All citations to sections of the General Statutes in this opinion relate, both as to section numbers and as to content, to the statutes in effect in 1969.
 G.S. 105-302 (a) provides that, except as otherwise provided in that section, tangible personal property must be listed for taxes in the township wherein the owner has his residence, which, in the case of a corporation, is the township in which it has its principal office in the State. McLean contends that this does not apply to the property here in question because subsection (d )of this statute provides that tangible personal property “shall be listed in the township in which such property is situated, rather than in the township in which the owner resides, if the owner * * * hires or occupies a * * * place for storage * * * for use in connection with such property.” This contention cannot be sustained for the reason that the tractors and trailers in question were not “situated” on the lot in Broadbay Township owned by McLean and designated by it as a place for storage of such property. In re Freight Carriers, 263 N.C. 345, 139 S.E. 2d 633. As of 1 January 1969, and for many months prior thereto, none of these vehicles was stored upon this lot or elsewhere in Broadbay Township, if, indeed, they ever were there. Consequently, Winston Township was the tax situs of these tractors and trailers as of 1 January 1969 and they should have been listed for 1969 taxes therein.
 The vehicles having been listed improperly in Broadbay Township, the County Board of Equalization and Review had the authority to correct the listing and cause the vehicles to be listed for 1969 taxes in Winston Township. G.S. 105-327 (g) (1), (3). This it could do on its own motion or on sufficient cause shown by any person. Subsection (e) of G.S. 105-327 provides, however, that the County Board of Equalization and Review “shall hold its first meeting not earlier than the first Monday in April and not later than the first Monday in May following *251the day on which the tax listing began, but it shall complete its duties on or before the third Monday following its first meeting,” except that it may continue in session for a longer period when necessary or expedient to a proper execution of its responsibilities, “but in no event shall said board sit later than July 1,” except for matters not pertinent to this appeal. The time limitation thus imposed upon the County Board of Equalization and Review by this statute is mandatory. Spiers v. Davenport, 263 N.C. 56, 138 S.E. 2d 762. Thus, at the time the Tax Supervisor undertook to change the listing of this property, the County Board of Equalization and Review was powerless to take such action.
G.S. 105-328 provides that when changes made by the County Board of Equalization and Review have been reflected upon the tax records, the members of the board, or a majority thereof, “shall sign a statement at the end of the scroll or tax book to the effect that the scroll is the fixed and permanent tax list and assessment roll for the current year, subject to the provisions of this subchapter.”
 The County Board of Equalization and Review is identical in membership with the Board of County Commissioners. G.S. 105-327(a). Nevertheless, after its authority has ceased, by lapse of time, the powers of the County Board of Equalization and Review do not evolve upon the Board of County Commissioners. The authority of the Board of County Commissioners thereafter to make changes in the tax records is limited to that conferred by G.S. 105-330, the pertinent portion of which provides :
“After the board of equalization has finished its work and the changes effected by it have been given effect on the tax records, the board of county commissioners may not authorize any changes to be made on said records except as follows:
‡ ‡ ‡
“(5) To add any discovered property under the provisions of this subchapter. * * * ” (Emphasis added.)
[4, 5] Thus, there was no authority in the Board of County Commissioners, and a fortiorari, none in the Tax Supervisor, to change the listing of McLean’s vehicles from Broadbay Township to Winston Township unless these vehicles constituted “dis*252covered property.” Nothing else appearing, the Legislature is presumed to have used the words of a statute to convey their natural and ordinary meaning. Yacht Company v. High, Commissioner of Revenue, 265 N.C. 653, 144 S.E. 2d 821; Seminary v. Wake County, 251 N.C. 775, 112 S.E. 2d 528. The ordinary meaning of “discovered” is newly found, not previously known. G.S. 105-381 (a) makes it clear that “discovered property,” as used in the Machinery Act, G.S. Chapter 105, Subchapter II, means property which has not been listed for taxation. Even if this term could be construed to include property improperly listed (see, Smith v. Dunn, 160 N.C. 174, 76 S.E. 242), we think G.S. 105-330 makes it clear that the authority of the Board of County Commissioners to change the listing extends no further than a change as to property “discovered” after the County Board of Equalization and Review has finished its work and ceased to function. In the present instance, it is clear that the matter came to the attention of both the county and the city at some time prior to 22 April 1969. Nothing in the record indicates that the county and the city were not fully aware of the facts governing the tax situs of the property in question prior to the date on which the County Board of Equalization and Review ceased to function. Thus, the tractors and trailers listed by McLean in Broadbay Township cannot be deemed “discovered property,” within the meaning of G.S. 105-330, as of the date of the attempted listing of these properties in Winston Township by the Tax Supervisor and such attempted listing was without legal effect.
The power conferred by G.S. 105-331 (e) upon cities and towns is, by the terms of that statutory provision, no more extensive than the power conferred by that section and by G.S. 105-330 upon the Board of County Commissioners.
Having concluded that the attempted listing of the property in Winston Township for 1969 taxes was ineffectual, we do not reach, in this case, the question of whether McLean was entitled in 1969 to have the full tax value of these vehicles apportioned so as to subject only part of it to taxation in Forsyth County.
The judgment of the superior court affirming the decision of the State Board of Assessment is, therefore, reversed, and the matter is remanded to the Superior Court of Forsyth County for the entry by it of a judgment in accordance with this opinion.
Reversed and remanded.