The mark, zhai, inside the foot is possibly a studio mark of Hu Jianzhong. The same mark was also carved on the interior of the foot of a circular cup of more simple lotus shape from the Arthur M. Sackler Collections, sold in these rooms, 1 December 1994, lot 13. The same mark, along with an inscription and a square seal that reads 'The seal of Hu Jianzhong', also appears on a rhinoceros horn cup in the Östasiatska Museet, Stockholm, and is illustrated by J. Chapman, The Art of Rhinoceros Horn Carving in China, London, 1999, p. 61, no. 31. The author also illustrates a cup of very similar shape with a similar openwork handle carved with a dragon amidst lotus stems, p. 61, no. 31.