Here are all four fruits before cutting.

Lemon, lime... in the Spanish speaking world, they are all limon. In the English speaking world lime means green; and lemon means yellow. As for size, there are "limes" that are way bigger than most "lemons".

Actually in some parts of the Spanish speaking world lime is lima, and lemon is limon.

Still hoping someone can take a guess as to the identity of the fruit I'm asking about, which doesn't appear to be or taste like either one. Could it be that a seedling lime tree (or orange tree for that matter) is producing this fruit which is some cross-pollinated lime-orange creation?

Zafra, I think you're probably correct in guessing this is a seedling and a hybrid of somthing sour, and possibly an orange. You can try posting your photos and questions over on the Citrus Grower's Forum. Lots of international folks there, and some real experts. They might possibly be able to ID this fruit for you. You'll need to join, but worth the couple of minutes to set up your account. Great and very knowledgeable folks there.

Patty S.

Here is a link that might be useful: Citrus Grower's Forum

Thanks so much Patty that's a great suggestion. I'll report back if I get any interesting info over there. Cheers!

I suggest that you just stick with limon frances (with proper accent marks of course). In fact you probably have something that will capture the imagination of the "gotta-have-something-rare" crowd. Give it some time and folks will be clamoring for seeds (you certainly have plenty) or budwood from you. A lemon by any other name would still make excellent salad dressing, but a new named variety with different characteristics will surely fan the "first on the block" fires. So just run with it and enjoy the fervor. :)