Augustine's interpretation of 1 Peter 3:18-20

[Tyrel]

There's a lot of confusion out there on the matter of Augustine's interpretation of 1 Peter 3:18-20

For Christ also suffered for sins once for all, the righteous for the unrighteous, in order to bring you to God. He was put to death in the flesh, but made alive in the spirit, in which also he went and made a proclamation to the spirits in prison, who in former times did not obey, when God waited patiently in the days of Noah, during the building of the ark, in which a few, that is, eight persons, were saved through water.
~ 1 Peter 3:18-20

Some say that the pre-incarnate Christ preached to the spirits in prison in Noah's day [referencing Epistolae 164], while others say that Christ as Logos was in Noah preaching to the people in the time of the Noahide flood [I've seen Augustine's letters referred to, from epistle 93, to 99, and others (http://www.newadvent.org/fathers/1102.htm), but none of them contain any trace of this interpretation].

So, I've been looking for everything I can find on Augustine's interpretation of Christ's Descensus. If anybody here has a scholarly article, a commentary, or a set of quotations from Augustine, or anything at all, please do share it. I'm looking for everything I can find about Augustine's treatment of Christ's descent into hell.

I should note that I am reading Letter 164 ( http://www.newadvent.org/fathers/1102164.htm ) so I'll be looking for quotes other than from that letter, but feel free to post things from that letter as well, if you like.