Combinatorial species

I'm reading an article (to appear in proceedings of Haskell'10) on combinatorial species by Brent Yorgey. Very interesting, although as I don't speak Haskell, the explanations were sometimes harder to understand than the things they were explaining. I did offer to tutor Haskell this year in the hope that I'd learn it, but I doubt it's going to happen. For purposes of reading this paper, the main thing you have to know, e.g. from here is that a "class" is an interface, and an "instance" of a "class" is a thing that implements the interface! I do hope they don't cover this aspect of Haskell in the course that precedes our first Java course...