Abstract: A study on the reproductive organs of Dermonema frappieri (Mont. et Mill.) Boergesen and Nemalion pulvinatum Grunow has been made. In both species the carpogonial branch is accessory, and is a specialized organ from its time of inception. The fertilized carpogonium undergoes no transverse division but directly sends out the gonimoblast which is diffuse and filamentous in structure. No cytoplasmic connection between the fecundated carpogonium and its supporting cell is seen. The antheridia arise as proliferations from the distal cells of the assimilative filament but the terminal cell of which usually remains sterile. All evidences at hand strongly indicate that the plant known as Nemalion pulvinatum Grunow is actually a member of the genus Dermoneraa. Accordingly, Dermonema pulvinata (Grunow) comb. nov. is suggested as the proper disposition of this alga.