Sift dry ingredients together. Cut in ¼ c. butter with pastry blender. Add Starter, and mix.
Turn dough out on a lightly floured board. Knead lightly until satiny.
Roll dough ½″ thick. Cut with floured 2½″ cutter. Place biscuits in well greased 9″ square baking pan. Brush with melted butter. Let rise about 1 hour in a warm place.