PHYLUM MOLLUSCA 



297 



is present, and the foot assumes the appearance of a system 

 of appendages of the head. In the Cuttle-fishes (Fig. 170), 





FIG. 170. Sepia cultrata. Entire animal viewed from the dorsal aspect. 



Squids (Fig. 175), Octopi, and Argonauts (constituting the 

 sub-class Dibranchiata) the main part of the foot is composed 



