called in France, mason-spiders; in England, trap-door spiders. Judged by the organism as a whole, they appear to be related to the mygales, but they present several differences in detail. Like the larger mygales, the trap-door spiders have stout bodies, large legs, eyes grouped on an eminence, and a dorsal buckler; but in the lower parts of their forceps-antennae they have a row of points, a kind of rake, with spines on their paws, and teeth in their claws, which give a resemblance to microscopic combs. These are tools, working instruments, of which the mygales, compelled to find a home where they can, are destitute; naturalists call these spiders ctenizas.
The domiciles or burrows of the trap-door spiders are so well disguised that only an experienced observer can distinguish their presence on the surface of the ground. But, while without everything is as far as possible from suggesting a comfortable habitation, within the hole reign neatness, elegance, and graceful adjustments. These structures abound in the south of France and in nearly all of southern Europe. In compact earth, free from stones and gravel, they are built quite close to one another. Each one of them consists of a vertical hole or pit (Fig. 13), of a size proportioned to that of the architect, the cylindrical tube flaring toward the mouth. The walls are tapestried with the softest of satin, prepared from the silk which the animal spins. The entrance is most skillfully closed by a solid door, which can not easily be broken or pushed in. It is made of the material thrown out during the digging of the pit, the earthy particles being held together by the
