THE DOG- WHELK'S DRILL. 1 5 



from the front of his head, which he carries high aloft 

 and waves to and fro ; and this organ, we see, fits into 

 the deep notch in front of the shell. This proboscis is 

 his drill ing- wimble. 



This organ is itself a study. Long as it is when ex- 

 tended, it can be thoroughly drawn within the body ; 

 and there it forms two fleshy cylinders, one within the 

 other, exactly like a stocking half turned on itself. 

 There are proper muscles attached to its walls, and to 

 the interior of the head, by extremities which are 

 branched in a fan-shape, so as greatly to strengthen 

 their insertions ; and these, by contraction, draw the 

 one portion within the other. Then there is a broad 

 hoop of muscle, which, passing round the inner cylin- 

 der, by contracting pushes it out, and lengthens it. 

 Within the interior of this latter there is a long narrow 

 ribbon of cartilage, which is armed with rows of sharp 

 flinty points, turned backwards ; and this tongue or 

 palate, as it is variously called, is the Dog-whelk's 

 weapon. 



We cannot induce the Whelk to attack his prey just 

 when we please ; but he has been detected in the ope- 

 ration, and I will describe it. With his broad muscular 

 foot he secures a good hold of the bivalve, and having 

 selected his point of attack, in general near the hinge 

 a selection which probably looks more at the superiority 



