Ma'ili Pt., Oahu, 4 feet, 27mm 

Uncommon on ledges from 40 to 100 feet.  Rounded axial ribs with spiral sculpture of overlapping scales often encrusted by coralline algae, aperture pale.  Preys upon coral but is free-living.  Attains 2 inches.  The closely related Coralliophilia bulbiformis is lighter, with longer spines, and  lilac aperture.  Reported as Coralliophila erosa in Kay, 1979.