Micraster

1 definition found

From The Collaborative International Dictionary of English v.0.48 [gcide]:

  Micraster \Mi*cras"ter\, n. [NL., fr. Gr. mikro`s small + ?
     star.] (Paleon.)
     A genus of sea urchins, similar to Spatangus, abounding in
     the chalk formation; -- from the starlike disposal of the
     ambulacral furrows.
     [1913 Webster]