EXTINCT ANIMALS 



Coo 



Jl 



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XV 



vvi 



xva 



[Anus 

 PA 



Fig. 213. — Dorsal view of the eighteen segments and post-anal 

 spine or sting (PA) of a Scorpion's body to compare 

 with those of Eurypterus (Fig. 209) and of the King-Crab 

 (Fig. 211). In each of these the head-shield corresponds 

 to six segments, as indicated by the legs (see Fig. 206 for 

 the legs of the Scorpion). 



were long ago called. They have a very inter- 

 esting history, for they were known as fossils as 



286 



