Kaiona, Oahu, 6 feet, 28 mm

Rare under Porites coral at any depth.  The spire is turreted, with a lilac aperture, and yellow operculum.  Attains 1.5 inches, 37 mm.  Red Sea to Hawaii and French Polynesia; Western Atlantic.  Reported as Coralliophila d'orbignyana in Kay, 1979, which is now considered a form of C. erosa with heavier sculpture.