Characters: Colonies are flat, narrow and elongate, usually with pointed ends. Mouths occur only within the axial furrow, which runs to the tips of the colony. Usually all septo-costae extend from the axial furrow to the perimeter. Tentacles may be extended day and night. Colour: Pale brown or mottled. Similar species: Herpolitha limax, which has secondary centres and seldom has axial furrows extending the full length of the colony. Habitat: Shallow reef environments. Abundance: Uncommon.