Aren't they the same thing? Kalamansi and calamondrin, I mean?

Here is a link that might be useful: Confusing!

I might be a little late but..

Yep.. kalamansi is the filipino version of the lemon. I've read that it is related to the calamondin, although I've never tasted the latter. I love them! I'm hoping to find someone who sells them here in FL.

Here's a couple of sites that has additional info:
http://www.seasite.niu.edu/TAGALog/Tagalog_Default_files/Philippine_Culture/Pagkaing%20Pilipino/philippine_fruits.htm

Here is a link that might be useful: kalamansi