It is the second-largest phylum of the kingdom Animalia.
These are aquatic and terrestrial animals.
The excretory organ of Mollusca is metanephridia. Excretion is a biological process through which harmful nitrogenous waste substances are removed from the body.
Metanephridia filters waste from internal body fluid.
Examples of Mollusca: Clams, Mussels, Octopus, Pila ( Snail), and Oyster.