Moontanman

Made me think of a Stephen Baxter story, but that was a squid called Sheena, and she was terrestrial.  Can't think where or when I heard about the ET cephalopods, but it sounds familiar.  Was this a recent novel?

Also reminded of the "heptapods" in Ted Chiang's wonderful short story, The Story of Your Life, which I recently praised in another thread here.  That was the basis for the movie, Arrival .

I think it's an old novel, the cephalopods were space fairing and had shells like nautiloids... I was thinking of what to read and a memory of this book came to mind. I think it was mentioned on here in a thread years ago. I know, good luck with that one.