ParallelodontidaeParallelodontidae is a family of saltwater clams, marine bivalve molluscs that are related to the ark clams. This family contains at least four genera.SpeciesSpecies within the family Parallelodontidae includes: Grammatodon Parallelodon* Parallelodon rugosus Pleurogrammatodon Porterius* ''Porterius dalli''