FOR EETEEATING. 183 



plates to be about one thousand nine hundred, each 

 of which is wielded by muscles at the will of the 

 animal ; while, as each plate carries seven teeth, there 

 are between thirteen and fourteen thousand teeth 

 hooked into the lining membrane of the cell, when the 

 animal chooses to descend. No wonder, with so many 

 muscles wielding so many grappling hooks, that the 

 retreat is so rapidly effected ! 



A group of 8erpul(B of the species which I have 

 been describing, is represented in Plate V. 



