It's beyond my skill lever. But at first glance this may have potential of being a major anomaly. If you haven't already, post this sucker over on Lincoln Cent Forum. Let those guys look at it.
Reading your title I thought, but only for a moment, that you were cracking up. lol. I've never seen anything like that but they looked raised to me. You have the coin so only you can do this. Look at what you are asking about. Don't limit your thinking to letters but look for designs, anything that you would normally see on any other penny. Twist, turn, flip, rotate or anything else you can think of that's on a normal cent. Does it resemble what you are seeing? I'm thinking it could be a die clash that is hidden by the word AMERICA.
I just can't see anything it may resemble. On the C it looks like an upside down clash of the Lincoln memorial possibly. It just doesn't look like a Lincoln memorial except the lines.
If it is die deteriration like Mike thinks it wouldn't pop like a plating bubble. I suggest sending it to Mike for his in hand review if he thinks it appropriate but he seems pretty confident of his assesment from the photos
There is definitely some lettering under there. Even these eyes can see that (aided by your great photography)