COMPOSITE SNARES AND SECTORAL ORBS. 



135 



and, indeed, may be described as the method which Agalena also uses when 



spinning the retitelarian supports of her long sheeted snare. 



The peculiar snare of Labyrinthea and other spiders making a composite 



web appears to be a larger development of a habit which is seen to a greater 

 or less degree in the genus Argiope. In considering the particular 



A Devel- gpinningwork of this genus I have already called attention to the 



Habit ^'^"^^ ^^^'^^ both Cophinaria and Argyraspis suspend the upper foun- 

 dation lines of their orbs to a series of intersecting straight lines 



which are spun with more or less consistency to the overhanging and sur- 

 rounding foliage. This sys- </ 



tern of crossed lines is very 



frequently carried downward 



to one side of the orb and 



sometimes upon both sides, 



so that it forms what I have 



called the protective wings or 



fenders. If the reader will 



compare the more perfect and 



permanent spinning habit of 



Labyrinthea and Triaranea with 



that wliich is described and fig- 

 ured as the work of Argiope, he 



will see the close resemblance be- 

 tween the two. One may therefore 



say that what appears as a rudimentary 



habit, or a habit more or less developed in 



the case of Argiope has appeared as a per 



veloped and fixed liabit in the spinning behav 



rinthea. There is a marked peculiarity in the fa 



Labyrinthea chooses for her snare. This 

 dead and leafless bush, or a leafless part of 

 branch. The habit is quite persistent, and I 



every well established habitat of the species. It is true 



spin her snare among leaves, but her preference is for a 



obstructed. In such sites she is often seen in little 



nies. In one such colony at Radnor, Pemisylvania, I 



Favorite 

 Sites. 



fectly de- 

 ior of Laby- 

 vorite site that 

 is noticeably a 

 a tree or dead 

 have seen it in 

 that she will 

 locality not so 

 groups or colo- 

 counted thirty 



adult spiders, whose snares were spun upon a dry fig. 120. coop- brush heap 

 within a space six feet long, six wide, and five f»*>^'^ house- j^jfrii q\^ 



r &' ' keeping by two ^ 



this " clearing " every individual settler had no Labyrinth spi- doubt been 

 attracted by the same favorable conditions for an un ^"^^^ obstructed 



habitation. Perhaps the instinct which induces this choice is under the 

 same influence as that which urges many Theridioid species to seek similar 

 sites for their retitelarian snares, which exactly resemble the maze of Laby- 

 rinthea's web. Certainly, it is interesting and curious to find these two 



