Page:Popular Science Monthly Volume 62.djvu/164

158 gapes and is not a true cylinder, that of the Hermachastes is neat, upright and regularly cylindrical. But the nests frequently occur side by side in the same ground and are almost identical in appearance. For instance, I recently found a nest of the Lycosa whose projecting tube was two inches high and so like that of the Hermachastes that I had to dig it up to ascertain for certain which spider was the builder.

Thus we have the interesting fact that a true trap-door spider here has abandoned its trap-door making and adopted the projecting tube habit characteristic of a Lycosa common to this part of the country; while, on the other hand, we have the equally interesting fact that two species of Lycosa have abandoned the habits of their tribe and family and have become regular trap-door makers.

The commoner and smaller of these two trap-door Lycosæ is a very alert, often ruddy, spider with banded legs. It makes a hole which is generally a true cylinder and deeper than the hole of L. subvittata, and at the opening it always has a door. The doors are thin lids, firm, cup-like in shape, and are attached to the rim of the hole by several almost invisible strands of web. So delicate are these strands (which serve as a hinge, being affixed at several points to the edge of the lid), that I almost invariably move the lid with the point of my knife to ascertain whether it is fixed; for it sometimes comes loose and lies at varying short distances from the mouth of the hole (remaining in use all the time apparently—though of this I am not quite sure). The spider closes the lid in the heat of the day, with the concave, web-lined side down, and opens it late in the afternoon and early in the morning, but so late and so early that it may be said to be open only during the night; though, before the weather became very hot and dry, it was common to see small lids open during the day. Sometimes the lid is attached, on the upper side, to a stone or stick or leaf, but generally it is just covered with earth and lies almost flush with the ground. It is practically undiscoverable when closed. It may be noted that the trap-door Lycosa is apparently (perhaps only when young) not wholly nocturnal, and that many have been found under stones, also that the adult male is as much a trap-door maker as the female, and that, when the spider comes from the hole, it opens the door and leaves it lying beside the opening with concave side up—all habits which are certainly not shared by the Ctenizidæ and are apparently peculiar to itself.

The Lycosidæ are an interesting family in other respects. The female, when about to lay her eggs, makes a neat cup with circular