morphology of a snail
tentacle
Small muscular appendage, long and retractable, having a tactile role.
growth line
Thin irregular protuberance of the whorl of the shell, corresponding to its successive growths.
head
Anterior portion of the foot of the snail containing the main sensory organs.
mouth
Anterior cavity of the digestive tract having a jaw and a rough tongue (radula) to graze on plants.
eyestalk
Large muscular appendage, elongated and retractable, bearing an eye at its terminal end.
eye
Organ of vision located at the terminal end of the eyestalk; the snail has poor eyesight.
shell
Calcareous spiral casing formed of three successive layers that protect the organs; the snail can withdraw into its shell.
whorl
Each of the swirls around the apex; they increase in diameter and form the shell.
apex
Crown from which the shell grows.
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