CHAPTER XXVI 

 Scorpions, Spiders, etc. 



Order SCORPIONIDEA : Scorpions. 



Scorpions are found in all warm parts of the world and are 

 dreaded for their sting, though as they are nocturnal and 

 retiring in habit they do not trouble man so much as is 

 commonly supposed. The sting is situated at the tip of the 

 " tail," and consists of a strong spine with a swollen base and 

 sharp tip ; in the base there is a pair of poison-glands, and 

 near the tip there are two small openings like the eye of a 

 needle, to give exit to the poison. To bring the sting into 

 action the " tail " is raised and bent forwards over the back 

 until it projects in front of the body. 



The body of a scorpion (Fig. 1 30) consists of two portions 

 — (i) a broader front portion, which is composed of the 

 cephalothorax and the 7 anterior segments of the abdomen, 

 and (2) a narrower " tail," or post-abdomen, which consists of 

 the 5 posterior abdominal segments and the terminal (post- 

 anal) spine aforesaid. The integument is strongly chitinised. 



The cephalothorax, which carries all the true appendages, 

 is covered dorsally by an unsegmented shield or carapace ; on 

 the carapace are the eyes — usually a pair in the middle, and 

 a row of two, three, or five lateral eyes in each anterior corner. 

 The ventral surface of the cephalothorax, between the coxae 

 of the last two pairs of legs is known as the sternum, the 

 shape of which is used in classification. 



The abdominal segments are all distinct On the ventral 

 surface of the ist is the genital flap, which covers the open- 

 ings of the reproductive organs. On the ventral surface of 

 the 2nd is a pair of comb-like appendages, the pectines. On 



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