Filling of casual vacancies

Any casual vacancy among the members, other than ex-officio members, of any authority shall be filled, as soon as conveniently may be, by the person, or Authority who appointed, elected, nominated or co-opted the member whose place has become vacant and the person appointed, elected, nominated or co-opted, to a casual vacancy shall be a member of such Authority for the residue of the term for which the person whose place he fills would have been a member.