Discolith \Dis"co*lith\, n. [Gr. ? a round plate + -lith.]
(Biol.)
One of a species of coccoliths, having an oval discoidal
body, with a thick strongly refracting rim, and a thinner
central portion. One of them measures about 1/50000 of an
inch in its longest diameter.
[1913 Webster]