2 5 8 



FIG. 122. The Devil-fish (Octopus). From Cooke, after Merculiano. A, at rest; 

 B, swimming, a, arms, with suckers on the inner aspect; e, eye; s, siphon or 

 funnel. 



Questions on the figure. Which is the anterior end of the animal? 

 What is the position of the mouth? What is the function of the siphon? 

 Of what structure is it a part? 



FIG. 123. 



Fie. 123. The Paper Nautilus (Argonauta argo~). From Cooke, after Lacaze-Duthiers. 

 e, eye; m, mouth; /, siphon; sh, shell; t, tentacles. 



Questions on the figure. In what way does the siphon serve in loco- 

 motion? In which direction will the animal move by means of the 

 siphon? How does the shell of Argonauta differ from that of Nautilus? 



