Spoon flour into measuring cup and level off. Pour into large bowl. Add 1/3 C. sugar, orange rind, baking powder and salt to flour. Stir well to blend. Stir in blueberries. Combine milk, orange juice, egg and oil in small bowl. Beat slightly. Add liquid ingredients to blended dry ingredients all at once. Stir just to moisten dry ingredients. Fill greased or paper lined muffin pan cups 2/3 full. Combine nuts, 2 T. sugar and nutmeg. Sprinkle on batter. Bake at 425 for 18 to 20 minutes. Serve warm with butter if desired.