Solnhofen Jellyfish?

[DarasFossils]

I just went to a local rock and fossil shop in Montana and they had an amazing selection of fossils for really reasonable prices, so I ended up getting quite a few. They had a lovely Solnhofen rack, mostly filled with fish, insects, and coprolites and some beautiful squid but I saw this questionable creature in the corner for very cheap so I decided it was worth it to purchase. I am guessing it is a jellyfish due to the shape, and I hope it is, but if it is something else, I really did not waste my money. It's around an inch and a half in diameter (4cm.) Just hoping it's not a coprolite lol. Anyone know a thing or two about Jurassic Jellies? 

Pic below, I can take a better quality photo in the daytime if that helps.