258 



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. 



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

 e, eye; m, mouth; f, 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 f 



