Simply begin typing or use the editing tools above to add to
this article. Once you are finished and click submit, your
modifications will be sent to our editors for review. ...pattern
around a central axis called the columella. Generally, the
coils, or whorls, added later in life are larger than those
added when the snail is young. At the end of the last whorl is
the aperture, or opening. The shell is secreted along the outer
lip of the aperture by the fleshy part of the animal called the
mantle, first by outward additions to the shell lip and then by
secretion... What made you want to look up "aperture"? Please
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