Instructions
Examine the seashell in question for binds or hinges that connect the top and bottom halves of the shell, sort of like a clam. If the shell has a join, it is a bilateral or bivalve shell.
Feel the seashell's texture. If it is smooth, long and curls into a tight shape, it is a gastropod or univalve shell.
Inspect the seashell's size and shape. If it is flattened and plated, and very primitive in appearance, it is a chiton shell. On the other hand, if it is tusk or tooth-like, the seashell is a scaphopod.
Visit shell identification Web sites and compare your shell to photographs online for further identification and classification.
Utilize online resources that teach visitors how to properly classify seashells. See "Lesson Planet" in Resources for access to lesson plans.