This shell is produced by a marine snail that lives in shallow water. Large and distinctive in its appearance, the Scotch Bonnet is china white to creamy in color with yellow to brown spiral bands. After the snail dies, its shell may be occupied by a hermit crab.
Scotch Bonnet  profile from NC Wildlife Resources Commission. (PDF)
Shell Club of North Carolina  has a page devoted to the Scotch Bonnet.