An unusual Chinese alter vessel and cover

An unusual Chinese alter vessel and cover, or Dou, moulded with lozenges, taotie masks and lappets beneath an all-over purple/blue glaze, the cover and base with a moulded seal mark of Qianlong and possibly of the period, 24cm. (2) Cf. S. Marchant & Son, Qing Mark and Period Monochrome and Two-Coloured Wares, No.25 for a similar vessel.