Note
Seven species of marine diatoms belonging to Hustedt's groups Inaequales, Lanceolatae , Sulcatae and Undulatae of
the genus Mastogloia were studied using transmitted light and scanning electron microscopy. External and internal
valve structure is described for M. funafutensis A. S.,M. lancettula CI.,M. gigantea Hust. ,M. testudinea Voigt, M.
peragalli Cl., M. bahamensis CI. and M. rhombica Cl. The valve structure of the seven species is contrasted to some
previously discussed Mastogloia species from the above groups.