Sunrise tellin shell. Interior of half of the shell of a sunrise tellin (Tellina radiata), a type of bivalve mollusc in the family Tellinidae. Shells of bivalve molluscs consist of two articulating parts, or valves. Tellins live in soft sediments in shallow seas and breathe using siphons which reach up to the surface of the sediment. This species is found in the Gulf of Mexico and the waters of the Carribean.