At such meeting, the county road commissioners, or the state highway commissioner, shall correct the errors aforesaid. Such meeting may be adjourned from time to time, public announcement of such adjournment being made in each case. Where lands within the boundaries of the assessment district as established have been omitted by clerical mistake from the apportionment of benefits, or from the special assessment roll, they may be added thereto, and shall be assessed their proportionate share of the cost of the improvement. Where lands have been erroneously described, they shall be correctly described as near as may be. Where the acreage of any parcel is erroneously stated to be more or less than it really is, such acreage shall be correctly stated as near as may be. Where the apportionment of benefits has already been determined by the state highway commissioner, or by the appellate boards, upon an acreage basis, the tax or apportionment upon any parcel where the acreage was wrong in the first instance shall be increased or reduced as the case may be, proportionate to the increase or decrease of the acreage of that parcel. Where any parcel of land is charged on the roll with an assessment that is improper because of some clerical error, such assessment shall be corrected.