A small carved rhinoceros horn libation cup, 19th century. Photo Bonhams

Loosely based on the sacrificial water vessel, yi, displaying a shallow, curving well of oval silhouette with a spout at one end and a loop handle at the other carved as an archaistic dragon, the exterior walls carved in delicate relief with further dragons arranged in two tiers descending toward the waisted oval foot with flat base. 4in (10cm) long. Sold for US$27,500

Bonhams. Fine Asian Works of Art, 20 Dec 2011. California, San Francisco www.bonhams.com