That's not a port, those are all simply transmission line (TL) enclosures.
The "Snailshell" is simply a compromised TL, essentially... funneling the enclosure quickly down to a smaller-than-ideal starting area for the TL.
(and since 1/4 wave theory TL's get no better than the same 90 degree phase difference as a ported enclosure, the benefit is...? //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif )
Normally, TL's naturally taper at any rate for many designs, and many more are stuffed to make them behave slightly longer than they are.
Here's some more information on transmission lines: