Hello Deane,

82 mm x 55 mm?  That's quite an Epitonium!  The biggest Caribbean species is
Amaea mitchelli, which is usually less than 60 mm in length.  The next
biggest Caribbean species is Sthenorytis pernobilis, which is not known to
reach 50 mm.  There are a couple of species of Epitoniidae that frequently
exceed 80 mm - Amaea magnifica from the central western Pacific, which
commonly exceeds that size; and Epitonium rugosum from the Philippines,
which uncommonly exceeds that size.  The problem is, an 82 mm specimen of
either of those species would be nowhere near 55 mm in diameter.  An 82 mm
E. rugosum would be about 25 mm in greatest diameter, while an 82 mm A.
magnifica might be 30-35 mm in diameter.  There are two other species for
which the world record size is slightly over 80 mm - Amaea ferminiana from
West Central America, and Epitonium scalare from the western Pacific.  A.
ferminiana, like the species mentioned above, would be far less than 55 mm
in diameter.  An 82 mm Epitonium scalare could be 55 mm in diameter, and if
that's what you have, and it is a full 82 mm in length, it is a new world
record size (the currently listed record is 81.8 mm).  It would be great if
you could furnish an image of this mystery shell.  Are you certain it is an
Epitonium?

Paul M.