Protoschmidtia grimmi f. globosa Czerniavsky, 1880

Protoschmidtia grimmi f. globosa Czerniavsky, 1880: 103 (no illustration).

Koltun (1962) revised the Caspian sponge fauna and concluded that this isolated ancient lake harbors only a single species, Metschnikowia tuberculata Grimm, 1877 . The present forma is a junior synonym.