Vermetus \Ver*me"tus\, n. [NL., from L. vermis worm.] (Zool.)
Any one of many species of marine gastropods belonging to
{Vermetus} and allied genera, of the family {Vermetidae}.
Their shells are regularly spiral when young, but later in
life the whorls become separate, and the shell is often
irregularly bent and contorted like a worm tube.
[1913 Webster]