The House of Delegates shall choose its own Speaker; and, in the absence of the Lieutenant Governor, or when he shall exercise the office of Governor, the Senate shall choose from its own body a president pro tempore. Each house shall select its officers and settle its rules of procedure. The houses may jointly provide for legislative continuity between sessions occurring during the term for which members of the House of Delegates are elected. Each house may direct writs of election for supplying vacancies which may occur during a session of the General Assembly. If vacancies exist while the General Assembly is not in session, such writs may be issued by the Governor under such regulations as may be prescribed by law. Each house shall judge of the election, qualification, and returns of its members, may punish them for disorderly behavior, and, with the concurrence of two-thirds of its elected membership, may expel a member.