Update

Actually, it was in the same letter; I didn't recognise it because it wasn't in the Greek alphabet.

"Para thina poluphloisboio thalasses: the turn of the wave and the scutter of receding pebbles." It literally means "beside the loud-murmuring sea".

Here it is in Greek:

So Pound is quite right to say that his variation is totally different, and a different movement of the water. Don't know about the "inferior" bit, though.

Comparatively, what have others made of the same phrase?
Chapman's translation: "the sea-beat shore"
Dryden (in the unfinished Ilias): "along the hoarse-resounding shore"
Pope: "along the Shore"

Actually, Pope seems remarkably constrained, although he is big on capitalising Important Things.

NB - I didn't actually have to chase these translations down completely; they're from this review, from Signals, a (seemingly) short-lived poetry magazine.