Mo. Rev. Stat. § 21.210

When any member, officer or employee of either house presents his account for his compensation, and the same is allowed, according to the rules of the house to which he belongs, a certificate shall be granted, specifying the amount and on what account, and directing that the same be paid out of appropriations made for the pay of the general assembly. The certificate, in the case of a member or officer of the senate, shall be signed by the president and attested by the secretary; and, in case of a member or officer of the house of representatives, it shall be signed by the speaker and attested by the chief clerk; and, upon the presentation of the certificate to the commissioner of administration, a warrant on the treasurer for the amount shall be issued.