LINED -EUKYLEPTA. 133 



her, for they have a cornea, a light-refracting body 

 surrounded with pigment, and a nerve-bulb. 



As the animal glides over the surface of the smooth 

 weed, or over the inequalities of the rough rock, we see 

 that its thin papery margin is frequently thrown up into 

 waves, or folds, more or less distinctly revealing the in- 

 ferior surface. The movement is very even and uniform, 

 but the mode by which it is effected has not been satis- 

 factorily explained. It has been asserted that certain 

 staff- like bristles which project from the skin are used 

 as oars, but this seems doubtful It is certain that the 

 whole body of the animal, as of the entire class to which 

 it belongs, is densely clothed with minute vibratory 

 cilia; and these, while they probably serve as organs 

 of locomotion in freely swimming, do also without doubt 

 make the whole skin a highly delicate and sensitive 

 organ of touch. 



It is asserted of the near allies of this species, and 

 probably is equally true in this case, that if an indivi- 

 dual be cut to pieces, every portion continues to live 

 and feel, from whatever part of the body it may be 

 taken ; and what is not a little remarkable, each piece, 

 even if it be the end of the tail, as soon as the first 

 moment of pain and irritation has passed, begins to 

 move in the same direction as that in which the entire 

 animal was advancing, as if the body were actuated 



