Neverita duplicata

Neverita duplicata, common name the shark eye, is a species of predatory sea snail, a marine gastropod mollusk in the family Naticidae, the moon snails.
In 2006 a paper was published which made it clear that a second, very similar species with a smaller range of distribution also lives in part of the range inhabited by Neverita duplicata. The second species had previously been considered to be simply a form of N. duplicata, but it is now recognized as Neverita delessertiana.
Distribution
This is a common western Atlantic species. It is found from Massachusetts and other parts of New England, south to Florida and other states on the Gulf of Mexico, south to Honduras.
Description
The shell has a flattened globular shape, and reaches about 88 to 90 millimetres (3.5 to 3.5 in) in maximum dimension. The color of the shell is variable, but is often a greyish brown. The central apex of the shell is often...