Description: Thalli are pink, unattached, calcareous algae. They are very irregular in shape, often with scattered protuberances that can harbor a variety of invertebrates, and reaching several cm in diameter (specimens to 12 cm, or 5 in, have been observed but are rare). Habitat: These occur in the subtidal in mostly protected habitats such as bays and lagoons with adequate current to prevent burial in the sediment.