Line 9 inch pie pan with half the pastry. Chill. Combine blackberries, flour, sugar, spices and lemon juice. Spoon into pie shell. Dot with butter. Cover with remaining pastry. Cut steam vents. Bake in 450 degree oven for 15 minutes. Reduce oven temperature to 350 degrees. Bake 34 to 40 minutes longer or until browned.