The Collaborative International Dictionary of English v.0.48:

Spongiae \Spon"gi*ae\ (sp[o^]n"j[i^]*[=e]), n. pl. [See
   Sponge.] (Zool.)
   The grand division of the animal kingdom which includes the
   sponges; -- called also Spongida, Spongiaria,
   Spongiozoa, and Porifera.
   [1913 Webster]

   Note: In the Spongiae, the soft sarcode of the body is
         usually supported by a skeleton consisting of horny
         fibers, or of siliceous or calcareous spicules. The
         common sponges contain larger and smaller cavities and
         canals, and numerous small ampullae which are lined
         with ciliated cells capable of taking in solid food.
         The outer surface usually has minute pores through
         which water enters, and large openings for its exit.
         Sponges produce eggs and spermatozoa, and the egg when
         fertilized undergoes segmentation to form a ciliated
         embryo.
         [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Porifera \Po*rif"e*ra\, n. pl. [NL., fr. L. porus pore + ferre
   to bear.] (Zool.)
   A grand division of the Invertebrata, including the sponges;
   -- called also Spongi[ae], Spongida, and Spongiozoa.
   The principal divisions are Calcispongi[ae], Keratosa or
   Fibrospongi[ae], and Silicea.
   [1913 Webster]

WordNet (r) 3.0 (2006):

Porifera
    n 1: coextensive with the subkingdom Parazoa: sponges [syn:
         Porifera, phylum Porifera]