​CYTHEREA (from Cytherea, a name for Venus, so called because she is said to have sprung from the foam of the sea near Cythera, now Cerigo, an island on the S. E. of the Morea), a genus of conchiferous mollusks belonging to the family veneridæ. The shell is like that of the genus Venus. The cythereas are in all seas; 176 recent species are known, and 200 fossils, the latter ranging from the Oölite till now.