The first known literary attestation of siren as a "mermaid" is not until the Middle Ages, in the Anglo-Latin catalogue Liber Monstrorum (early 8th century AD), where it says that sirens were "sea-girls. Miniature illustration of a siren enticing sailors who try to resist her, from an English Bestiary, c. Another is a terracotta oil lamp, possibly from the Roman period. The sirens are depicted as mermaids or "tritonesses" in examples dating to the 3rd century BC, including the image of the siren impressed onto an earthenware bowl, found in Athens. Overall, the partly fish (mermaid) form characteristic became iconic in the medieval period, but actually, there have survived examples from the Classical period where the siren is depicted as mermaid-like. Originally, sirens were shown as male or female, but the male siren disappeared from art around the fifth century BC. Later, they were represented as female figures with the legs of birds, with or without wings, playing a variety of musical instruments, especially harps and lyres. In early Greek art, the sirens were generally represented as birds with large women's heads, bird feathers and scaly feet. It was Apollonius of Rhodes in Argonautica (3rd century BC) who described the sirens in writing as part woman and part fish. Sirens began to be depicted in art as human-headed birds by the 7th century BC. The sirens of Greek mythology which appear in Homer's Odyssey, but Homer did not provide any physical descriptions, and their visual appearance was left to the readers' imagination.
Moaning siren statuette from Myrina, first century BC