Cerithium
Cerithium is a genus of small to medium-sized sea snails, marine gastropod molluscs in the family Cerithiidae, the ceriths.[2]
The genus is known from the Triassic to the Recent periods (age range: from 221.5 to 0.0 million years ago). Fossils shells have been found all over the world. There are about 100 extinct species[4][5] including:
50 second video of snails (most likely Natica chemnitzi and Cerithium muscarum) feeding on the sea floor in the Gulf of California, Puerto Peñasco, Mexico