EXTINCT ANIMALS 



(CO 



:j 



,^ 



XV 



XVI 



xva 



-xvin 



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 tliese 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 



