Phylum Mollusca - Gastropods, Bivalves, Cephalopods
Class Bivalvia - Clams, Mussels, Cockles, Scallops, etc.
Class Cephalopoda - Squids, Octopuses, Cuttlefishes
Order Teuthida - Squids
Order Octopoda - Octopuses
Class Gastropoda - Snails, Slugs, Limpets and Nudibranchs
Subclass Prosobranchia - Shelled Gastropods
Subclass Opisthobranchia - Sea Slugs and Nudibranchs
Class Polyplacophora - Chitons