Mollusca

• They are bilaterally symmetrical, with a reduced coelomic cavity and little segmentation.
• The size of a body varies from a microscopic to a giant form such as Octopus of up to 50 feet.
•  The coelomic cavity is reduced.
• They have an open circulatory system and kidney-like organs for excretion.
• The muscular foot helps in locomotion.
• Digestive tract has a simple structure.
• They are mostly found in marine and freshwater. Very few are terrestrial and found in moist soil.
• In some animals, sensory organs of touch, smell, taste, equilibrium and vision.

For Example: Snails, Mussels, Octopus