Defn: A grand division of the Invertebrata, including the sponges; — called also Spongiæ, Spongida, and Spongiozoa. The principal divisions are Calcispongiæ, Keratosa or Fibrospongiæ, and Silicea.

PORIFERAN
Po*rif"er*an, n. (Zoöl.)

Defn: One of the Polifera.

PORIFERATA
Po*rif`e*ra"ta, n. pl. Etym: [NL.]

Defn: The Polifera.

PORIFORM
Po"ri*form, a. Etym: [L. porus pore + -form: cf. F. poriforme.]

Defn: Resembling a pore, or small puncture.

PORIME
Po"rime, n. Etym: [Gr. (Math.)

Defn: A theorem or proposition so easy of demonstration as to be almost self-evident. [R.] Crabb.

PORINESS
Por"i*ness, n.