Phylum: Mollusca
Class: Gastropoda
Order: Neogastropoda
Key morphological characteristic: Lettered Olives have smooth, glossy shells that are shaped like bullets that are commonly around 60mm in length.
Fun fact: The Lettered Olive is carnivorous, and uses its foot to capture prey such as small crustaceans and bivalves.
Sifted from a partially filled gallon zip-lock bag of shelly sand, and sorted under a binocular scope. Over 60 species of marine mollusks were identified. The surface has fine spiral lines, with 9 on the next to the last whorl.
Found this either on a beach or up around the high tide line near trees of Pavilion Key in ENP. Found several.