The Knobbed Whelk is also known as Busycon Carica. In this species, mating occurs by coupling. Mating and egg laying occur during the spring and fall migration. Internally fertilized eggs are surrounded by albumen, a gel-like material. The eggs are laid in protective eggs capsules and the capsules join to form a chain of egg-cases. Each capsule holds anywhere from 0-100 eggs and each chain of egg-cases holds 40-160 capsules. After laying the eggs cases, the female will bury one end of the egg case into the ocean floors the egg case doesn't wash ashore.
This picture shows the egg case of a Knobbed Whelk.