Xiangbeijing 相貝經 "The book of inspecting shells and conches" is a very short book on shells attributed to a Han-period 漢 (206 BCE-220 CE) writer called Zhu Zhong 朱仲, of which virtually nothing is known. Zhu Zhong is said to have been a Daoist adept who learned the art of prolonging life from a certain Qin Gao 琴高. He might have belonged to some magicians sent out to search for materia medica prolonging life. On his travels Zhu came to the Eastern Sea and studied sea life to find something suitable for his attempts to become an immortal.
Authorship of the book is also attributed to Yan Zhu 嚴助 (Zhuang Zhu 莊助), prefect of Guiji 會稽 (modern Shaoxing 紹興, Zhejiang), who lived during the Former Han period, but this seems quite improbable.
The book, of which only less than 400 characters have survived, describes 14 kinds of shells, all of them eatable, at least for Daoist adepts. The molluscs are named according to the patterns of their outer shell. The shortness of the description makes it impossible to identify them with living species. The descriptions of the conches in the Xiangbeijing are also not identical to such still used in traditional Chinese medicine, as Mauritia arabica L.