What is an important genus of reef-building corals having small twelve- rayed calicles, and a very porous coral. Some species are branched, others grow in large massive or globular forms called?

porites — An important genus of reef-building corals having small twelve- rayed calicles, and a very porous coral. Some species are branched, others grow in large massive or globular forms. (Webster's 1913.)

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