Person with Volume X (Moul-Ovum) of the second edition OED in front of them here..

a simple reply to this would be that in no dictionary 'pu' comes before 'po' :)

granted, octopodes comes under the heading of octopus, as it's plural, so it is technically after.

but following the loose nature of the quote in hand, it is also in fact true that octopi comes before octopuses, it just so happens to be attached to the full word 'octopian' - suggestive of an octopus