Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Talassia coriacea is a species of very small sea snail, a marine gastropod mollusk in the family Vanikoridae. Vanikoridae is a family of very small or medium sized sea snails, marine gastropod molluscs in the clade Littorinimorpha. Littorinimorpha is a large clade of gastropods within Hypsogastropoda consisting primarily of marine species, but also aquatic and terrestrial species as well.