An SEM observation on the sporic diatom Muelleriopsis limbata (Ehrenb. ) Hendey

Abstract

The ultrastructure of the sporic diatom Muelleriopsis limbata (Ehrenb. ) Hendey is observed by SEM. Complete frustules recovered from the Miocene marine formations have shown trilayered wall and complicate attachment of opposed valves within a frustule. The epivalve always has a compressed bowl-shape and hypovalve is highly vaulted with the valvar edge extended to a broad circumferential flange. Preliminary considerations are given to affiliation and vegetative/sporic problems of this enigmatic fossil.