X. marxii. Pachylomerus furris is the spider represented in fig 15 & 16 

 of the Ento. Am. for Aug. excavating in a "novel way". In making the 

 trap door, sometimes when.in this position it would cement the particle 

 to the door by pressing on top of the door with its posterior legs, against 

 the ventral surface of thecephalothorax. When the hole was about 3cm. 

 deep it would occasionally take earth out in the normal way. 



It will be seen that the habit of this spider is not wholly nocturnal in 

 building its nest. During the month of July while I was at Ithaca, 

 N. Y. I had a specimen of P. caribrvorus make a nest for Prof. Corn- 

 stock. This was made entirely during the day. By reference to the 

 young trap-door spiders 1 it will be seen that P. 4-spinosus works just 

 about as well in day as at night. 



Nest of Nidivalvata marxii. The first one of this species which I 

 found was taken Jan. 2, 1886, and which I have formerly mentioned as 

 making in captivity a "folding door. " 2 In tearing up some moss I ob- 

 served a tube in the bottom of which was the spider. Whatever there 

 was at the upper end of the tube was destroyed in removing the moss, so 

 that I have not had an opportunity to observe the door to the nest where 

 the spider makes its nest in a patch of moss. I have found several nests 

 ol this species by gathering moss. In all there were what appeared to 

 1 e branches just above the surface of the ground at the base of the moss. 

 1 iiese I regard as avenues in which the spider would search, or lie in 

 wait, for ants. 



In captivity this spider made a very interesting nest with folding 

 doors (See figs. 17 and 18 Plate V) and I believe it is with some such ar- 

 rangement that it closes its tube in a state of nature, for the spider makes 

 use of it in catching its prey, as will be described in the food-habits <.f 

 this species. This kind of a door, I believe, has never before been seen 

 or described, and adds one to the different types of nests which Mr. 

 Moggridge has described and named. 3 The right name for this type 

 should be -'double door", but as Mr. Moggridge has used that name for 

 a nest which has two doors, one at the upper end of the tube and another 

 some distance below at the opening of a branch in the main tube, it can- 

 not be applied to this one. So I have called this new type the folding 

 </oor yiest, from the manner in which the door opens and shuts. 



This species begins the excavation of its tube by parting the earth 

 from a central point with its anterior legs and palpi turning around at 

 the same time so as to push the earth on all sides. It works with ex- 



1 Entomologica Americana, August 1886. 



1 American Naturalist, Vol. XX, p. 592. 



a Harvesting Ants and Trap door Spiders; and Supplement. 



