Ileuthyeria, fair Dafne of sea-bords,
The swimmer's arms turned to branches, (124-125)
Like Tyro, a mythical woman named Ileuthyeria finds herself being chased by a bunch of mermen who want to sexually assault her. But, according to myth, the only way she can escape being assaulted is to be turned into ocean coral. In other words, Pound seems to be saying that the only way you can keep a woman sexually "pure" is if you treat her as a dead—though still beautiful—object.
Lithe turning of water,
sinews of Poseidon,
Black azure and hyaline,
glass wave over Tyro, (132-135)
Toward the end of the poem, Pound returns one more time to describing the scene of Poseidon assaulting Tyro. It's still not totally clear what he means by including this scene. On a vague level, he seems to suggest that women's beauty can inspire many different responses in men, some of them being more productive than others. Pound doesn't seem to realize, though, that in every example he gives, the woman is a totally passive object of beauty. Hmm. What about that, Ezra?