The Collaborative International Dictionary of English v.0.48:

Mniaceae \Mniaceae\ prop. n.
   A natural family of erect mosses with club-shaped paraphyses
   andgonal cells of the upper leaf surface; sometimes treated
   as a subfamily of Bryaceae.

   Syn: family Mniaceae.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

Mniaceae
    n 1: family of erect mosses with club-shaped paraphyses and the
         hexagonal cells of the upper leaf surface; sometimes
         treated as a subfamily of Bryaceae [syn: Mniaceae,
         family Mniaceae]