The Preparation for Higher Life 



sea scorpions and yet a lower form than the true fishes that 

 were to follow. They were, doubtless, the immediate ances- 

 tors of the lampreys and ganoids, the most primitive of the 

 true fishes. Their fossil remains are among the rarest 

 known as only a few entire forms have been discovered, but 

 sufficient fragmentary remains have been found to give them 

 their important place in the tree of life. 



[191] 



