Habitat: Inhabit sloping reef faces and along walls. One of the most abundant corals on deep reefs and walls. Most common between 65-120 feet. Massive overlapping plates often cover large areas. Characteristics: Colonies grow in massive, thin sheets or flattened plates that often form large whorls and occasionally spirals and bowls. Concentric rows of long rounded ridges and relatively wide valleys run parallel to the colonies outer edges. Yellow-brown to golden-brown and brown, may have greenish, bluish or grayish. Fragile.