ACERATA. 



233 



lower surface of the basal abdominal segments are the 

 openings to four pairs of lungs. Scorpions are not found 

 in cold climates, but in the warmer regions they abound, 

 and their stings, which rarely prove fatal to man, render 

 them unpleasant companions. 



ORDER II. ARAXEIDA. 



The Araneida, or spiders, have the cephalothorax and 

 abdomen unsegmented, but sharply separated from each 

 other by a narrow waist. In front are the poison-jaws 

 (mandibles), each with a poison-gland inside. At the tip 

 of the lower surface of the abdomen are two or three pairs 

 of spinnerets. These are modified appendages with num- 

 bers of small openings at the tip. Connected with each 

 spinneret is a gland which secretes a fluid with the prop- 

 erty of hardening as soon as it comes in contact with the 



FIG. 61. Round-web spider (Epeira insularis). After Emerton. 



air. This is forced out at will through the spinnerets, and 

 forms the silk with which the spiders wind their prey, 

 wrap up their eggs, and build those marvellous webs, 

 interesting to all except the housekeeper. The poison- 



