HEAD-FOOTED MOLLUSCS {Cephalopods) 

 From the Bay of Naples. (After Mgrculiano and Jatta) 



One of the most characteristic organs in Molluscs generally is 

 a fleshy foot, formed as a muscular thickening on the under side of 

 the body. In Cephalopods the front part of this organ has grown 

 round the head, and is drawn out into sucker-studded tentacles 

 used for seizing prey, and also for creeping. The skin contains 

 numerous little rounded colour-bodies (chromatophores), the size 

 of which alters from time to time, causing different shades that 

 harmonize with the surroundings for the time being. By forcible 

 expulsion of water from the gill-cavity through a short tube (funnel) 

 these molluscs can dart backwards through the water with great 

 rapidity. 



1. The Paper Nautilus {Argonauta argo), female. The body 



is sheltered in a thin symmetrically spiral shell, and there 

 are eight tentacles. The male is small and shell-less. 



2. A Squid {Loligo Forbesii). Ten tentacles, two much longer 



than the rest. The. body is stiffened by an internal "pen", 

 shaped like a spear-head. 



3. Egg-capsules of (2). 



4. An Octopus or Poulpe (Octopus vulgaris). Eight tentacles. 



internal shell absent. 



