\Mi`cro*bac*te"ri*a\, n. pl. [NL. See {Micro-},
and {Bacterium}.] (Biol.)
In the classification of Cohn, one of the four tribes of
Bacteria.
Note: In this classification bacteria are divided into four
      tribes: 1. {Spherobacteria}, or spherical bacteria, as
      the genus {Micrococcus}. 2. {Microbacteria}, or
      bacteria in the form of short rods, including the genus
      {Bacterium}. 3. {Desmobacteria}, or bacteria in
      straight filaments, of which the genus {Bacillus} is a
      type. 4. {Spirobacteria}, or bacteria in spiral
      filaments, as the genus {Vibrio}.