Corallum :: Corallum (n.) The coral or skeleton of a zoophyte, whether calcareous of horny, simple or compound. See Coral..
Hydrocorallia :: Hydrocorallia (n. pl.) A division of Hydroidea, including those genera that secrete a stony coral, as Millepora and Stylaster. Two forms of zooids in life project from small pores in the coral and resemble those of other hydroids. See Millepora..