398 



MOLLUSCA : CEPHALOPODA. 

 FIG. 537. 



''Pen" or "Cuttle-bone" of Loligo pallida, Verrill. 

 FIG. 538. 



Lnlign pallida, Verrill. Reduced to one- third natural size. 



colored pigment-cells; and these animals have the power 

 of effecting such changes in these cells, that the hues of 

 the skin. differ from one moment to another. 



