physemaria

from The Century Dictionary.

• noun A group formed by Haeckel for the reception of two genera of low metazoic animals, Haliphysema and Gastrophysema, which had been confounded partly with the sponges and partly with the protozoans. The validity of the group has been denied.

from the GNU version of the Collaborative International Dictionary of English.

• noun plural (Zoöl.) A group of simple marine organisms, usually classed as the lowest of the sponges. They have inflated hollow bodies.