158 POPULAR SCIENCE MONTHLY. 



and 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 appear- 

 ance. For instance, I recently found a nest of the Lycosa whose pro- 

 jecting 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 Lycosa 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 some- 

 times 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 undis- 

 coverable 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 open- 

 ing with concave side up all habits which are certainly not shared 

 by the Ctenizidae and are apparently peculiar to itself.* 



The Lycosidse are an interesting family in other respects. The 

 female, when about to lay her eggs, makes a neat cup with circular 



* I have described the commoner trap-door Lycosa, because I have had 

 greater opportunities of observing it; but, as far as my observation goes, the 

 description applies equally to the larger and less common trap-door species. 



