164 



AMERICAN SPIDERS AND THEIR SPINNINGWORK. 



fauna, while Gasteracantha has never been found farther north than the 

 southern areas of our Gulf States. Both these genera, like Nephila, appear 

 to be more especially characteristic of the tropical spider fauna, among 

 which they also have a great variety of prolific and peculiar species. 



One's curiosity is sorely puzzled to know why our three northern repre- 

 sentatives of Acrosoma have been able to find and hold a place among 

 the fauna, not only of the temperate, but of the more northern areas, 

 while other species, and the genus Gasteracantha in all species, have ceased 

 their northward march at the line already indicated. Or has the progress 

 been in the reverse direction from the north towards the south? And 

 are our indigenous species of Acrosoma the survivors of a fauna 'that once 

 held sway throughout the region stretching from New England to the 

 Pacific? 



IV. 



Closely associated with spiders making a horizontal snare is the Bas- 

 ilica spider, the sole known representative of species that spin what I have 



called a Domed orb. The 

 history of this species, 

 which I have heretofore 

 recorded, is as follows: 1 

 In the month of June, 



1877, I was en- 

 Domed 

 Orbs, 

 Epeira 



basilica. 



FIG. 154. The dome shaped snare of the Basilica spider, 

 telanan snare; d, the dome. 



camped upon 

 the hills of the 

 Colorado River 

 of Texas, a few 

 miles southwest of Aus- 

 tin, studying the habits 

 of the agricultural and 

 cutting ants. 2 A limited 

 portion of my time was 

 given to observing spi- 

 ders, in the course of 

 which the object of this 

 sketch was discovered. 

 Her snare was hung about 

 two feet from the ground, 

 upon a bush which stood 

 in the midst of a grove 



the reti- 



of young live oaks. This 



1 Proceedings Academy of Natural Sciences of Philadelphia, 1878, pages 124-132. 



2 Observations upon the former species are recorded in a volume entitled " The Agricul- 

 tural Ant of Texas," J. B. Lippincott Company, Philadelphia. For some account of the 

 Cutting Ants see " Proceedings Acad. Nat. Sci. Phila.," 1871), page 33, and Chapters XIII. and 

 XIV. in my popular work entitled " The Tenants of an Old Farm." 



