I found them in the Retroarch nightlies thread:I've not updated my 3ds retroarch cores for a good couple of months, so I'm a little out of touch with developments.
As I mentioned, there are a few different snes emus to choose from in the retroarch stable (although, other than Catsfc, I can't remember the names)...
- catsfc has 60fps on n3DS
- catsfc plus has better sound but poorer framerate
- snes9x has poorer compatibility