\Hy`dro*co*ral"li*a\, n. pl. [NL. See {Hydra}, and
{Coral}.] (Zo["o]l.)
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}.