REMARKABLY CONSTRUCTED MOUTH. 315 



out, in which condition it protrudes from the mouth 

 like a great proboscis ; and the teeth, which were 

 before concealed in the interior of the cavity, now 

 become external, and display as formidable an assort- 

 ment of rasps, files, knives, saws, hooks, or crooked 

 fangs, as any one could wish to see. Let us suppose 

 them, when in this condition, plunged into the body of 

 some poor helpless victim, while at the same moment 

 the proboscis is rapidly inverted and withdrawn ; the 

 prey thus seized is at the same instant swallowed, 

 and at once plunged into a gulf where all struggles 

 are unavailing, there to be bruised and crushed, and 

 sucked at leisure. 



It is, moreover, extremely probable, that creatures 

 furnished with such tremendous teeth are not formi- 

 dable to small animals only, but that, like the Lam- 

 prey, they can fasten themselves on living or dead 

 fishes, and bore or tear their way through the skin 

 and flesh, thus procuring a meal at the expense of the 

 lives of their victims. 



Many species of these worms appear to be entirely 

 destitute of any visual apparatus ; in others numerous 

 minute specks are distinctly visible, which are ar- 

 ranged with more or less regularity upon the upper 

 part of their head, and which, notwithstanding the 

 simplicity of their structure, seem, in a more or less 

 perfect manner, to perform the functions of eyes. 



Those who have watched the habits of the Nereids, 

 says Dr. Williams, will scarcely doubt that they are 

 gifted with the power of discriminating external ob- 

 jects, of making towards some point, and avoiding 

 others. In the absence, however, of such an optical 



