Mo. Rev. Stat. § 513.120: Execution on such shares, how levied.

The officer upon obtaining such information, or in any other manner, may make a levy of such execution on such rights or shares by leaving a true copy of such writ with the cashier, secretary or chief clerk; and if there be no such officer, then with some officer of such bank, association, joint stock company or corporation, with an attested certificate by the officer making the levy that he levies upon and takes such rights and shares to satisfy such execution.