Meow thinks its a drop of paint that fell on to a wet quarter. A dried glob in the middle, and where the liquid thinly spread it around the fields.
Looks like smoke coming out of those steam locomotives! You better call @dwhiz. He might pay a premium for that!
Thanks. Yes I saw how it looks like smoke coming out of the train too, but didn't see the dolphin. See it now. It is a cool looking coin. I think I'll keep it. Thanks