ANNELIDANS. 335 



with medical men, on account of the facility 

 with which it can be applied to any part of the 

 body where bleeding is required, that they are 

 now become scarce in our own waters, and 

 consequently dear, so that large numbers are 

 imported from the Continent. 



Providence has gifted these animals with a 

 sucker on the underside at each extremity of 

 their body, by which their locomotions are per- 

 formed, and by means of the anterior one they 

 fix themselves to any animal that comes in 

 their way. We see therefore in them, though 

 on a larger scale, some approximation to the 

 locomotive and prehensile organs of some of the 

 Cephalopods, and prior to them, of the Stelle- 

 ridans and Echinidans, 1 which likewise move 

 and fix themselves by suckers. The mouth is 

 situated in the cavity of the oral sucker, it 

 is triangular and armed with three sharp teeth 

 disposed longitudinally in a triangle, two being- 

 lateral and one intermediate, and higher up. 

 These teeth are sharp enough to pierce not 

 only the human skin, but even the hide of an 

 ox, and have their edge armed with two rows of 

 very minute teeth ; at the bottom of the mouth 

 is the organ of suction which imbibes the blood 

 flowing from the wound made by the teeth. 

 These animals inhabit fresh waters, in which 



1 See above, p. 306, 201, 205. 



