ELISHA MITCHELL SCIENTIFIC SOCIETY. 35 



moved a portion of the soil and placed in a portion of clay 

 intermixed with loam, scattering over this a few bits of moss. 

 I did not see the spider make the burrow, but next day saw 

 it make two-thirds of a door, when I put an end to opera- 

 tions on that nest. The door was made practically in the 

 same manner as that by P. carahivorus, but was a wafer door. 



From the appearance of the tube and the soil about it in 

 both of the nests made in captivity, I felt sure this spider did 

 not dig the hole in the normal ivaij. Accordingly, Mar, 8, 

 I prepared a jar of wet clay. Up to 1 1 p. m. the spider had 

 not begun work, but in the morning the work had not pro- 

 gressed too far for me to observe it. The spider begins the 

 burrow in a manner similar to that practiced by Nidivalvata 

 Marxli by pressing the earth aside from a central point with 

 its anterior legs, using also its mandibles, but it is much slower 

 in its movements than' N. marxii. Paehy/omerus turris is 

 the spider represented in fig. 15 and 16 of Plate III. 

 excavating in a "novel way." In making the trap 

 door, sometimes when in this position tt would cement the 

 particle to the door by pressing on top of the door with its 

 posterior legs, against the ventral surface of the cephalotho- 

 rax. When the hole was about 3cm, deep it would occa- 

 sionally 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. carahi- 

 vorus make a nest for Prof. Comstock. This was made en- 



trap-door spiders which inhabit climates less favored than that of Men" 

 tone." He also speaks of a Lycossa that is said to close her nest in Can 

 nes in winter. I.atreille, in Mem Soc. Hist. Nat. Paris, (an VII, de la 

 Repubique) p. 124, says "L'araignee tarentule ferrae aussi son habitation, 

 mais cet opercule n'est pas mobile, et n'est construit que pour I'hiver." I 

 have on stveral occasions found that P. cnrahivorus. after eating one or 

 two beetles, fastens down the lid with silk. Nklivalvafa Marxli, I have 

 found fastens the door at times (See Amer. Nat. \o\. XX, p. 592.) 



O. P. Cambridge, in Annals of Nat. Hist 1878, 5th series. Vol. I, p. 107, 

 says that in all cases that came under his notice the upper extremity of 

 the nest of ^f?/p?t.s' p/Vf'u.s was without any perceptible orifice. He finally 

 came to the conclusion that the spider gnawed its way out and then 

 closed it with fresll thread again. These examples seem to indicate that 

 spiders will very frequently at least fasten the doors to their nests during 

 a period of rest, when inactive and more liable to be injured, when hav- 

 ing had sufiicient food, and perhaps sometimes at regular periods when 

 not engaged in watching for food. It seems reasonable to suppose that 

 in climates where the spiders are in a torpid state they would fasten their 

 doors during this period. 



