seroon

Not a unit, but a type of packaging, a bale wrapped in animal hide. The word occurs in colonial American manifests describing shipments of cocoa beans.¹

1. Richard M. Lederer, Jr.
Colonial American English. A Glossary.
Essex, Connecticut: A Verbatim Book, 1985.

Page 208.

Examples

During the year 900 bales of Ambalema, 35,00 bales of Carmen, 9,200 bales of Paraguay, 50,000 seroons¹ of Habana, and 5000 bales of Hungarian tobacco wee imported and sold in Bremen.
1. A seroon or seron is a hamper or basket used for packing raisons, figs, tobacco, tea, etc. but without any exact weight. A seroon of Paraguayan tea weighs about 200 pounds. — Bureau of Foreign and Domestic Commerce.

Dept. of Commerce, Bureau of Foreign and Domestic Commerce.
Daily Consular and Trade Reports.
Nos. 75-151; Volume 2; April, May and June 1913.
Washington: U.S.G.P.O., 1913.
Page 1252. Report 133, June 9, 1913.