Tibia fusus. Family: Strombidae. So named in reference to the tibia or "shinbone" in humans. A beautiful species of the family strombidae ("conch") although there is some discussion that it should be recognized as a separate family. The graceful lines and sheer beauty of the Tibia fusus fusus makes it probably the most desirable of the tibias. It is a fairly common species where it occurs, but because of its attractive appearance, it is highly sought after by shell collectors.