The Collaborative International Dictionary of English v.0.48:

Eschara \Es"cha*ra\, prop. n. [NL., fr. Gr. ? a grate, a pan of
   coals.] (Zo["o]l.)
   A genus of Bryozoa which produce delicate corals, often
   incrusting like lichens, but sometimes branched.
   [1913 Webster]