[HarryT]

Originally Posted by FlorenceArt

If Websters is the same as Merriam-Webster, they don't, according to their online dictionary, but they do accept octopi.

Thank you; I read Darqref's post as saying that Mr. Spoor would have wrong to use "octopuses", and that the style manual he refers to says that "octopi" must be used.

Changing the subject for a moment, I find that Merriam-Webster dictionary entry to which you've linked a little odd. It claims that octopus comes from "New Latin octopod". My issue with this is that there is no conceivable grammatical rule in Latin that will give you a plural of "pi" from a singular of "pod", so I'm still at a loss to see how "octopi" can be considered a grammatically valid plural.