unmounted mint Block Larger Than four 3p. ultramarine (1 centre band), a block of fifty (severed vertically in half) being the top five rows of a sheet, the top two horizontal rows imperforate and the adjoining row with blind perforations at top and partly at sides; the left block with creased stamp in top row causing a surface defect, and the right block with horizontal crease through lower two rows. S.G. X856a