"The writer has studied the types of the upper Tertiary species of Cytheridea (Leptocytheridea), a subgenus based on larval molts, and the adult species (primarily of Haplocytheridea) to which they belong. The resulting taxonomic revisions and synonymies are presented in the systematics. Lectotypes are designated for several species. The antimerodont hinge seems to be the common larval hinge of the Cytherideinae, regardless of the adult hinge type. This suggests that the primitive hinge of the Cytheracea is the hemisolenic type (e.g., antimerodont), rather than the holosolenic type (e.g., holomerodont)."