mollusk

Kingdom Animalia
Subphylum Invertebrata
Phylum Mollusca

Containing the classes:

• Monoplacophora (deep-sea limpet-like creatures)
• Polyplacophora (chitons, rocky marine shorelines)
• Aplacophora (solenogasters, deep-sea wormlike creatures)
• Scaphopoda (tusk shells, marine)
• Gastropoda (snails, slugs, limpets, sea hares, sea butterfly)
• Bivalvia (AKA Pelecypoda; clams, oysters, scallops, mussels
• Cephalopoda (squids, octopuses, nautilus, cuttlefish; marine)
• Caudofoveata (deep-sea wormlike creatures)

They have soft bodies, consisting of a head, a visceral mass, and a foot (sometimes multiple feet -- but none of these feet have bones). Usually there's some type of shell to cover all of this (but octopi and squid are mollusks too {class Cephalopoda}). Most also have a radula ('psuedo-tongue') to help do work that the foot can't handle on its own. Most live in the water, although snails and slugs are also mollusks.

Mol"lusk (?), n. [F. mollusque, L. mollusca a kind of soft nut with a thin shell, fr. molluscus soft, mollis soft. See Mollify.] Zool.

One of the Mollusca.

© Webster 1913.