And of course, Database Administrators, when talking about a database index, don’t use the plural “indices”, they say indexes.
How exactly do you pronounce that with only one syllable?
No need to get snitty, Keeve. I have to admit though, I like “bra”. A possible headline: “Greyhound modernizes its fleet of bra”.
Meanwhile, my head is spinning with plurals of omni and second and fourth declensions. (What happenend to first and third declensions … or do declensions only come in even sizes?) Also, I learned here on the SDMB that “octopus”, being derived from a Greek root, is properly pluralized as “octopodes”, not “octopi”. However, no dictionaries seem to confirm that. Maybe she of the gray eyes could help out with that one?
We’ve been over this before <sigh> and no doubt will have to again…
In the first place, these nouns are not Latin, they’re Greek. The -us here is not a Latin second or fourth declension ending, nor is it a Latinization of Greek -os. So a plural in -i just cannot apply here.
The original Greek is oktopous. The Greek for ‘foot’ is pous and the plural is podes.
In English, it’s perfectly correct to use the plural “octopuses.” That’s what marine biologists call them. But if you want to use the original Greek plural, it would have to be “octopodes.” Same with “platypodes.”
Just to put in my two cents… the “buses” spelling irritates the hell out of me. I want to read it aloud as “byoozus” for fault of the single-s-e spelling.
I’m the only one I know who consistently spells it “busses.” If I were dictator of the USA, I’d make everyone spell it that way. 
Do I put footnotes at the feet of all the different pages?
Oh, what silly oxen we be!
Just to annoy everyone, the plural of “bus” in both French and Italian is “bus”. (Despite what Robert-Collins might have to say about it, “bus” means “bus” in French, at least in Quebec.)
Kaus
Omphaloskeptic, while we’re digging out old Latin poems, here’s one:
Civile, si ergo
Fortibus es inero
Novile deus trux
Vatis inem causan dux
Well I’d rather be hit by a buss than a bus.
Don’t you know that using “busses” as the plural of bus in signs is the single biggest cause of car accidents at train stations that have both a bus turnaround and a kiss-and-ride area? 