A Californian species was able to leave its nest when the trap-door was weighted with three ounces of lead. On re-entering, it seized the edge of the door with its mandibles, and, raising it slightly, inserted its front legs. It then turned round and slipped backwards into the tube. It always resisted the forcible opening of its door to the last moment, when it let go and slid into the tube “as though going down a well.” The larger Aviculariidae have acquired a reputation for feeding on birds, and this has given rise both to their scientific and their popular name—bird-eating spiders. Several travellers have stated that they have observed them with birds in their grasp, and there is no doubt of their ability to kill any small bird or mammal, though it is probable that they seldom have the opportunity, for they spin no snare in which birds may be caught. Even without the aid of their poison, their jaws are so large and powerful that they may easily attain the vital organs of small animals. Probably their staple food consists of the larger insects. They live in holes in the ground or in trees, or sometimes in the fork of a tree-branch. In such hiding places they spend the hours of day-light, emerging at night in search of food. Their large size and uncanny appearance have attracted the attention of the collector, and a great many species are known, but the fact that they chiefly inhabit tropical countries has militated against any very extended study of their habits, and the few items of information we possess are best related with regard to the particular spider observed, and not taken as necessarily characteristic of the whole tribe. There is little doubt that they live for several years. McCook kept a specimen of _Dugesiella hentzi_ in captivity for five and a half years, and he considered that when it reached him it was at least a year and a half old, and probably more. The same species has recently been made the subject of some very interesting observations by Petrunkewitch, who obtained numerous living specimens from Texas and kept them in captivity; unless carefully packed, they bore the railway journey badly, and it was above all things necessary to supply them with water. The captives were fed on grass-hoppers, crickets, cockroaches and wolf-spiders, but they ate sparingly, one grass-hopper sufficing for three days in the summer, while in the winter hardly any food at all was taken.