WORMS 321 



ten distinct eye-spots. In the mouth are three semicircular saws, each with 

 eighty or ninety teeth, with which it makes its bite ; then, clinging with its 

 suctorial mouth, it fills itself with blood until it is gorged, after which hearty 

 meal it can fast and digest for a year. 



The Horse Leech (Hcemopsis sanguisuga) is the commonest British species, 

 about 4! inches long, feeding largely on worms. It has much blunter teeth, 

 and is to be found in many ponds and ditches. 



Platyhelminthes. 



Flatworms. A group which includes the Cestoid Worms, which live 

 inside other creatures. There are more than 500 species in the world, 

 among them the Tapeworm (Tcenia), the Bladder- worm, and the Flukes, of 

 which little need be said here. 



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