254 



MANUAL OF ZOOLOGY 



SECT. 



small cephalothoracic shield or carapace, covering over a short 

 anterior region or cephalothorax dorsally. This is followed 

 by a long posterior region or abdomen, the terminal part of 

 which in the living animal is habitually carried over the 

 back, constituting the "tail," at the end of which 



the sting is placed. The 

 carapace bears a pair of large 

 eyes about its middle, and 

 several pairs of smaller eyes 

 on the antero-lateral margin. 

 The anterior, broader part of 

 the abdomen, which is termed 

 the pra-abdomen, consists of 

 seven segments, each of which 

 is enclosed in firm, chitinous, 

 dorsal and ventral plates, or 

 terga and sterna. The tergum 

 and sternum of each segment 

 are separated from one an- 

 other laterally by intervals of 

 soft skin, except in the seventh, 

 where they are united later- 

 ally for a longer or shorter 

 distance. The posterior, nar- 

 rower part of the abdomen, 

 known as the post-abdomen, 

 consists of five segments, each 



enclosed in a complete investing ring of hard chitinous 

 matter. Articulating with the last segment of the post- 

 abdomen is a terminal appendage, the caudal spine or 

 sting, swollen at the base and acutely pointed at the apex, 

 where the ducts of two poison-glands open. The anal 

 opening is situated on the ventral surface of the last 



FIG. 140. Scorpion (Euscorpio). 

 (From Cuvier's Animal Kingdom.) 



