FIG. 7. SCORPION. 



A scorpion, one of the Arachnids, a fine illustration of the combina- 

 tion of armour and weapons. It is covered with a mail of hard chitin. 

 It has a sting at the end of its tail, in the sharp-pointed post-anal piece 

 called the telson (see figure of crayfish, fig. 72). 



In front of the mouth are two small chelicerte for holding an insect 

 close to the mouth to be sucked. The second pair of appendages are the 

 strong forceps or pedipalps, which seize insects and may hold them 

 towards the sting. It should be noted that spiders have the same two 

 mouth-parts, chelicerse and pedipalps. But the poison of spiders is in 

 the chelicerse, and the pedipalps do not form forceps. 



There are four pairs of walking legs furnished with claws. These legs 

 arise from under the fused head and thorax, which is covered by a cephalo- 

 thorax shield bearing eyes, two of which are clearly shown in the figure. 



The abdomen of spiders is unsegmented ; that of scorpions has twelve 

 segments, seven forming the broad prse-abdomen, in which region there 

 are four pairs of lung-books, and five forming the narrow post-abdomen. 

 There are numerous setse on the body and limbs. 



37 



