168 Mr. S. S. Saunders's Additional 



there appears at all times a dulness of perception about these 

 insects when abroad (however much kept from the light), which 

 ill comports with their wonted sagacity at home. Indeed, during 

 a long course of observation, I have never, under ordinary cir- 

 cumstances, seen one of these spiders quit its nest of its own 

 accord (which is evidently a rare occurrence), or even to have its 

 door open, whether by night or by day. 



I have not been able to observe sufBciently the process of con- 

 structing a nest ab initio, although I had desired to do so, and 

 for this purpose placed one of the spiders in a glass jar, with a 

 sufficient quantity of its natural earth, after the required precau- 

 tion of moistening, &c. By the next day no work had apparently 

 been done beyond a partial disarrangement of the surface in one 

 or two parts. Tlie jar was placed in a corner of the room and 

 completely shaded from the light, but no further progress was 

 made during the day or evening. The subsequent morning, 

 however, I found my spider partially imbedded in the earth, in 

 which state it remained quiet throughout the day, and the follow- 

 ing morning it had disappeared ; when after close inspection, 1 

 observed an indistinct circular mark in one part near the side of 

 the vessel, which proved to be the door of a new nest, as I as- 

 sured myself a few days after by extracting the same, it having 

 however only been carried down an inch or thereabouts into the 

 earth, and being therefore still in progress of construction. 

 Hence it appears, that it is not requisite to finish the tube in the 

 first instance, the primary object being that of defence from with- 

 out ; neither did I observe that any portion of the soil had been 

 thrown out in the process of excavation, the earth being probably 

 got rid of in the formation of the compressed mass, known as the 

 exterior walls of these habitations. 



After having thus provided a variety of occupation for these 

 little labourers, and obtained several nests with varying modifi- 

 cations, (and among these one which leads me to suppose that 

 the double valves of the West Indian nests, described by Brown 

 and Olivier, were probably the result of a new operculum being 

 substituted for a damaged one, the old valve still remaining 

 attached ; or otherwise originated in the separation of the outer- 

 most layer of one of these valves, warped by tropical heat), I 

 found that a new process had been adopted for the purpose of 

 more effectually precluding further disturbances, the opercula 

 being in two or three instances retained close shut by means of a 

 firm texture of web ; which having obliged me to tear away the 

 whole top of one tube in the course of opening, I determined to 



