The radula is a ribbon of repeating tooth rows that the animal rasps along surfaces scouring for food. In cowries, the radulae consist of rows of seven teeth, as seen below. Radular features, such as the number of cusps, presence or absence and positioning of basal denticles and general tooth shape, have been used in cowrie systematics for over a century. There are some really cool aspects to radular development that are currently being examined.