HORIZONTAL SNAKES AND DOMED ORBS. 



153 



Orb 



Charac- 

 teristics 



arrangement of the unbeaded and notched spirals (n) is represented. If 

 one will imagine a Meb thus constituted throughout the entire orbicular 

 space, and hung in a pretty 

 site among meadow plants 

 or wild flowers, lie will have 

 a true conception of the del- 

 icate beauty of this work of 

 aranead art. 



In appearance the orb 

 resembles that of Acrosoma. 

 The oj^en hub, 

 the numerous spi- 

 rals, and the nu- 

 merous and deli- 

 cately spun radii and bead- 

 ed sjjirals are characteristic 

 of Hortorum, as they are 

 of Acrosoma. But I have 

 never seen in Hortorum any 

 of the ribboned decorations 

 whicli mark the spinning- 

 work of Acrosoma. The free 

 space also is decided in Hoi'- 

 torum, but small or lacking 

 in Acrosoma. When dis- 

 turbed the spider usually 

 runs along the dragline to 

 which she hangs underneath 

 the hub, to the remotest part of her foundation lines, with which the drag- 

 line is generally connected. She remains stationary at her point of refuge, 

 or hides beneath a leaf, or sometimes drops to the earth. 



I have never seen the snare of Hortorum in a vertical position, and 

 have rarely noticed it inclined in any degree from the horizontal ; but have 

 record of one web that inclined about forty-five degrees. In this orb the 

 foundation lines were attached to the leaves of a plant eighteen inches high, 



upon which the snare was hung. From these, 

 retitelarian lines were carried downward to an 

 adjoining tree, making a rude appearance of an 

 inverted pjTamid. This apron was not carried up 

 close to the orb, but separated from it about the 

 distance of five or six inches. This is the ordi- 

 nary position of the apron, and in this respect is 

 quite analogous to the corresponding situation of orb and laljyrinth in the 

 snare of Epeira labyrinthea. Indeed, it may be said as a general fact that 



Section of foundation lines and orb of the Orchard 

 spider. Natural size. 



Fit.. 144. Central section of Or- 

 chard spider's orb. f, free space ; 

 n, notched zone ; c, open hub. 



