ἐν πέτροισι πέτρον ἐκτρίβων → by grinding stone against stones
Ămăsēnus: i, m.,I a small river in Latium, eastward from the Pontine Marshes, now Amaseno, Verg. A. 7, 685; cf. Mann. Ital. 1, 626; Müll. Röms Camp. 2, 235.