Vessels of this type, with these distinctive small, double-ringed lips, are known as xiakou ping (small-mouthed bottles) and were probably sealed with a fabric-wrapped wooden dowel and used for storing wine and other liquids. Typically dark-glazed, such bottles are often painted in russet or rust-brown slip with abstract floral decoration or designs suggestive of birds in flight, such as that seen on the present example, characteristically rendered with vigorous calligraphic strokes. The present example, however, is distinguished by its elegant, elongated tapering ovoid body rather than the more characteristic squat, globular body. A bottle of this latter type, from the collection of Robert M. Ferris IV, with similarly painted birds in flight rendered in russet against a black glaze, is illustrated by R. Mowry, Hare's Fur, Tortoiseshell, and Partridge Feathers, Cambridge, 1996, p. 162, no. 53. Another black-glazed example painted with birds in russet is published by R. Krahl, Chinese Ceramics from the Meiyintang Collection, vol. 1, London, 1994, p. 255, no. 465.