Your pet snail, Sammy, is one example of a mollusk, or a soft, spineless animal. In Sammy's case, he has a shell, though some mollusks don't.

It's a bit ironic that this term for a large phylum of invertebrates comes from a Latin word that means "soft," mollis, since many mollusks (or molluscs in Britspeak) have hard shells. The epithet comes from the nature of the creatures' bodies, whether in shell (like a snail) or without (like a slug).

Definitions of mollusk

n invertebrate having a soft unsegmented body usually enclosed in a shell

mollusc, shellfish
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burrowing marine mollusk
gastropod, univalve
a class of mollusks typically having a one-piece coiled shell and flattened muscular foot with a head bearing stalked eyes
chiton, coat-of-mail shell, polyplacophore, sea cradle
primitive elongated bilaterally symmetrical marine mollusk having a mantle covered with eight calcareous plates
bivalve, lamellibranch, pelecypod
marine or freshwater mollusks having a soft body with platelike gills enclosed within two shells hinged together
cephalopod, cephalopod mollusk
marine mollusk characterized by well-developed head and eyes and sucker-bearing tentacles
tooth shell, tusk shell
any of various seashore mollusks having a tapering tubular shell open at each end and a foot pointed like a spade for burrowing
abalone, ear-shell
any of various large edible marine gastropods of the genus Haliotis having an ear-shaped shell with pearly interior
any of various edible tropical marine gastropods of the genus Strombus having a brightly-colored spiral shell with large outer lip
freshwater or marine or terrestrial gastropod mollusk usually having an external enclosing spiral shell
any of various terrestrial gastropods having an elongated slimy body and no external shell
any of several creeping marine gastropods with a spirally coiled shell: whelks; tritons; moon shells; neritids
Ancylus fluviatilis, freshwater limpet, river limpet
minute conical gastropod superficially resembling a limpet but living and feeding on freshwater plants
nudibranch, sea slug
any of various marine gastropods of the suborder Nudibranchia having a shell-less and often beautifully colored body
Aplysia punctata, sea hare
naked marine gastropod having a soft body with reduced internal shell and two pairs of ear-like tentacles
bubble shell
marine gastropod mollusk having a very small thin shell
any member of the genus Physa
cowrie, cowry
any of numerous tropical marine gastropods of the genus Cypraea having highly polished usually brightly marked shells
aplacophoran, solenogaster
deep-water wormlike mollusks lacking calcareous plates on the body but having fine slimy spicules on the covering mantle
burrowing marine mollusk living on sand or mud; the shell closes with viselike firmness
common edible, burrowing European bivalve mollusk that has a strong, rounded shell with radiating ribs
marine mollusks having a rough irregular shell; found on the sea bed mostly in coastal waters
ark shell
marine bivalve mollusk having a heavy toothed shell with a deep boat-like inner surface
blood clam
red-blooded clam
marine or freshwater bivalve mollusk that lives attached to rocks etc.
escallop, scallop, scollop
edible marine bivalve having a fluted fan-shaped shell that swim by expelling water from the shell in a series of snapping motions
marine bivalve that bores into rock or clay or wood by means of saw-like shells
chambered nautilus, nautilus, pearly nautilus
cephalopod of the Indian and Pacific oceans having a spiral shell with pale pearly partitions
dibranch, dibranchiate, dibranchiate mollusk
cephalopods having two gills
a cephalopod with eight arms but lacking an internal shell
cephalopods having eight short tentacles plus two long ones
Type of:
any animal lacking a backbone or notochord; the term is not used as a scientific classification

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