58 RADUL/E 



holes in the shells of other creatures for what 

 may be termed sarcophagous purposes. This 

 remarkable organ has a variety of names, and is 

 known as a radula, a spiny tongue, an odonto- 

 phore, a lingual ribbon, lingual band, &c. 

 In any case the word ' tongue ' is hardly so 

 appropriate as ' radula ' or ' odontophore.' In 

 the Gasteropods this apparatus, together with 

 the jaws, completes a marvellous mouth- 

 armature admirably adapted for the rasping 

 or trituration of their food before it reaches 

 the oesophagus and stomach. 



The bivalves are not provided with radulae. 



With regard to the structure of the radula, 

 in general terms it may be said to consist of a 

 cartilaginous strap which carries a long series 

 of transversely disposed teeth. By means of a 

 perfect arrangement of muscles and cushions 

 the strap works backwards and forwards as 

 though over a pulley, after the manner of a 

 chain-saw. When the food has passed beyond 

 the operation of the jaws it comes within the 

 province of the radula to tear or scratch, not to 

 bite it. The food passes over it and is carded 



