Mix the sugar, nutmeg, salt & lemon juice in a small bowl. Slice the bananas & mix them gently in the lemon-spice mixture. Heat a skillet & add a little vegetable oil. Fry each crepe on both sides. Spread each cooked crepe with the melted margarine & some of the banana mixture. Keep everything warm until ready to serve. Sprinkle the crepes with icing sugar & garnish with lemon wedges.