In colonial corals, growth results from the budding of new polyps. There are two types of budding, intratentacular and extratentacular. In intratentacular budding, a new polyp develops on the oral disc, inside the ring of tentacles. This can form individual, separate polyps or a row of partially separated polyps sharing an elongate oral disc with a series of mouths. Tentacles grow around the margin of this elongated oral disc and not around the individual mouths. This is surrounded by a single corallite wall, as is the case in the meandroid corallites of brain corals.