I somehow accidentally have a "merged loop" playing in my midi track for AD.  What is this, and how can I get rid of it?  I don't want it to be merged, but I don't know how to "unmerge" it, and in the PRV, the original beat shows up, but the beat that it was merged with does not show up.  I cannot see the midi data of the merged thing that was added (in this case a 16th beat ride cymbal).  I just want to get rid of that, but it does not show on the PRV.
 
Just when I thought I had a good handle on midi.  Any ideas here?

Try looking in the take lanes. This image shows audio take lanes, but it's the same deal for MIDI.
 
To open the take lanes on the track in question,
 
Click on button that is highlighted in blue, directly under the similarly highlighted #23 in this image. Obviously, your track # will be different.