Herpolitha
Herpolitha is a monotypic genus of mushroom corals in the family Fungiidae. The only member of the genus is Herpolitha limax, commonly known as the tongue, slipper, mole or striate boomerang coral. It is a free-living species and is native to reefs and lagoons in the Indo-Pacific region. The International Union for Conservation of Nature has assessed this coral as being of "least concern".
Description
Herpolitha limax has an elongated structure with somewhat rounded ends and a single, central, axial furrow that extends nearly from end to end. In the furrow are many conspicuous slit-like mouths and there are irregularly spaced, less-distinct mouths elsewhere. The primary septa are densely-toothed with fine spines and do not reach the edge of the colony. The costae are low with crowded, obtuse teeth. Sometimes the furrow is forked and forms a "Y" shape, a "T" shape, or even an "X" shape. This coral can grow to about 45 cm (18 in) long and 10 to 15 cm (4 to 6 in) wide and is usually some shade of grey, brown or greenish-brown.