This isn't even a scientific wild azzed guess, it's just a wild azzed guess. Perhaps shoulder scales. I know it's different from the Civil War shoulder scales, but perhaps the Seminole War uniforms were different. That's a guess from a guy that knows nothing, hopefully someone will get on here and identify your find, because I'm also interested in finding out.
Yeah, I guess epaulette would be the proper word/name, but I've also heard them called shoulder scales, at least I think I have, at 76 sometimes I get confused and get stuff mixed up with reality.