ceeding rapidity, and in tliis respect is in strong contrast with the mem- 

 bers of the genus Pachylomcrus, though the young ones of that genus 

 work more rapidly than the older ones When beginning the nest in a 

 patch of moss the spider will dive down into tiie moss and begin turn- 

 ing rapidly in all directions, at the same time spinning threads to fasten 

 together the pieces of moss around and over it, I have watched four 

 different ones make the nest, two beginning in moss which I had placed 

 over the earth, and two beginning in soil. Two of these I had make a 

 nest several times, and thus far everyone has first entirely closed the en 

 trance to the tube by building a sort of dome above it. Later, in one 

 case a week, cutting through this and making the folding door.^ Usual- 

 ly while at work near the surface of the earth it will burrow out in differ- 

 ent directions and elevate the surface of the earth. This I think is part- 

 ly for the purpose of providing a place to put the earth which it excavates 

 from the lower portion of the tube, as I have seen these filled up; and 

 in one specimen, after the tube was about 2 cm. deep I observed the 

 same habit of digging and cementing to the edge of the tube, as observed 

 in the case of Pachylovierus caribivorus and 4-spinosus. This individual 

 made the dome by carrying up three sides regularly until it had com- 

 pletely covered the entrance. Usually m making the dome earth is 

 placed on and about the edge of the tube, occasionally applying viscid 

 liquid and spinning threads over it. Then the spider would, with its an- 

 terior legs and palpi pull the edge over the tube. This operation would 

 b2 repeated until the dome was complete.^ When moss is convenient the 

 door is made almost entirely of moss and silk; each door is a surface of 

 a half circle, is hung by a semicircular hinge, and the twt) meet, when 



iNoTE. — In the Encyclopedia Brittannica, 9th ecliiion, 1875, Vol.11, p. 291. 

 O. P. Cambridge says: "The preseiit writer was once told by a gentlcn an ^^ h > had 

 formerly resided in the West Indies that trap- door spiders invariably made the tube 

 and lid of one continuous, solid, homogeneous piece, and then cut out the lil \\ith tin- 

 fakers. This account, especially as coming from a non Naturalist seems improbable, a 

 spiders falcers being in no way fitted apparently for huch an operation." Where the 

 silk lininingAvas thin, it would be a very easy matter for a spider to cut through, and 

 then repair the roughness by cementing on particles. It is probably an exaggeration to 

 say that they "invariably "construct them in that manner, but I should not be surprised 

 if some species made the trap, door in the manner described by this non "naturalist." 



2 I have never .seen this spider press the lid on the ends of its mandibles as does 

 P. carrbivonis. I think this shows the adaptation of the special armature of the man- 

 dbile of P. car'\bvoTVi.s, and related forms, for fastening the earth to the lid. P. car- 

 ih'worus usually makes no thread in applying the viscid liquid to the door while ad- 

 ding particles, but puts it on as a cement. The large point of the mandibles, which is 

 covered with short strong spines serves admirably to punch the earth irregularly into 

 the portion of the door already made, and causing it to adhere firmly. 



