To add, here's an interesting site that explains coral skeleton classification in more detail...Branching euphylliids have a phaceloid colony structure (like caulastrea or astraeosmilia), while wall euphylliids have a flabello-meandroid colony structure (like trachyphyllia or catalaphyllia). All euphyllias (torches) grow in a branching form, while fimbriaphyllias (hammers and frogspawn) can grow in either a wall or branching form depending on the species.
Corals of the World
www.coralsoftheworld.org
