The big ones. I think they are mystery or apple, forgot what I ordered way back when. There are 3 in the tank - are they mail/female or all just one sex? Haven't seen any eggs (or new baby ones) yet. In that second picture I tried to leave some space above the water because I believe some snails crawl out to lay eggs in the water - does that look like enough space if they are indeed those types of snails? FYI that is a 29 gallon tank.