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130 



triangular plates. The edge of each plate is cut very 

 regularly into six sharp teeth, which curve in one direc- 

 tion, and one other, curved so as to face these. The 

 combs stand side by side, parallel to each other, along the 

 whole length of the ribbon ; and there are muscular bands 

 or fibres seen affixed to the smaller end of every plate, 

 which doubtless give it independent motion. We have 

 counted one hundred and thirty-six plates on one ribbon ; 

 there are two ribbons on each thoracic segment, and there 

 are seven such segments ; hence we may compute the 

 total number of prehensile comb-like 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 four- 

 teen thousand teeth hooked into the minute cavities and 

 roughnesses of the interior surface of the cell, when the 

 animal chooses to descend. No wonder, with so many 

 muscles wielding so many grappling hooks, that the re- 

 treat is so rapidly effected ! 



The bundles of bristles which line the wart-like feet, 

 are very extensively found in this class of animals ; and 

 in some species they exhibit strange and singular forms, 

 resembling the fantastic but formidable weapons of some 

 semi-savage people. Thus in a flat scaly worm (Polynoe), 

 common enough under stones at the water's edge, the 

 armoury consists of several sorts of weapons. First, there 

 are long lances made like scythe-blades set on a staff, 

 with a hook at the tip to capture the fleeing foe, and 

 bring him within reach of the blade. Among them are 

 others of similar shape, but with the edge cut into deli- 

 cate slanting notches, which run along the sides of the 



