[edit]
http://the-magi.us/stuff/virus.html
where a position is definitely taken (viruses).
I think I should not have summarized the document that way. Instead,
I should have called it a thorough investigation of the problem.
That said, the author definitely does not see "virii" as an acceptable
solution.
| Those confused souls who write *virii are tacitly positing the existence
| of the non-word *virius, and declining it as though it were like filius.
| It's true that l/r are both linguals that sometimes get interchanged,
| and that f/v are just a change in voicing[2], but that's just reaching.
| *Virii is still completely silly, so don't do that; otherwise, everyone
| will know you're just a blathering script kiddie.