N.J. Stat. § 40:33-13
When any municipality, maintaining a public library and situate in a county which has adopted a county library system under the provisions of this article, desires to participate in the benefits of this article, the governing body thereof, by resolution, may apply to the county library commission of such county to be included in the county library system, and the municipality shall be admitted to said county library system upon such terms and conditions as may be agreed upon by the governing body thereof and the county library commission of the county, not inconsistent with the provisions of this act; provided, and so long as provision is made for assessing, levying and collecting within the municipality the special tax assessed, levied and collected in the other municipalities served by such county library system and thereafter such municipal public library shall continue to be operated as a municipal public library under its own governing board or body and shall be entitled to receive municipal appropriations notwithstanding its inclusion in the county library system and shall be entitled to receive from the county library system the same book loan, advisory, and other services as are received by the other municipalities within said system.
N.J.S. § 40:33-13