And we have heard the fauns chiding Proteus in the smell of hay under the olive-trees, And the frogs singing against the fauns in the half-light. And...
Line 153 is a really tough one to pin down, since it talks about how we have all heard a bunch of half-goat, half-men ("fauns") making fun of ("chiding") the god Proteus. Proteus was famous for being able to change his shape into anything he wanted, and he also had a ton of knowledge about the world.
But what does all of this have to do with what we've read so far? Well if we think of fauns as mythical creatures who were down with the whole Dionysius thing, then maybe these literal party animals are mocking the modern world, with its emphasis on constant change and new fashions. In other words, Pound might be criticizing the modern world for constantly changing its tastes and not being rooted in anything lasting.
So even though we might all think our changing modern society is cool, Pound says that those who still worship the classical beauty of Dionysius are laughing at us and scolding us.
The poem closes with the image of frogs singing at twilight—romantic, right? Still, at the close of the day, it's the sounds of nature that we should focus on, not the sound of industry and progress.
And like "Canto I," Pound decides to end "Canto II" on a cliffhanger. He uses the word "And…" to show that there's more to be said on this subject. But it's up to us to figure out what comes next. Pound has already put in the work of exposing us to classical Greek stories. Now it's our turn to go figure out what comes next for our continuing education. Pound is willing to point you in the right direction; but it's you who need to start walking.