Diploria clivosa is usually encrusting, rarely hemispherical. Hills are sharp and narrow--to 1.5 mm wide (valleys to 6 mm); alternating wide and narrow septa, ~35/cm; not found in Bermuda or Brazil. (Kaplan 1982)

Diploria labyrinthiformis has flat, wide hills--to 2 cm wide, with much narrower valleys. A depression runs the length of each hill. 14-17 septa per cm. Common in rear zone. (Kaplan 1982)