A new species of the lucinid bivalve genus Rastafaria is described from the Western Indian Ocean and Red Sea. This differs from the type and previously only known species R. thiophila from Western Australia, in being larger more rounded in outline and with a shorter, less sunken, anterior dorsal area. Additionally, three species of Megaxinus, two new, are described from the Indian Ocean. These are the first records of the genus in the Indian Ocean. Other species of Megaxinus are found in the Mediterranean and western Atlantic and in Miocene to Pliocene deposits of western Europe. These other living species of Megaxinus and some of the closely related fossil species are briefly reviewed.