The Collaborative International Dictionary of English v.0.48:

Mycothrix \Myc"o*thrix\ (m[imac]k"[-o]*thr[i^]ks), n. [NL., fr.
   Gr. (spurious) my`khs mucus (L. mucus) + qri`x, tricho`s,
   hair.] (Biol.)
   The chain of micrococci formed by the division of the
   micrococci in multiplication.
   [1913 Webster]