The Collaborative International Dictionary of English v.0.48:

Porites \Po*ri"tes\, n. [NL., fr. Gr. po`ros a pore.] (Zool.)
   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.
   [1913 Webster]