It's quite possible that they are reversed; I'm sort of guessing. PMOS transistors are usually bigger, so I think it's the one on the left. The chip could have

It's quite possible that they are reversed; I'm sort of guessing. PMOS transistors are usually bigger, so I think it's the one on the left. The chip could have n-wells or p-wells, so it could go either way with the extra diffusion.