Chap. 31 



MOLLUSKS SPECIALISTS IN SECURITY 



631 



CLASS AMPHINEURA 

 Chiton 



CLASS CEPHALOPODA 



Squid Cuttlefish 



Nautilus Octopus 



CLASS SCAPHOPODA 

 Tooth Shell 



Fig. 31.1. Mollusks. the shelled animals. They are predominantly marine, except 

 for the snails and mussels, many of which live in fresh water, or on land. In per- 

 sistence, distribution and numbers Mollusks are highly successful. The majority of 

 them are hindered as well as helped by the safety of their shells. Except in the 

 cephalopods the nervous and sensory structures are only moderately developed. 



