can anyone translate these pottery marks?
 

Looks like it says 粡 .

As a word, it means "a steamed rice cake wrapped in a bamboo leaf". However, I couldn't imagine they would put that kani there for that meaning. It may have something to do with the name of the town or person that made the pottery. You sure this is from Japan?

not sure
 

I found the mark, that looks like a mirror imaged three, in a list of Japanese makers but I am not at all sure that these are really Japanese. Thanks for the response. That's an intriguing interpretation.

Do you think it could be 桐 instead—still, I'm not really sure what it could mean (it's just used in tree names in Chinese, I think). I think in stamp style (or whatever it's called), that left radical could be きへん or こめへん. Am I incorrect?

No, I can't say you're incorrect. All I know is that whatever it says there is not a message of any kind, meaning the OP shouldn't worry about it particularly when he doesn't know what country this piece even comes from.

Pottery marks ARE about the person and the town, or the name of the studio. That is what I am looking for. I believed this was Japanese due to its appearance and the one mark that I mentioned above.

So you are asking which town and artist this pottery is from. Keep in mind this is very specialized knowledge.

I understand. I hope that I did not cause too much confusion. Thanks

No, as Kyle said, it's 桐, "kiri", paulownia. The left hand part is the tensho (seal script) form of 木.

The seal script for 米 is exactly the same as the kaisho (block script) form.

Ben, that book you just scanned from is pretty awesome. What is it called?