The Small China-mark (Cataclysta lemnata) is a species of moth of the family Crambidae. It is found in Europe and Morocco. The wingspan is 18–19 mm for males and 22–24 mm for females. The forewings are white. The costa, discal spot and a series of terminal spots are all fuscous. The hindwings are white with scatted pale fuscous scales. The moth flies from May to August depending on the location. The larvae feed on Lemna species.