Spiders and Their Near Relatives 



Fig. 23. CARAPACE OF A 

 SCORPION 



drag it along behind. They feed upon spiders and large insects, 

 which they seize with the large chelae of their pedipalps, and 

 sting to death with their caudal poison-sting. 



Scorpions are shy animals; when disturbed they attempt to 

 run away and hide and do not sting unless molested. 



The sting of a scorpion rarely if ever proves fatal to man, 

 although the larger species, which occur in the Tropics, produce 

 serious wounds. It is said that the best 

 remedy for the sting of a scorpion is 

 ammonia applied externally, and also 

 administered in small doses internally. 



Scorpions attain maturity slowly, 

 Fabre (07) who studied them in con- 

 finement, came to the conclusion that it 

 required five years for them to reach 

 their full size. 



In the classification of scorpions the 

 following special terms are used: 



Upon the carapace, the dorsal covering of the cephalothorax, 

 ihere are often more or less distinct keels; these are distinguished 

 as the fore, middle, and hind, median and lateral 

 keels respectively; these keels are connected with 

 each other in various ways (Fig. 23). That part 

 of the fore median keel which is above a median 

 eye is termed the superciliary ridge. 



Upon the postabdomen, or cauda, there are 

 often two pairs of keels upon the dorsal aspect 

 and two pairs on the ventral aspect of some or 

 of all of the segments. The two pairs of keels 

 nearest the middle line of the body are designated 

 as the dorsal median keels and the ventral median 

 keels respectively. Outside of these are the dorsal 

 lateral keels and the ventral lateral keels. In 

 Fig. 24. the addition to these eight principal keels accessory 



CHELA OF A , , , 



scorpion " ee ' s ma >' be present. 

 ff, fixed finger ] he large basal portion of the chela of a 



mj. movable finger pedipalp fc termed fa /W (F j g ^ . and the 



apposed portions are distinguished as the fixed finger and the 

 movable finger respectively, the movable finger being the last 

 segment of the pedipalp. 



23 



