I doubt it is mescaline, more likely a research chemical if anything.
It is important that you realize the "Blue Dolphins" in your area probably are not the same "Blue Dolphins" you had last year, or even the same "Blue Dolphins" that your neighbor has. There are guaranteed to be multiple batches of blue pills with a dolphin stamp going around pressed by different suppliers worldwide. Some may be good, some may be bunk. You never really know.