Cup. Transparent deep blue. Blown (parison inflated in dip mold). Rim very slightly everted with plain, rounded lip; wall descends vertically, bulges slightly, and curves in at bottom; base disklike, with 10 sides; pontil mark. Mold-blown decoration: on wall, 10 ribs extending from base to near rim; these are vertical at bottom but bent toward left at top; on underside of base, recessed circular panel containing ring of sixteen circular bosses between two concentric circles in relief.