1888.] NATURAL SCIENCES OF PHILADELPHIA. 215- 



Among the spicier fauna this habit is particularly i:)roniinent. It 

 does not exist as with insects in a larval estate, but in the pei'fect 

 animal, the only one, Avith possibly one exception,' of which we have 

 knowledge, the tube-making instinct of insects being confined to the 

 larval period. This habit, which characterizes the larvre of insects 

 is carried forward to the perfect animal among the Aranere. The 

 habit of protecting themselves by tubular spinning work in one 

 form or another exists among some species of every section or tribe 

 of the spiders. 



Among the Orbw'eavers we have such examples as Epeira strix, 

 which spins a tough silken cylinder, open at one end. Within this 

 she makes her home, and holds a connection with her round snare 

 by means of a thread. This tube is spun within cavities of various 

 sorts, and often wdthin a curled leaf The habit is again illustrated 

 among the Orbweavers by the beautiful silken domes or tents with 

 or without a leafy covering, such as are formed by the Insular spi- 

 der, Epeira insularis or the Shamrock spider, Epeira trifolium. 



Among the RetitelarijB or Lineweavers we have such examples 

 as the pretty tubular tent of Theridium zelotyppmn which I have- 

 found swinging among pine leaves in the Adirondack forests contain- 

 ing the mother and young. The Saltigrades or Vaulting spiders- 

 spin thick silken tubes within which they shelter themselves during 

 summer and winter, and in which also they bestow their egg-sacs. 

 The Laterigrades I have found sheltered underneath a little tubular 

 tent, guarding their cocoons, although the tube making habit seems 

 to be least decided among these of all the aranead families. The 

 Tubeweavers, of course, as their name implies, have a strong ten- 

 dency in this direction. Indeed, some remarkable examples of 

 tubular nests may be found among them, as in the case of our 

 Medicinal spider {Tegenaria medidnalis), and the funnel-shaped 

 snare of the Speckled tubeweaver (Agalena ncevia), which is one of 

 the most common spiders of America. 



The nest of this Agalena is a tube, oftentimes of considerable 

 length, which broadens out from the top-opening into a sheeted 

 snare that is spread over surrounding surfaces, and is usually guyed 

 or supported by lines reaching upward. It may be seen extending- 

 within little cavities and openings, insect burrows, gopher holes and 

 the like, and in some cases I have thought that I have seen indica- 



1 Psocus. See my "Note on a Web-spinning Neuropterous Insect, Psocus 

 sexpunctatus." Proceed. Acad. Nat. Sci. of Philadelphia 1883, pp. 278-9. 



