ἐν πέτροισι πέτρον ἐκτρίβων → by grinding stone against stones
crŏtălum: i, n., = κρόταλον,I a rattle, a bell, castanet, used to accompany wanton dances, P. Scip. ap. Macr. S. 2, 10; Cic. Pis. 9, 20 al.
