E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Glaucus, a fisherman, was in love with Scylla; but Circ, out of jealousy, changed her into a hideous monster, and set dogs and wolves to bark round her incessantly. On this Scylla threw herself into the sea and became a rock. It is said that the rock Scylla somewhat resembles a woman at a distance, and the noise of the waves dashing against it is not unlike the barking of dogs and wolves.
Glaucus, lost to joy,
Curst in his love by vengeful Circës hate,
Attending wept his Scyllas hapless fate.
Camoens: Lusiad, bk. vi.
Avoiding Scylla, he fell into Charybdis. Trying to avoid one error, he fell into another; or, trying to avoid one danger, he fell into another equally fatal. Scylla and Charybdis are two rocks between Italy and Sicily. In one was a cave where Scylla dwelt, and on the other Charybdis dwelt under a fig-tree. Ships which tried to avoid one were often wrecked on the other rock. It was Circe who changed Scylla into a frightful seamonster, and Jupiter who changed Charybdis into a whirlpool.
When I shun Scylla your father, I fall into Charybdis your mother.Shakespeare: Merchant of Venice, iii. 5.
Between Scylla and Charybdis. Between two difficulties or fatal works.
To fall from Scylla into Charybdisout of the frying-pan into the fire.