The said Corporation may accept from the lessees surrender of the leases now current of Sections eight, nine, ten, eleven, twelve, thirteen, fourteen, sixteen, seventeen, eighteen, nineteen, twenty, twenty-one, twenty-two, twenty-three, twenty-four, twenty-five, twenty-six, twenty-seven, twenty-eight, twenty-nine, thirty, thirty-one, thirty-two, and part of Section fifteen, Block forty-two, in the City of Dunedin, and in lieu of such leases may grant new leases of the sections aforesaid, or any parts thereof, on such terms as may be agreed on between the said Corporation and the lessees: such new lease, or each of such new leases respectively, to be granted for such term of years not exceeding the then unexpired residue of the longest of the several terms of years for which such lands shall then be held by the said lessees.