Disabilities for continuing as member

If any member other than an ex-officio member of a Local Library Authority, during the period for which he has been nominated or elected,- (a) absents himself without excuse sufficient in the opinion of the Authority, from three consecutive meetings of the Authority; or (b) in the case of a member elected by any body referred to in section 17 or section 18 ceases to be member of the body concerned, his office in the Authority shall become vacant.