BURROWING HABITS OF 8PII:i:>. 27 



habits of other Arthropods is responsible for this habit? Our American 

 Carpenter ants, Camponotus peimsylvanicus, when burrowing their balls 



and galleries within a tree, cast out the fresh chippage from the 

 aess l H ' lim g s through the bark. But these are invariably gathered up 



by a squad of workers at the foot of the trunk, and 



away to a distance, as though it were thus intended to conceal all traces 

 of the neighborhood of the formicary. At least, I can find no other satis- 

 factory motive for such behavior. May it not be that the Turret spider 

 is moved by a similar sentiment ? 



VII. 



Atypus digs obliquely a deep tunnel of fifteen to. twenty centimetres, 

 the size of its own body. It drapes the tunnel with a straight silken tube, 

 of close tissue, of which the upper part, longer than the subter- 

 ranean gallery, is laid horizontally upon the soil and terminates 

 in a point. Near its lower extremity the tube presents a considerable en- 

 largement, forming a quite spacious chamber in which the spider dwells. 

 At the entrance or throat of this enlargement the cocoon is suspended by 

 a number of threads. M. Simon says that he has many times taken Atypus 

 holding worms in its mandibles, and he believes that these worms form the 

 substance of their nourishment. In effect, if one examines the silken cham- 

 ber he remarks a place where the tissue is much thinner and transparent, 

 and Simon thinks it probable that Atypus removes the silk lining and thus 

 readily procures prey without the necessity of mounting to the surface of 

 the earth. However this may be, the actual observations heretofore made 

 upon the feeding habits of Atypus show that she subsists on insects which 

 she captures by seizing them through her tube as they rest or crawl upon 

 the outer surface thereof. She then drags her prey inside to feed thereon 

 and repairs the rent. 



Mr. Bates describes Territelarian spiders (Mygale Blond ii and M. avicu- 



laria) as inhabiting broad tubular galleries smoothly lined with silken webs. 



The galleries are two inches in diameter and run in a slanting 



direction two feet. 1 Again he speaks of them as spreading a 



thick web beneath a deep crevice in trees, and having their cells 



under stones. 2 Once more, in alluding to their diversified habits, he says 



that some species construct among the tiles or thatch of houses dens of 



closely woven web which resembles fine muslin in texture. From these 



domiciles they invade the house apartments. Others, according to Mr. Bates, 



build similar nests in trees. 3 I believe it will be found that the creatures 



that burrow in the earth are identical with those which spread sheeted 



webs among the trees. Numbers of tarantulas come to our port (Phila- 



delphia) in fruiting vessels, and are often found in the great pendant 



1 Bates' "The Naturalist on the Amazon," Vol. II., page 58. 



2 Ibid., Vol. I., page 61. 3 Ibid., Vol. I., page 106. 



