Section 624(1)(b) in The Calcutta Municipal Corporation Act, 1980
(b)except as the State Government may, by notification, otherwise direct, any rules, regulations or orders made or any directions issued or any powers conferred under the provisions of this Act as so extended, which are in force at the date of such extension, shall apply to such municipality or Government Township or area or part thereof in supersession of the corresponding rules, regulations or orders made or directions issued or powers conferred under the Bengal Municipal Act, 1932, or the West Bengal Government Townships (Extension of Civic Amenities) Act, 1975, or such enactment, as the case may be.