Section 218
SEC. 218. If a package be found by the examining officer to contain any article not specified in the invoice, and if the collector shall be of the opinion that such article was omitted from the invoice with fraudulent intent, the contents of the entire package will be liable to seizure and forfeiture. But when, in the opinion of the collector, no fraudulent intent is apparent, the dutiable value or quantity of the excess shall be added to the entry and duties paid accordingly.