AliAKElDA. 



499 



posterior lung sacs (Mygalidce) or into a system of trachea? (Argyro- 

 neta, Dysdera). The anus is placed ventrally at the end of the 



abdomen, and is surrounded 

 by four or six wart-like pro- 

 tuberances (fig. 395, Spic\ 

 tne spinning or arachnidial 

 mammillae, from which the 

 secretion of the spinning 

 glands passes out. In front 



FIG. 394. a, Leg of the fourth pair 

 ferox. Ca, Calamistrum. I, End of foot of 

 cJiri/fops with two claws and pencil consisting of 

 spatulate hairs (S). c, End of foot of Epeira 

 dittdema ; -fiT, web-claws ; Tk, ambulatory claw ; 

 Gb, toothed bristles (accessory elaws) (after O. 

 Hermann). 



of these protuberances there often lies a 

 peculiar structure called the cribrellum, 

 with a covering of very fine hairs (fig. 

 395, Or). The spinning glands (fig. 396) 

 are tubes of various shapes ; they open by 

 fine pores on the surface of the spinning 

 papilke, and secrete a viscid material, which 

 in the air hardens to a fine thread and 

 is woven by the aid of the claws on the 

 "feet into the well-known spider's web. 



Nervous system (fig. 367). Besides the 

 brain, with the nerves to the eyes and che- 

 licera), there is a single, usually star-shaped 

 ganglionic mass in the thorax, from which 

 nerves pass to the pedipalpi and legs, and 

 also to the abdomen. Visceral nerves have 

 also been observed on the alimentary canal. 

 As a rule there are eight, or more rarely 

 are disposed in two curved lines or more 



FIG. b"95. Spinning organ of 

 Amaurollus ferox (after O. 

 Hermann). Cr, Cribrellum ; 

 Spw, spinning mammillae. 



TcC 



Fio. 396. Lungs (P), spinning 

 glands (Spd) and generative 

 organs (Vd) of a, male Pholciit 

 phalangista (regne animal). 

 .R, Rectum with Malpighian 

 vessels opening into it. 



six simple eyes, which 

 in a quadrate on the 



