Is it geniuses or geniusi?

[swimmeringer]

Octopuses
Octopi

Styluses
Styli

Geniuses
or
Geniusi?

And if it's geniuses (which I suspect it is because nothing in this world makes any sense) then why?



Also just a side note really:

I know there are cases where it does apply, but the "I before E except after C" rule doesn't seem to apply all that often. What I mean is, after a "c" in a word, it's usually still I before E.

Example:
Science
(I would have more but I have to leave right now)



(Also I know the "and when sounding like "A" as in "neighbor" and "weigh"" part, just for your information)

 

[m3rox]

geniuses, also,
http://www.google.com