2i6 C Q N C H O L O G Y. 



that the animal, properly fpeaking, cai> 

 bore or perforate Shells, as it would im- 

 ply a motion of turning brlfkly backwards 

 and forwards, or on an axis or point, mo- 

 tions it cannot weU be capable of. Per- 

 haps therefore it may perform this adliou 

 of perforating other Shells by virtue of 

 fome jLiienriiuurn it emits through the? 

 tongue, whereby it foftens or corrodes 

 the other fiiell, and then digs put the 

 corroded fubPtance with the beak, and all 

 this without any verfatilc or other ftrong 

 motion *, 



Lifter 



f I fuipefl the doiirine contained In this article. 

 To make this hole it is not neceffary that the fifh fhould 

 have a rotatory motion ; that is, that, like a wheel, 

 the tongue fnould always move circularly the fame 

 \vay. It is fufficient that it turns bri(kly b^ickwards 

 and forwards. And, if the holes, which are moil 

 commonly found in fome fpecies of the Chama?, and 

 the Screw Shells particularly, are examined with a 

 giafs, they will be found to be fp finely circular, 

 that it is ir.:pof]il:)le to conceive any meiiftruum 

 fliouid ad upo^i u ja fo regular a manner. 



Further^ 



