Lucina pensylvanica
This bivalve is misnamed as it occurs from North Carolina south and is not found in the waters off of Pennsylvania. It is extremely rare on the gulf coast. The 1” to 2” smooth white shell has a deep crease behind the umbo (pointed top). The live clam has a ridged periostracum (semi-soft outer covering) that may help secure it while buried. The periostracum easily flakes off and is often missing on shells found on the beach.
This Lucine is a filter feeder, and lives in sand and gravel at depths from 2 to 250 feet. It has been reported in extreme environments such as hydrothermal seafloor vents. Their embryos change into free-swimming larvae before developing into juvenile clams. The genus name Lucina is one of the names of the Roman goddess Juno, “giver of light”.
Live shells should never be taken from any Florida State Park.