Crenulated Pyram Pyramidella crenulata (Holmes) is a small (1/2 inch) shell with smooth, flat-sided whorls and deeply incised sutures. It's cream with tan blotches and lives in mud and in grass from the low-tide line to 50' sandy ocean bottoms. It can be found from North Carolina to Texas. It is a parasite that feeds on the soft tissues of other mollusks and marine animals.The Atlantic Oyster Drill
Urosalpinx cinerea (Say) Is a small shell measuring from 1/2 inch to 1 1/2 inch high. It's oval with an elevated spire and is grayish or yellow-white with a rough exterior with large axial ribs forming a pattern of raised wavy lines. It lives in sounds and inlets. Commonly found living in oyster reefs and on pilings. It's range is from Nova Scotia to Florida and is a carnivore that prefers barnacles and oysters. It drills a hole into the shell and feeds on the soft parts of the animal.
The New England basket shell, Nassarius trivittatus(Say) is sometimes called a threeline mudsnail, New England Dog Whelk or a New England Nassa is a small shell with a rough surface and strong axial ribbing with beaded whorls. It's between 1/2-7/8" high and is white to yellowish-gray. Southern specimens (as found in North Carolina) have 3 reddish-brown spiral bands on the body whorl. Located on sand and muddy sand and intertidally to water 300 feet deep, it's range is from Canada to Florida. It feeds on egg cases of the Northern Moon Shell and is a scavenger. 
