19 CFR 148.67: Penalties for failure to declare articles.

(a) Avoidance of inspection. When articles may be presented to the Customs office on the pier or at the landing place for inspection and clearance, if the circumstances under which the articles are landed indicate an attempt to avoid inspection, the penalties prescribed in section 453, Tariff Act of 1930, as amended (19 U.S.C. 1453), shall be assessed.

(b) Articles landed without declaration. Any article landed without having been properly declared as provided in § 148.62 shall be considered as having been unladen without a permit and the penalties provided in 19 U.S.C. 1453 or 19 U.S.C. 1644 and 1644a shall be assessed as applicable.

(c) Articles omitted from declaration. If the declaration does not include all the articles landed, the crewmember shall be subject to the penalties prescribed in section 497, Tariff Act of 1930 (19 U.S.C. 1497), with respect to the articles omitted. The penalties prescribed in section 453, Tariff Act of 1930, as amended (19 U.S.C. 1453), shall not be assessed if any, though not all, of the articles are declared, except as provided in paragraph (a) of this section.