Symmetrical Brain Coral

Diplora strigosa
Symmetrical brain coral grows in either small domes or plates. They have long valleys and thin ridges with no (or very slight) groove along the ridge top. They never have knobs and can be grey, brown or yellowish in color. Also known as "Smooth" or "Common" brain coral. Often the valleys are a different color than the ridges. Colonies can be found on the sea floor in shallow water (2-3 feet and deeper ) or growing on rock surfaces as plates or domes and  can be small or large from 6 inches to 6 feet in diameter.