I think what I'm seeing on these neg's is dust on the negative. Some of this I was able to remove by blowing the negative off, some I think is stuck because it settled there during or shortly after I processed the negs (I was really just experementing with these, my first 4 x 5 negs to see if the lens/camera worked).
I also have some water spots (I think.) I'm guessing that I could rewet these negs in some sort of solution, maybe water, and then remove them.
I'm just getting ready to process another batch, and I plan to take much more care this time! My thought is to get them into sleeves as soon as I have them dry.