Snails, slugs, clams, squids, and octopi are all Mollusks. Many mollusks have a unique rasping tongue, called a radula, which is used for feeding. They move around with their foot.
Different classes get their names from how the foot is modified.
Clam Gills Clam Gonad Cephlapods-Octopi, cuttlefish, nautilus Nautilus Annelids include sandworms, earthworms, and leeches. They are segmented, with a repetition of organs. They have a coelom, so their gut and organs are suspended within a fluid sack.