This shell is very common on our beaches. It's called a Sharp-knobbed Nassa but other names are sharp-knobbed dog whelk or narrow basket shell. It's a scavenger and is reported to feed on mollusk egg capsules. It's found on the sand from the low-tide line to 20' deep in the water. It's range is NC to Texas. It's scientific name is Nassarius acutus (Say). The size is from 1/4 - 1/2".
