EXTINCT ANIMALS 



the eyes and in the number of segments or rings 

 which build up the body and the head. 



A very interesting animal which is still alive 

 (but is also found in ancient rocks) connects the 



Fig. 207. — View from below of the anterior part of the great 

 Silurian Scorpion-like creature, Pterygotus osiliensis 

 (From Zittel's Palceontology, lent by Messrs. Mac- 

 millan. ) 



scorpions with the great extinct Eurypterids 

 and also with the Trilobites. This is the King- 

 crab (Figs. 210, 211, 212), which is not a true 

 crab — that is to say, a member of the class 



280 



