I had to register just so I could answer your question. But heck, it's not often I know the answer.
This site and many other sites separate Canon "lenses", meaning EF lenses and "EF-S Lenses". In this case they had to make a judgement call and they put the EF-S 60mm Macro in with the EF-S lenses. I wouldn't have done it that way, but you could make an argument either way.
So go to EF-S lenses and it's there.
I have the 100L Macro and I love it, but I've heard good things about the EF-S 60mm.