Molluscs have soft, moist bodies, which are often protected by a shell. They do not have legs. Most molluscs live in water, but slugs and snails live on land.

Molluscs

2.- WORMS AND MOLLUSCS

* Gastropods usually have a shell that they hide in when they sense danger. They move by sliding on a slimy, mocus substance thay they excrete. Ex. slugs and snails

* Bivalves have one shell divided into two moving parts, called valves, which they close when they sense danger. They usually stay in one place. They eat small organisms that are in the water. Ex. mussels and clams

* Cephalopods have no protective external covering, but some have a shell hidden under their skin. All cephalopods are marine animals. They have eight to ten tentacles that help them to swim and catch their prey. 

Ex. Squid, cuttlefish and octopuses