ORNIA was the Naiad Nymph of the spring, well or fountain of the town of Orneai in Sikyonia (southern Greece).

Diodorus Siculus, Library of History 4. 72. 1 (trans. Oldfather) (Greek historian C1st B.C.) :
"Asopos made his home in Phlios [the region of Sikyon], where he married Metope, the daughter of Ladon, to whom were born two sons, Pelasgos and Ismenos, and twelve daughters, Korkyra and Salamis, also Aigina, Peirene, and Kleone, then Thebe, Tanagra, Thespeia, and Asopis, also Sinope, and finally Ornia and Khalkis."

Sources:

• Diodorus Siculus, The Library of History - Greek History C1st BC